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1 | /* Reload pseudo regs into hard regs for insns that require hard regs. | |
2 | Copyright (C) 1987, 88, 89, 92, 93, 1994 Free Software Foundation, Inc. | |
3 | ||
4 | This file is part of GNU CC. | |
5 | ||
6 | GNU CC is free software; you can redistribute it and/or modify | |
7 | it under the terms of the GNU General Public License as published by | |
8 | the Free Software Foundation; either version 2, or (at your option) | |
9 | any later version. | |
10 | ||
11 | GNU CC is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | GNU General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
17 | along with GNU CC; see the file COPYING. If not, write to | |
18 | the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ | |
19 | ||
20 | ||
21 | #include <stdio.h> | |
22 | #include "config.h" | |
23 | #include "rtl.h" | |
24 | #include "obstack.h" | |
25 | #include "insn-config.h" | |
26 | #include "insn-flags.h" | |
27 | #include "insn-codes.h" | |
28 | #include "flags.h" | |
29 | #include "expr.h" | |
30 | #include "regs.h" | |
31 | #include "hard-reg-set.h" | |
32 | #include "reload.h" | |
33 | #include "recog.h" | |
34 | #include "basic-block.h" | |
35 | #include "output.h" | |
36 | ||
37 | /* This file contains the reload pass of the compiler, which is | |
38 | run after register allocation has been done. It checks that | |
39 | each insn is valid (operands required to be in registers really | |
40 | are in registers of the proper class) and fixes up invalid ones | |
41 | by copying values temporarily into registers for the insns | |
42 | that need them. | |
43 | ||
44 | The results of register allocation are described by the vector | |
45 | reg_renumber; the insns still contain pseudo regs, but reg_renumber | |
46 | can be used to find which hard reg, if any, a pseudo reg is in. | |
47 | ||
48 | The technique we always use is to free up a few hard regs that are | |
49 | called ``reload regs'', and for each place where a pseudo reg | |
50 | must be in a hard reg, copy it temporarily into one of the reload regs. | |
51 | ||
52 | All the pseudos that were formerly allocated to the hard regs that | |
53 | are now in use as reload regs must be ``spilled''. This means | |
54 | that they go to other hard regs, or to stack slots if no other | |
55 | available hard regs can be found. Spilling can invalidate more | |
56 | insns, requiring additional need for reloads, so we must keep checking | |
57 | until the process stabilizes. | |
58 | ||
59 | For machines with different classes of registers, we must keep track | |
60 | of the register class needed for each reload, and make sure that | |
61 | we allocate enough reload registers of each class. | |
62 | ||
63 | The file reload.c contains the code that checks one insn for | |
64 | validity and reports the reloads that it needs. This file | |
65 | is in charge of scanning the entire rtl code, accumulating the | |
66 | reload needs, spilling, assigning reload registers to use for | |
67 | fixing up each insn, and generating the new insns to copy values | |
68 | into the reload registers. */ | |
69 | ||
70 | ||
71 | #ifndef REGISTER_MOVE_COST | |
72 | #define REGISTER_MOVE_COST(x, y) 2 | |
73 | #endif | |
74 | ||
75 | #ifndef MEMORY_MOVE_COST | |
76 | #define MEMORY_MOVE_COST(x) 4 | |
77 | #endif | |
78 | \f | |
79 | /* During reload_as_needed, element N contains a REG rtx for the hard reg | |
80 | into which reg N has been reloaded (perhaps for a previous insn). */ | |
81 | static rtx *reg_last_reload_reg; | |
82 | ||
83 | /* Elt N nonzero if reg_last_reload_reg[N] has been set in this insn | |
84 | for an output reload that stores into reg N. */ | |
85 | static char *reg_has_output_reload; | |
86 | ||
87 | /* Indicates which hard regs are reload-registers for an output reload | |
88 | in the current insn. */ | |
89 | static HARD_REG_SET reg_is_output_reload; | |
90 | ||
91 | /* Element N is the constant value to which pseudo reg N is equivalent, | |
92 | or zero if pseudo reg N is not equivalent to a constant. | |
93 | find_reloads looks at this in order to replace pseudo reg N | |
94 | with the constant it stands for. */ | |
95 | rtx *reg_equiv_constant; | |
96 | ||
97 | /* Element N is a memory location to which pseudo reg N is equivalent, | |
98 | prior to any register elimination (such as frame pointer to stack | |
99 | pointer). Depending on whether or not it is a valid address, this value | |
100 | is transferred to either reg_equiv_address or reg_equiv_mem. */ | |
101 | rtx *reg_equiv_memory_loc; | |
102 | ||
103 | /* Element N is the address of stack slot to which pseudo reg N is equivalent. | |
104 | This is used when the address is not valid as a memory address | |
105 | (because its displacement is too big for the machine.) */ | |
106 | rtx *reg_equiv_address; | |
107 | ||
108 | /* Element N is the memory slot to which pseudo reg N is equivalent, | |
109 | or zero if pseudo reg N is not equivalent to a memory slot. */ | |
110 | rtx *reg_equiv_mem; | |
111 | ||
112 | /* Widest width in which each pseudo reg is referred to (via subreg). */ | |
113 | static int *reg_max_ref_width; | |
114 | ||
115 | /* Element N is the insn that initialized reg N from its equivalent | |
116 | constant or memory slot. */ | |
117 | static rtx *reg_equiv_init; | |
118 | ||
119 | /* During reload_as_needed, element N contains the last pseudo regno | |
120 | reloaded into the Nth reload register. This vector is in parallel | |
121 | with spill_regs. If that pseudo reg occupied more than one register, | |
122 | reg_reloaded_contents points to that pseudo for each spill register in | |
123 | use; all of these must remain set for an inheritance to occur. */ | |
124 | static int reg_reloaded_contents[FIRST_PSEUDO_REGISTER]; | |
125 | ||
126 | /* During reload_as_needed, element N contains the insn for which | |
127 | the Nth reload register was last used. This vector is in parallel | |
128 | with spill_regs, and its contents are significant only when | |
129 | reg_reloaded_contents is significant. */ | |
130 | static rtx reg_reloaded_insn[FIRST_PSEUDO_REGISTER]; | |
131 | ||
132 | /* Number of spill-regs so far; number of valid elements of spill_regs. */ | |
133 | static int n_spills; | |
134 | ||
135 | /* In parallel with spill_regs, contains REG rtx's for those regs. | |
136 | Holds the last rtx used for any given reg, or 0 if it has never | |
137 | been used for spilling yet. This rtx is reused, provided it has | |
138 | the proper mode. */ | |
139 | static rtx spill_reg_rtx[FIRST_PSEUDO_REGISTER]; | |
140 | ||
141 | /* In parallel with spill_regs, contains nonzero for a spill reg | |
142 | that was stored after the last time it was used. | |
143 | The precise value is the insn generated to do the store. */ | |
144 | static rtx spill_reg_store[FIRST_PSEUDO_REGISTER]; | |
145 | ||
146 | /* This table is the inverse mapping of spill_regs: | |
147 | indexed by hard reg number, | |
148 | it contains the position of that reg in spill_regs, | |
149 | or -1 for something that is not in spill_regs. */ | |
150 | static short spill_reg_order[FIRST_PSEUDO_REGISTER]; | |
151 | ||
152 | /* This reg set indicates registers that may not be used for retrying global | |
153 | allocation. The registers that may not be used include all spill registers | |
154 | and the frame pointer (if we are using one). */ | |
155 | HARD_REG_SET forbidden_regs; | |
156 | ||
157 | /* This reg set indicates registers that are not good for spill registers. | |
158 | They will not be used to complete groups of spill registers. This includes | |
159 | all fixed registers, registers that may be eliminated, and, if | |
160 | SMALL_REGISTER_CLASSES is not defined, registers explicitly used in the rtl. | |
161 | ||
162 | (spill_reg_order prevents these registers from being used to start a | |
163 | group.) */ | |
164 | static HARD_REG_SET bad_spill_regs; | |
165 | ||
166 | /* Describes order of use of registers for reloading | |
167 | of spilled pseudo-registers. `spills' is the number of | |
168 | elements that are actually valid; new ones are added at the end. */ | |
169 | static short spill_regs[FIRST_PSEUDO_REGISTER]; | |
170 | ||
171 | /* Describes order of preference for putting regs into spill_regs. | |
172 | Contains the numbers of all the hard regs, in order most preferred first. | |
173 | This order is different for each function. | |
174 | It is set up by order_regs_for_reload. | |
175 | Empty elements at the end contain -1. */ | |
176 | static short potential_reload_regs[FIRST_PSEUDO_REGISTER]; | |
177 | ||
178 | /* 1 for a hard register that appears explicitly in the rtl | |
179 | (for example, function value registers, special registers | |
180 | used by insns, structure value pointer registers). */ | |
181 | static char regs_explicitly_used[FIRST_PSEUDO_REGISTER]; | |
182 | ||
183 | /* Indicates if a register was counted against the need for | |
184 | groups. 0 means it can count against max_nongroup instead. */ | |
185 | static HARD_REG_SET counted_for_groups; | |
186 | ||
187 | /* Indicates if a register was counted against the need for | |
188 | non-groups. 0 means it can become part of a new group. | |
189 | During choose_reload_regs, 1 here means don't use this reg | |
190 | as part of a group, even if it seems to be otherwise ok. */ | |
191 | static HARD_REG_SET counted_for_nongroups; | |
192 | ||
193 | /* Indexed by pseudo reg number N, | |
194 | says may not delete stores into the real (memory) home of pseudo N. | |
195 | This is set if we already substituted a memory equivalent in some uses, | |
196 | which happens when we have to eliminate the fp from it. */ | |
197 | static char *cannot_omit_stores; | |
198 | ||
199 | /* Nonzero if indirect addressing is supported on the machine; this means | |
200 | that spilling (REG n) does not require reloading it into a register in | |
201 | order to do (MEM (REG n)) or (MEM (PLUS (REG n) (CONST_INT c))). The | |
202 | value indicates the level of indirect addressing supported, e.g., two | |
203 | means that (MEM (MEM (REG n))) is also valid if (REG n) does not get | |
204 | a hard register. */ | |
205 | ||
206 | static char spill_indirect_levels; | |
207 | ||
208 | /* Nonzero if indirect addressing is supported when the innermost MEM is | |
209 | of the form (MEM (SYMBOL_REF sym)). It is assumed that the level to | |
210 | which these are valid is the same as spill_indirect_levels, above. */ | |
211 | ||
212 | char indirect_symref_ok; | |
213 | ||
214 | /* Nonzero if an address (plus (reg frame_pointer) (reg ...)) is valid. */ | |
215 | ||
216 | char double_reg_address_ok; | |
217 | ||
218 | /* Record the stack slot for each spilled hard register. */ | |
219 | ||
220 | static rtx spill_stack_slot[FIRST_PSEUDO_REGISTER]; | |
221 | ||
222 | /* Width allocated so far for that stack slot. */ | |
223 | ||
224 | static int spill_stack_slot_width[FIRST_PSEUDO_REGISTER]; | |
225 | ||
226 | /* Indexed by register class and basic block number, nonzero if there is | |
227 | any need for a spill register of that class in that basic block. | |
228 | The pointer is 0 if we did stupid allocation and don't know | |
229 | the structure of basic blocks. */ | |
230 | ||
231 | char *basic_block_needs[N_REG_CLASSES]; | |
232 | ||
233 | /* First uid used by insns created by reload in this function. | |
234 | Used in find_equiv_reg. */ | |
235 | int reload_first_uid; | |
236 | ||
237 | /* Flag set by local-alloc or global-alloc if anything is live in | |
238 | a call-clobbered reg across calls. */ | |
239 | ||
240 | int caller_save_needed; | |
241 | ||
242 | /* Set to 1 while reload_as_needed is operating. | |
243 | Required by some machines to handle any generated moves differently. */ | |
244 | ||
245 | int reload_in_progress = 0; | |
246 | ||
247 | /* These arrays record the insn_code of insns that may be needed to | |
248 | perform input and output reloads of special objects. They provide a | |
249 | place to pass a scratch register. */ | |
250 | ||
251 | enum insn_code reload_in_optab[NUM_MACHINE_MODES]; | |
252 | enum insn_code reload_out_optab[NUM_MACHINE_MODES]; | |
253 | ||
254 | /* This obstack is used for allocation of rtl during register elimination. | |
255 | The allocated storage can be freed once find_reloads has processed the | |
256 | insn. */ | |
257 | ||
258 | struct obstack reload_obstack; | |
259 | char *reload_firstobj; | |
260 | ||
261 | #define obstack_chunk_alloc xmalloc | |
262 | #define obstack_chunk_free free | |
263 | ||
264 | /* List of labels that must never be deleted. */ | |
265 | extern rtx forced_labels; | |
266 | \f | |
267 | /* This structure is used to record information about register eliminations. | |
268 | Each array entry describes one possible way of eliminating a register | |
269 | in favor of another. If there is more than one way of eliminating a | |
270 | particular register, the most preferred should be specified first. */ | |
271 | ||
272 | static struct elim_table | |
273 | { | |
274 | int from; /* Register number to be eliminated. */ | |
275 | int to; /* Register number used as replacement. */ | |
276 | int initial_offset; /* Initial difference between values. */ | |
277 | int can_eliminate; /* Non-zero if this elimination can be done. */ | |
278 | int can_eliminate_previous; /* Value of CAN_ELIMINATE in previous scan over | |
279 | insns made by reload. */ | |
280 | int offset; /* Current offset between the two regs. */ | |
281 | int max_offset; /* Maximum offset between the two regs. */ | |
282 | int previous_offset; /* Offset at end of previous insn. */ | |
283 | int ref_outside_mem; /* "to" has been referenced outside a MEM. */ | |
284 | rtx from_rtx; /* REG rtx for the register to be eliminated. | |
285 | We cannot simply compare the number since | |
286 | we might then spuriously replace a hard | |
287 | register corresponding to a pseudo | |
288 | assigned to the reg to be eliminated. */ | |
289 | rtx to_rtx; /* REG rtx for the replacement. */ | |
290 | } reg_eliminate[] = | |
291 | ||
292 | /* If a set of eliminable registers was specified, define the table from it. | |
293 | Otherwise, default to the normal case of the frame pointer being | |
294 | replaced by the stack pointer. */ | |
295 | ||
296 | #ifdef ELIMINABLE_REGS | |
297 | ELIMINABLE_REGS; | |
298 | #else | |
299 | {{ FRAME_POINTER_REGNUM, STACK_POINTER_REGNUM}}; | |
300 | #endif | |
301 | ||
302 | #define NUM_ELIMINABLE_REGS (sizeof reg_eliminate / sizeof reg_eliminate[0]) | |
303 | ||
304 | /* Record the number of pending eliminations that have an offset not equal | |
305 | to their initial offset. If non-zero, we use a new copy of each | |
306 | replacement result in any insns encountered. */ | |
307 | static int num_not_at_initial_offset; | |
308 | ||
309 | /* Count the number of registers that we may be able to eliminate. */ | |
310 | static int num_eliminable; | |
311 | ||
312 | /* For each label, we record the offset of each elimination. If we reach | |
313 | a label by more than one path and an offset differs, we cannot do the | |
314 | elimination. This information is indexed by the number of the label. | |
315 | The first table is an array of flags that records whether we have yet | |
316 | encountered a label and the second table is an array of arrays, one | |
317 | entry in the latter array for each elimination. */ | |
318 | ||
319 | static char *offsets_known_at; | |
320 | static int (*offsets_at)[NUM_ELIMINABLE_REGS]; | |
321 | ||
322 | /* Number of labels in the current function. */ | |
323 | ||
324 | static int num_labels; | |
325 | ||
326 | struct hard_reg_n_uses { int regno; int uses; }; | |
327 | \f | |
328 | static int possible_group_p PROTO((int, int *)); | |
329 | static void count_possible_groups PROTO((int *, enum machine_mode *, | |
330 | int *)); | |
331 | static int modes_equiv_for_class_p PROTO((enum machine_mode, | |
332 | enum machine_mode, | |
333 | enum reg_class)); | |
334 | static void spill_failure PROTO((rtx)); | |
335 | static int new_spill_reg PROTO((int, int, int *, int *, int, | |
336 | FILE *)); | |
337 | static void delete_dead_insn PROTO((rtx)); | |
338 | static void alter_reg PROTO((int, int)); | |
339 | static void mark_scratch_live PROTO((rtx)); | |
340 | static void set_label_offsets PROTO((rtx, rtx, int)); | |
341 | static int eliminate_regs_in_insn PROTO((rtx, int)); | |
342 | static void mark_not_eliminable PROTO((rtx, rtx)); | |
343 | static int spill_hard_reg PROTO((int, int, FILE *, int)); | |
344 | static void scan_paradoxical_subregs PROTO((rtx)); | |
345 | static int hard_reg_use_compare PROTO((struct hard_reg_n_uses *, | |
346 | struct hard_reg_n_uses *)); | |
347 | static void order_regs_for_reload PROTO((void)); | |
348 | static int compare_spill_regs PROTO((short *, short *)); | |
349 | static void reload_as_needed PROTO((rtx, int)); | |
350 | static void forget_old_reloads_1 PROTO((rtx, rtx)); | |
351 | static int reload_reg_class_lower PROTO((short *, short *)); | |
352 | static void mark_reload_reg_in_use PROTO((int, int, enum reload_type, | |
353 | enum machine_mode)); | |
354 | static void clear_reload_reg_in_use PROTO((int, int, enum reload_type, | |
355 | enum machine_mode)); | |
356 | static int reload_reg_free_p PROTO((int, int, enum reload_type)); | |
357 | static int reload_reg_free_before_p PROTO((int, int, enum reload_type)); | |
358 | static int reload_reg_reaches_end_p PROTO((int, int, enum reload_type)); | |
359 | static int reloads_conflict PROTO((int, int)); | |
360 | static int allocate_reload_reg PROTO((int, rtx, int, int)); | |
361 | static void choose_reload_regs PROTO((rtx, rtx)); | |
362 | static void merge_assigned_reloads PROTO((rtx)); | |
363 | static void emit_reload_insns PROTO((rtx)); | |
364 | static void delete_output_reload PROTO((rtx, int, rtx)); | |
365 | static void inc_for_reload PROTO((rtx, rtx, int)); | |
366 | static int constraint_accepts_reg_p PROTO((char *, rtx)); | |
367 | static int count_occurrences PROTO((rtx, rtx)); | |
368 | \f | |
369 | /* Initialize the reload pass once per compilation. */ | |
370 | ||
371 | void | |
372 | init_reload () | |
373 | { | |
374 | register int i; | |
375 | ||
376 | /* Often (MEM (REG n)) is still valid even if (REG n) is put on the stack. | |
377 | Set spill_indirect_levels to the number of levels such addressing is | |
378 | permitted, zero if it is not permitted at all. */ | |
379 | ||
380 | register rtx tem | |
381 | = gen_rtx (MEM, Pmode, | |
382 | gen_rtx (PLUS, Pmode, | |
383 | gen_rtx (REG, Pmode, LAST_VIRTUAL_REGISTER + 1), | |
384 | GEN_INT (4))); | |
385 | spill_indirect_levels = 0; | |
386 | ||
387 | while (memory_address_p (QImode, tem)) | |
388 | { | |
389 | spill_indirect_levels++; | |
390 | tem = gen_rtx (MEM, Pmode, tem); | |
391 | } | |
392 | ||
393 | /* See if indirect addressing is valid for (MEM (SYMBOL_REF ...)). */ | |
394 | ||
395 | tem = gen_rtx (MEM, Pmode, gen_rtx (SYMBOL_REF, Pmode, "foo")); | |
396 | indirect_symref_ok = memory_address_p (QImode, tem); | |
397 | ||
398 | /* See if reg+reg is a valid (and offsettable) address. */ | |
399 | ||
400 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
401 | { | |
402 | tem = gen_rtx (PLUS, Pmode, | |
403 | gen_rtx (REG, Pmode, HARD_FRAME_POINTER_REGNUM), | |
404 | gen_rtx (REG, Pmode, i)); | |
405 | /* This way, we make sure that reg+reg is an offsettable address. */ | |
406 | tem = plus_constant (tem, 4); | |
407 | ||
408 | if (memory_address_p (QImode, tem)) | |
409 | { | |
410 | double_reg_address_ok = 1; | |
411 | break; | |
412 | } | |
413 | } | |
414 | ||
415 | /* Initialize obstack for our rtl allocation. */ | |
416 | gcc_obstack_init (&reload_obstack); | |
417 | reload_firstobj = (char *) obstack_alloc (&reload_obstack, 0); | |
418 | } | |
419 | ||
420 | /* Main entry point for the reload pass. | |
421 | ||
422 | FIRST is the first insn of the function being compiled. | |
423 | ||
424 | GLOBAL nonzero means we were called from global_alloc | |
425 | and should attempt to reallocate any pseudoregs that we | |
426 | displace from hard regs we will use for reloads. | |
427 | If GLOBAL is zero, we do not have enough information to do that, | |
428 | so any pseudo reg that is spilled must go to the stack. | |
429 | ||
430 | DUMPFILE is the global-reg debugging dump file stream, or 0. | |
431 | If it is nonzero, messages are written to it to describe | |
432 | which registers are seized as reload regs, which pseudo regs | |
433 | are spilled from them, and where the pseudo regs are reallocated to. | |
434 | ||
435 | Return value is nonzero if reload failed | |
436 | and we must not do any more for this function. */ | |
437 | ||
438 | int | |
439 | reload (first, global, dumpfile) | |
440 | rtx first; | |
441 | int global; | |
442 | FILE *dumpfile; | |
443 | { | |
444 | register int class; | |
445 | register int i, j, k; | |
446 | register rtx insn; | |
447 | register struct elim_table *ep; | |
448 | ||
449 | int something_changed; | |
450 | int something_needs_reloads; | |
451 | int something_needs_elimination; | |
452 | int new_basic_block_needs; | |
453 | enum reg_class caller_save_spill_class = NO_REGS; | |
454 | int caller_save_group_size = 1; | |
455 | ||
456 | /* Nonzero means we couldn't get enough spill regs. */ | |
457 | int failure = 0; | |
458 | ||
459 | /* The basic block number currently being processed for INSN. */ | |
460 | int this_block; | |
461 | ||
462 | /* Make sure even insns with volatile mem refs are recognizable. */ | |
463 | init_recog (); | |
464 | ||
465 | /* Enable find_equiv_reg to distinguish insns made by reload. */ | |
466 | reload_first_uid = get_max_uid (); | |
467 | ||
468 | for (i = 0; i < N_REG_CLASSES; i++) | |
469 | basic_block_needs[i] = 0; | |
470 | ||
471 | #ifdef SECONDARY_MEMORY_NEEDED | |
472 | /* Initialize the secondary memory table. */ | |
473 | clear_secondary_mem (); | |
474 | #endif | |
475 | ||
476 | /* Remember which hard regs appear explicitly | |
477 | before we merge into `regs_ever_live' the ones in which | |
478 | pseudo regs have been allocated. */ | |
479 | bcopy (regs_ever_live, regs_explicitly_used, sizeof regs_ever_live); | |
480 | ||
481 | /* We don't have a stack slot for any spill reg yet. */ | |
482 | bzero (spill_stack_slot, sizeof spill_stack_slot); | |
483 | bzero (spill_stack_slot_width, sizeof spill_stack_slot_width); | |
484 | ||
485 | /* Initialize the save area information for caller-save, in case some | |
486 | are needed. */ | |
487 | init_save_areas (); | |
488 | ||
489 | /* Compute which hard registers are now in use | |
490 | as homes for pseudo registers. | |
491 | This is done here rather than (eg) in global_alloc | |
492 | because this point is reached even if not optimizing. */ | |
493 | ||
494 | for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++) | |
495 | mark_home_live (i); | |
496 | ||
497 | for (i = 0; i < scratch_list_length; i++) | |
498 | if (scratch_list[i]) | |
499 | mark_scratch_live (scratch_list[i]); | |
500 | ||
501 | /* Make sure that the last insn in the chain | |
502 | is not something that needs reloading. */ | |
503 | emit_note (NULL_PTR, NOTE_INSN_DELETED); | |
504 | ||
505 | /* Find all the pseudo registers that didn't get hard regs | |
506 | but do have known equivalent constants or memory slots. | |
507 | These include parameters (known equivalent to parameter slots) | |
508 | and cse'd or loop-moved constant memory addresses. | |
509 | ||
510 | Record constant equivalents in reg_equiv_constant | |
511 | so they will be substituted by find_reloads. | |
512 | Record memory equivalents in reg_mem_equiv so they can | |
513 | be substituted eventually by altering the REG-rtx's. */ | |
514 | ||
515 | reg_equiv_constant = (rtx *) alloca (max_regno * sizeof (rtx)); | |
516 | bzero (reg_equiv_constant, max_regno * sizeof (rtx)); | |
517 | reg_equiv_memory_loc = (rtx *) alloca (max_regno * sizeof (rtx)); | |
518 | bzero (reg_equiv_memory_loc, max_regno * sizeof (rtx)); | |
519 | reg_equiv_mem = (rtx *) alloca (max_regno * sizeof (rtx)); | |
520 | bzero (reg_equiv_mem, max_regno * sizeof (rtx)); | |
521 | reg_equiv_init = (rtx *) alloca (max_regno * sizeof (rtx)); | |
522 | bzero (reg_equiv_init, max_regno * sizeof (rtx)); | |
523 | reg_equiv_address = (rtx *) alloca (max_regno * sizeof (rtx)); | |
524 | bzero (reg_equiv_address, max_regno * sizeof (rtx)); | |
525 | reg_max_ref_width = (int *) alloca (max_regno * sizeof (int)); | |
526 | bzero (reg_max_ref_width, max_regno * sizeof (int)); | |
527 | cannot_omit_stores = (char *) alloca (max_regno); | |
528 | bzero (cannot_omit_stores, max_regno); | |
529 | ||
530 | #ifdef SMALL_REGISTER_CLASSES | |
531 | CLEAR_HARD_REG_SET (forbidden_regs); | |
532 | #endif | |
533 | ||
534 | /* Look for REG_EQUIV notes; record what each pseudo is equivalent to. | |
535 | Also find all paradoxical subregs and find largest such for each pseudo. | |
536 | On machines with small register classes, record hard registers that | |
537 | are used for user variables. These can never be used for spills. */ | |
538 | ||
539 | for (insn = first; insn; insn = NEXT_INSN (insn)) | |
540 | { | |
541 | rtx set = single_set (insn); | |
542 | ||
543 | if (set != 0 && GET_CODE (SET_DEST (set)) == REG) | |
544 | { | |
545 | rtx note = find_reg_note (insn, REG_EQUIV, NULL_RTX); | |
546 | if (note | |
547 | #ifdef LEGITIMATE_PIC_OPERAND_P | |
548 | && (! CONSTANT_P (XEXP (note, 0)) || ! flag_pic | |
549 | || LEGITIMATE_PIC_OPERAND_P (XEXP (note, 0))) | |
550 | #endif | |
551 | ) | |
552 | { | |
553 | rtx x = XEXP (note, 0); | |
554 | i = REGNO (SET_DEST (set)); | |
555 | if (i > LAST_VIRTUAL_REGISTER) | |
556 | { | |
557 | if (GET_CODE (x) == MEM) | |
558 | reg_equiv_memory_loc[i] = x; | |
559 | else if (CONSTANT_P (x)) | |
560 | { | |
561 | if (LEGITIMATE_CONSTANT_P (x)) | |
562 | reg_equiv_constant[i] = x; | |
563 | else | |
564 | reg_equiv_memory_loc[i] | |
565 | = force_const_mem (GET_MODE (SET_DEST (set)), x); | |
566 | } | |
567 | else | |
568 | continue; | |
569 | ||
570 | /* If this register is being made equivalent to a MEM | |
571 | and the MEM is not SET_SRC, the equivalencing insn | |
572 | is one with the MEM as a SET_DEST and it occurs later. | |
573 | So don't mark this insn now. */ | |
574 | if (GET_CODE (x) != MEM | |
575 | || rtx_equal_p (SET_SRC (set), x)) | |
576 | reg_equiv_init[i] = insn; | |
577 | } | |
578 | } | |
579 | } | |
580 | ||
581 | /* If this insn is setting a MEM from a register equivalent to it, | |
582 | this is the equivalencing insn. */ | |
583 | else if (set && GET_CODE (SET_DEST (set)) == MEM | |
584 | && GET_CODE (SET_SRC (set)) == REG | |
585 | && reg_equiv_memory_loc[REGNO (SET_SRC (set))] | |
586 | && rtx_equal_p (SET_DEST (set), | |
587 | reg_equiv_memory_loc[REGNO (SET_SRC (set))])) | |
588 | reg_equiv_init[REGNO (SET_SRC (set))] = insn; | |
589 | ||
590 | if (GET_RTX_CLASS (GET_CODE (insn)) == 'i') | |
591 | scan_paradoxical_subregs (PATTERN (insn)); | |
592 | } | |
593 | ||
594 | /* Does this function require a frame pointer? */ | |
595 | ||
596 | frame_pointer_needed = (! flag_omit_frame_pointer | |
597 | #ifdef EXIT_IGNORE_STACK | |
598 | /* ?? If EXIT_IGNORE_STACK is set, we will not save | |
599 | and restore sp for alloca. So we can't eliminate | |
600 | the frame pointer in that case. At some point, | |
601 | we should improve this by emitting the | |
602 | sp-adjusting insns for this case. */ | |
603 | || (current_function_calls_alloca | |
604 | && EXIT_IGNORE_STACK) | |
605 | #endif | |
606 | || FRAME_POINTER_REQUIRED); | |
607 | ||
608 | num_eliminable = 0; | |
609 | ||
610 | /* Initialize the table of registers to eliminate. The way we do this | |
611 | depends on how the eliminable registers were defined. */ | |
612 | #ifdef ELIMINABLE_REGS | |
613 | for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++) | |
614 | { | |
615 | ep->can_eliminate = ep->can_eliminate_previous | |
616 | = (CAN_ELIMINATE (ep->from, ep->to) | |
617 | && (ep->from != HARD_FRAME_POINTER_REGNUM | |
618 | || ! frame_pointer_needed)); | |
619 | } | |
620 | #else | |
621 | reg_eliminate[0].can_eliminate = reg_eliminate[0].can_eliminate_previous | |
622 | = ! frame_pointer_needed; | |
623 | #endif | |
624 | ||
625 | /* Count the number of eliminable registers and build the FROM and TO | |
626 | REG rtx's. Note that code in gen_rtx will cause, e.g., | |
627 | gen_rtx (REG, Pmode, STACK_POINTER_REGNUM) to equal stack_pointer_rtx. | |
628 | We depend on this. */ | |
629 | for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++) | |
630 | { | |
631 | num_eliminable += ep->can_eliminate; | |
632 | ep->from_rtx = gen_rtx (REG, Pmode, ep->from); | |
633 | ep->to_rtx = gen_rtx (REG, Pmode, ep->to); | |
634 | } | |
635 | ||
636 | num_labels = max_label_num () - get_first_label_num (); | |
637 | ||
638 | /* Allocate the tables used to store offset information at labels. */ | |
639 | offsets_known_at = (char *) alloca (num_labels); | |
640 | offsets_at | |
641 | = (int (*)[NUM_ELIMINABLE_REGS]) | |
642 | alloca (num_labels * NUM_ELIMINABLE_REGS * sizeof (int)); | |
643 | ||
644 | offsets_known_at -= get_first_label_num (); | |
645 | offsets_at -= get_first_label_num (); | |
646 | ||
647 | /* Alter each pseudo-reg rtx to contain its hard reg number. | |
648 | Assign stack slots to the pseudos that lack hard regs or equivalents. | |
649 | Do not touch virtual registers. */ | |
650 | ||
651 | for (i = LAST_VIRTUAL_REGISTER + 1; i < max_regno; i++) | |
652 | alter_reg (i, -1); | |
653 | ||
654 | /* Round size of stack frame to BIGGEST_ALIGNMENT. This must be done here | |
655 | because the stack size may be a part of the offset computation for | |
656 | register elimination. */ | |
657 | assign_stack_local (BLKmode, 0, 0); | |
658 | ||
659 | /* If we have some registers we think can be eliminated, scan all insns to | |
660 | see if there is an insn that sets one of these registers to something | |
661 | other than itself plus a constant. If so, the register cannot be | |
662 | eliminated. Doing this scan here eliminates an extra pass through the | |
663 | main reload loop in the most common case where register elimination | |
664 | cannot be done. */ | |
665 | for (insn = first; insn && num_eliminable; insn = NEXT_INSN (insn)) | |
666 | if (GET_CODE (insn) == INSN || GET_CODE (insn) == JUMP_INSN | |
667 | || GET_CODE (insn) == CALL_INSN) | |
668 | note_stores (PATTERN (insn), mark_not_eliminable); | |
669 | ||
670 | #ifndef REGISTER_CONSTRAINTS | |
671 | /* If all the pseudo regs have hard regs, | |
672 | except for those that are never referenced, | |
673 | we know that no reloads are needed. */ | |
674 | /* But that is not true if there are register constraints, since | |
675 | in that case some pseudos might be in the wrong kind of hard reg. */ | |
676 | ||
677 | for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++) | |
678 | if (reg_renumber[i] == -1 && reg_n_refs[i] != 0) | |
679 | break; | |
680 | ||
681 | if (i == max_regno && num_eliminable == 0 && ! caller_save_needed) | |
682 | return; | |
683 | #endif | |
684 | ||
685 | /* Compute the order of preference for hard registers to spill. | |
686 | Store them by decreasing preference in potential_reload_regs. */ | |
687 | ||
688 | order_regs_for_reload (); | |
689 | ||
690 | /* So far, no hard regs have been spilled. */ | |
691 | n_spills = 0; | |
692 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
693 | spill_reg_order[i] = -1; | |
694 | ||
695 | /* On most machines, we can't use any register explicitly used in the | |
696 | rtl as a spill register. But on some, we have to. Those will have | |
697 | taken care to keep the life of hard regs as short as possible. */ | |
698 | ||
699 | #ifndef SMALL_REGISTER_CLASSES | |
700 | COPY_HARD_REG_SET (forbidden_regs, bad_spill_regs); | |
701 | #endif | |
702 | ||
703 | /* Spill any hard regs that we know we can't eliminate. */ | |
704 | for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++) | |
705 | if (! ep->can_eliminate) | |
706 | { | |
707 | spill_hard_reg (ep->from, global, dumpfile, 1); | |
708 | regs_ever_live[ep->from] = 1; | |
709 | } | |
710 | ||
711 | if (global) | |
712 | for (i = 0; i < N_REG_CLASSES; i++) | |
713 | { | |
714 | basic_block_needs[i] = (char *)alloca (n_basic_blocks); | |
715 | bzero (basic_block_needs[i], n_basic_blocks); | |
716 | } | |
717 | ||
718 | /* From now on, we need to emit any moves without making new pseudos. */ | |
719 | reload_in_progress = 1; | |
720 | ||
721 | /* This loop scans the entire function each go-round | |
722 | and repeats until one repetition spills no additional hard regs. */ | |
723 | ||
724 | /* This flag is set when a pseudo reg is spilled, | |
725 | to require another pass. Note that getting an additional reload | |
726 | reg does not necessarily imply any pseudo reg was spilled; | |
727 | sometimes we find a reload reg that no pseudo reg was allocated in. */ | |
728 | something_changed = 1; | |
729 | /* This flag is set if there are any insns that require reloading. */ | |
730 | something_needs_reloads = 0; | |
731 | /* This flag is set if there are any insns that require register | |
732 | eliminations. */ | |
733 | something_needs_elimination = 0; | |
734 | while (something_changed) | |
735 | { | |
736 | rtx after_call = 0; | |
737 | ||
738 | /* For each class, number of reload regs needed in that class. | |
739 | This is the maximum over all insns of the needs in that class | |
740 | of the individual insn. */ | |
741 | int max_needs[N_REG_CLASSES]; | |
742 | /* For each class, size of group of consecutive regs | |
743 | that is needed for the reloads of this class. */ | |
744 | int group_size[N_REG_CLASSES]; | |
745 | /* For each class, max number of consecutive groups needed. | |
746 | (Each group contains group_size[CLASS] consecutive registers.) */ | |
747 | int max_groups[N_REG_CLASSES]; | |
748 | /* For each class, max number needed of regs that don't belong | |
749 | to any of the groups. */ | |
750 | int max_nongroups[N_REG_CLASSES]; | |
751 | /* For each class, the machine mode which requires consecutive | |
752 | groups of regs of that class. | |
753 | If two different modes ever require groups of one class, | |
754 | they must be the same size and equally restrictive for that class, | |
755 | otherwise we can't handle the complexity. */ | |
756 | enum machine_mode group_mode[N_REG_CLASSES]; | |
757 | /* Record the insn where each maximum need is first found. */ | |
758 | rtx max_needs_insn[N_REG_CLASSES]; | |
759 | rtx max_groups_insn[N_REG_CLASSES]; | |
760 | rtx max_nongroups_insn[N_REG_CLASSES]; | |
761 | rtx x; | |
762 | int starting_frame_size = get_frame_size (); | |
763 | static char *reg_class_names[] = REG_CLASS_NAMES; | |
764 | ||
765 | something_changed = 0; | |
766 | bzero (max_needs, sizeof max_needs); | |
767 | bzero (max_groups, sizeof max_groups); | |
768 | bzero (max_nongroups, sizeof max_nongroups); | |
769 | bzero (max_needs_insn, sizeof max_needs_insn); | |
770 | bzero (max_groups_insn, sizeof max_groups_insn); | |
771 | bzero (max_nongroups_insn, sizeof max_nongroups_insn); | |
772 | bzero (group_size, sizeof group_size); | |
773 | for (i = 0; i < N_REG_CLASSES; i++) | |
774 | group_mode[i] = VOIDmode; | |
775 | ||
776 | /* Keep track of which basic blocks are needing the reloads. */ | |
777 | this_block = 0; | |
778 | ||
779 | /* Remember whether any element of basic_block_needs | |
780 | changes from 0 to 1 in this pass. */ | |
781 | new_basic_block_needs = 0; | |
782 | ||
783 | /* Reset all offsets on eliminable registers to their initial values. */ | |
784 | #ifdef ELIMINABLE_REGS | |
785 | for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++) | |
786 | { | |
787 | INITIAL_ELIMINATION_OFFSET (ep->from, ep->to, ep->initial_offset); | |
788 | ep->previous_offset = ep->offset | |
789 | = ep->max_offset = ep->initial_offset; | |
790 | } | |
791 | #else | |
792 | #ifdef INITIAL_FRAME_POINTER_OFFSET | |
793 | INITIAL_FRAME_POINTER_OFFSET (reg_eliminate[0].initial_offset); | |
794 | #else | |
795 | if (!FRAME_POINTER_REQUIRED) | |
796 | abort (); | |
797 | reg_eliminate[0].initial_offset = 0; | |
798 | #endif | |
799 | reg_eliminate[0].previous_offset = reg_eliminate[0].max_offset | |
800 | = reg_eliminate[0].offset = reg_eliminate[0].initial_offset; | |
801 | #endif | |
802 | ||
803 | num_not_at_initial_offset = 0; | |
804 | ||
805 | bzero (&offsets_known_at[get_first_label_num ()], num_labels); | |
806 | ||
807 | /* Set a known offset for each forced label to be at the initial offset | |
808 | of each elimination. We do this because we assume that all | |
809 | computed jumps occur from a location where each elimination is | |
810 | at its initial offset. */ | |
811 | ||
812 | for (x = forced_labels; x; x = XEXP (x, 1)) | |
813 | if (XEXP (x, 0)) | |
814 | set_label_offsets (XEXP (x, 0), NULL_RTX, 1); | |
815 | ||
816 | /* For each pseudo register that has an equivalent location defined, | |
817 | try to eliminate any eliminable registers (such as the frame pointer) | |
818 | assuming initial offsets for the replacement register, which | |
819 | is the normal case. | |
820 | ||
821 | If the resulting location is directly addressable, substitute | |
822 | the MEM we just got directly for the old REG. | |
823 | ||
824 | If it is not addressable but is a constant or the sum of a hard reg | |
825 | and constant, it is probably not addressable because the constant is | |
826 | out of range, in that case record the address; we will generate | |
827 | hairy code to compute the address in a register each time it is | |
828 | needed. Similarly if it is a hard register, but one that is not | |
829 | valid as an address register. | |
830 | ||
831 | If the location is not addressable, but does not have one of the | |
832 | above forms, assign a stack slot. We have to do this to avoid the | |
833 | potential of producing lots of reloads if, e.g., a location involves | |
834 | a pseudo that didn't get a hard register and has an equivalent memory | |
835 | location that also involves a pseudo that didn't get a hard register. | |
836 | ||
837 | Perhaps at some point we will improve reload_when_needed handling | |
838 | so this problem goes away. But that's very hairy. */ | |
839 | ||
840 | for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++) | |
841 | if (reg_renumber[i] < 0 && reg_equiv_memory_loc[i]) | |
842 | { | |
843 | rtx x = eliminate_regs (reg_equiv_memory_loc[i], 0, NULL_RTX); | |
844 | ||
845 | if (strict_memory_address_p (GET_MODE (regno_reg_rtx[i]), | |
846 | XEXP (x, 0))) | |
847 | reg_equiv_mem[i] = x, reg_equiv_address[i] = 0; | |
848 | else if (CONSTANT_P (XEXP (x, 0)) | |
849 | || (GET_CODE (XEXP (x, 0)) == REG | |
850 | && REGNO (XEXP (x, 0)) < FIRST_PSEUDO_REGISTER) | |
851 | || (GET_CODE (XEXP (x, 0)) == PLUS | |
852 | && GET_CODE (XEXP (XEXP (x, 0), 0)) == REG | |
853 | && (REGNO (XEXP (XEXP (x, 0), 0)) | |
854 | < FIRST_PSEUDO_REGISTER) | |
855 | && CONSTANT_P (XEXP (XEXP (x, 0), 1)))) | |
856 | reg_equiv_address[i] = XEXP (x, 0), reg_equiv_mem[i] = 0; | |
857 | else | |
858 | { | |
859 | /* Make a new stack slot. Then indicate that something | |
860 | changed so we go back and recompute offsets for | |
861 | eliminable registers because the allocation of memory | |
862 | below might change some offset. reg_equiv_{mem,address} | |
863 | will be set up for this pseudo on the next pass around | |
864 | the loop. */ | |
865 | reg_equiv_memory_loc[i] = 0; | |
866 | reg_equiv_init[i] = 0; | |
867 | alter_reg (i, -1); | |
868 | something_changed = 1; | |
869 | } | |
870 | } | |
871 | ||
872 | /* If we allocated another pseudo to the stack, redo elimination | |
873 | bookkeeping. */ | |
874 | if (something_changed) | |
875 | continue; | |
876 | ||
877 | /* If caller-saves needs a group, initialize the group to include | |
878 | the size and mode required for caller-saves. */ | |
879 | ||
880 | if (caller_save_group_size > 1) | |
881 | { | |
882 | group_mode[(int) caller_save_spill_class] = Pmode; | |
883 | group_size[(int) caller_save_spill_class] = caller_save_group_size; | |
884 | } | |
885 | ||
886 | /* Compute the most additional registers needed by any instruction. | |
887 | Collect information separately for each class of regs. */ | |
888 | ||
889 | for (insn = first; insn; insn = NEXT_INSN (insn)) | |
890 | { | |
891 | if (global && this_block + 1 < n_basic_blocks | |
892 | && insn == basic_block_head[this_block+1]) | |
893 | ++this_block; | |
894 | ||
895 | /* If this is a label, a JUMP_INSN, or has REG_NOTES (which | |
896 | might include REG_LABEL), we need to see what effects this | |
897 | has on the known offsets at labels. */ | |
898 | ||
899 | if (GET_CODE (insn) == CODE_LABEL || GET_CODE (insn) == JUMP_INSN | |
900 | || (GET_RTX_CLASS (GET_CODE (insn)) == 'i' | |
901 | && REG_NOTES (insn) != 0)) | |
902 | set_label_offsets (insn, insn, 0); | |
903 | ||
904 | if (GET_RTX_CLASS (GET_CODE (insn)) == 'i') | |
905 | { | |
906 | /* Nonzero means don't use a reload reg that overlaps | |
907 | the place where a function value can be returned. */ | |
908 | rtx avoid_return_reg = 0; | |
909 | ||
910 | rtx old_body = PATTERN (insn); | |
911 | int old_code = INSN_CODE (insn); | |
912 | rtx old_notes = REG_NOTES (insn); | |
913 | int did_elimination = 0; | |
914 | ||
915 | /* To compute the number of reload registers of each class | |
916 | needed for an insn, we must similate what choose_reload_regs | |
917 | can do. We do this by splitting an insn into an "input" and | |
918 | an "output" part. RELOAD_OTHER reloads are used in both. | |
919 | The input part uses those reloads, RELOAD_FOR_INPUT reloads, | |
920 | which must be live over the entire input section of reloads, | |
921 | and the maximum of all the RELOAD_FOR_INPUT_ADDRESS and | |
922 | RELOAD_FOR_OPERAND_ADDRESS reloads, which conflict with the | |
923 | inputs. | |
924 | ||
925 | The registers needed for output are RELOAD_OTHER and | |
926 | RELOAD_FOR_OUTPUT, which are live for the entire output | |
927 | portion, and the maximum of all the RELOAD_FOR_OUTPUT_ADDRESS | |
928 | reloads for each operand. | |
929 | ||
930 | The total number of registers needed is the maximum of the | |
931 | inputs and outputs. */ | |
932 | ||
933 | struct needs | |
934 | { | |
935 | /* [0] is normal, [1] is nongroup. */ | |
936 | int regs[2][N_REG_CLASSES]; | |
937 | int groups[N_REG_CLASSES]; | |
938 | }; | |
939 | ||
940 | /* Each `struct needs' corresponds to one RELOAD_... type. */ | |
941 | struct { | |
942 | struct needs other; | |
943 | struct needs input; | |
944 | struct needs output; | |
945 | struct needs insn; | |
946 | struct needs other_addr; | |
947 | struct needs op_addr; | |
948 | struct needs in_addr[MAX_RECOG_OPERANDS]; | |
949 | struct needs out_addr[MAX_RECOG_OPERANDS]; | |
950 | } insn_needs; | |
951 | ||
952 | /* If needed, eliminate any eliminable registers. */ | |
953 | if (num_eliminable) | |
954 | did_elimination = eliminate_regs_in_insn (insn, 0); | |
955 | ||
956 | #ifdef SMALL_REGISTER_CLASSES | |
957 | /* Set avoid_return_reg if this is an insn | |
958 | that might use the value of a function call. */ | |
959 | if (GET_CODE (insn) == CALL_INSN) | |
960 | { | |
961 | if (GET_CODE (PATTERN (insn)) == SET) | |
962 | after_call = SET_DEST (PATTERN (insn)); | |
963 | else if (GET_CODE (PATTERN (insn)) == PARALLEL | |
964 | && GET_CODE (XVECEXP (PATTERN (insn), 0, 0)) == SET) | |
965 | after_call = SET_DEST (XVECEXP (PATTERN (insn), 0, 0)); | |
966 | else | |
967 | after_call = 0; | |
968 | } | |
969 | else if (after_call != 0 | |
970 | && !(GET_CODE (PATTERN (insn)) == SET | |
971 | && SET_DEST (PATTERN (insn)) == stack_pointer_rtx)) | |
972 | { | |
973 | if (reg_referenced_p (after_call, PATTERN (insn))) | |
974 | avoid_return_reg = after_call; | |
975 | after_call = 0; | |
976 | } | |
977 | #endif /* SMALL_REGISTER_CLASSES */ | |
978 | ||
979 | /* Analyze the instruction. */ | |
980 | find_reloads (insn, 0, spill_indirect_levels, global, | |
981 | spill_reg_order); | |
982 | ||
983 | /* Remember for later shortcuts which insns had any reloads or | |
984 | register eliminations. | |
985 | ||
986 | One might think that it would be worthwhile to mark insns | |
987 | that need register replacements but not reloads, but this is | |
988 | not safe because find_reloads may do some manipulation of | |
989 | the insn (such as swapping commutative operands), which would | |
990 | be lost when we restore the old pattern after register | |
991 | replacement. So the actions of find_reloads must be redone in | |
992 | subsequent passes or in reload_as_needed. | |
993 | ||
994 | However, it is safe to mark insns that need reloads | |
995 | but not register replacement. */ | |
996 | ||
997 | PUT_MODE (insn, (did_elimination ? QImode | |
998 | : n_reloads ? HImode | |
999 | : GET_MODE (insn) == DImode ? DImode | |
1000 | : VOIDmode)); | |
1001 | ||
1002 | /* Discard any register replacements done. */ | |
1003 | if (did_elimination) | |
1004 | { | |
1005 | obstack_free (&reload_obstack, reload_firstobj); | |
1006 | PATTERN (insn) = old_body; | |
1007 | INSN_CODE (insn) = old_code; | |
1008 | REG_NOTES (insn) = old_notes; | |
1009 | something_needs_elimination = 1; | |
1010 | } | |
1011 | ||
1012 | /* If this insn has no reloads, we need not do anything except | |
1013 | in the case of a CALL_INSN when we have caller-saves and | |
1014 | caller-save needs reloads. */ | |
1015 | ||
1016 | if (n_reloads == 0 | |
1017 | && ! (GET_CODE (insn) == CALL_INSN | |
1018 | && caller_save_spill_class != NO_REGS)) | |
1019 | continue; | |
1020 | ||
1021 | something_needs_reloads = 1; | |
1022 | bzero (&insn_needs, sizeof insn_needs); | |
1023 | ||
1024 | /* Count each reload once in every class | |
1025 | containing the reload's own class. */ | |
1026 | ||
1027 | for (i = 0; i < n_reloads; i++) | |
1028 | { | |
1029 | register enum reg_class *p; | |
1030 | enum reg_class class = reload_reg_class[i]; | |
1031 | int size; | |
1032 | enum machine_mode mode; | |
1033 | int nongroup_need; | |
1034 | struct needs *this_needs; | |
1035 | ||
1036 | /* Don't count the dummy reloads, for which one of the | |
1037 | regs mentioned in the insn can be used for reloading. | |
1038 | Don't count optional reloads. | |
1039 | Don't count reloads that got combined with others. */ | |
1040 | if (reload_reg_rtx[i] != 0 | |
1041 | || reload_optional[i] != 0 | |
1042 | || (reload_out[i] == 0 && reload_in[i] == 0 | |
1043 | && ! reload_secondary_p[i])) | |
1044 | continue; | |
1045 | ||
1046 | /* Show that a reload register of this class is needed | |
1047 | in this basic block. We do not use insn_needs and | |
1048 | insn_groups because they are overly conservative for | |
1049 | this purpose. */ | |
1050 | if (global && ! basic_block_needs[(int) class][this_block]) | |
1051 | { | |
1052 | basic_block_needs[(int) class][this_block] = 1; | |
1053 | new_basic_block_needs = 1; | |
1054 | } | |
1055 | ||
1056 | ||
1057 | mode = reload_inmode[i]; | |
1058 | if (GET_MODE_SIZE (reload_outmode[i]) > GET_MODE_SIZE (mode)) | |
1059 | mode = reload_outmode[i]; | |
1060 | size = CLASS_MAX_NREGS (class, mode); | |
1061 | ||
1062 | /* If this class doesn't want a group, determine if we have | |
1063 | a nongroup need or a regular need. We have a nongroup | |
1064 | need if this reload conflicts with a group reload whose | |
1065 | class intersects with this reload's class. */ | |
1066 | ||
1067 | nongroup_need = 0; | |
1068 | if (size == 1) | |
1069 | for (j = 0; j < n_reloads; j++) | |
1070 | if ((CLASS_MAX_NREGS (reload_reg_class[j], | |
1071 | (GET_MODE_SIZE (reload_outmode[j]) | |
1072 | > GET_MODE_SIZE (reload_inmode[j])) | |
1073 | ? reload_outmode[j] | |
1074 | : reload_inmode[j]) | |
1075 | > 1) | |
1076 | && reloads_conflict (i, j) | |
1077 | && reg_classes_intersect_p (class, | |
1078 | reload_reg_class[j])) | |
1079 | { | |
1080 | nongroup_need = 1; | |
1081 | break; | |
1082 | } | |
1083 | ||
1084 | /* Decide which time-of-use to count this reload for. */ | |
1085 | switch (reload_when_needed[i]) | |
1086 | { | |
1087 | case RELOAD_OTHER: | |
1088 | this_needs = &insn_needs.other; | |
1089 | break; | |
1090 | case RELOAD_FOR_INPUT: | |
1091 | this_needs = &insn_needs.input; | |
1092 | break; | |
1093 | case RELOAD_FOR_OUTPUT: | |
1094 | this_needs = &insn_needs.output; | |
1095 | break; | |
1096 | case RELOAD_FOR_INSN: | |
1097 | this_needs = &insn_needs.insn; | |
1098 | break; | |
1099 | case RELOAD_FOR_OTHER_ADDRESS: | |
1100 | this_needs = &insn_needs.other_addr; | |
1101 | break; | |
1102 | case RELOAD_FOR_INPUT_ADDRESS: | |
1103 | this_needs = &insn_needs.in_addr[reload_opnum[i]]; | |
1104 | break; | |
1105 | case RELOAD_FOR_OUTPUT_ADDRESS: | |
1106 | this_needs = &insn_needs.out_addr[reload_opnum[i]]; | |
1107 | break; | |
1108 | case RELOAD_FOR_OPERAND_ADDRESS: | |
1109 | this_needs = &insn_needs.op_addr; | |
1110 | break; | |
1111 | } | |
1112 | ||
1113 | if (size > 1) | |
1114 | { | |
1115 | enum machine_mode other_mode, allocate_mode; | |
1116 | ||
1117 | /* Count number of groups needed separately from | |
1118 | number of individual regs needed. */ | |
1119 | this_needs->groups[(int) class]++; | |
1120 | p = reg_class_superclasses[(int) class]; | |
1121 | while (*p != LIM_REG_CLASSES) | |
1122 | this_needs->groups[(int) *p++]++; | |
1123 | ||
1124 | /* Record size and mode of a group of this class. */ | |
1125 | /* If more than one size group is needed, | |
1126 | make all groups the largest needed size. */ | |
1127 | if (group_size[(int) class] < size) | |
1128 | { | |
1129 | other_mode = group_mode[(int) class]; | |
1130 | allocate_mode = mode; | |
1131 | ||
1132 | group_size[(int) class] = size; | |
1133 | group_mode[(int) class] = mode; | |
1134 | } | |
1135 | else | |
1136 | { | |
1137 | other_mode = mode; | |
1138 | allocate_mode = group_mode[(int) class]; | |
1139 | } | |
1140 | ||
1141 | /* Crash if two dissimilar machine modes both need | |
1142 | groups of consecutive regs of the same class. */ | |
1143 | ||
1144 | if (other_mode != VOIDmode && other_mode != allocate_mode | |
1145 | && ! modes_equiv_for_class_p (allocate_mode, | |
1146 | other_mode, class)) | |
1147 | abort (); | |
1148 | } | |
1149 | else if (size == 1) | |
1150 | { | |
1151 | this_needs->regs[nongroup_need][(int) class] += 1; | |
1152 | p = reg_class_superclasses[(int) class]; | |
1153 | while (*p != LIM_REG_CLASSES) | |
1154 | this_needs->regs[nongroup_need][(int) *p++] += 1; | |
1155 | } | |
1156 | else | |
1157 | abort (); | |
1158 | } | |
1159 | ||
1160 | /* All reloads have been counted for this insn; | |
1161 | now merge the various times of use. | |
1162 | This sets insn_needs, etc., to the maximum total number | |
1163 | of registers needed at any point in this insn. */ | |
1164 | ||
1165 | for (i = 0; i < N_REG_CLASSES; i++) | |
1166 | { | |
1167 | int in_max, out_max; | |
1168 | ||
1169 | /* Compute normal and nongroup needs. */ | |
1170 | for (j = 0; j <= 1; j++) | |
1171 | { | |
1172 | for (in_max = 0, out_max = 0, k = 0; | |
1173 | k < reload_n_operands; k++) | |
1174 | { | |
1175 | in_max | |
1176 | = MAX (in_max, insn_needs.in_addr[k].regs[j][i]); | |
1177 | out_max | |
1178 | = MAX (out_max, insn_needs.out_addr[k].regs[j][i]); | |
1179 | } | |
1180 | ||
1181 | /* RELOAD_FOR_INSN reloads conflict with inputs, outputs, | |
1182 | and operand addresses but not things used to reload | |
1183 | them. Similarly, RELOAD_FOR_OPERAND_ADDRESS reloads | |
1184 | don't conflict with things needed to reload inputs or | |
1185 | outputs. */ | |
1186 | ||
1187 | in_max = MAX (in_max, insn_needs.op_addr.regs[j][i]); | |
1188 | out_max = MAX (out_max, insn_needs.insn.regs[j][i]); | |
1189 | ||
1190 | insn_needs.input.regs[j][i] | |
1191 | = MAX (insn_needs.input.regs[j][i] | |
1192 | + insn_needs.op_addr.regs[j][i] | |
1193 | + insn_needs.insn.regs[j][i], | |
1194 | in_max + insn_needs.input.regs[j][i]); | |
1195 | ||
1196 | insn_needs.output.regs[j][i] += out_max; | |
1197 | insn_needs.other.regs[j][i] | |
1198 | += MAX (MAX (insn_needs.input.regs[j][i], | |
1199 | insn_needs.output.regs[j][i]), | |
1200 | insn_needs.other_addr.regs[j][i]); | |
1201 | ||
1202 | } | |
1203 | ||
1204 | /* Now compute group needs. */ | |
1205 | for (in_max = 0, out_max = 0, j = 0; | |
1206 | j < reload_n_operands; j++) | |
1207 | { | |
1208 | in_max = MAX (in_max, insn_needs.in_addr[j].groups[i]); | |
1209 | out_max | |
1210 | = MAX (out_max, insn_needs.out_addr[j].groups[i]); | |
1211 | } | |
1212 | ||
1213 | in_max = MAX (in_max, insn_needs.op_addr.groups[i]); | |
1214 | out_max = MAX (out_max, insn_needs.insn.groups[i]); | |
1215 | ||
1216 | insn_needs.input.groups[i] | |
1217 | = MAX (insn_needs.input.groups[i] | |
1218 | + insn_needs.op_addr.groups[i] | |
1219 | + insn_needs.insn.groups[i], | |
1220 | in_max + insn_needs.input.groups[i]); | |
1221 | ||
1222 | insn_needs.output.groups[i] += out_max; | |
1223 | insn_needs.other.groups[i] | |
1224 | += MAX (MAX (insn_needs.input.groups[i], | |
1225 | insn_needs.output.groups[i]), | |
1226 | insn_needs.other_addr.groups[i]); | |
1227 | } | |
1228 | ||
1229 | /* If this is a CALL_INSN and caller-saves will need | |
1230 | a spill register, act as if the spill register is | |
1231 | needed for this insn. However, the spill register | |
1232 | can be used by any reload of this insn, so we only | |
1233 | need do something if no need for that class has | |
1234 | been recorded. | |
1235 | ||
1236 | The assumption that every CALL_INSN will trigger a | |
1237 | caller-save is highly conservative, however, the number | |
1238 | of cases where caller-saves will need a spill register but | |
1239 | a block containing a CALL_INSN won't need a spill register | |
1240 | of that class should be quite rare. | |
1241 | ||
1242 | If a group is needed, the size and mode of the group will | |
1243 | have been set up at the beginning of this loop. */ | |
1244 | ||
1245 | if (GET_CODE (insn) == CALL_INSN | |
1246 | && caller_save_spill_class != NO_REGS) | |
1247 | { | |
1248 | /* See if this register would conflict with any reload | |
1249 | that needs a group. */ | |
1250 | int nongroup_need = 0; | |
1251 | int *caller_save_needs; | |
1252 | ||
1253 | for (j = 0; j < n_reloads; j++) | |
1254 | if ((CLASS_MAX_NREGS (reload_reg_class[j], | |
1255 | (GET_MODE_SIZE (reload_outmode[j]) | |
1256 | > GET_MODE_SIZE (reload_inmode[j])) | |
1257 | ? reload_outmode[j] | |
1258 | : reload_inmode[j]) | |
1259 | > 1) | |
1260 | && reg_classes_intersect_p (caller_save_spill_class, | |
1261 | reload_reg_class[j])) | |
1262 | { | |
1263 | nongroup_need = 1; | |
1264 | break; | |
1265 | } | |
1266 | ||
1267 | caller_save_needs | |
1268 | = (caller_save_group_size > 1 | |
1269 | ? insn_needs.other.groups | |
1270 | : insn_needs.other.regs[nongroup_need]); | |
1271 | ||
1272 | if (caller_save_needs[(int) caller_save_spill_class] == 0) | |
1273 | { | |
1274 | register enum reg_class *p | |
1275 | = reg_class_superclasses[(int) caller_save_spill_class]; | |
1276 | ||
1277 | caller_save_needs[(int) caller_save_spill_class]++; | |
1278 | ||
1279 | while (*p != LIM_REG_CLASSES) | |
1280 | caller_save_needs[(int) *p++] += 1; | |
1281 | } | |
1282 | ||
1283 | /* Show that this basic block will need a register of | |
1284 | this class. */ | |
1285 | ||
1286 | if (global | |
1287 | && ! (basic_block_needs[(int) caller_save_spill_class] | |
1288 | [this_block])) | |
1289 | { | |
1290 | basic_block_needs[(int) caller_save_spill_class] | |
1291 | [this_block] = 1; | |
1292 | new_basic_block_needs = 1; | |
1293 | } | |
1294 | } | |
1295 | ||
1296 | #ifdef SMALL_REGISTER_CLASSES | |
1297 | /* If this insn stores the value of a function call, | |
1298 | and that value is in a register that has been spilled, | |
1299 | and if the insn needs a reload in a class | |
1300 | that might use that register as the reload register, | |
1301 | then add add an extra need in that class. | |
1302 | This makes sure we have a register available that does | |
1303 | not overlap the return value. */ | |
1304 | ||
1305 | if (avoid_return_reg) | |
1306 | { | |
1307 | int regno = REGNO (avoid_return_reg); | |
1308 | int nregs | |
1309 | = HARD_REGNO_NREGS (regno, GET_MODE (avoid_return_reg)); | |
1310 | int r; | |
1311 | int basic_needs[N_REG_CLASSES], basic_groups[N_REG_CLASSES]; | |
1312 | ||
1313 | /* First compute the "basic needs", which counts a | |
1314 | need only in the smallest class in which it | |
1315 | is required. */ | |
1316 | ||
1317 | bcopy (insn_needs.other.regs[0], basic_needs, | |
1318 | sizeof basic_needs); | |
1319 | bcopy (insn_needs.other.groups, basic_groups, | |
1320 | sizeof basic_groups); | |
1321 | ||
1322 | for (i = 0; i < N_REG_CLASSES; i++) | |
1323 | { | |
1324 | enum reg_class *p; | |
1325 | ||
1326 | if (basic_needs[i] >= 0) | |
1327 | for (p = reg_class_superclasses[i]; | |
1328 | *p != LIM_REG_CLASSES; p++) | |
1329 | basic_needs[(int) *p] -= basic_needs[i]; | |
1330 | ||
1331 | if (basic_groups[i] >= 0) | |
1332 | for (p = reg_class_superclasses[i]; | |
1333 | *p != LIM_REG_CLASSES; p++) | |
1334 | basic_groups[(int) *p] -= basic_groups[i]; | |
1335 | } | |
1336 | ||
1337 | /* Now count extra regs if there might be a conflict with | |
1338 | the return value register. | |
1339 | ||
1340 | ??? This is not quite correct because we don't properly | |
1341 | handle the case of groups, but if we end up doing | |
1342 | something wrong, it either will end up not mattering or | |
1343 | we will abort elsewhere. */ | |
1344 | ||
1345 | for (r = regno; r < regno + nregs; r++) | |
1346 | if (spill_reg_order[r] >= 0) | |
1347 | for (i = 0; i < N_REG_CLASSES; i++) | |
1348 | if (TEST_HARD_REG_BIT (reg_class_contents[i], r)) | |
1349 | { | |
1350 | if (basic_needs[i] > 0 || basic_groups[i] > 0) | |
1351 | { | |
1352 | enum reg_class *p; | |
1353 | ||
1354 | insn_needs.other.regs[0][i]++; | |
1355 | p = reg_class_superclasses[i]; | |
1356 | while (*p != LIM_REG_CLASSES) | |
1357 | insn_needs.other.regs[0][(int) *p++]++; | |
1358 | } | |
1359 | } | |
1360 | } | |
1361 | #endif /* SMALL_REGISTER_CLASSES */ | |
1362 | ||
1363 | /* For each class, collect maximum need of any insn. */ | |
1364 | ||
1365 | for (i = 0; i < N_REG_CLASSES; i++) | |
1366 | { | |
1367 | if (max_needs[i] < insn_needs.other.regs[0][i]) | |
1368 | { | |
1369 | max_needs[i] = insn_needs.other.regs[0][i]; | |
1370 | max_needs_insn[i] = insn; | |
1371 | } | |
1372 | if (max_groups[i] < insn_needs.other.groups[i]) | |
1373 | { | |
1374 | max_groups[i] = insn_needs.other.groups[i]; | |
1375 | max_groups_insn[i] = insn; | |
1376 | } | |
1377 | if (max_nongroups[i] < insn_needs.other.regs[1][i]) | |
1378 | { | |
1379 | max_nongroups[i] = insn_needs.other.regs[1][i]; | |
1380 | max_nongroups_insn[i] = insn; | |
1381 | } | |
1382 | } | |
1383 | } | |
1384 | /* Note that there is a continue statement above. */ | |
1385 | } | |
1386 | ||
1387 | /* If we allocated any new memory locations, make another pass | |
1388 | since it might have changed elimination offsets. */ | |
1389 | if (starting_frame_size != get_frame_size ()) | |
1390 | something_changed = 1; | |
1391 | ||
1392 | if (dumpfile) | |
1393 | for (i = 0; i < N_REG_CLASSES; i++) | |
1394 | { | |
1395 | if (max_needs[i] > 0) | |
1396 | fprintf (dumpfile, | |
1397 | ";; Need %d reg%s of class %s (for insn %d).\n", | |
1398 | max_needs[i], max_needs[i] == 1 ? "" : "s", | |
1399 | reg_class_names[i], INSN_UID (max_needs_insn[i])); | |
1400 | if (max_nongroups[i] > 0) | |
1401 | fprintf (dumpfile, | |
1402 | ";; Need %d nongroup reg%s of class %s (for insn %d).\n", | |
1403 | max_nongroups[i], max_nongroups[i] == 1 ? "" : "s", | |
1404 | reg_class_names[i], INSN_UID (max_nongroups_insn[i])); | |
1405 | if (max_groups[i] > 0) | |
1406 | fprintf (dumpfile, | |
1407 | ";; Need %d group%s (%smode) of class %s (for insn %d).\n", | |
1408 | max_groups[i], max_groups[i] == 1 ? "" : "s", | |
1409 | mode_name[(int) group_mode[i]], | |
1410 | reg_class_names[i], INSN_UID (max_groups_insn[i])); | |
1411 | } | |
1412 | ||
1413 | /* If we have caller-saves, set up the save areas and see if caller-save | |
1414 | will need a spill register. */ | |
1415 | ||
1416 | if (caller_save_needed | |
1417 | && ! setup_save_areas (&something_changed) | |
1418 | && caller_save_spill_class == NO_REGS) | |
1419 | { | |
1420 | /* The class we will need depends on whether the machine | |
1421 | supports the sum of two registers for an address; see | |
1422 | find_address_reloads for details. */ | |
1423 | ||
1424 | caller_save_spill_class | |
1425 | = double_reg_address_ok ? INDEX_REG_CLASS : BASE_REG_CLASS; | |
1426 | caller_save_group_size | |
1427 | = CLASS_MAX_NREGS (caller_save_spill_class, Pmode); | |
1428 | something_changed = 1; | |
1429 | } | |
1430 | ||
1431 | /* See if anything that happened changes which eliminations are valid. | |
1432 | For example, on the Sparc, whether or not the frame pointer can | |
1433 | be eliminated can depend on what registers have been used. We need | |
1434 | not check some conditions again (such as flag_omit_frame_pointer) | |
1435 | since they can't have changed. */ | |
1436 | ||
1437 | for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++) | |
1438 | if ((ep->from == HARD_FRAME_POINTER_REGNUM && FRAME_POINTER_REQUIRED) | |
1439 | #ifdef ELIMINABLE_REGS | |
1440 | || ! CAN_ELIMINATE (ep->from, ep->to) | |
1441 | #endif | |
1442 | ) | |
1443 | ep->can_eliminate = 0; | |
1444 | ||
1445 | /* Look for the case where we have discovered that we can't replace | |
1446 | register A with register B and that means that we will now be | |
1447 | trying to replace register A with register C. This means we can | |
1448 | no longer replace register C with register B and we need to disable | |
1449 | such an elimination, if it exists. This occurs often with A == ap, | |
1450 | B == sp, and C == fp. */ | |
1451 | ||
1452 | for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++) | |
1453 | { | |
1454 | struct elim_table *op; | |
1455 | register int new_to = -1; | |
1456 | ||
1457 | if (! ep->can_eliminate && ep->can_eliminate_previous) | |
1458 | { | |
1459 | /* Find the current elimination for ep->from, if there is a | |
1460 | new one. */ | |
1461 | for (op = reg_eliminate; | |
1462 | op < ®_eliminate[NUM_ELIMINABLE_REGS]; op++) | |
1463 | if (op->from == ep->from && op->can_eliminate) | |
1464 | { | |
1465 | new_to = op->to; | |
1466 | break; | |
1467 | } | |
1468 | ||
1469 | /* See if there is an elimination of NEW_TO -> EP->TO. If so, | |
1470 | disable it. */ | |
1471 | for (op = reg_eliminate; | |
1472 | op < ®_eliminate[NUM_ELIMINABLE_REGS]; op++) | |
1473 | if (op->from == new_to && op->to == ep->to) | |
1474 | op->can_eliminate = 0; | |
1475 | } | |
1476 | } | |
1477 | ||
1478 | /* See if any registers that we thought we could eliminate the previous | |
1479 | time are no longer eliminable. If so, something has changed and we | |
1480 | must spill the register. Also, recompute the number of eliminable | |
1481 | registers and see if the frame pointer is needed; it is if there is | |
1482 | no elimination of the frame pointer that we can perform. */ | |
1483 | ||
1484 | frame_pointer_needed = 1; | |
1485 | for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++) | |
1486 | { | |
1487 | if (ep->can_eliminate && ep->from == FRAME_POINTER_REGNUM | |
1488 | && ep->to != HARD_FRAME_POINTER_REGNUM) | |
1489 | frame_pointer_needed = 0; | |
1490 | ||
1491 | if (! ep->can_eliminate && ep->can_eliminate_previous) | |
1492 | { | |
1493 | ep->can_eliminate_previous = 0; | |
1494 | spill_hard_reg (ep->from, global, dumpfile, 1); | |
1495 | regs_ever_live[ep->from] = 1; | |
1496 | something_changed = 1; | |
1497 | num_eliminable--; | |
1498 | } | |
1499 | } | |
1500 | ||
1501 | /* If all needs are met, we win. */ | |
1502 | ||
1503 | for (i = 0; i < N_REG_CLASSES; i++) | |
1504 | if (max_needs[i] > 0 || max_groups[i] > 0 || max_nongroups[i] > 0) | |
1505 | break; | |
1506 | if (i == N_REG_CLASSES && !new_basic_block_needs && ! something_changed) | |
1507 | break; | |
1508 | ||
1509 | /* Not all needs are met; must spill some hard regs. */ | |
1510 | ||
1511 | /* Put all registers spilled so far back in potential_reload_regs, but | |
1512 | put them at the front, since we've already spilled most of the | |
1513 | psuedos in them (we might have left some pseudos unspilled if they | |
1514 | were in a block that didn't need any spill registers of a conflicting | |
1515 | class. We used to try to mark off the need for those registers, | |
1516 | but doing so properly is very complex and reallocating them is the | |
1517 | simpler approach. First, "pack" potential_reload_regs by pushing | |
1518 | any nonnegative entries towards the end. That will leave room | |
1519 | for the registers we already spilled. | |
1520 | ||
1521 | Also, undo the marking of the spill registers from the last time | |
1522 | around in FORBIDDEN_REGS since we will be probably be allocating | |
1523 | them again below. | |
1524 | ||
1525 | ??? It is theoretically possible that we might end up not using one | |
1526 | of our previously-spilled registers in this allocation, even though | |
1527 | they are at the head of the list. It's not clear what to do about | |
1528 | this, but it was no better before, when we marked off the needs met | |
1529 | by the previously-spilled registers. With the current code, globals | |
1530 | can be allocated into these registers, but locals cannot. */ | |
1531 | ||
1532 | if (n_spills) | |
1533 | { | |
1534 | for (i = j = FIRST_PSEUDO_REGISTER - 1; i >= 0; i--) | |
1535 | if (potential_reload_regs[i] != -1) | |
1536 | potential_reload_regs[j--] = potential_reload_regs[i]; | |
1537 | ||
1538 | for (i = 0; i < n_spills; i++) | |
1539 | { | |
1540 | potential_reload_regs[i] = spill_regs[i]; | |
1541 | spill_reg_order[spill_regs[i]] = -1; | |
1542 | CLEAR_HARD_REG_BIT (forbidden_regs, spill_regs[i]); | |
1543 | } | |
1544 | ||
1545 | n_spills = 0; | |
1546 | } | |
1547 | ||
1548 | /* Now find more reload regs to satisfy the remaining need | |
1549 | Do it by ascending class number, since otherwise a reg | |
1550 | might be spilled for a big class and might fail to count | |
1551 | for a smaller class even though it belongs to that class. | |
1552 | ||
1553 | Count spilled regs in `spills', and add entries to | |
1554 | `spill_regs' and `spill_reg_order'. | |
1555 | ||
1556 | ??? Note there is a problem here. | |
1557 | When there is a need for a group in a high-numbered class, | |
1558 | and also need for non-group regs that come from a lower class, | |
1559 | the non-group regs are chosen first. If there aren't many regs, | |
1560 | they might leave no room for a group. | |
1561 | ||
1562 | This was happening on the 386. To fix it, we added the code | |
1563 | that calls possible_group_p, so that the lower class won't | |
1564 | break up the last possible group. | |
1565 | ||
1566 | Really fixing the problem would require changes above | |
1567 | in counting the regs already spilled, and in choose_reload_regs. | |
1568 | It might be hard to avoid introducing bugs there. */ | |
1569 | ||
1570 | CLEAR_HARD_REG_SET (counted_for_groups); | |
1571 | CLEAR_HARD_REG_SET (counted_for_nongroups); | |
1572 | ||
1573 | for (class = 0; class < N_REG_CLASSES; class++) | |
1574 | { | |
1575 | /* First get the groups of registers. | |
1576 | If we got single registers first, we might fragment | |
1577 | possible groups. */ | |
1578 | while (max_groups[class] > 0) | |
1579 | { | |
1580 | /* If any single spilled regs happen to form groups, | |
1581 | count them now. Maybe we don't really need | |
1582 | to spill another group. */ | |
1583 | count_possible_groups (group_size, group_mode, max_groups); | |
1584 | ||
1585 | if (max_groups[class] <= 0) | |
1586 | break; | |
1587 | ||
1588 | /* Groups of size 2 (the only groups used on most machines) | |
1589 | are treated specially. */ | |
1590 | if (group_size[class] == 2) | |
1591 | { | |
1592 | /* First, look for a register that will complete a group. */ | |
1593 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
1594 | { | |
1595 | int other; | |
1596 | ||
1597 | j = potential_reload_regs[i]; | |
1598 | if (j >= 0 && ! TEST_HARD_REG_BIT (bad_spill_regs, j) | |
1599 | && | |
1600 | ((j > 0 && (other = j - 1, spill_reg_order[other] >= 0) | |
1601 | && TEST_HARD_REG_BIT (reg_class_contents[class], j) | |
1602 | && TEST_HARD_REG_BIT (reg_class_contents[class], other) | |
1603 | && HARD_REGNO_MODE_OK (other, group_mode[class]) | |
1604 | && ! TEST_HARD_REG_BIT (counted_for_nongroups, | |
1605 | other) | |
1606 | /* We don't want one part of another group. | |
1607 | We could get "two groups" that overlap! */ | |
1608 | && ! TEST_HARD_REG_BIT (counted_for_groups, other)) | |
1609 | || | |
1610 | (j < FIRST_PSEUDO_REGISTER - 1 | |
1611 | && (other = j + 1, spill_reg_order[other] >= 0) | |
1612 | && TEST_HARD_REG_BIT (reg_class_contents[class], j) | |
1613 | && TEST_HARD_REG_BIT (reg_class_contents[class], other) | |
1614 | && HARD_REGNO_MODE_OK (j, group_mode[class]) | |
1615 | && ! TEST_HARD_REG_BIT (counted_for_nongroups, | |
1616 | other) | |
1617 | && ! TEST_HARD_REG_BIT (counted_for_groups, | |
1618 | other)))) | |
1619 | { | |
1620 | register enum reg_class *p; | |
1621 | ||
1622 | /* We have found one that will complete a group, | |
1623 | so count off one group as provided. */ | |
1624 | max_groups[class]--; | |
1625 | p = reg_class_superclasses[class]; | |
1626 | while (*p != LIM_REG_CLASSES) | |
1627 | max_groups[(int) *p++]--; | |
1628 | ||
1629 | /* Indicate both these regs are part of a group. */ | |
1630 | SET_HARD_REG_BIT (counted_for_groups, j); | |
1631 | SET_HARD_REG_BIT (counted_for_groups, other); | |
1632 | break; | |
1633 | } | |
1634 | } | |
1635 | /* We can't complete a group, so start one. */ | |
1636 | #ifdef SMALL_REGISTER_CLASSES | |
1637 | /* Look for a pair neither of which is explicitly used. */ | |
1638 | if (i == FIRST_PSEUDO_REGISTER) | |
1639 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
1640 | { | |
1641 | int k; | |
1642 | j = potential_reload_regs[i]; | |
1643 | /* Verify that J+1 is a potential reload reg. */ | |
1644 | for (k = 0; k < FIRST_PSEUDO_REGISTER; k++) | |
1645 | if (potential_reload_regs[k] == j + 1) | |
1646 | break; | |
1647 | if (j >= 0 && j + 1 < FIRST_PSEUDO_REGISTER | |
1648 | && k < FIRST_PSEUDO_REGISTER | |
1649 | && spill_reg_order[j] < 0 && spill_reg_order[j + 1] < 0 | |
1650 | && TEST_HARD_REG_BIT (reg_class_contents[class], j) | |
1651 | && TEST_HARD_REG_BIT (reg_class_contents[class], j + 1) | |
1652 | && HARD_REGNO_MODE_OK (j, group_mode[class]) | |
1653 | && ! TEST_HARD_REG_BIT (counted_for_nongroups, | |
1654 | j + 1) | |
1655 | && ! TEST_HARD_REG_BIT (bad_spill_regs, j + 1) | |
1656 | /* Reject J at this stage | |
1657 | if J+1 was explicitly used. */ | |
1658 | && ! regs_explicitly_used[j + 1]) | |
1659 | break; | |
1660 | } | |
1661 | #endif | |
1662 | /* Now try any group at all | |
1663 | whose registers are not in bad_spill_regs. */ | |
1664 | if (i == FIRST_PSEUDO_REGISTER) | |
1665 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
1666 | { | |
1667 | int k; | |
1668 | j = potential_reload_regs[i]; | |
1669 | /* Verify that J+1 is a potential reload reg. */ | |
1670 | for (k = 0; k < FIRST_PSEUDO_REGISTER; k++) | |
1671 | if (potential_reload_regs[k] == j + 1) | |
1672 | break; | |
1673 | if (j >= 0 && j + 1 < FIRST_PSEUDO_REGISTER | |
1674 | && k < FIRST_PSEUDO_REGISTER | |
1675 | && spill_reg_order[j] < 0 && spill_reg_order[j + 1] < 0 | |
1676 | && TEST_HARD_REG_BIT (reg_class_contents[class], j) | |
1677 | && TEST_HARD_REG_BIT (reg_class_contents[class], j + 1) | |
1678 | && HARD_REGNO_MODE_OK (j, group_mode[class]) | |
1679 | && ! TEST_HARD_REG_BIT (counted_for_nongroups, | |
1680 | j + 1) | |
1681 | && ! TEST_HARD_REG_BIT (bad_spill_regs, j + 1)) | |
1682 | break; | |
1683 | } | |
1684 | ||
1685 | /* I should be the index in potential_reload_regs | |
1686 | of the new reload reg we have found. */ | |
1687 | ||
1688 | if (i >= FIRST_PSEUDO_REGISTER) | |
1689 | { | |
1690 | /* There are no groups left to spill. */ | |
1691 | spill_failure (max_groups_insn[class]); | |
1692 | failure = 1; | |
1693 | goto failed; | |
1694 | } | |
1695 | else | |
1696 | something_changed | |
1697 | |= new_spill_reg (i, class, max_needs, NULL_PTR, | |
1698 | global, dumpfile); | |
1699 | } | |
1700 | else | |
1701 | { | |
1702 | /* For groups of more than 2 registers, | |
1703 | look for a sufficient sequence of unspilled registers, | |
1704 | and spill them all at once. */ | |
1705 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
1706 | { | |
1707 | int k; | |
1708 | ||
1709 | j = potential_reload_regs[i]; | |
1710 | if (j >= 0 | |
1711 | && j + group_size[class] <= FIRST_PSEUDO_REGISTER | |
1712 | && HARD_REGNO_MODE_OK (j, group_mode[class])) | |
1713 | { | |
1714 | /* Check each reg in the sequence. */ | |
1715 | for (k = 0; k < group_size[class]; k++) | |
1716 | if (! (spill_reg_order[j + k] < 0 | |
1717 | && ! TEST_HARD_REG_BIT (bad_spill_regs, j + k) | |
1718 | && TEST_HARD_REG_BIT (reg_class_contents[class], j + k))) | |
1719 | break; | |
1720 | /* We got a full sequence, so spill them all. */ | |
1721 | if (k == group_size[class]) | |
1722 | { | |
1723 | register enum reg_class *p; | |
1724 | for (k = 0; k < group_size[class]; k++) | |
1725 | { | |
1726 | int idx; | |
1727 | SET_HARD_REG_BIT (counted_for_groups, j + k); | |
1728 | for (idx = 0; idx < FIRST_PSEUDO_REGISTER; idx++) | |
1729 | if (potential_reload_regs[idx] == j + k) | |
1730 | break; | |
1731 | something_changed | |
1732 | |= new_spill_reg (idx, class, | |
1733 | max_needs, NULL_PTR, | |
1734 | global, dumpfile); | |
1735 | } | |
1736 | ||
1737 | /* We have found one that will complete a group, | |
1738 | so count off one group as provided. */ | |
1739 | max_groups[class]--; | |
1740 | p = reg_class_superclasses[class]; | |
1741 | while (*p != LIM_REG_CLASSES) | |
1742 | max_groups[(int) *p++]--; | |
1743 | ||
1744 | break; | |
1745 | } | |
1746 | } | |
1747 | } | |
1748 | /* We couldn't find any registers for this reload. | |
1749 | Avoid going into an infinite loop. */ | |
1750 | if (i >= FIRST_PSEUDO_REGISTER) | |
1751 | { | |
1752 | /* There are no groups left. */ | |
1753 | spill_failure (max_groups_insn[class]); | |
1754 | failure = 1; | |
1755 | goto failed; | |
1756 | } | |
1757 | } | |
1758 | } | |
1759 | ||
1760 | /* Now similarly satisfy all need for single registers. */ | |
1761 | ||
1762 | while (max_needs[class] > 0 || max_nongroups[class] > 0) | |
1763 | { | |
1764 | #ifdef SMALL_REGISTER_CLASSES | |
1765 | /* This should be right for all machines, but only the 386 | |
1766 | is known to need it, so this conditional plays safe. | |
1767 | ??? For 2.5, try making this unconditional. */ | |
1768 | /* If we spilled enough regs, but they weren't counted | |
1769 | against the non-group need, see if we can count them now. | |
1770 | If so, we can avoid some actual spilling. */ | |
1771 | if (max_needs[class] <= 0 && max_nongroups[class] > 0) | |
1772 | for (i = 0; i < n_spills; i++) | |
1773 | if (TEST_HARD_REG_BIT (reg_class_contents[class], | |
1774 | spill_regs[i]) | |
1775 | && !TEST_HARD_REG_BIT (counted_for_groups, | |
1776 | spill_regs[i]) | |
1777 | && !TEST_HARD_REG_BIT (counted_for_nongroups, | |
1778 | spill_regs[i]) | |
1779 | && max_nongroups[class] > 0) | |
1780 | { | |
1781 | register enum reg_class *p; | |
1782 | ||
1783 | SET_HARD_REG_BIT (counted_for_nongroups, spill_regs[i]); | |
1784 | max_nongroups[class]--; | |
1785 | p = reg_class_superclasses[class]; | |
1786 | while (*p != LIM_REG_CLASSES) | |
1787 | max_nongroups[(int) *p++]--; | |
1788 | } | |
1789 | if (max_needs[class] <= 0 && max_nongroups[class] <= 0) | |
1790 | break; | |
1791 | #endif | |
1792 | ||
1793 | /* Consider the potential reload regs that aren't | |
1794 | yet in use as reload regs, in order of preference. | |
1795 | Find the most preferred one that's in this class. */ | |
1796 | ||
1797 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
1798 | if (potential_reload_regs[i] >= 0 | |
1799 | && TEST_HARD_REG_BIT (reg_class_contents[class], | |
1800 | potential_reload_regs[i]) | |
1801 | /* If this reg will not be available for groups, | |
1802 | pick one that does not foreclose possible groups. | |
1803 | This is a kludge, and not very general, | |
1804 | but it should be sufficient to make the 386 work, | |
1805 | and the problem should not occur on machines with | |
1806 | more registers. */ | |
1807 | && (max_nongroups[class] == 0 | |
1808 | || possible_group_p (potential_reload_regs[i], max_groups))) | |
1809 | break; | |
1810 | ||
1811 | /* If we couldn't get a register, try to get one even if we | |
1812 | might foreclose possible groups. This may cause problems | |
1813 | later, but that's better than aborting now, since it is | |
1814 | possible that we will, in fact, be able to form the needed | |
1815 | group even with this allocation. */ | |
1816 | ||
1817 | if (i >= FIRST_PSEUDO_REGISTER | |
1818 | && (asm_noperands (max_needs[class] > 0 | |
1819 | ? max_needs_insn[class] | |
1820 | : max_nongroups_insn[class]) | |
1821 | < 0)) | |
1822 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
1823 | if (potential_reload_regs[i] >= 0 | |
1824 | && TEST_HARD_REG_BIT (reg_class_contents[class], | |
1825 | potential_reload_regs[i])) | |
1826 | break; | |
1827 | ||
1828 | /* I should be the index in potential_reload_regs | |
1829 | of the new reload reg we have found. */ | |
1830 | ||
1831 | if (i >= FIRST_PSEUDO_REGISTER) | |
1832 | { | |
1833 | /* There are no possible registers left to spill. */ | |
1834 | spill_failure (max_needs[class] > 0 ? max_needs_insn[class] | |
1835 | : max_nongroups_insn[class]); | |
1836 | failure = 1; | |
1837 | goto failed; | |
1838 | } | |
1839 | else | |
1840 | something_changed | |
1841 | |= new_spill_reg (i, class, max_needs, max_nongroups, | |
1842 | global, dumpfile); | |
1843 | } | |
1844 | } | |
1845 | } | |
1846 | ||
1847 | /* If global-alloc was run, notify it of any register eliminations we have | |
1848 | done. */ | |
1849 | if (global) | |
1850 | for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++) | |
1851 | if (ep->can_eliminate) | |
1852 | mark_elimination (ep->from, ep->to); | |
1853 | ||
1854 | /* Insert code to save and restore call-clobbered hard regs | |
1855 | around calls. Tell if what mode to use so that we will process | |
1856 | those insns in reload_as_needed if we have to. */ | |
1857 | ||
1858 | if (caller_save_needed) | |
1859 | save_call_clobbered_regs (num_eliminable ? QImode | |
1860 | : caller_save_spill_class != NO_REGS ? HImode | |
1861 | : VOIDmode); | |
1862 | ||
1863 | /* If a pseudo has no hard reg, delete the insns that made the equivalence. | |
1864 | If that insn didn't set the register (i.e., it copied the register to | |
1865 | memory), just delete that insn instead of the equivalencing insn plus | |
1866 | anything now dead. If we call delete_dead_insn on that insn, we may | |
1867 | delete the insn that actually sets the register if the register die | |
1868 | there and that is incorrect. */ | |
1869 | ||
1870 | for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++) | |
1871 | if (reg_renumber[i] < 0 && reg_equiv_init[i] != 0 | |
1872 | && GET_CODE (reg_equiv_init[i]) != NOTE) | |
1873 | { | |
1874 | if (reg_set_p (regno_reg_rtx[i], PATTERN (reg_equiv_init[i]))) | |
1875 | delete_dead_insn (reg_equiv_init[i]); | |
1876 | else | |
1877 | { | |
1878 | PUT_CODE (reg_equiv_init[i], NOTE); | |
1879 | NOTE_SOURCE_FILE (reg_equiv_init[i]) = 0; | |
1880 | NOTE_LINE_NUMBER (reg_equiv_init[i]) = NOTE_INSN_DELETED; | |
1881 | } | |
1882 | } | |
1883 | ||
1884 | /* Use the reload registers where necessary | |
1885 | by generating move instructions to move the must-be-register | |
1886 | values into or out of the reload registers. */ | |
1887 | ||
1888 | if (something_needs_reloads || something_needs_elimination | |
1889 | || (caller_save_needed && num_eliminable) | |
1890 | || caller_save_spill_class != NO_REGS) | |
1891 | reload_as_needed (first, global); | |
1892 | ||
1893 | /* If we were able to eliminate the frame pointer, show that it is no | |
1894 | longer live at the start of any basic block. If it ls live by | |
1895 | virtue of being in a pseudo, that pseudo will be marked live | |
1896 | and hence the frame pointer will be known to be live via that | |
1897 | pseudo. */ | |
1898 | ||
1899 | if (! frame_pointer_needed) | |
1900 | for (i = 0; i < n_basic_blocks; i++) | |
1901 | basic_block_live_at_start[i][HARD_FRAME_POINTER_REGNUM / REGSET_ELT_BITS] | |
1902 | &= ~ ((REGSET_ELT_TYPE) 1 << (HARD_FRAME_POINTER_REGNUM | |
1903 | % REGSET_ELT_BITS)); | |
1904 | ||
1905 | /* Come here (with failure set nonzero) if we can't get enough spill regs | |
1906 | and we decide not to abort about it. */ | |
1907 | failed: | |
1908 | ||
1909 | reload_in_progress = 0; | |
1910 | ||
1911 | /* Now eliminate all pseudo regs by modifying them into | |
1912 | their equivalent memory references. | |
1913 | The REG-rtx's for the pseudos are modified in place, | |
1914 | so all insns that used to refer to them now refer to memory. | |
1915 | ||
1916 | For a reg that has a reg_equiv_address, all those insns | |
1917 | were changed by reloading so that no insns refer to it any longer; | |
1918 | but the DECL_RTL of a variable decl may refer to it, | |
1919 | and if so this causes the debugging info to mention the variable. */ | |
1920 | ||
1921 | for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++) | |
1922 | { | |
1923 | rtx addr = 0; | |
1924 | int in_struct = 0; | |
1925 | if (reg_equiv_mem[i]) | |
1926 | { | |
1927 | addr = XEXP (reg_equiv_mem[i], 0); | |
1928 | in_struct = MEM_IN_STRUCT_P (reg_equiv_mem[i]); | |
1929 | } | |
1930 | if (reg_equiv_address[i]) | |
1931 | addr = reg_equiv_address[i]; | |
1932 | if (addr) | |
1933 | { | |
1934 | if (reg_renumber[i] < 0) | |
1935 | { | |
1936 | rtx reg = regno_reg_rtx[i]; | |
1937 | XEXP (reg, 0) = addr; | |
1938 | REG_USERVAR_P (reg) = 0; | |
1939 | MEM_IN_STRUCT_P (reg) = in_struct; | |
1940 | PUT_CODE (reg, MEM); | |
1941 | } | |
1942 | else if (reg_equiv_mem[i]) | |
1943 | XEXP (reg_equiv_mem[i], 0) = addr; | |
1944 | } | |
1945 | } | |
1946 | ||
1947 | #ifdef PRESERVE_DEATH_INFO_REGNO_P | |
1948 | /* Make a pass over all the insns and remove death notes for things that | |
1949 | are no longer registers or no longer die in the insn (e.g., an input | |
1950 | and output pseudo being tied). */ | |
1951 | ||
1952 | for (insn = first; insn; insn = NEXT_INSN (insn)) | |
1953 | if (GET_RTX_CLASS (GET_CODE (insn)) == 'i') | |
1954 | { | |
1955 | rtx note, next; | |
1956 | ||
1957 | for (note = REG_NOTES (insn); note; note = next) | |
1958 | { | |
1959 | next = XEXP (note, 1); | |
1960 | if (REG_NOTE_KIND (note) == REG_DEAD | |
1961 | && (GET_CODE (XEXP (note, 0)) != REG | |
1962 | || reg_set_p (XEXP (note, 0), PATTERN (insn)))) | |
1963 | remove_note (insn, note); | |
1964 | } | |
1965 | } | |
1966 | #endif | |
1967 | ||
1968 | /* Indicate that we no longer have known memory locations or constants. */ | |
1969 | reg_equiv_constant = 0; | |
1970 | reg_equiv_memory_loc = 0; | |
1971 | ||
1972 | if (scratch_list) | |
1973 | free (scratch_list); | |
1974 | scratch_list = 0; | |
1975 | if (scratch_block) | |
1976 | free (scratch_block); | |
1977 | scratch_block = 0; | |
1978 | ||
1979 | return failure; | |
1980 | } | |
1981 | \f | |
1982 | /* Nonzero if, after spilling reg REGNO for non-groups, | |
1983 | it will still be possible to find a group if we still need one. */ | |
1984 | ||
1985 | static int | |
1986 | possible_group_p (regno, max_groups) | |
1987 | int regno; | |
1988 | int *max_groups; | |
1989 | { | |
1990 | int i; | |
1991 | int class = (int) NO_REGS; | |
1992 | ||
1993 | for (i = 0; i < (int) N_REG_CLASSES; i++) | |
1994 | if (max_groups[i] > 0) | |
1995 | { | |
1996 | class = i; | |
1997 | break; | |
1998 | } | |
1999 | ||
2000 | if (class == (int) NO_REGS) | |
2001 | return 1; | |
2002 | ||
2003 | /* Consider each pair of consecutive registers. */ | |
2004 | for (i = 0; i < FIRST_PSEUDO_REGISTER - 1; i++) | |
2005 | { | |
2006 | /* Ignore pairs that include reg REGNO. */ | |
2007 | if (i == regno || i + 1 == regno) | |
2008 | continue; | |
2009 | ||
2010 | /* Ignore pairs that are outside the class that needs the group. | |
2011 | ??? Here we fail to handle the case where two different classes | |
2012 | independently need groups. But this never happens with our | |
2013 | current machine descriptions. */ | |
2014 | if (! (TEST_HARD_REG_BIT (reg_class_contents[class], i) | |
2015 | && TEST_HARD_REG_BIT (reg_class_contents[class], i + 1))) | |
2016 | continue; | |
2017 | ||
2018 | /* A pair of consecutive regs we can still spill does the trick. */ | |
2019 | if (spill_reg_order[i] < 0 && spill_reg_order[i + 1] < 0 | |
2020 | && ! TEST_HARD_REG_BIT (bad_spill_regs, i) | |
2021 | && ! TEST_HARD_REG_BIT (bad_spill_regs, i + 1)) | |
2022 | return 1; | |
2023 | ||
2024 | /* A pair of one already spilled and one we can spill does it | |
2025 | provided the one already spilled is not otherwise reserved. */ | |
2026 | if (spill_reg_order[i] < 0 | |
2027 | && ! TEST_HARD_REG_BIT (bad_spill_regs, i) | |
2028 | && spill_reg_order[i + 1] >= 0 | |
2029 | && ! TEST_HARD_REG_BIT (counted_for_groups, i + 1) | |
2030 | && ! TEST_HARD_REG_BIT (counted_for_nongroups, i + 1)) | |
2031 | return 1; | |
2032 | if (spill_reg_order[i + 1] < 0 | |
2033 | && ! TEST_HARD_REG_BIT (bad_spill_regs, i + 1) | |
2034 | && spill_reg_order[i] >= 0 | |
2035 | && ! TEST_HARD_REG_BIT (counted_for_groups, i) | |
2036 | && ! TEST_HARD_REG_BIT (counted_for_nongroups, i)) | |
2037 | return 1; | |
2038 | } | |
2039 | ||
2040 | return 0; | |
2041 | } | |
2042 | \f | |
2043 | /* Count any groups that can be formed from the registers recently spilled. | |
2044 | This is done class by class, in order of ascending class number. */ | |
2045 | ||
2046 | static void | |
2047 | count_possible_groups (group_size, group_mode, max_groups) | |
2048 | int *group_size; | |
2049 | enum machine_mode *group_mode; | |
2050 | int *max_groups; | |
2051 | { | |
2052 | int i; | |
2053 | /* Now find all consecutive groups of spilled registers | |
2054 | and mark each group off against the need for such groups. | |
2055 | But don't count them against ordinary need, yet. */ | |
2056 | ||
2057 | for (i = 0; i < N_REG_CLASSES; i++) | |
2058 | if (group_size[i] > 1) | |
2059 | { | |
2060 | HARD_REG_SET new; | |
2061 | int j; | |
2062 | ||
2063 | CLEAR_HARD_REG_SET (new); | |
2064 | ||
2065 | /* Make a mask of all the regs that are spill regs in class I. */ | |
2066 | for (j = 0; j < n_spills; j++) | |
2067 | if (TEST_HARD_REG_BIT (reg_class_contents[i], spill_regs[j]) | |
2068 | && ! TEST_HARD_REG_BIT (counted_for_groups, spill_regs[j]) | |
2069 | && ! TEST_HARD_REG_BIT (counted_for_nongroups, | |
2070 | spill_regs[j])) | |
2071 | SET_HARD_REG_BIT (new, spill_regs[j]); | |
2072 | ||
2073 | /* Find each consecutive group of them. */ | |
2074 | for (j = 0; j < FIRST_PSEUDO_REGISTER && max_groups[i] > 0; j++) | |
2075 | if (TEST_HARD_REG_BIT (new, j) | |
2076 | && j + group_size[i] <= FIRST_PSEUDO_REGISTER | |
2077 | /* Next line in case group-mode for this class | |
2078 | demands an even-odd pair. */ | |
2079 | && HARD_REGNO_MODE_OK (j, group_mode[i])) | |
2080 | { | |
2081 | int k; | |
2082 | for (k = 1; k < group_size[i]; k++) | |
2083 | if (! TEST_HARD_REG_BIT (new, j + k)) | |
2084 | break; | |
2085 | if (k == group_size[i]) | |
2086 | { | |
2087 | /* We found a group. Mark it off against this class's | |
2088 | need for groups, and against each superclass too. */ | |
2089 | register enum reg_class *p; | |
2090 | max_groups[i]--; | |
2091 | p = reg_class_superclasses[i]; | |
2092 | while (*p != LIM_REG_CLASSES) | |
2093 | max_groups[(int) *p++]--; | |
2094 | /* Don't count these registers again. */ | |
2095 | for (k = 0; k < group_size[i]; k++) | |
2096 | SET_HARD_REG_BIT (counted_for_groups, j + k); | |
2097 | } | |
2098 | /* Skip to the last reg in this group. When j is incremented | |
2099 | above, it will then point to the first reg of the next | |
2100 | possible group. */ | |
2101 | j += k - 1; | |
2102 | } | |
2103 | } | |
2104 | ||
2105 | } | |
2106 | \f | |
2107 | /* ALLOCATE_MODE is a register mode that needs to be reloaded. OTHER_MODE is | |
2108 | another mode that needs to be reloaded for the same register class CLASS. | |
2109 | If any reg in CLASS allows ALLOCATE_MODE but not OTHER_MODE, fail. | |
2110 | ALLOCATE_MODE will never be smaller than OTHER_MODE. | |
2111 | ||
2112 | This code used to also fail if any reg in CLASS allows OTHER_MODE but not | |
2113 | ALLOCATE_MODE. This test is unnecessary, because we will never try to put | |
2114 | something of mode ALLOCATE_MODE into an OTHER_MODE register. Testing this | |
2115 | causes unnecessary failures on machines requiring alignment of register | |
2116 | groups when the two modes are different sizes, because the larger mode has | |
2117 | more strict alignment rules than the smaller mode. */ | |
2118 | ||
2119 | static int | |
2120 | modes_equiv_for_class_p (allocate_mode, other_mode, class) | |
2121 | enum machine_mode allocate_mode, other_mode; | |
2122 | enum reg_class class; | |
2123 | { | |
2124 | register int regno; | |
2125 | for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++) | |
2126 | { | |
2127 | if (TEST_HARD_REG_BIT (reg_class_contents[(int) class], regno) | |
2128 | && HARD_REGNO_MODE_OK (regno, allocate_mode) | |
2129 | && ! HARD_REGNO_MODE_OK (regno, other_mode)) | |
2130 | return 0; | |
2131 | } | |
2132 | return 1; | |
2133 | } | |
2134 | ||
2135 | /* Handle the failure to find a register to spill. | |
2136 | INSN should be one of the insns which needed this particular spill reg. */ | |
2137 | ||
2138 | static void | |
2139 | spill_failure (insn) | |
2140 | rtx insn; | |
2141 | { | |
2142 | if (asm_noperands (PATTERN (insn)) >= 0) | |
2143 | error_for_asm (insn, "`asm' needs too many reloads"); | |
2144 | else | |
2145 | abort (); | |
2146 | } | |
2147 | ||
2148 | /* Add a new register to the tables of available spill-registers | |
2149 | (as well as spilling all pseudos allocated to the register). | |
2150 | I is the index of this register in potential_reload_regs. | |
2151 | CLASS is the regclass whose need is being satisfied. | |
2152 | MAX_NEEDS and MAX_NONGROUPS are the vectors of needs, | |
2153 | so that this register can count off against them. | |
2154 | MAX_NONGROUPS is 0 if this register is part of a group. | |
2155 | GLOBAL and DUMPFILE are the same as the args that `reload' got. */ | |
2156 | ||
2157 | static int | |
2158 | new_spill_reg (i, class, max_needs, max_nongroups, global, dumpfile) | |
2159 | int i; | |
2160 | int class; | |
2161 | int *max_needs; | |
2162 | int *max_nongroups; | |
2163 | int global; | |
2164 | FILE *dumpfile; | |
2165 | { | |
2166 | register enum reg_class *p; | |
2167 | int val; | |
2168 | int regno = potential_reload_regs[i]; | |
2169 | ||
2170 | if (i >= FIRST_PSEUDO_REGISTER) | |
2171 | abort (); /* Caller failed to find any register. */ | |
2172 | ||
2173 | if (fixed_regs[regno] || TEST_HARD_REG_BIT (forbidden_regs, regno)) | |
2174 | fatal ("fixed or forbidden register was spilled.\n\ | |
2175 | This may be due to a compiler bug or to impossible asm\n\ | |
2176 | statements or clauses."); | |
2177 | ||
2178 | /* Make reg REGNO an additional reload reg. */ | |
2179 | ||
2180 | potential_reload_regs[i] = -1; | |
2181 | spill_regs[n_spills] = regno; | |
2182 | spill_reg_order[regno] = n_spills; | |
2183 | if (dumpfile) | |
2184 | fprintf (dumpfile, "Spilling reg %d.\n", spill_regs[n_spills]); | |
2185 | ||
2186 | /* Clear off the needs we just satisfied. */ | |
2187 | ||
2188 | max_needs[class]--; | |
2189 | p = reg_class_superclasses[class]; | |
2190 | while (*p != LIM_REG_CLASSES) | |
2191 | max_needs[(int) *p++]--; | |
2192 | ||
2193 | if (max_nongroups && max_nongroups[class] > 0) | |
2194 | { | |
2195 | SET_HARD_REG_BIT (counted_for_nongroups, regno); | |
2196 | max_nongroups[class]--; | |
2197 | p = reg_class_superclasses[class]; | |
2198 | while (*p != LIM_REG_CLASSES) | |
2199 | max_nongroups[(int) *p++]--; | |
2200 | } | |
2201 | ||
2202 | /* Spill every pseudo reg that was allocated to this reg | |
2203 | or to something that overlaps this reg. */ | |
2204 | ||
2205 | val = spill_hard_reg (spill_regs[n_spills], global, dumpfile, 0); | |
2206 | ||
2207 | /* If there are some registers still to eliminate and this register | |
2208 | wasn't ever used before, additional stack space may have to be | |
2209 | allocated to store this register. Thus, we may have changed the offset | |
2210 | between the stack and frame pointers, so mark that something has changed. | |
2211 | (If new pseudos were spilled, thus requiring more space, VAL would have | |
2212 | been set non-zero by the call to spill_hard_reg above since additional | |
2213 | reloads may be needed in that case. | |
2214 | ||
2215 | One might think that we need only set VAL to 1 if this is a call-used | |
2216 | register. However, the set of registers that must be saved by the | |
2217 | prologue is not identical to the call-used set. For example, the | |
2218 | register used by the call insn for the return PC is a call-used register, | |
2219 | but must be saved by the prologue. */ | |
2220 | if (num_eliminable && ! regs_ever_live[spill_regs[n_spills]]) | |
2221 | val = 1; | |
2222 | ||
2223 | regs_ever_live[spill_regs[n_spills]] = 1; | |
2224 | n_spills++; | |
2225 | ||
2226 | return val; | |
2227 | } | |
2228 | \f | |
2229 | /* Delete an unneeded INSN and any previous insns who sole purpose is loading | |
2230 | data that is dead in INSN. */ | |
2231 | ||
2232 | static void | |
2233 | delete_dead_insn (insn) | |
2234 | rtx insn; | |
2235 | { | |
2236 | rtx prev = prev_real_insn (insn); | |
2237 | rtx prev_dest; | |
2238 | ||
2239 | /* If the previous insn sets a register that dies in our insn, delete it | |
2240 | too. */ | |
2241 | if (prev && GET_CODE (PATTERN (prev)) == SET | |
2242 | && (prev_dest = SET_DEST (PATTERN (prev)), GET_CODE (prev_dest) == REG) | |
2243 | && reg_mentioned_p (prev_dest, PATTERN (insn)) | |
2244 | && find_regno_note (insn, REG_DEAD, REGNO (prev_dest))) | |
2245 | delete_dead_insn (prev); | |
2246 | ||
2247 | PUT_CODE (insn, NOTE); | |
2248 | NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED; | |
2249 | NOTE_SOURCE_FILE (insn) = 0; | |
2250 | } | |
2251 | ||
2252 | /* Modify the home of pseudo-reg I. | |
2253 | The new home is present in reg_renumber[I]. | |
2254 | ||
2255 | FROM_REG may be the hard reg that the pseudo-reg is being spilled from; | |
2256 | or it may be -1, meaning there is none or it is not relevant. | |
2257 | This is used so that all pseudos spilled from a given hard reg | |
2258 | can share one stack slot. */ | |
2259 | ||
2260 | static void | |
2261 | alter_reg (i, from_reg) | |
2262 | register int i; | |
2263 | int from_reg; | |
2264 | { | |
2265 | /* When outputting an inline function, this can happen | |
2266 | for a reg that isn't actually used. */ | |
2267 | if (regno_reg_rtx[i] == 0) | |
2268 | return; | |
2269 | ||
2270 | /* If the reg got changed to a MEM at rtl-generation time, | |
2271 | ignore it. */ | |
2272 | if (GET_CODE (regno_reg_rtx[i]) != REG) | |
2273 | return; | |
2274 | ||
2275 | /* Modify the reg-rtx to contain the new hard reg | |
2276 | number or else to contain its pseudo reg number. */ | |
2277 | REGNO (regno_reg_rtx[i]) | |
2278 | = reg_renumber[i] >= 0 ? reg_renumber[i] : i; | |
2279 | ||
2280 | /* If we have a pseudo that is needed but has no hard reg or equivalent, | |
2281 | allocate a stack slot for it. */ | |
2282 | ||
2283 | if (reg_renumber[i] < 0 | |
2284 | && reg_n_refs[i] > 0 | |
2285 | && reg_equiv_constant[i] == 0 | |
2286 | && reg_equiv_memory_loc[i] == 0) | |
2287 | { | |
2288 | register rtx x; | |
2289 | int inherent_size = PSEUDO_REGNO_BYTES (i); | |
2290 | int total_size = MAX (inherent_size, reg_max_ref_width[i]); | |
2291 | int adjust = 0; | |
2292 | ||
2293 | /* Each pseudo reg has an inherent size which comes from its own mode, | |
2294 | and a total size which provides room for paradoxical subregs | |
2295 | which refer to the pseudo reg in wider modes. | |
2296 | ||
2297 | We can use a slot already allocated if it provides both | |
2298 | enough inherent space and enough total space. | |
2299 | Otherwise, we allocate a new slot, making sure that it has no less | |
2300 | inherent space, and no less total space, then the previous slot. */ | |
2301 | if (from_reg == -1) | |
2302 | { | |
2303 | /* No known place to spill from => no slot to reuse. */ | |
2304 | x = assign_stack_local (GET_MODE (regno_reg_rtx[i]), total_size, -1); | |
2305 | #if BYTES_BIG_ENDIAN | |
2306 | /* Cancel the big-endian correction done in assign_stack_local. | |
2307 | Get the address of the beginning of the slot. | |
2308 | This is so we can do a big-endian correction unconditionally | |
2309 | below. */ | |
2310 | adjust = inherent_size - total_size; | |
2311 | #endif | |
2312 | } | |
2313 | /* Reuse a stack slot if possible. */ | |
2314 | else if (spill_stack_slot[from_reg] != 0 | |
2315 | && spill_stack_slot_width[from_reg] >= total_size | |
2316 | && (GET_MODE_SIZE (GET_MODE (spill_stack_slot[from_reg])) | |
2317 | >= inherent_size)) | |
2318 | x = spill_stack_slot[from_reg]; | |
2319 | /* Allocate a bigger slot. */ | |
2320 | else | |
2321 | { | |
2322 | /* Compute maximum size needed, both for inherent size | |
2323 | and for total size. */ | |
2324 | enum machine_mode mode = GET_MODE (regno_reg_rtx[i]); | |
2325 | if (spill_stack_slot[from_reg]) | |
2326 | { | |
2327 | if (GET_MODE_SIZE (GET_MODE (spill_stack_slot[from_reg])) | |
2328 | > inherent_size) | |
2329 | mode = GET_MODE (spill_stack_slot[from_reg]); | |
2330 | if (spill_stack_slot_width[from_reg] > total_size) | |
2331 | total_size = spill_stack_slot_width[from_reg]; | |
2332 | } | |
2333 | /* Make a slot with that size. */ | |
2334 | x = assign_stack_local (mode, total_size, -1); | |
2335 | #if BYTES_BIG_ENDIAN | |
2336 | /* Cancel the big-endian correction done in assign_stack_local. | |
2337 | Get the address of the beginning of the slot. | |
2338 | This is so we can do a big-endian correction unconditionally | |
2339 | below. */ | |
2340 | adjust = GET_MODE_SIZE (mode) - total_size; | |
2341 | #endif | |
2342 | spill_stack_slot[from_reg] = x; | |
2343 | spill_stack_slot_width[from_reg] = total_size; | |
2344 | } | |
2345 | ||
2346 | #if BYTES_BIG_ENDIAN | |
2347 | /* On a big endian machine, the "address" of the slot | |
2348 | is the address of the low part that fits its inherent mode. */ | |
2349 | if (inherent_size < total_size) | |
2350 | adjust += (total_size - inherent_size); | |
2351 | #endif /* BYTES_BIG_ENDIAN */ | |
2352 | ||
2353 | /* If we have any adjustment to make, or if the stack slot is the | |
2354 | wrong mode, make a new stack slot. */ | |
2355 | if (adjust != 0 || GET_MODE (x) != GET_MODE (regno_reg_rtx[i])) | |
2356 | { | |
2357 | x = gen_rtx (MEM, GET_MODE (regno_reg_rtx[i]), | |
2358 | plus_constant (XEXP (x, 0), adjust)); | |
2359 | RTX_UNCHANGING_P (x) = RTX_UNCHANGING_P (regno_reg_rtx[i]); | |
2360 | } | |
2361 | ||
2362 | /* Save the stack slot for later. */ | |
2363 | reg_equiv_memory_loc[i] = x; | |
2364 | } | |
2365 | } | |
2366 | ||
2367 | /* Mark the slots in regs_ever_live for the hard regs | |
2368 | used by pseudo-reg number REGNO. */ | |
2369 | ||
2370 | void | |
2371 | mark_home_live (regno) | |
2372 | int regno; | |
2373 | { | |
2374 | register int i, lim; | |
2375 | i = reg_renumber[regno]; | |
2376 | if (i < 0) | |
2377 | return; | |
2378 | lim = i + HARD_REGNO_NREGS (i, PSEUDO_REGNO_MODE (regno)); | |
2379 | while (i < lim) | |
2380 | regs_ever_live[i++] = 1; | |
2381 | } | |
2382 | ||
2383 | /* Mark the registers used in SCRATCH as being live. */ | |
2384 | ||
2385 | static void | |
2386 | mark_scratch_live (scratch) | |
2387 | rtx scratch; | |
2388 | { | |
2389 | register int i; | |
2390 | int regno = REGNO (scratch); | |
2391 | int lim = regno + HARD_REGNO_NREGS (regno, GET_MODE (scratch)); | |
2392 | ||
2393 | for (i = regno; i < lim; i++) | |
2394 | regs_ever_live[i] = 1; | |
2395 | } | |
2396 | \f | |
2397 | /* This function handles the tracking of elimination offsets around branches. | |
2398 | ||
2399 | X is a piece of RTL being scanned. | |
2400 | ||
2401 | INSN is the insn that it came from, if any. | |
2402 | ||
2403 | INITIAL_P is non-zero if we are to set the offset to be the initial | |
2404 | offset and zero if we are setting the offset of the label to be the | |
2405 | current offset. */ | |
2406 | ||
2407 | static void | |
2408 | set_label_offsets (x, insn, initial_p) | |
2409 | rtx x; | |
2410 | rtx insn; | |
2411 | int initial_p; | |
2412 | { | |
2413 | enum rtx_code code = GET_CODE (x); | |
2414 | rtx tem; | |
2415 | int i; | |
2416 | struct elim_table *p; | |
2417 | ||
2418 | switch (code) | |
2419 | { | |
2420 | case LABEL_REF: | |
2421 | if (LABEL_REF_NONLOCAL_P (x)) | |
2422 | return; | |
2423 | ||
2424 | x = XEXP (x, 0); | |
2425 | ||
2426 | /* ... fall through ... */ | |
2427 | ||
2428 | case CODE_LABEL: | |
2429 | /* If we know nothing about this label, set the desired offsets. Note | |
2430 | that this sets the offset at a label to be the offset before a label | |
2431 | if we don't know anything about the label. This is not correct for | |
2432 | the label after a BARRIER, but is the best guess we can make. If | |
2433 | we guessed wrong, we will suppress an elimination that might have | |
2434 | been possible had we been able to guess correctly. */ | |
2435 | ||
2436 | if (! offsets_known_at[CODE_LABEL_NUMBER (x)]) | |
2437 | { | |
2438 | for (i = 0; i < NUM_ELIMINABLE_REGS; i++) | |
2439 | offsets_at[CODE_LABEL_NUMBER (x)][i] | |
2440 | = (initial_p ? reg_eliminate[i].initial_offset | |
2441 | : reg_eliminate[i].offset); | |
2442 | offsets_known_at[CODE_LABEL_NUMBER (x)] = 1; | |
2443 | } | |
2444 | ||
2445 | /* Otherwise, if this is the definition of a label and it is | |
2446 | preceded by a BARRIER, set our offsets to the known offset of | |
2447 | that label. */ | |
2448 | ||
2449 | else if (x == insn | |
2450 | && (tem = prev_nonnote_insn (insn)) != 0 | |
2451 | && GET_CODE (tem) == BARRIER) | |
2452 | { | |
2453 | num_not_at_initial_offset = 0; | |
2454 | for (i = 0; i < NUM_ELIMINABLE_REGS; i++) | |
2455 | { | |
2456 | reg_eliminate[i].offset = reg_eliminate[i].previous_offset | |
2457 | = offsets_at[CODE_LABEL_NUMBER (x)][i]; | |
2458 | if (reg_eliminate[i].can_eliminate | |
2459 | && (reg_eliminate[i].offset | |
2460 | != reg_eliminate[i].initial_offset)) | |
2461 | num_not_at_initial_offset++; | |
2462 | } | |
2463 | } | |
2464 | ||
2465 | else | |
2466 | /* If neither of the above cases is true, compare each offset | |
2467 | with those previously recorded and suppress any eliminations | |
2468 | where the offsets disagree. */ | |
2469 | ||
2470 | for (i = 0; i < NUM_ELIMINABLE_REGS; i++) | |
2471 | if (offsets_at[CODE_LABEL_NUMBER (x)][i] | |
2472 | != (initial_p ? reg_eliminate[i].initial_offset | |
2473 | : reg_eliminate[i].offset)) | |
2474 | reg_eliminate[i].can_eliminate = 0; | |
2475 | ||
2476 | return; | |
2477 | ||
2478 | case JUMP_INSN: | |
2479 | set_label_offsets (PATTERN (insn), insn, initial_p); | |
2480 | ||
2481 | /* ... fall through ... */ | |
2482 | ||
2483 | case INSN: | |
2484 | case CALL_INSN: | |
2485 | /* Any labels mentioned in REG_LABEL notes can be branched to indirectly | |
2486 | and hence must have all eliminations at their initial offsets. */ | |
2487 | for (tem = REG_NOTES (x); tem; tem = XEXP (tem, 1)) | |
2488 | if (REG_NOTE_KIND (tem) == REG_LABEL) | |
2489 | set_label_offsets (XEXP (tem, 0), insn, 1); | |
2490 | return; | |
2491 | ||
2492 | case ADDR_VEC: | |
2493 | case ADDR_DIFF_VEC: | |
2494 | /* Each of the labels in the address vector must be at their initial | |
2495 | offsets. We want the first first for ADDR_VEC and the second | |
2496 | field for ADDR_DIFF_VEC. */ | |
2497 | ||
2498 | for (i = 0; i < XVECLEN (x, code == ADDR_DIFF_VEC); i++) | |
2499 | set_label_offsets (XVECEXP (x, code == ADDR_DIFF_VEC, i), | |
2500 | insn, initial_p); | |
2501 | return; | |
2502 | ||
2503 | case SET: | |
2504 | /* We only care about setting PC. If the source is not RETURN, | |
2505 | IF_THEN_ELSE, or a label, disable any eliminations not at | |
2506 | their initial offsets. Similarly if any arm of the IF_THEN_ELSE | |
2507 | isn't one of those possibilities. For branches to a label, | |
2508 | call ourselves recursively. | |
2509 | ||
2510 | Note that this can disable elimination unnecessarily when we have | |
2511 | a non-local goto since it will look like a non-constant jump to | |
2512 | someplace in the current function. This isn't a significant | |
2513 | problem since such jumps will normally be when all elimination | |
2514 | pairs are back to their initial offsets. */ | |
2515 | ||
2516 | if (SET_DEST (x) != pc_rtx) | |
2517 | return; | |
2518 | ||
2519 | switch (GET_CODE (SET_SRC (x))) | |
2520 | { | |
2521 | case PC: | |
2522 | case RETURN: | |
2523 | return; | |
2524 | ||
2525 | case LABEL_REF: | |
2526 | set_label_offsets (XEXP (SET_SRC (x), 0), insn, initial_p); | |
2527 | return; | |
2528 | ||
2529 | case IF_THEN_ELSE: | |
2530 | tem = XEXP (SET_SRC (x), 1); | |
2531 | if (GET_CODE (tem) == LABEL_REF) | |
2532 | set_label_offsets (XEXP (tem, 0), insn, initial_p); | |
2533 | else if (GET_CODE (tem) != PC && GET_CODE (tem) != RETURN) | |
2534 | break; | |
2535 | ||
2536 | tem = XEXP (SET_SRC (x), 2); | |
2537 | if (GET_CODE (tem) == LABEL_REF) | |
2538 | set_label_offsets (XEXP (tem, 0), insn, initial_p); | |
2539 | else if (GET_CODE (tem) != PC && GET_CODE (tem) != RETURN) | |
2540 | break; | |
2541 | return; | |
2542 | } | |
2543 | ||
2544 | /* If we reach here, all eliminations must be at their initial | |
2545 | offset because we are doing a jump to a variable address. */ | |
2546 | for (p = reg_eliminate; p < ®_eliminate[NUM_ELIMINABLE_REGS]; p++) | |
2547 | if (p->offset != p->initial_offset) | |
2548 | p->can_eliminate = 0; | |
2549 | } | |
2550 | } | |
2551 | \f | |
2552 | /* Used for communication between the next two function to properly share | |
2553 | the vector for an ASM_OPERANDS. */ | |
2554 | ||
2555 | static struct rtvec_def *old_asm_operands_vec, *new_asm_operands_vec; | |
2556 | ||
2557 | /* Scan X and replace any eliminable registers (such as fp) with a | |
2558 | replacement (such as sp), plus an offset. | |
2559 | ||
2560 | MEM_MODE is the mode of an enclosing MEM. We need this to know how | |
2561 | much to adjust a register for, e.g., PRE_DEC. Also, if we are inside a | |
2562 | MEM, we are allowed to replace a sum of a register and the constant zero | |
2563 | with the register, which we cannot do outside a MEM. In addition, we need | |
2564 | to record the fact that a register is referenced outside a MEM. | |
2565 | ||
2566 | If INSN is an insn, it is the insn containing X. If we replace a REG | |
2567 | in a SET_DEST with an equivalent MEM and INSN is non-zero, write a | |
2568 | CLOBBER of the pseudo after INSN so find_equiv_regs will know that | |
2569 | that the REG is being modified. | |
2570 | ||
2571 | Alternatively, INSN may be a note (an EXPR_LIST or INSN_LIST). | |
2572 | That's used when we eliminate in expressions stored in notes. | |
2573 | This means, do not set ref_outside_mem even if the reference | |
2574 | is outside of MEMs. | |
2575 | ||
2576 | If we see a modification to a register we know about, take the | |
2577 | appropriate action (see case SET, below). | |
2578 | ||
2579 | REG_EQUIV_MEM and REG_EQUIV_ADDRESS contain address that have had | |
2580 | replacements done assuming all offsets are at their initial values. If | |
2581 | they are not, or if REG_EQUIV_ADDRESS is nonzero for a pseudo we | |
2582 | encounter, return the actual location so that find_reloads will do | |
2583 | the proper thing. */ | |
2584 | ||
2585 | rtx | |
2586 | eliminate_regs (x, mem_mode, insn) | |
2587 | rtx x; | |
2588 | enum machine_mode mem_mode; | |
2589 | rtx insn; | |
2590 | { | |
2591 | enum rtx_code code = GET_CODE (x); | |
2592 | struct elim_table *ep; | |
2593 | int regno; | |
2594 | rtx new; | |
2595 | int i, j; | |
2596 | char *fmt; | |
2597 | int copied = 0; | |
2598 | ||
2599 | switch (code) | |
2600 | { | |
2601 | case CONST_INT: | |
2602 | case CONST_DOUBLE: | |
2603 | case CONST: | |
2604 | case SYMBOL_REF: | |
2605 | case CODE_LABEL: | |
2606 | case PC: | |
2607 | case CC0: | |
2608 | case ASM_INPUT: | |
2609 | case ADDR_VEC: | |
2610 | case ADDR_DIFF_VEC: | |
2611 | case RETURN: | |
2612 | return x; | |
2613 | ||
2614 | case REG: | |
2615 | regno = REGNO (x); | |
2616 | ||
2617 | /* First handle the case where we encounter a bare register that | |
2618 | is eliminable. Replace it with a PLUS. */ | |
2619 | if (regno < FIRST_PSEUDO_REGISTER) | |
2620 | { | |
2621 | for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; | |
2622 | ep++) | |
2623 | if (ep->from_rtx == x && ep->can_eliminate) | |
2624 | { | |
2625 | if (! mem_mode | |
2626 | /* Refs inside notes don't count for this purpose. */ | |
2627 | && ! (insn != 0 && (GET_CODE (insn) == EXPR_LIST | |
2628 | || GET_CODE (insn) == INSN_LIST))) | |
2629 | ep->ref_outside_mem = 1; | |
2630 | return plus_constant (ep->to_rtx, ep->previous_offset); | |
2631 | } | |
2632 | ||
2633 | } | |
2634 | else if (reg_equiv_memory_loc && reg_equiv_memory_loc[regno] | |
2635 | && (reg_equiv_address[regno] || num_not_at_initial_offset)) | |
2636 | { | |
2637 | /* In this case, find_reloads would attempt to either use an | |
2638 | incorrect address (if something is not at its initial offset) | |
2639 | or substitute an replaced address into an insn (which loses | |
2640 | if the offset is changed by some later action). So we simply | |
2641 | return the replaced stack slot (assuming it is changed by | |
2642 | elimination) and ignore the fact that this is actually a | |
2643 | reference to the pseudo. Ensure we make a copy of the | |
2644 | address in case it is shared. */ | |
2645 | new = eliminate_regs (reg_equiv_memory_loc[regno], | |
2646 | mem_mode, insn); | |
2647 | if (new != reg_equiv_memory_loc[regno]) | |
2648 | { | |
2649 | cannot_omit_stores[regno] = 1; | |
2650 | return copy_rtx (new); | |
2651 | } | |
2652 | } | |
2653 | return x; | |
2654 | ||
2655 | case PLUS: | |
2656 | /* If this is the sum of an eliminable register and a constant, rework | |
2657 | the sum. */ | |
2658 | if (GET_CODE (XEXP (x, 0)) == REG | |
2659 | && REGNO (XEXP (x, 0)) < FIRST_PSEUDO_REGISTER | |
2660 | && CONSTANT_P (XEXP (x, 1))) | |
2661 | { | |
2662 | for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; | |
2663 | ep++) | |
2664 | if (ep->from_rtx == XEXP (x, 0) && ep->can_eliminate) | |
2665 | { | |
2666 | if (! mem_mode | |
2667 | /* Refs inside notes don't count for this purpose. */ | |
2668 | && ! (insn != 0 && (GET_CODE (insn) == EXPR_LIST | |
2669 | || GET_CODE (insn) == INSN_LIST))) | |
2670 | ep->ref_outside_mem = 1; | |
2671 | ||
2672 | /* The only time we want to replace a PLUS with a REG (this | |
2673 | occurs when the constant operand of the PLUS is the negative | |
2674 | of the offset) is when we are inside a MEM. We won't want | |
2675 | to do so at other times because that would change the | |
2676 | structure of the insn in a way that reload can't handle. | |
2677 | We special-case the commonest situation in | |
2678 | eliminate_regs_in_insn, so just replace a PLUS with a | |
2679 | PLUS here, unless inside a MEM. */ | |
2680 | if (mem_mode != 0 && GET_CODE (XEXP (x, 1)) == CONST_INT | |
2681 | && INTVAL (XEXP (x, 1)) == - ep->previous_offset) | |
2682 | return ep->to_rtx; | |
2683 | else | |
2684 | return gen_rtx (PLUS, Pmode, ep->to_rtx, | |
2685 | plus_constant (XEXP (x, 1), | |
2686 | ep->previous_offset)); | |
2687 | } | |
2688 | ||
2689 | /* If the register is not eliminable, we are done since the other | |
2690 | operand is a constant. */ | |
2691 | return x; | |
2692 | } | |
2693 | ||
2694 | /* If this is part of an address, we want to bring any constant to the | |
2695 | outermost PLUS. We will do this by doing register replacement in | |
2696 | our operands and seeing if a constant shows up in one of them. | |
2697 | ||
2698 | We assume here this is part of an address (or a "load address" insn) | |
2699 | since an eliminable register is not likely to appear in any other | |
2700 | context. | |
2701 | ||
2702 | If we have (plus (eliminable) (reg)), we want to produce | |
2703 | (plus (plus (replacement) (reg) (const))). If this was part of a | |
2704 | normal add insn, (plus (replacement) (reg)) will be pushed as a | |
2705 | reload. This is the desired action. */ | |
2706 | ||
2707 | { | |
2708 | rtx new0 = eliminate_regs (XEXP (x, 0), mem_mode, insn); | |
2709 | rtx new1 = eliminate_regs (XEXP (x, 1), mem_mode, insn); | |
2710 | ||
2711 | if (new0 != XEXP (x, 0) || new1 != XEXP (x, 1)) | |
2712 | { | |
2713 | /* If one side is a PLUS and the other side is a pseudo that | |
2714 | didn't get a hard register but has a reg_equiv_constant, | |
2715 | we must replace the constant here since it may no longer | |
2716 | be in the position of any operand. */ | |
2717 | if (GET_CODE (new0) == PLUS && GET_CODE (new1) == REG | |
2718 | && REGNO (new1) >= FIRST_PSEUDO_REGISTER | |
2719 | && reg_renumber[REGNO (new1)] < 0 | |
2720 | && reg_equiv_constant != 0 | |
2721 | && reg_equiv_constant[REGNO (new1)] != 0) | |
2722 | new1 = reg_equiv_constant[REGNO (new1)]; | |
2723 | else if (GET_CODE (new1) == PLUS && GET_CODE (new0) == REG | |
2724 | && REGNO (new0) >= FIRST_PSEUDO_REGISTER | |
2725 | && reg_renumber[REGNO (new0)] < 0 | |
2726 | && reg_equiv_constant[REGNO (new0)] != 0) | |
2727 | new0 = reg_equiv_constant[REGNO (new0)]; | |
2728 | ||
2729 | new = form_sum (new0, new1); | |
2730 | ||
2731 | /* As above, if we are not inside a MEM we do not want to | |
2732 | turn a PLUS into something else. We might try to do so here | |
2733 | for an addition of 0 if we aren't optimizing. */ | |
2734 | if (! mem_mode && GET_CODE (new) != PLUS) | |
2735 | return gen_rtx (PLUS, GET_MODE (x), new, const0_rtx); | |
2736 | else | |
2737 | return new; | |
2738 | } | |
2739 | } | |
2740 | return x; | |
2741 | ||
2742 | case MULT: | |
2743 | /* If this is the product of an eliminable register and a | |
2744 | constant, apply the distribute law and move the constant out | |
2745 | so that we have (plus (mult ..) ..). This is needed in order | |
2746 | to keep load-address insns valid. This case is pathalogical. | |
2747 | We ignore the possibility of overflow here. */ | |
2748 | if (GET_CODE (XEXP (x, 0)) == REG | |
2749 | && REGNO (XEXP (x, 0)) < FIRST_PSEUDO_REGISTER | |
2750 | && GET_CODE (XEXP (x, 1)) == CONST_INT) | |
2751 | for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; | |
2752 | ep++) | |
2753 | if (ep->from_rtx == XEXP (x, 0) && ep->can_eliminate) | |
2754 | { | |
2755 | if (! mem_mode | |
2756 | /* Refs inside notes don't count for this purpose. */ | |
2757 | && ! (insn != 0 && (GET_CODE (insn) == EXPR_LIST | |
2758 | || GET_CODE (insn) == INSN_LIST))) | |
2759 | ep->ref_outside_mem = 1; | |
2760 | ||
2761 | return | |
2762 | plus_constant (gen_rtx (MULT, Pmode, ep->to_rtx, XEXP (x, 1)), | |
2763 | ep->previous_offset * INTVAL (XEXP (x, 1))); | |
2764 | } | |
2765 | ||
2766 | /* ... fall through ... */ | |
2767 | ||
2768 | case CALL: | |
2769 | case COMPARE: | |
2770 | case MINUS: | |
2771 | case DIV: case UDIV: | |
2772 | case MOD: case UMOD: | |
2773 | case AND: case IOR: case XOR: | |
2774 | case ROTATERT: case ROTATE: | |
2775 | case ASHIFTRT: case LSHIFTRT: case ASHIFT: | |
2776 | case NE: case EQ: | |
2777 | case GE: case GT: case GEU: case GTU: | |
2778 | case LE: case LT: case LEU: case LTU: | |
2779 | { | |
2780 | rtx new0 = eliminate_regs (XEXP (x, 0), mem_mode, insn); | |
2781 | rtx new1 | |
2782 | = XEXP (x, 1) ? eliminate_regs (XEXP (x, 1), mem_mode, insn) : 0; | |
2783 | ||
2784 | if (new0 != XEXP (x, 0) || new1 != XEXP (x, 1)) | |
2785 | return gen_rtx (code, GET_MODE (x), new0, new1); | |
2786 | } | |
2787 | return x; | |
2788 | ||
2789 | case EXPR_LIST: | |
2790 | /* If we have something in XEXP (x, 0), the usual case, eliminate it. */ | |
2791 | if (XEXP (x, 0)) | |
2792 | { | |
2793 | new = eliminate_regs (XEXP (x, 0), mem_mode, insn); | |
2794 | if (new != XEXP (x, 0)) | |
2795 | x = gen_rtx (EXPR_LIST, REG_NOTE_KIND (x), new, XEXP (x, 1)); | |
2796 | } | |
2797 | ||
2798 | /* ... fall through ... */ | |
2799 | ||
2800 | case INSN_LIST: | |
2801 | /* Now do eliminations in the rest of the chain. If this was | |
2802 | an EXPR_LIST, this might result in allocating more memory than is | |
2803 | strictly needed, but it simplifies the code. */ | |
2804 | if (XEXP (x, 1)) | |
2805 | { | |
2806 | new = eliminate_regs (XEXP (x, 1), mem_mode, insn); | |
2807 | if (new != XEXP (x, 1)) | |
2808 | return gen_rtx (GET_CODE (x), GET_MODE (x), XEXP (x, 0), new); | |
2809 | } | |
2810 | return x; | |
2811 | ||
2812 | case PRE_INC: | |
2813 | case POST_INC: | |
2814 | case PRE_DEC: | |
2815 | case POST_DEC: | |
2816 | for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++) | |
2817 | if (ep->to_rtx == XEXP (x, 0)) | |
2818 | { | |
2819 | int size = GET_MODE_SIZE (mem_mode); | |
2820 | ||
2821 | /* If more bytes than MEM_MODE are pushed, account for them. */ | |
2822 | #ifdef PUSH_ROUNDING | |
2823 | if (ep->to_rtx == stack_pointer_rtx) | |
2824 | size = PUSH_ROUNDING (size); | |
2825 | #endif | |
2826 | if (code == PRE_DEC || code == POST_DEC) | |
2827 | ep->offset += size; | |
2828 | else | |
2829 | ep->offset -= size; | |
2830 | } | |
2831 | ||
2832 | /* Fall through to generic unary operation case. */ | |
2833 | case USE: | |
2834 | case STRICT_LOW_PART: | |
2835 | case NEG: case NOT: | |
2836 | case SIGN_EXTEND: case ZERO_EXTEND: | |
2837 | case TRUNCATE: case FLOAT_EXTEND: case FLOAT_TRUNCATE: | |
2838 | case FLOAT: case FIX: | |
2839 | case UNSIGNED_FIX: case UNSIGNED_FLOAT: | |
2840 | case ABS: | |
2841 | case SQRT: | |
2842 | case FFS: | |
2843 | new = eliminate_regs (XEXP (x, 0), mem_mode, insn); | |
2844 | if (new != XEXP (x, 0)) | |
2845 | return gen_rtx (code, GET_MODE (x), new); | |
2846 | return x; | |
2847 | ||
2848 | case SUBREG: | |
2849 | /* Similar to above processing, but preserve SUBREG_WORD. | |
2850 | Convert (subreg (mem)) to (mem) if not paradoxical. | |
2851 | Also, if we have a non-paradoxical (subreg (pseudo)) and the | |
2852 | pseudo didn't get a hard reg, we must replace this with the | |
2853 | eliminated version of the memory location because push_reloads | |
2854 | may do the replacement in certain circumstances. */ | |
2855 | if (GET_CODE (SUBREG_REG (x)) == REG | |
2856 | && (GET_MODE_SIZE (GET_MODE (x)) | |
2857 | <= GET_MODE_SIZE (GET_MODE (SUBREG_REG (x)))) | |
2858 | && reg_equiv_memory_loc != 0 | |
2859 | && reg_equiv_memory_loc[REGNO (SUBREG_REG (x))] != 0) | |
2860 | { | |
2861 | new = eliminate_regs (reg_equiv_memory_loc[REGNO (SUBREG_REG (x))], | |
2862 | mem_mode, insn); | |
2863 | ||
2864 | /* If we didn't change anything, we must retain the pseudo. */ | |
2865 | if (new == reg_equiv_memory_loc[REGNO (SUBREG_REG (x))]) | |
2866 | new = XEXP (x, 0); | |
2867 | else | |
2868 | /* Otherwise, ensure NEW isn't shared in case we have to reload | |
2869 | it. */ | |
2870 | new = copy_rtx (new); | |
2871 | } | |
2872 | else | |
2873 | new = eliminate_regs (SUBREG_REG (x), mem_mode, insn); | |
2874 | ||
2875 | if (new != XEXP (x, 0)) | |
2876 | { | |
2877 | if (GET_CODE (new) == MEM | |
2878 | && (GET_MODE_SIZE (GET_MODE (x)) | |
2879 | <= GET_MODE_SIZE (GET_MODE (new))) | |
2880 | #ifdef LOAD_EXTEND_OP | |
2881 | /* On these machines we will be reloading what is | |
2882 | inside the SUBREG if it originally was a pseudo and | |
2883 | the inner and outer modes are both a word or | |
2884 | smaller. So leave the SUBREG then. */ | |
2885 | && ! (GET_CODE (SUBREG_REG (x)) == REG | |
2886 | && GET_MODE_SIZE (GET_MODE (x)) <= UNITS_PER_WORD | |
2887 | && GET_MODE_SIZE (GET_MODE (new)) <= UNITS_PER_WORD) | |
2888 | #endif | |
2889 | ) | |
2890 | { | |
2891 | int offset = SUBREG_WORD (x) * UNITS_PER_WORD; | |
2892 | enum machine_mode mode = GET_MODE (x); | |
2893 | ||
2894 | #if BYTES_BIG_ENDIAN | |
2895 | offset += (MIN (UNITS_PER_WORD, | |
2896 | GET_MODE_SIZE (GET_MODE (new))) | |
2897 | - MIN (UNITS_PER_WORD, GET_MODE_SIZE (mode))); | |
2898 | #endif | |
2899 | ||
2900 | PUT_MODE (new, mode); | |
2901 | XEXP (new, 0) = plus_constant (XEXP (new, 0), offset); | |
2902 | return new; | |
2903 | } | |
2904 | else | |
2905 | return gen_rtx (SUBREG, GET_MODE (x), new, SUBREG_WORD (x)); | |
2906 | } | |
2907 | ||
2908 | return x; | |
2909 | ||
2910 | case CLOBBER: | |
2911 | /* If clobbering a register that is the replacement register for an | |
2912 | elimination we still think can be performed, note that it cannot | |
2913 | be performed. Otherwise, we need not be concerned about it. */ | |
2914 | for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++) | |
2915 | if (ep->to_rtx == XEXP (x, 0)) | |
2916 | ep->can_eliminate = 0; | |
2917 | ||
2918 | new = eliminate_regs (XEXP (x, 0), mem_mode, insn); | |
2919 | if (new != XEXP (x, 0)) | |
2920 | return gen_rtx (code, GET_MODE (x), new); | |
2921 | return x; | |
2922 | ||
2923 | case ASM_OPERANDS: | |
2924 | { | |
2925 | rtx *temp_vec; | |
2926 | /* Properly handle sharing input and constraint vectors. */ | |
2927 | if (ASM_OPERANDS_INPUT_VEC (x) != old_asm_operands_vec) | |
2928 | { | |
2929 | /* When we come to a new vector not seen before, | |
2930 | scan all its elements; keep the old vector if none | |
2931 | of them changes; otherwise, make a copy. */ | |
2932 | old_asm_operands_vec = ASM_OPERANDS_INPUT_VEC (x); | |
2933 | temp_vec = (rtx *) alloca (XVECLEN (x, 3) * sizeof (rtx)); | |
2934 | for (i = 0; i < ASM_OPERANDS_INPUT_LENGTH (x); i++) | |
2935 | temp_vec[i] = eliminate_regs (ASM_OPERANDS_INPUT (x, i), | |
2936 | mem_mode, insn); | |
2937 | ||
2938 | for (i = 0; i < ASM_OPERANDS_INPUT_LENGTH (x); i++) | |
2939 | if (temp_vec[i] != ASM_OPERANDS_INPUT (x, i)) | |
2940 | break; | |
2941 | ||
2942 | if (i == ASM_OPERANDS_INPUT_LENGTH (x)) | |
2943 | new_asm_operands_vec = old_asm_operands_vec; | |
2944 | else | |
2945 | new_asm_operands_vec | |
2946 | = gen_rtvec_v (ASM_OPERANDS_INPUT_LENGTH (x), temp_vec); | |
2947 | } | |
2948 | ||
2949 | /* If we had to copy the vector, copy the entire ASM_OPERANDS. */ | |
2950 | if (new_asm_operands_vec == old_asm_operands_vec) | |
2951 | return x; | |
2952 | ||
2953 | new = gen_rtx (ASM_OPERANDS, VOIDmode, ASM_OPERANDS_TEMPLATE (x), | |
2954 | ASM_OPERANDS_OUTPUT_CONSTRAINT (x), | |
2955 | ASM_OPERANDS_OUTPUT_IDX (x), new_asm_operands_vec, | |
2956 | ASM_OPERANDS_INPUT_CONSTRAINT_VEC (x), | |
2957 | ASM_OPERANDS_SOURCE_FILE (x), | |
2958 | ASM_OPERANDS_SOURCE_LINE (x)); | |
2959 | new->volatil = x->volatil; | |
2960 | return new; | |
2961 | } | |
2962 | ||
2963 | case SET: | |
2964 | /* Check for setting a register that we know about. */ | |
2965 | if (GET_CODE (SET_DEST (x)) == REG) | |
2966 | { | |
2967 | /* See if this is setting the replacement register for an | |
2968 | elimination. | |
2969 | ||
2970 | If DEST is the hard frame pointer, we do nothing because we | |
2971 | assume that all assignments to the frame pointer are for | |
2972 | non-local gotos and are being done at a time when they are valid | |
2973 | and do not disturb anything else. Some machines want to | |
2974 | eliminate a fake argument pointer (or even a fake frame pointer) | |
2975 | with either the real frame or the stack pointer. Assignments to | |
2976 | the hard frame pointer must not prevent this elimination. */ | |
2977 | ||
2978 | for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; | |
2979 | ep++) | |
2980 | if (ep->to_rtx == SET_DEST (x) | |
2981 | && SET_DEST (x) != hard_frame_pointer_rtx) | |
2982 | { | |
2983 | /* If it is being incremented, adjust the offset. Otherwise, | |
2984 | this elimination can't be done. */ | |
2985 | rtx src = SET_SRC (x); | |
2986 | ||
2987 | if (GET_CODE (src) == PLUS | |
2988 | && XEXP (src, 0) == SET_DEST (x) | |
2989 | && GET_CODE (XEXP (src, 1)) == CONST_INT) | |
2990 | ep->offset -= INTVAL (XEXP (src, 1)); | |
2991 | else | |
2992 | ep->can_eliminate = 0; | |
2993 | } | |
2994 | ||
2995 | /* Now check to see we are assigning to a register that can be | |
2996 | eliminated. If so, it must be as part of a PARALLEL, since we | |
2997 | will not have been called if this is a single SET. So indicate | |
2998 | that we can no longer eliminate this reg. */ | |
2999 | for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; | |
3000 | ep++) | |
3001 | if (ep->from_rtx == SET_DEST (x) && ep->can_eliminate) | |
3002 | ep->can_eliminate = 0; | |
3003 | } | |
3004 | ||
3005 | /* Now avoid the loop below in this common case. */ | |
3006 | { | |
3007 | rtx new0 = eliminate_regs (SET_DEST (x), 0, insn); | |
3008 | rtx new1 = eliminate_regs (SET_SRC (x), 0, insn); | |
3009 | ||
3010 | /* If SET_DEST changed from a REG to a MEM and INSN is an insn, | |
3011 | write a CLOBBER insn. */ | |
3012 | if (GET_CODE (SET_DEST (x)) == REG && GET_CODE (new0) == MEM | |
3013 | && insn != 0 && GET_CODE (insn) != EXPR_LIST | |
3014 | && GET_CODE (insn) != INSN_LIST) | |
3015 | emit_insn_after (gen_rtx (CLOBBER, VOIDmode, SET_DEST (x)), insn); | |
3016 | ||
3017 | if (new0 != SET_DEST (x) || new1 != SET_SRC (x)) | |
3018 | return gen_rtx (SET, VOIDmode, new0, new1); | |
3019 | } | |
3020 | ||
3021 | return x; | |
3022 | ||
3023 | case MEM: | |
3024 | /* Our only special processing is to pass the mode of the MEM to our | |
3025 | recursive call and copy the flags. While we are here, handle this | |
3026 | case more efficiently. */ | |
3027 | new = eliminate_regs (XEXP (x, 0), GET_MODE (x), insn); | |
3028 | if (new != XEXP (x, 0)) | |
3029 | { | |
3030 | new = gen_rtx (MEM, GET_MODE (x), new); | |
3031 | new->volatil = x->volatil; | |
3032 | new->unchanging = x->unchanging; | |
3033 | new->in_struct = x->in_struct; | |
3034 | return new; | |
3035 | } | |
3036 | else | |
3037 | return x; | |
3038 | } | |
3039 | ||
3040 | /* Process each of our operands recursively. If any have changed, make a | |
3041 | copy of the rtx. */ | |
3042 | fmt = GET_RTX_FORMAT (code); | |
3043 | for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++) | |
3044 | { | |
3045 | if (*fmt == 'e') | |
3046 | { | |
3047 | new = eliminate_regs (XEXP (x, i), mem_mode, insn); | |
3048 | if (new != XEXP (x, i) && ! copied) | |
3049 | { | |
3050 | rtx new_x = rtx_alloc (code); | |
3051 | bcopy (x, new_x, (sizeof (*new_x) - sizeof (new_x->fld) | |
3052 | + (sizeof (new_x->fld[0]) | |
3053 | * GET_RTX_LENGTH (code)))); | |
3054 | x = new_x; | |
3055 | copied = 1; | |
3056 | } | |
3057 | XEXP (x, i) = new; | |
3058 | } | |
3059 | else if (*fmt == 'E') | |
3060 | { | |
3061 | int copied_vec = 0; | |
3062 | for (j = 0; j < XVECLEN (x, i); j++) | |
3063 | { | |
3064 | new = eliminate_regs (XVECEXP (x, i, j), mem_mode, insn); | |
3065 | if (new != XVECEXP (x, i, j) && ! copied_vec) | |
3066 | { | |
3067 | rtvec new_v = gen_rtvec_v (XVECLEN (x, i), | |
3068 | &XVECEXP (x, i, 0)); | |
3069 | if (! copied) | |
3070 | { | |
3071 | rtx new_x = rtx_alloc (code); | |
3072 | bcopy (x, new_x, (sizeof (*new_x) - sizeof (new_x->fld) | |
3073 | + (sizeof (new_x->fld[0]) | |
3074 | * GET_RTX_LENGTH (code)))); | |
3075 | x = new_x; | |
3076 | copied = 1; | |
3077 | } | |
3078 | XVEC (x, i) = new_v; | |
3079 | copied_vec = 1; | |
3080 | } | |
3081 | XVECEXP (x, i, j) = new; | |
3082 | } | |
3083 | } | |
3084 | } | |
3085 | ||
3086 | return x; | |
3087 | } | |
3088 | \f | |
3089 | /* Scan INSN and eliminate all eliminable registers in it. | |
3090 | ||
3091 | If REPLACE is nonzero, do the replacement destructively. Also | |
3092 | delete the insn as dead it if it is setting an eliminable register. | |
3093 | ||
3094 | If REPLACE is zero, do all our allocations in reload_obstack. | |
3095 | ||
3096 | If no eliminations were done and this insn doesn't require any elimination | |
3097 | processing (these are not identical conditions: it might be updating sp, | |
3098 | but not referencing fp; this needs to be seen during reload_as_needed so | |
3099 | that the offset between fp and sp can be taken into consideration), zero | |
3100 | is returned. Otherwise, 1 is returned. */ | |
3101 | ||
3102 | static int | |
3103 | eliminate_regs_in_insn (insn, replace) | |
3104 | rtx insn; | |
3105 | int replace; | |
3106 | { | |
3107 | rtx old_body = PATTERN (insn); | |
3108 | rtx new_body; | |
3109 | int val = 0; | |
3110 | struct elim_table *ep; | |
3111 | ||
3112 | if (! replace) | |
3113 | push_obstacks (&reload_obstack, &reload_obstack); | |
3114 | ||
3115 | if (GET_CODE (old_body) == SET && GET_CODE (SET_DEST (old_body)) == REG | |
3116 | && REGNO (SET_DEST (old_body)) < FIRST_PSEUDO_REGISTER) | |
3117 | { | |
3118 | /* Check for setting an eliminable register. */ | |
3119 | for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++) | |
3120 | if (ep->from_rtx == SET_DEST (old_body) && ep->can_eliminate) | |
3121 | { | |
3122 | /* In this case this insn isn't serving a useful purpose. We | |
3123 | will delete it in reload_as_needed once we know that this | |
3124 | elimination is, in fact, being done. | |
3125 | ||
3126 | If REPLACE isn't set, we can't delete this insn, but neededn't | |
3127 | process it since it won't be used unless something changes. */ | |
3128 | if (replace) | |
3129 | delete_dead_insn (insn); | |
3130 | val = 1; | |
3131 | goto done; | |
3132 | } | |
3133 | ||
3134 | /* Check for (set (reg) (plus (reg from) (offset))) where the offset | |
3135 | in the insn is the negative of the offset in FROM. Substitute | |
3136 | (set (reg) (reg to)) for the insn and change its code. | |
3137 | ||
3138 | We have to do this here, rather than in eliminate_regs, do that we can | |
3139 | change the insn code. */ | |
3140 | ||
3141 | if (GET_CODE (SET_SRC (old_body)) == PLUS | |
3142 | && GET_CODE (XEXP (SET_SRC (old_body), 0)) == REG | |
3143 | && GET_CODE (XEXP (SET_SRC (old_body), 1)) == CONST_INT) | |
3144 | for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; | |
3145 | ep++) | |
3146 | if (ep->from_rtx == XEXP (SET_SRC (old_body), 0) | |
3147 | && ep->can_eliminate) | |
3148 | { | |
3149 | /* We must stop at the first elimination that will be used. | |
3150 | If this one would replace the PLUS with a REG, do it | |
3151 | now. Otherwise, quit the loop and let eliminate_regs | |
3152 | do its normal replacement. */ | |
3153 | if (ep->offset == - INTVAL (XEXP (SET_SRC (old_body), 1))) | |
3154 | { | |
3155 | PATTERN (insn) = gen_rtx (SET, VOIDmode, | |
3156 | SET_DEST (old_body), ep->to_rtx); | |
3157 | INSN_CODE (insn) = -1; | |
3158 | val = 1; | |
3159 | goto done; | |
3160 | } | |
3161 | ||
3162 | break; | |
3163 | } | |
3164 | } | |
3165 | ||
3166 | old_asm_operands_vec = 0; | |
3167 | ||
3168 | /* Replace the body of this insn with a substituted form. If we changed | |
3169 | something, return non-zero. | |
3170 | ||
3171 | If we are replacing a body that was a (set X (plus Y Z)), try to | |
3172 | re-recognize the insn. We do this in case we had a simple addition | |
3173 | but now can do this as a load-address. This saves an insn in this | |
3174 | common case. */ | |
3175 | ||
3176 | new_body = eliminate_regs (old_body, 0, replace ? insn : NULL_RTX); | |
3177 | if (new_body != old_body) | |
3178 | { | |
3179 | /* If we aren't replacing things permanently and we changed something, | |
3180 | make another copy to ensure that all the RTL is new. Otherwise | |
3181 | things can go wrong if find_reload swaps commutative operands | |
3182 | and one is inside RTL that has been copied while the other is not. */ | |
3183 | ||
3184 | /* Don't copy an asm_operands because (1) there's no need and (2) | |
3185 | copy_rtx can't do it properly when there are multiple outputs. */ | |
3186 | if (! replace && asm_noperands (old_body) < 0) | |
3187 | new_body = copy_rtx (new_body); | |
3188 | ||
3189 | /* If we had a move insn but now we don't, rerecognize it. */ | |
3190 | if ((GET_CODE (old_body) == SET && GET_CODE (SET_SRC (old_body)) == REG | |
3191 | && (GET_CODE (new_body) != SET | |
3192 | || GET_CODE (SET_SRC (new_body)) != REG)) | |
3193 | /* If this was a load from or store to memory, compare | |
3194 | the MEM in recog_operand to the one in the insn. If they | |
3195 | are not equal, then rerecognize the insn. */ | |
3196 | || (GET_CODE (old_body) == SET | |
3197 | && ((GET_CODE (SET_SRC (old_body)) == MEM | |
3198 | && SET_SRC (old_body) != recog_operand[1]) | |
3199 | || (GET_CODE (SET_DEST (old_body)) == MEM | |
3200 | && SET_DEST (old_body) != recog_operand[0]))) | |
3201 | /* If this was an add insn before, rerecognize. */ | |
3202 | || | |
3203 | (GET_CODE (old_body) == SET | |
3204 | && GET_CODE (SET_SRC (old_body)) == PLUS)) | |
3205 | { | |
3206 | if (! validate_change (insn, &PATTERN (insn), new_body, 0)) | |
3207 | /* If recognition fails, store the new body anyway. | |
3208 | It's normal to have recognition failures here | |
3209 | due to bizarre memory addresses; reloading will fix them. */ | |
3210 | PATTERN (insn) = new_body; | |
3211 | } | |
3212 | else | |
3213 | PATTERN (insn) = new_body; | |
3214 | ||
3215 | val = 1; | |
3216 | } | |
3217 | ||
3218 | /* Loop through all elimination pairs. See if any have changed and | |
3219 | recalculate the number not at initial offset. | |
3220 | ||
3221 | Compute the maximum offset (minimum offset if the stack does not | |
3222 | grow downward) for each elimination pair. | |
3223 | ||
3224 | We also detect a cases where register elimination cannot be done, | |
3225 | namely, if a register would be both changed and referenced outside a MEM | |
3226 | in the resulting insn since such an insn is often undefined and, even if | |
3227 | not, we cannot know what meaning will be given to it. Note that it is | |
3228 | valid to have a register used in an address in an insn that changes it | |
3229 | (presumably with a pre- or post-increment or decrement). | |
3230 | ||
3231 | If anything changes, return nonzero. */ | |
3232 | ||
3233 | num_not_at_initial_offset = 0; | |
3234 | for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++) | |
3235 | { | |
3236 | if (ep->previous_offset != ep->offset && ep->ref_outside_mem) | |
3237 | ep->can_eliminate = 0; | |
3238 | ||
3239 | ep->ref_outside_mem = 0; | |
3240 | ||
3241 | if (ep->previous_offset != ep->offset) | |
3242 | val = 1; | |
3243 | ||
3244 | ep->previous_offset = ep->offset; | |
3245 | if (ep->can_eliminate && ep->offset != ep->initial_offset) | |
3246 | num_not_at_initial_offset++; | |
3247 | ||
3248 | #ifdef STACK_GROWS_DOWNWARD | |
3249 | ep->max_offset = MAX (ep->max_offset, ep->offset); | |
3250 | #else | |
3251 | ep->max_offset = MIN (ep->max_offset, ep->offset); | |
3252 | #endif | |
3253 | } | |
3254 | ||
3255 | done: | |
3256 | /* If we changed something, perform elmination in REG_NOTES. This is | |
3257 | needed even when REPLACE is zero because a REG_DEAD note might refer | |
3258 | to a register that we eliminate and could cause a different number | |
3259 | of spill registers to be needed in the final reload pass than in | |
3260 | the pre-passes. */ | |
3261 | if (val && REG_NOTES (insn) != 0) | |
3262 | REG_NOTES (insn) = eliminate_regs (REG_NOTES (insn), 0, REG_NOTES (insn)); | |
3263 | ||
3264 | if (! replace) | |
3265 | pop_obstacks (); | |
3266 | ||
3267 | return val; | |
3268 | } | |
3269 | ||
3270 | /* Given X, a SET or CLOBBER of DEST, if DEST is the target of a register | |
3271 | replacement we currently believe is valid, mark it as not eliminable if X | |
3272 | modifies DEST in any way other than by adding a constant integer to it. | |
3273 | ||
3274 | If DEST is the frame pointer, we do nothing because we assume that | |
3275 | all assignments to the hard frame pointer are nonlocal gotos and are being | |
3276 | done at a time when they are valid and do not disturb anything else. | |
3277 | Some machines want to eliminate a fake argument pointer with either the | |
3278 | frame or stack pointer. Assignments to the hard frame pointer must not | |
3279 | prevent this elimination. | |
3280 | ||
3281 | Called via note_stores from reload before starting its passes to scan | |
3282 | the insns of the function. */ | |
3283 | ||
3284 | static void | |
3285 | mark_not_eliminable (dest, x) | |
3286 | rtx dest; | |
3287 | rtx x; | |
3288 | { | |
3289 | register int i; | |
3290 | ||
3291 | /* A SUBREG of a hard register here is just changing its mode. We should | |
3292 | not see a SUBREG of an eliminable hard register, but check just in | |
3293 | case. */ | |
3294 | if (GET_CODE (dest) == SUBREG) | |
3295 | dest = SUBREG_REG (dest); | |
3296 | ||
3297 | if (dest == hard_frame_pointer_rtx) | |
3298 | return; | |
3299 | ||
3300 | for (i = 0; i < NUM_ELIMINABLE_REGS; i++) | |
3301 | if (reg_eliminate[i].can_eliminate && dest == reg_eliminate[i].to_rtx | |
3302 | && (GET_CODE (x) != SET | |
3303 | || GET_CODE (SET_SRC (x)) != PLUS | |
3304 | || XEXP (SET_SRC (x), 0) != dest | |
3305 | || GET_CODE (XEXP (SET_SRC (x), 1)) != CONST_INT)) | |
3306 | { | |
3307 | reg_eliminate[i].can_eliminate_previous | |
3308 | = reg_eliminate[i].can_eliminate = 0; | |
3309 | num_eliminable--; | |
3310 | } | |
3311 | } | |
3312 | \f | |
3313 | /* Kick all pseudos out of hard register REGNO. | |
3314 | If GLOBAL is nonzero, try to find someplace else to put them. | |
3315 | If DUMPFILE is nonzero, log actions taken on that file. | |
3316 | ||
3317 | If CANT_ELIMINATE is nonzero, it means that we are doing this spill | |
3318 | because we found we can't eliminate some register. In the case, no pseudos | |
3319 | are allowed to be in the register, even if they are only in a block that | |
3320 | doesn't require spill registers, unlike the case when we are spilling this | |
3321 | hard reg to produce another spill register. | |
3322 | ||
3323 | Return nonzero if any pseudos needed to be kicked out. */ | |
3324 | ||
3325 | static int | |
3326 | spill_hard_reg (regno, global, dumpfile, cant_eliminate) | |
3327 | register int regno; | |
3328 | int global; | |
3329 | FILE *dumpfile; | |
3330 | int cant_eliminate; | |
3331 | { | |
3332 | enum reg_class class = REGNO_REG_CLASS (regno); | |
3333 | int something_changed = 0; | |
3334 | register int i; | |
3335 | ||
3336 | SET_HARD_REG_BIT (forbidden_regs, regno); | |
3337 | ||
3338 | /* Spill every pseudo reg that was allocated to this reg | |
3339 | or to something that overlaps this reg. */ | |
3340 | ||
3341 | for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++) | |
3342 | if (reg_renumber[i] >= 0 | |
3343 | && reg_renumber[i] <= regno | |
3344 | && (reg_renumber[i] | |
3345 | + HARD_REGNO_NREGS (reg_renumber[i], | |
3346 | PSEUDO_REGNO_MODE (i)) | |
3347 | > regno)) | |
3348 | { | |
3349 | /* If this register belongs solely to a basic block which needed no | |
3350 | spilling of any class that this register is contained in, | |
3351 | leave it be, unless we are spilling this register because | |
3352 | it was a hard register that can't be eliminated. */ | |
3353 | ||
3354 | if (! cant_eliminate | |
3355 | && basic_block_needs[0] | |
3356 | && reg_basic_block[i] >= 0 | |
3357 | && basic_block_needs[(int) class][reg_basic_block[i]] == 0) | |
3358 | { | |
3359 | enum reg_class *p; | |
3360 | ||
3361 | for (p = reg_class_superclasses[(int) class]; | |
3362 | *p != LIM_REG_CLASSES; p++) | |
3363 | if (basic_block_needs[(int) *p][reg_basic_block[i]] > 0) | |
3364 | break; | |
3365 | ||
3366 | if (*p == LIM_REG_CLASSES) | |
3367 | continue; | |
3368 | } | |
3369 | ||
3370 | /* Mark it as no longer having a hard register home. */ | |
3371 | reg_renumber[i] = -1; | |
3372 | /* We will need to scan everything again. */ | |
3373 | something_changed = 1; | |
3374 | if (global) | |
3375 | retry_global_alloc (i, forbidden_regs); | |
3376 | ||
3377 | alter_reg (i, regno); | |
3378 | if (dumpfile) | |
3379 | { | |
3380 | if (reg_renumber[i] == -1) | |
3381 | fprintf (dumpfile, " Register %d now on stack.\n\n", i); | |
3382 | else | |
3383 | fprintf (dumpfile, " Register %d now in %d.\n\n", | |
3384 | i, reg_renumber[i]); | |
3385 | } | |
3386 | } | |
3387 | for (i = 0; i < scratch_list_length; i++) | |
3388 | { | |
3389 | if (scratch_list[i] && REGNO (scratch_list[i]) == regno) | |
3390 | { | |
3391 | if (! cant_eliminate && basic_block_needs[0] | |
3392 | && ! basic_block_needs[(int) class][scratch_block[i]]) | |
3393 | { | |
3394 | enum reg_class *p; | |
3395 | ||
3396 | for (p = reg_class_superclasses[(int) class]; | |
3397 | *p != LIM_REG_CLASSES; p++) | |
3398 | if (basic_block_needs[(int) *p][scratch_block[i]] > 0) | |
3399 | break; | |
3400 | ||
3401 | if (*p == LIM_REG_CLASSES) | |
3402 | continue; | |
3403 | } | |
3404 | PUT_CODE (scratch_list[i], SCRATCH); | |
3405 | scratch_list[i] = 0; | |
3406 | something_changed = 1; | |
3407 | continue; | |
3408 | } | |
3409 | } | |
3410 | ||
3411 | return something_changed; | |
3412 | } | |
3413 | \f | |
3414 | /* Find all paradoxical subregs within X and update reg_max_ref_width. | |
3415 | Also mark any hard registers used to store user variables as | |
3416 | forbidden from being used for spill registers. */ | |
3417 | ||
3418 | static void | |
3419 | scan_paradoxical_subregs (x) | |
3420 | register rtx x; | |
3421 | { | |
3422 | register int i; | |
3423 | register char *fmt; | |
3424 | register enum rtx_code code = GET_CODE (x); | |
3425 | ||
3426 | switch (code) | |
3427 | { | |
3428 | case REG: | |
3429 | #ifdef SMALL_REGISTER_CLASSES | |
3430 | if (REGNO (x) < FIRST_PSEUDO_REGISTER && REG_USERVAR_P (x)) | |
3431 | SET_HARD_REG_BIT (forbidden_regs, REGNO (x)); | |
3432 | #endif | |
3433 | return; | |
3434 | ||
3435 | case CONST_INT: | |
3436 | case CONST: | |
3437 | case SYMBOL_REF: | |
3438 | case LABEL_REF: | |
3439 | case CONST_DOUBLE: | |
3440 | case CC0: | |
3441 | case PC: | |
3442 | case USE: | |
3443 | case CLOBBER: | |
3444 | return; | |
3445 | ||
3446 | case SUBREG: | |
3447 | if (GET_CODE (SUBREG_REG (x)) == REG | |
3448 | && GET_MODE_SIZE (GET_MODE (x)) > GET_MODE_SIZE (GET_MODE (SUBREG_REG (x)))) | |
3449 | reg_max_ref_width[REGNO (SUBREG_REG (x))] | |
3450 | = GET_MODE_SIZE (GET_MODE (x)); | |
3451 | return; | |
3452 | } | |
3453 | ||
3454 | fmt = GET_RTX_FORMAT (code); | |
3455 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
3456 | { | |
3457 | if (fmt[i] == 'e') | |
3458 | scan_paradoxical_subregs (XEXP (x, i)); | |
3459 | else if (fmt[i] == 'E') | |
3460 | { | |
3461 | register int j; | |
3462 | for (j = XVECLEN (x, i) - 1; j >=0; j--) | |
3463 | scan_paradoxical_subregs (XVECEXP (x, i, j)); | |
3464 | } | |
3465 | } | |
3466 | } | |
3467 | \f | |
3468 | static int | |
3469 | hard_reg_use_compare (p1, p2) | |
3470 | struct hard_reg_n_uses *p1, *p2; | |
3471 | { | |
3472 | int tem = p1->uses - p2->uses; | |
3473 | if (tem != 0) return tem; | |
3474 | /* If regs are equally good, sort by regno, | |
3475 | so that the results of qsort leave nothing to chance. */ | |
3476 | return p1->regno - p2->regno; | |
3477 | } | |
3478 | ||
3479 | /* Choose the order to consider regs for use as reload registers | |
3480 | based on how much trouble would be caused by spilling one. | |
3481 | Store them in order of decreasing preference in potential_reload_regs. */ | |
3482 | ||
3483 | static void | |
3484 | order_regs_for_reload () | |
3485 | { | |
3486 | register int i; | |
3487 | register int o = 0; | |
3488 | int large = 0; | |
3489 | ||
3490 | struct hard_reg_n_uses hard_reg_n_uses[FIRST_PSEUDO_REGISTER]; | |
3491 | ||
3492 | CLEAR_HARD_REG_SET (bad_spill_regs); | |
3493 | ||
3494 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
3495 | potential_reload_regs[i] = -1; | |
3496 | ||
3497 | /* Count number of uses of each hard reg by pseudo regs allocated to it | |
3498 | and then order them by decreasing use. */ | |
3499 | ||
3500 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
3501 | { | |
3502 | hard_reg_n_uses[i].uses = 0; | |
3503 | hard_reg_n_uses[i].regno = i; | |
3504 | } | |
3505 | ||
3506 | for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++) | |
3507 | { | |
3508 | int regno = reg_renumber[i]; | |
3509 | if (regno >= 0) | |
3510 | { | |
3511 | int lim = regno + HARD_REGNO_NREGS (regno, PSEUDO_REGNO_MODE (i)); | |
3512 | while (regno < lim) | |
3513 | hard_reg_n_uses[regno++].uses += reg_n_refs[i]; | |
3514 | } | |
3515 | large += reg_n_refs[i]; | |
3516 | } | |
3517 | ||
3518 | /* Now fixed registers (which cannot safely be used for reloading) | |
3519 | get a very high use count so they will be considered least desirable. | |
3520 | Registers used explicitly in the rtl code are almost as bad. */ | |
3521 | ||
3522 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
3523 | { | |
3524 | if (fixed_regs[i]) | |
3525 | { | |
3526 | hard_reg_n_uses[i].uses += 2 * large + 2; | |
3527 | SET_HARD_REG_BIT (bad_spill_regs, i); | |
3528 | } | |
3529 | else if (regs_explicitly_used[i]) | |
3530 | { | |
3531 | hard_reg_n_uses[i].uses += large + 1; | |
3532 | #ifndef SMALL_REGISTER_CLASSES | |
3533 | /* ??? We are doing this here because of the potential that | |
3534 | bad code may be generated if a register explicitly used in | |
3535 | an insn was used as a spill register for that insn. But | |
3536 | not using these are spill registers may lose on some machine. | |
3537 | We'll have to see how this works out. */ | |
3538 | SET_HARD_REG_BIT (bad_spill_regs, i); | |
3539 | #endif | |
3540 | } | |
3541 | } | |
3542 | hard_reg_n_uses[HARD_FRAME_POINTER_REGNUM].uses += 2 * large + 2; | |
3543 | SET_HARD_REG_BIT (bad_spill_regs, HARD_FRAME_POINTER_REGNUM); | |
3544 | ||
3545 | #ifdef ELIMINABLE_REGS | |
3546 | /* If registers other than the frame pointer are eliminable, mark them as | |
3547 | poor choices. */ | |
3548 | for (i = 0; i < NUM_ELIMINABLE_REGS; i++) | |
3549 | { | |
3550 | hard_reg_n_uses[reg_eliminate[i].from].uses += 2 * large + 2; | |
3551 | SET_HARD_REG_BIT (bad_spill_regs, reg_eliminate[i].from); | |
3552 | } | |
3553 | #endif | |
3554 | ||
3555 | /* Prefer registers not so far used, for use in temporary loading. | |
3556 | Among them, if REG_ALLOC_ORDER is defined, use that order. | |
3557 | Otherwise, prefer registers not preserved by calls. */ | |
3558 | ||
3559 | #ifdef REG_ALLOC_ORDER | |
3560 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
3561 | { | |
3562 | int regno = reg_alloc_order[i]; | |
3563 | ||
3564 | if (hard_reg_n_uses[regno].uses == 0) | |
3565 | potential_reload_regs[o++] = regno; | |
3566 | } | |
3567 | #else | |
3568 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
3569 | { | |
3570 | if (hard_reg_n_uses[i].uses == 0 && call_used_regs[i]) | |
3571 | potential_reload_regs[o++] = i; | |
3572 | } | |
3573 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
3574 | { | |
3575 | if (hard_reg_n_uses[i].uses == 0 && ! call_used_regs[i]) | |
3576 | potential_reload_regs[o++] = i; | |
3577 | } | |
3578 | #endif | |
3579 | ||
3580 | qsort (hard_reg_n_uses, FIRST_PSEUDO_REGISTER, | |
3581 | sizeof hard_reg_n_uses[0], hard_reg_use_compare); | |
3582 | ||
3583 | /* Now add the regs that are already used, | |
3584 | preferring those used less often. The fixed and otherwise forbidden | |
3585 | registers will be at the end of this list. */ | |
3586 | ||
3587 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
3588 | if (hard_reg_n_uses[i].uses != 0) | |
3589 | potential_reload_regs[o++] = hard_reg_n_uses[i].regno; | |
3590 | } | |
3591 | \f | |
3592 | /* Used in reload_as_needed to sort the spilled regs. */ | |
3593 | static int | |
3594 | compare_spill_regs (r1, r2) | |
3595 | short *r1, *r2; | |
3596 | { | |
3597 | return *r1 < *r2 ? -1: 1; | |
3598 | } | |
3599 | ||
3600 | /* Reload pseudo-registers into hard regs around each insn as needed. | |
3601 | Additional register load insns are output before the insn that needs it | |
3602 | and perhaps store insns after insns that modify the reloaded pseudo reg. | |
3603 | ||
3604 | reg_last_reload_reg and reg_reloaded_contents keep track of | |
3605 | which registers are already available in reload registers. | |
3606 | We update these for the reloads that we perform, | |
3607 | as the insns are scanned. */ | |
3608 | ||
3609 | static void | |
3610 | reload_as_needed (first, live_known) | |
3611 | rtx first; | |
3612 | int live_known; | |
3613 | { | |
3614 | register rtx insn; | |
3615 | register int i; | |
3616 | int this_block = 0; | |
3617 | rtx x; | |
3618 | rtx after_call = 0; | |
3619 | ||
3620 | bzero (spill_reg_rtx, sizeof spill_reg_rtx); | |
3621 | reg_last_reload_reg = (rtx *) alloca (max_regno * sizeof (rtx)); | |
3622 | bzero (reg_last_reload_reg, max_regno * sizeof (rtx)); | |
3623 | reg_has_output_reload = (char *) alloca (max_regno); | |
3624 | for (i = 0; i < n_spills; i++) | |
3625 | { | |
3626 | reg_reloaded_contents[i] = -1; | |
3627 | reg_reloaded_insn[i] = 0; | |
3628 | } | |
3629 | ||
3630 | /* Reset all offsets on eliminable registers to their initial values. */ | |
3631 | #ifdef ELIMINABLE_REGS | |
3632 | for (i = 0; i < NUM_ELIMINABLE_REGS; i++) | |
3633 | { | |
3634 | INITIAL_ELIMINATION_OFFSET (reg_eliminate[i].from, reg_eliminate[i].to, | |
3635 | reg_eliminate[i].initial_offset); | |
3636 | reg_eliminate[i].previous_offset | |
3637 | = reg_eliminate[i].offset = reg_eliminate[i].initial_offset; | |
3638 | } | |
3639 | #else | |
3640 | INITIAL_FRAME_POINTER_OFFSET (reg_eliminate[0].initial_offset); | |
3641 | reg_eliminate[0].previous_offset | |
3642 | = reg_eliminate[0].offset = reg_eliminate[0].initial_offset; | |
3643 | #endif | |
3644 | ||
3645 | num_not_at_initial_offset = 0; | |
3646 | ||
3647 | /* Order the spilled regs, so that allocate_reload_regs can guarantee to | |
3648 | pack registers with group needs. */ | |
3649 | if (n_spills > 1) | |
3650 | qsort (spill_regs, n_spills, sizeof (short), compare_spill_regs); | |
3651 | ||
3652 | for (insn = first; insn;) | |
3653 | { | |
3654 | register rtx next = NEXT_INSN (insn); | |
3655 | ||
3656 | /* Notice when we move to a new basic block. */ | |
3657 | if (live_known && this_block + 1 < n_basic_blocks | |
3658 | && insn == basic_block_head[this_block+1]) | |
3659 | ++this_block; | |
3660 | ||
3661 | /* If we pass a label, copy the offsets from the label information | |
3662 | into the current offsets of each elimination. */ | |
3663 | if (GET_CODE (insn) == CODE_LABEL) | |
3664 | { | |
3665 | num_not_at_initial_offset = 0; | |
3666 | for (i = 0; i < NUM_ELIMINABLE_REGS; i++) | |
3667 | { | |
3668 | reg_eliminate[i].offset = reg_eliminate[i].previous_offset | |
3669 | = offsets_at[CODE_LABEL_NUMBER (insn)][i]; | |
3670 | if (reg_eliminate[i].can_eliminate | |
3671 | && (reg_eliminate[i].offset | |
3672 | != reg_eliminate[i].initial_offset)) | |
3673 | num_not_at_initial_offset++; | |
3674 | } | |
3675 | } | |
3676 | ||
3677 | else if (GET_RTX_CLASS (GET_CODE (insn)) == 'i') | |
3678 | { | |
3679 | rtx avoid_return_reg = 0; | |
3680 | ||
3681 | #ifdef SMALL_REGISTER_CLASSES | |
3682 | /* Set avoid_return_reg if this is an insn | |
3683 | that might use the value of a function call. */ | |
3684 | if (GET_CODE (insn) == CALL_INSN) | |
3685 | { | |
3686 | if (GET_CODE (PATTERN (insn)) == SET) | |
3687 | after_call = SET_DEST (PATTERN (insn)); | |
3688 | else if (GET_CODE (PATTERN (insn)) == PARALLEL | |
3689 | && GET_CODE (XVECEXP (PATTERN (insn), 0, 0)) == SET) | |
3690 | after_call = SET_DEST (XVECEXP (PATTERN (insn), 0, 0)); | |
3691 | else | |
3692 | after_call = 0; | |
3693 | } | |
3694 | else if (after_call != 0 | |
3695 | && !(GET_CODE (PATTERN (insn)) == SET | |
3696 | && SET_DEST (PATTERN (insn)) == stack_pointer_rtx)) | |
3697 | { | |
3698 | if (reg_referenced_p (after_call, PATTERN (insn))) | |
3699 | avoid_return_reg = after_call; | |
3700 | after_call = 0; | |
3701 | } | |
3702 | #endif /* SMALL_REGISTER_CLASSES */ | |
3703 | ||
3704 | /* If this is a USE and CLOBBER of a MEM, ensure that any | |
3705 | references to eliminable registers have been removed. */ | |
3706 | ||
3707 | if ((GET_CODE (PATTERN (insn)) == USE | |
3708 | || GET_CODE (PATTERN (insn)) == CLOBBER) | |
3709 | && GET_CODE (XEXP (PATTERN (insn), 0)) == MEM) | |
3710 | XEXP (XEXP (PATTERN (insn), 0), 0) | |
3711 | = eliminate_regs (XEXP (XEXP (PATTERN (insn), 0), 0), | |
3712 | GET_MODE (XEXP (PATTERN (insn), 0)), NULL_RTX); | |
3713 | ||
3714 | /* If we need to do register elimination processing, do so. | |
3715 | This might delete the insn, in which case we are done. */ | |
3716 | if (num_eliminable && GET_MODE (insn) == QImode) | |
3717 | { | |
3718 | eliminate_regs_in_insn (insn, 1); | |
3719 | if (GET_CODE (insn) == NOTE) | |
3720 | { | |
3721 | insn = next; | |
3722 | continue; | |
3723 | } | |
3724 | } | |
3725 | ||
3726 | if (GET_MODE (insn) == VOIDmode) | |
3727 | n_reloads = 0; | |
3728 | /* First find the pseudo regs that must be reloaded for this insn. | |
3729 | This info is returned in the tables reload_... (see reload.h). | |
3730 | Also modify the body of INSN by substituting RELOAD | |
3731 | rtx's for those pseudo regs. */ | |
3732 | else | |
3733 | { | |
3734 | bzero (reg_has_output_reload, max_regno); | |
3735 | CLEAR_HARD_REG_SET (reg_is_output_reload); | |
3736 | ||
3737 | find_reloads (insn, 1, spill_indirect_levels, live_known, | |
3738 | spill_reg_order); | |
3739 | } | |
3740 | ||
3741 | if (n_reloads > 0) | |
3742 | { | |
3743 | rtx prev = PREV_INSN (insn), next = NEXT_INSN (insn); | |
3744 | rtx p; | |
3745 | int class; | |
3746 | ||
3747 | /* If this block has not had spilling done for a | |
3748 | particular clas and we have any non-optionals that need a | |
3749 | spill reg in that class, abort. */ | |
3750 | ||
3751 | for (class = 0; class < N_REG_CLASSES; class++) | |
3752 | if (basic_block_needs[class] != 0 | |
3753 | && basic_block_needs[class][this_block] == 0) | |
3754 | for (i = 0; i < n_reloads; i++) | |
3755 | if (class == (int) reload_reg_class[i] | |
3756 | && reload_reg_rtx[i] == 0 | |
3757 | && ! reload_optional[i] | |
3758 | && (reload_in[i] != 0 || reload_out[i] != 0 | |
3759 | || reload_secondary_p[i] != 0)) | |
3760 | abort (); | |
3761 | ||
3762 | /* Now compute which reload regs to reload them into. Perhaps | |
3763 | reusing reload regs from previous insns, or else output | |
3764 | load insns to reload them. Maybe output store insns too. | |
3765 | Record the choices of reload reg in reload_reg_rtx. */ | |
3766 | choose_reload_regs (insn, avoid_return_reg); | |
3767 | ||
3768 | #ifdef SMALL_REGISTER_CLASSES | |
3769 | /* Merge any reloads that we didn't combine for fear of | |
3770 | increasing the number of spill registers needed but now | |
3771 | discover can be safely merged. */ | |
3772 | merge_assigned_reloads (insn); | |
3773 | #endif | |
3774 | ||
3775 | /* Generate the insns to reload operands into or out of | |
3776 | their reload regs. */ | |
3777 | emit_reload_insns (insn); | |
3778 | ||
3779 | /* Substitute the chosen reload regs from reload_reg_rtx | |
3780 | into the insn's body (or perhaps into the bodies of other | |
3781 | load and store insn that we just made for reloading | |
3782 | and that we moved the structure into). */ | |
3783 | subst_reloads (); | |
3784 | ||
3785 | /* If this was an ASM, make sure that all the reload insns | |
3786 | we have generated are valid. If not, give an error | |
3787 | and delete them. */ | |
3788 | ||
3789 | if (asm_noperands (PATTERN (insn)) >= 0) | |
3790 | for (p = NEXT_INSN (prev); p != next; p = NEXT_INSN (p)) | |
3791 | if (p != insn && GET_RTX_CLASS (GET_CODE (p)) == 'i' | |
3792 | && (recog_memoized (p) < 0 | |
3793 | || (insn_extract (p), | |
3794 | ! constrain_operands (INSN_CODE (p), 1)))) | |
3795 | { | |
3796 | error_for_asm (insn, | |
3797 | "`asm' operand requires impossible reload"); | |
3798 | PUT_CODE (p, NOTE); | |
3799 | NOTE_SOURCE_FILE (p) = 0; | |
3800 | NOTE_LINE_NUMBER (p) = NOTE_INSN_DELETED; | |
3801 | } | |
3802 | } | |
3803 | /* Any previously reloaded spilled pseudo reg, stored in this insn, | |
3804 | is no longer validly lying around to save a future reload. | |
3805 | Note that this does not detect pseudos that were reloaded | |
3806 | for this insn in order to be stored in | |
3807 | (obeying register constraints). That is correct; such reload | |
3808 | registers ARE still valid. */ | |
3809 | note_stores (PATTERN (insn), forget_old_reloads_1); | |
3810 | ||
3811 | /* There may have been CLOBBER insns placed after INSN. So scan | |
3812 | between INSN and NEXT and use them to forget old reloads. */ | |
3813 | for (x = NEXT_INSN (insn); x != next; x = NEXT_INSN (x)) | |
3814 | if (GET_CODE (x) == INSN && GET_CODE (PATTERN (x)) == CLOBBER) | |
3815 | note_stores (PATTERN (x), forget_old_reloads_1); | |
3816 | ||
3817 | #ifdef AUTO_INC_DEC | |
3818 | /* Likewise for regs altered by auto-increment in this insn. | |
3819 | But note that the reg-notes are not changed by reloading: | |
3820 | they still contain the pseudo-regs, not the spill regs. */ | |
3821 | for (x = REG_NOTES (insn); x; x = XEXP (x, 1)) | |
3822 | if (REG_NOTE_KIND (x) == REG_INC) | |
3823 | { | |
3824 | /* See if this pseudo reg was reloaded in this insn. | |
3825 | If so, its last-reload info is still valid | |
3826 | because it is based on this insn's reload. */ | |
3827 | for (i = 0; i < n_reloads; i++) | |
3828 | if (reload_out[i] == XEXP (x, 0)) | |
3829 | break; | |
3830 | ||
3831 | if (i == n_reloads) | |
3832 | forget_old_reloads_1 (XEXP (x, 0), NULL_RTX); | |
3833 | } | |
3834 | #endif | |
3835 | } | |
3836 | /* A reload reg's contents are unknown after a label. */ | |
3837 | if (GET_CODE (insn) == CODE_LABEL) | |
3838 | for (i = 0; i < n_spills; i++) | |
3839 | { | |
3840 | reg_reloaded_contents[i] = -1; | |
3841 | reg_reloaded_insn[i] = 0; | |
3842 | } | |
3843 | ||
3844 | /* Don't assume a reload reg is still good after a call insn | |
3845 | if it is a call-used reg. */ | |
3846 | else if (GET_CODE (insn) == CALL_INSN) | |
3847 | for (i = 0; i < n_spills; i++) | |
3848 | if (call_used_regs[spill_regs[i]]) | |
3849 | { | |
3850 | reg_reloaded_contents[i] = -1; | |
3851 | reg_reloaded_insn[i] = 0; | |
3852 | } | |
3853 | ||
3854 | /* In case registers overlap, allow certain insns to invalidate | |
3855 | particular hard registers. */ | |
3856 | ||
3857 | #ifdef INSN_CLOBBERS_REGNO_P | |
3858 | for (i = 0 ; i < n_spills ; i++) | |
3859 | if (INSN_CLOBBERS_REGNO_P (insn, spill_regs[i])) | |
3860 | { | |
3861 | reg_reloaded_contents[i] = -1; | |
3862 | reg_reloaded_insn[i] = 0; | |
3863 | } | |
3864 | #endif | |
3865 | ||
3866 | insn = next; | |
3867 | ||
3868 | #ifdef USE_C_ALLOCA | |
3869 | alloca (0); | |
3870 | #endif | |
3871 | } | |
3872 | } | |
3873 | ||
3874 | /* Discard all record of any value reloaded from X, | |
3875 | or reloaded in X from someplace else; | |
3876 | unless X is an output reload reg of the current insn. | |
3877 | ||
3878 | X may be a hard reg (the reload reg) | |
3879 | or it may be a pseudo reg that was reloaded from. */ | |
3880 | ||
3881 | static void | |
3882 | forget_old_reloads_1 (x, ignored) | |
3883 | rtx x; | |
3884 | rtx ignored; | |
3885 | { | |
3886 | register int regno; | |
3887 | int nr; | |
3888 | int offset = 0; | |
3889 | ||
3890 | /* note_stores does give us subregs of hard regs. */ | |
3891 | while (GET_CODE (x) == SUBREG) | |
3892 | { | |
3893 | offset += SUBREG_WORD (x); | |
3894 | x = SUBREG_REG (x); | |
3895 | } | |
3896 | ||
3897 | if (GET_CODE (x) != REG) | |
3898 | return; | |
3899 | ||
3900 | regno = REGNO (x) + offset; | |
3901 | ||
3902 | if (regno >= FIRST_PSEUDO_REGISTER) | |
3903 | nr = 1; | |
3904 | else | |
3905 | { | |
3906 | int i; | |
3907 | nr = HARD_REGNO_NREGS (regno, GET_MODE (x)); | |
3908 | /* Storing into a spilled-reg invalidates its contents. | |
3909 | This can happen if a block-local pseudo is allocated to that reg | |
3910 | and it wasn't spilled because this block's total need is 0. | |
3911 | Then some insn might have an optional reload and use this reg. */ | |
3912 | for (i = 0; i < nr; i++) | |
3913 | if (spill_reg_order[regno + i] >= 0 | |
3914 | /* But don't do this if the reg actually serves as an output | |
3915 | reload reg in the current instruction. */ | |
3916 | && (n_reloads == 0 | |
3917 | || ! TEST_HARD_REG_BIT (reg_is_output_reload, regno + i))) | |
3918 | { | |
3919 | reg_reloaded_contents[spill_reg_order[regno + i]] = -1; | |
3920 | reg_reloaded_insn[spill_reg_order[regno + i]] = 0; | |
3921 | } | |
3922 | } | |
3923 | ||
3924 | /* Since value of X has changed, | |
3925 | forget any value previously copied from it. */ | |
3926 | ||
3927 | while (nr-- > 0) | |
3928 | /* But don't forget a copy if this is the output reload | |
3929 | that establishes the copy's validity. */ | |
3930 | if (n_reloads == 0 || reg_has_output_reload[regno + nr] == 0) | |
3931 | reg_last_reload_reg[regno + nr] = 0; | |
3932 | } | |
3933 | \f | |
3934 | /* For each reload, the mode of the reload register. */ | |
3935 | static enum machine_mode reload_mode[MAX_RELOADS]; | |
3936 | ||
3937 | /* For each reload, the largest number of registers it will require. */ | |
3938 | static int reload_nregs[MAX_RELOADS]; | |
3939 | ||
3940 | /* Comparison function for qsort to decide which of two reloads | |
3941 | should be handled first. *P1 and *P2 are the reload numbers. */ | |
3942 | ||
3943 | static int | |
3944 | reload_reg_class_lower (p1, p2) | |
3945 | short *p1, *p2; | |
3946 | { | |
3947 | register int r1 = *p1, r2 = *p2; | |
3948 | register int t; | |
3949 | ||
3950 | /* Consider required reloads before optional ones. */ | |
3951 | t = reload_optional[r1] - reload_optional[r2]; | |
3952 | if (t != 0) | |
3953 | return t; | |
3954 | ||
3955 | /* Count all solitary classes before non-solitary ones. */ | |
3956 | t = ((reg_class_size[(int) reload_reg_class[r2]] == 1) | |
3957 | - (reg_class_size[(int) reload_reg_class[r1]] == 1)); | |
3958 | if (t != 0) | |
3959 | return t; | |
3960 | ||
3961 | /* Aside from solitaires, consider all multi-reg groups first. */ | |
3962 | t = reload_nregs[r2] - reload_nregs[r1]; | |
3963 | if (t != 0) | |
3964 | return t; | |
3965 | ||
3966 | /* Consider reloads in order of increasing reg-class number. */ | |
3967 | t = (int) reload_reg_class[r1] - (int) reload_reg_class[r2]; | |
3968 | if (t != 0) | |
3969 | return t; | |
3970 | ||
3971 | /* If reloads are equally urgent, sort by reload number, | |
3972 | so that the results of qsort leave nothing to chance. */ | |
3973 | return r1 - r2; | |
3974 | } | |
3975 | \f | |
3976 | /* The following HARD_REG_SETs indicate when each hard register is | |
3977 | used for a reload of various parts of the current insn. */ | |
3978 | ||
3979 | /* If reg is in use as a reload reg for a RELOAD_OTHER reload. */ | |
3980 | static HARD_REG_SET reload_reg_used; | |
3981 | /* If reg is in use for a RELOAD_FOR_INPUT_ADDRESS reload for operand I. */ | |
3982 | static HARD_REG_SET reload_reg_used_in_input_addr[MAX_RECOG_OPERANDS]; | |
3983 | /* If reg is in use for a RELOAD_FOR_OUTPUT_ADDRESS reload for operand I. */ | |
3984 | static HARD_REG_SET reload_reg_used_in_output_addr[MAX_RECOG_OPERANDS]; | |
3985 | /* If reg is in use for a RELOAD_FOR_INPUT reload for operand I. */ | |
3986 | static HARD_REG_SET reload_reg_used_in_input[MAX_RECOG_OPERANDS]; | |
3987 | /* If reg is in use for a RELOAD_FOR_OUTPUT reload for operand I. */ | |
3988 | static HARD_REG_SET reload_reg_used_in_output[MAX_RECOG_OPERANDS]; | |
3989 | /* If reg is in use for a RELOAD_FOR_OPERAND_ADDRESS reload. */ | |
3990 | static HARD_REG_SET reload_reg_used_in_op_addr; | |
3991 | /* If reg is in use for a RELOAD_FOR_INSN reload. */ | |
3992 | static HARD_REG_SET reload_reg_used_in_insn; | |
3993 | /* If reg is in use for a RELOAD_FOR_OTHER_ADDRESS reload. */ | |
3994 | static HARD_REG_SET reload_reg_used_in_other_addr; | |
3995 | ||
3996 | /* If reg is in use as a reload reg for any sort of reload. */ | |
3997 | static HARD_REG_SET reload_reg_used_at_all; | |
3998 | ||
3999 | /* If reg is use as an inherited reload. We just mark the first register | |
4000 | in the group. */ | |
4001 | static HARD_REG_SET reload_reg_used_for_inherit; | |
4002 | ||
4003 | /* Mark reg REGNO as in use for a reload of the sort spec'd by OPNUM and | |
4004 | TYPE. MODE is used to indicate how many consecutive regs are | |
4005 | actually used. */ | |
4006 | ||
4007 | static void | |
4008 | mark_reload_reg_in_use (regno, opnum, type, mode) | |
4009 | int regno; | |
4010 | int opnum; | |
4011 | enum reload_type type; | |
4012 | enum machine_mode mode; | |
4013 | { | |
4014 | int nregs = HARD_REGNO_NREGS (regno, mode); | |
4015 | int i; | |
4016 | ||
4017 | for (i = regno; i < nregs + regno; i++) | |
4018 | { | |
4019 | switch (type) | |
4020 | { | |
4021 | case RELOAD_OTHER: | |
4022 | SET_HARD_REG_BIT (reload_reg_used, i); | |
4023 | break; | |
4024 | ||
4025 | case RELOAD_FOR_INPUT_ADDRESS: | |
4026 | SET_HARD_REG_BIT (reload_reg_used_in_input_addr[opnum], i); | |
4027 | break; | |
4028 | ||
4029 | case RELOAD_FOR_OUTPUT_ADDRESS: | |
4030 | SET_HARD_REG_BIT (reload_reg_used_in_output_addr[opnum], i); | |
4031 | break; | |
4032 | ||
4033 | case RELOAD_FOR_OPERAND_ADDRESS: | |
4034 | SET_HARD_REG_BIT (reload_reg_used_in_op_addr, i); | |
4035 | break; | |
4036 | ||
4037 | case RELOAD_FOR_OTHER_ADDRESS: | |
4038 | SET_HARD_REG_BIT (reload_reg_used_in_other_addr, i); | |
4039 | break; | |
4040 | ||
4041 | case RELOAD_FOR_INPUT: | |
4042 | SET_HARD_REG_BIT (reload_reg_used_in_input[opnum], i); | |
4043 | break; | |
4044 | ||
4045 | case RELOAD_FOR_OUTPUT: | |
4046 | SET_HARD_REG_BIT (reload_reg_used_in_output[opnum], i); | |
4047 | break; | |
4048 | ||
4049 | case RELOAD_FOR_INSN: | |
4050 | SET_HARD_REG_BIT (reload_reg_used_in_insn, i); | |
4051 | break; | |
4052 | } | |
4053 | ||
4054 | SET_HARD_REG_BIT (reload_reg_used_at_all, i); | |
4055 | } | |
4056 | } | |
4057 | ||
4058 | /* Similarly, but show REGNO is no longer in use for a reload. */ | |
4059 | ||
4060 | static void | |
4061 | clear_reload_reg_in_use (regno, opnum, type, mode) | |
4062 | int regno; | |
4063 | int opnum; | |
4064 | enum reload_type type; | |
4065 | enum machine_mode mode; | |
4066 | { | |
4067 | int nregs = HARD_REGNO_NREGS (regno, mode); | |
4068 | int i; | |
4069 | ||
4070 | for (i = regno; i < nregs + regno; i++) | |
4071 | { | |
4072 | switch (type) | |
4073 | { | |
4074 | case RELOAD_OTHER: | |
4075 | CLEAR_HARD_REG_BIT (reload_reg_used, i); | |
4076 | break; | |
4077 | ||
4078 | case RELOAD_FOR_INPUT_ADDRESS: | |
4079 | CLEAR_HARD_REG_BIT (reload_reg_used_in_input_addr[opnum], i); | |
4080 | break; | |
4081 | ||
4082 | case RELOAD_FOR_OUTPUT_ADDRESS: | |
4083 | CLEAR_HARD_REG_BIT (reload_reg_used_in_output_addr[opnum], i); | |
4084 | break; | |
4085 | ||
4086 | case RELOAD_FOR_OPERAND_ADDRESS: | |
4087 | CLEAR_HARD_REG_BIT (reload_reg_used_in_op_addr, i); | |
4088 | break; | |
4089 | ||
4090 | case RELOAD_FOR_OTHER_ADDRESS: | |
4091 | CLEAR_HARD_REG_BIT (reload_reg_used_in_other_addr, i); | |
4092 | break; | |
4093 | ||
4094 | case RELOAD_FOR_INPUT: | |
4095 | CLEAR_HARD_REG_BIT (reload_reg_used_in_input[opnum], i); | |
4096 | break; | |
4097 | ||
4098 | case RELOAD_FOR_OUTPUT: | |
4099 | CLEAR_HARD_REG_BIT (reload_reg_used_in_output[opnum], i); | |
4100 | break; | |
4101 | ||
4102 | case RELOAD_FOR_INSN: | |
4103 | CLEAR_HARD_REG_BIT (reload_reg_used_in_insn, i); | |
4104 | break; | |
4105 | } | |
4106 | } | |
4107 | } | |
4108 | ||
4109 | /* 1 if reg REGNO is free as a reload reg for a reload of the sort | |
4110 | specified by OPNUM and TYPE. */ | |
4111 | ||
4112 | static int | |
4113 | reload_reg_free_p (regno, opnum, type) | |
4114 | int regno; | |
4115 | int opnum; | |
4116 | enum reload_type type; | |
4117 | { | |
4118 | int i; | |
4119 | ||
4120 | /* In use for a RELOAD_OTHER means it's not available for anything except | |
4121 | RELOAD_FOR_OTHER_ADDRESS. Recall that RELOAD_FOR_OTHER_ADDRESS is known | |
4122 | to be used only for inputs. */ | |
4123 | ||
4124 | if (type != RELOAD_FOR_OTHER_ADDRESS | |
4125 | && TEST_HARD_REG_BIT (reload_reg_used, regno)) | |
4126 | return 0; | |
4127 | ||
4128 | switch (type) | |
4129 | { | |
4130 | case RELOAD_OTHER: | |
4131 | /* In use for anything means not available for a RELOAD_OTHER. */ | |
4132 | return ! TEST_HARD_REG_BIT (reload_reg_used_at_all, regno); | |
4133 | ||
4134 | /* The other kinds of use can sometimes share a register. */ | |
4135 | case RELOAD_FOR_INPUT: | |
4136 | if (TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno) | |
4137 | || TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno)) | |
4138 | return 0; | |
4139 | ||
4140 | /* If it is used for some other input, can't use it. */ | |
4141 | for (i = 0; i < reload_n_operands; i++) | |
4142 | if (TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno)) | |
4143 | return 0; | |
4144 | ||
4145 | /* If it is used in a later operand's address, can't use it. */ | |
4146 | for (i = opnum + 1; i < reload_n_operands; i++) | |
4147 | if (TEST_HARD_REG_BIT (reload_reg_used_in_input_addr[i], regno)) | |
4148 | return 0; | |
4149 | ||
4150 | return 1; | |
4151 | ||
4152 | case RELOAD_FOR_INPUT_ADDRESS: | |
4153 | /* Can't use a register if it is used for an input address for this | |
4154 | operand or used as an input in an earlier one. */ | |
4155 | if (TEST_HARD_REG_BIT (reload_reg_used_in_input_addr[opnum], regno)) | |
4156 | return 0; | |
4157 | ||
4158 | for (i = 0; i < opnum; i++) | |
4159 | if (TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno)) | |
4160 | return 0; | |
4161 | ||
4162 | return 1; | |
4163 | ||
4164 | case RELOAD_FOR_OUTPUT_ADDRESS: | |
4165 | /* Can't use a register if it is used for an output address for this | |
4166 | operand or used as an output in this or a later operand. */ | |
4167 | if (TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[opnum], regno)) | |
4168 | return 0; | |
4169 | ||
4170 | for (i = opnum; i < reload_n_operands; i++) | |
4171 | if (TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno)) | |
4172 | return 0; | |
4173 | ||
4174 | return 1; | |
4175 | ||
4176 | case RELOAD_FOR_OPERAND_ADDRESS: | |
4177 | for (i = 0; i < reload_n_operands; i++) | |
4178 | if (TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno)) | |
4179 | return 0; | |
4180 | ||
4181 | return (! TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno) | |
4182 | && ! TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno)); | |
4183 | ||
4184 | case RELOAD_FOR_OUTPUT: | |
4185 | /* This cannot share a register with RELOAD_FOR_INSN reloads, other | |
4186 | outputs, or an operand address for this or an earlier output. */ | |
4187 | if (TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno)) | |
4188 | return 0; | |
4189 | ||
4190 | for (i = 0; i < reload_n_operands; i++) | |
4191 | if (TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno)) | |
4192 | return 0; | |
4193 | ||
4194 | for (i = 0; i <= opnum; i++) | |
4195 | if (TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[i], regno)) | |
4196 | return 0; | |
4197 | ||
4198 | return 1; | |
4199 | ||
4200 | case RELOAD_FOR_INSN: | |
4201 | for (i = 0; i < reload_n_operands; i++) | |
4202 | if (TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno) | |
4203 | || TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno)) | |
4204 | return 0; | |
4205 | ||
4206 | return (! TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno) | |
4207 | && ! TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno)); | |
4208 | ||
4209 | case RELOAD_FOR_OTHER_ADDRESS: | |
4210 | return ! TEST_HARD_REG_BIT (reload_reg_used_in_other_addr, regno); | |
4211 | } | |
4212 | abort (); | |
4213 | } | |
4214 | ||
4215 | /* Return 1 if the value in reload reg REGNO, as used by a reload | |
4216 | needed for the part of the insn specified by OPNUM and TYPE, | |
4217 | is not in use for a reload in any prior part of the insn. | |
4218 | ||
4219 | We can assume that the reload reg was already tested for availability | |
4220 | at the time it is needed, and we should not check this again, | |
4221 | in case the reg has already been marked in use. */ | |
4222 | ||
4223 | static int | |
4224 | reload_reg_free_before_p (regno, opnum, type) | |
4225 | int regno; | |
4226 | int opnum; | |
4227 | enum reload_type type; | |
4228 | { | |
4229 | int i; | |
4230 | ||
4231 | switch (type) | |
4232 | { | |
4233 | case RELOAD_FOR_OTHER_ADDRESS: | |
4234 | /* These always come first. */ | |
4235 | return 1; | |
4236 | ||
4237 | case RELOAD_OTHER: | |
4238 | return ! TEST_HARD_REG_BIT (reload_reg_used_in_other_addr, regno); | |
4239 | ||
4240 | /* If this use is for part of the insn, | |
4241 | check the reg is not in use for any prior part. It is tempting | |
4242 | to try to do this by falling through from objecs that occur | |
4243 | later in the insn to ones that occur earlier, but that will not | |
4244 | correctly take into account the fact that here we MUST ignore | |
4245 | things that would prevent the register from being allocated in | |
4246 | the first place, since we know that it was allocated. */ | |
4247 | ||
4248 | case RELOAD_FOR_OUTPUT_ADDRESS: | |
4249 | /* Earlier reloads are for earlier outputs or their addresses, | |
4250 | any RELOAD_FOR_INSN reloads, any inputs or their addresses, or any | |
4251 | RELOAD_FOR_OTHER_ADDRESS reloads (we know it can't conflict with | |
4252 | RELOAD_OTHER).. */ | |
4253 | for (i = 0; i < opnum; i++) | |
4254 | if (TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[i], regno) | |
4255 | || TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno)) | |
4256 | return 0; | |
4257 | ||
4258 | if (TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno)) | |
4259 | return 0; | |
4260 | ||
4261 | for (i = 0; i < reload_n_operands; i++) | |
4262 | if (TEST_HARD_REG_BIT (reload_reg_used_in_input_addr[i], regno) | |
4263 | || TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno)) | |
4264 | return 0; | |
4265 | ||
4266 | return (! TEST_HARD_REG_BIT (reload_reg_used_in_other_addr, regno) | |
4267 | && ! TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno) | |
4268 | && ! TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno)); | |
4269 | ||
4270 | case RELOAD_FOR_OUTPUT: | |
4271 | /* This can't be used in the output address for this operand and | |
4272 | anything that can't be used for it, except that we've already | |
4273 | tested for RELOAD_FOR_INSN objects. */ | |
4274 | ||
4275 | if (TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[opnum], regno)) | |
4276 | return 0; | |
4277 | ||
4278 | for (i = 0; i < opnum; i++) | |
4279 | if (TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[i], regno) | |
4280 | || TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno)) | |
4281 | return 0; | |
4282 | ||
4283 | for (i = 0; i < reload_n_operands; i++) | |
4284 | if (TEST_HARD_REG_BIT (reload_reg_used_in_input_addr[i], regno) | |
4285 | || TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno) | |
4286 | || TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno)) | |
4287 | return 0; | |
4288 | ||
4289 | return ! TEST_HARD_REG_BIT (reload_reg_used_in_other_addr, regno); | |
4290 | ||
4291 | case RELOAD_FOR_OPERAND_ADDRESS: | |
4292 | case RELOAD_FOR_INSN: | |
4293 | /* These can't conflict with inputs, or each other, so all we have to | |
4294 | test is input addresses and the addresses of OTHER items. */ | |
4295 | ||
4296 | for (i = 0; i < reload_n_operands; i++) | |
4297 | if (TEST_HARD_REG_BIT (reload_reg_used_in_input_addr[i], regno)) | |
4298 | return 0; | |
4299 | ||
4300 | return ! TEST_HARD_REG_BIT (reload_reg_used_in_other_addr, regno); | |
4301 | ||
4302 | case RELOAD_FOR_INPUT: | |
4303 | /* The only things earlier are the address for this and | |
4304 | earlier inputs, other inputs (which we know we don't conflict | |
4305 | with), and addresses of RELOAD_OTHER objects. */ | |
4306 | ||
4307 | for (i = 0; i <= opnum; i++) | |
4308 | if (TEST_HARD_REG_BIT (reload_reg_used_in_input_addr[i], regno)) | |
4309 | return 0; | |
4310 | ||
4311 | return ! TEST_HARD_REG_BIT (reload_reg_used_in_other_addr, regno); | |
4312 | ||
4313 | case RELOAD_FOR_INPUT_ADDRESS: | |
4314 | /* Similarly, all we have to check is for use in earlier inputs' | |
4315 | addresses. */ | |
4316 | for (i = 0; i < opnum; i++) | |
4317 | if (TEST_HARD_REG_BIT (reload_reg_used_in_input_addr[i], regno)) | |
4318 | return 0; | |
4319 | ||
4320 | return ! TEST_HARD_REG_BIT (reload_reg_used_in_other_addr, regno); | |
4321 | } | |
4322 | abort (); | |
4323 | } | |
4324 | ||
4325 | /* Return 1 if the value in reload reg REGNO, as used by a reload | |
4326 | needed for the part of the insn specified by OPNUM and TYPE, | |
4327 | is still available in REGNO at the end of the insn. | |
4328 | ||
4329 | We can assume that the reload reg was already tested for availability | |
4330 | at the time it is needed, and we should not check this again, | |
4331 | in case the reg has already been marked in use. */ | |
4332 | ||
4333 | static int | |
4334 | reload_reg_reaches_end_p (regno, opnum, type) | |
4335 | int regno; | |
4336 | int opnum; | |
4337 | enum reload_type type; | |
4338 | { | |
4339 | int i; | |
4340 | ||
4341 | switch (type) | |
4342 | { | |
4343 | case RELOAD_OTHER: | |
4344 | /* Since a RELOAD_OTHER reload claims the reg for the entire insn, | |
4345 | its value must reach the end. */ | |
4346 | return 1; | |
4347 | ||
4348 | /* If this use is for part of the insn, | |
4349 | its value reaches if no subsequent part uses the same register. | |
4350 | Just like the above function, don't try to do this with lots | |
4351 | of fallthroughs. */ | |
4352 | ||
4353 | case RELOAD_FOR_OTHER_ADDRESS: | |
4354 | /* Here we check for everything else, since these don't conflict | |
4355 | with anything else and everything comes later. */ | |
4356 | ||
4357 | for (i = 0; i < reload_n_operands; i++) | |
4358 | if (TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[i], regno) | |
4359 | || TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno) | |
4360 | || TEST_HARD_REG_BIT (reload_reg_used_in_input_addr[i], regno) | |
4361 | || TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno)) | |
4362 | return 0; | |
4363 | ||
4364 | return (! TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno) | |
4365 | && ! TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno) | |
4366 | && ! TEST_HARD_REG_BIT (reload_reg_used, regno)); | |
4367 | ||
4368 | case RELOAD_FOR_INPUT_ADDRESS: | |
4369 | /* Similar, except that we check only for this and subsequent inputs | |
4370 | and the address of only subsequent inputs and we do not need | |
4371 | to check for RELOAD_OTHER objects since they are known not to | |
4372 | conflict. */ | |
4373 | ||
4374 | for (i = opnum; i < reload_n_operands; i++) | |
4375 | if (TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno)) | |
4376 | return 0; | |
4377 | ||
4378 | for (i = opnum + 1; i < reload_n_operands; i++) | |
4379 | if (TEST_HARD_REG_BIT (reload_reg_used_in_input_addr[i], regno)) | |
4380 | return 0; | |
4381 | ||
4382 | for (i = 0; i < reload_n_operands; i++) | |
4383 | if (TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[i], regno) | |
4384 | || TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno)) | |
4385 | return 0; | |
4386 | ||
4387 | return (! TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno) | |
4388 | && ! TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno)); | |
4389 | ||
4390 | case RELOAD_FOR_INPUT: | |
4391 | /* Similar to input address, except we start at the next operand for | |
4392 | both input and input address and we do not check for | |
4393 | RELOAD_FOR_OPERAND_ADDRESS and RELOAD_FOR_INSN since these | |
4394 | would conflict. */ | |
4395 | ||
4396 | for (i = opnum + 1; i < reload_n_operands; i++) | |
4397 | if (TEST_HARD_REG_BIT (reload_reg_used_in_input_addr[i], regno) | |
4398 | || TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno)) | |
4399 | return 0; | |
4400 | ||
4401 | /* ... fall through ... */ | |
4402 | ||
4403 | case RELOAD_FOR_OPERAND_ADDRESS: | |
4404 | /* Check outputs and their addresses. */ | |
4405 | ||
4406 | for (i = 0; i < reload_n_operands; i++) | |
4407 | if (TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[i], regno) | |
4408 | || TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno)) | |
4409 | return 0; | |
4410 | ||
4411 | return 1; | |
4412 | ||
4413 | case RELOAD_FOR_INSN: | |
4414 | /* These conflict with other outputs with with RELOAD_OTHER. So | |
4415 | we need only check for output addresses. */ | |
4416 | ||
4417 | opnum = -1; | |
4418 | ||
4419 | /* ... fall through ... */ | |
4420 | ||
4421 | case RELOAD_FOR_OUTPUT: | |
4422 | case RELOAD_FOR_OUTPUT_ADDRESS: | |
4423 | /* We already know these can't conflict with a later output. So the | |
4424 | only thing to check are later output addresses. */ | |
4425 | for (i = opnum + 1; i < reload_n_operands; i++) | |
4426 | if (TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[i], regno)) | |
4427 | return 0; | |
4428 | ||
4429 | return 1; | |
4430 | } | |
4431 | ||
4432 | abort (); | |
4433 | } | |
4434 | \f | |
4435 | /* Return 1 if the reloads denoted by R1 and R2 cannot share a register. | |
4436 | Return 0 otherwise. | |
4437 | ||
4438 | This function uses the same algorithm as reload_reg_free_p above. */ | |
4439 | ||
4440 | static int | |
4441 | reloads_conflict (r1, r2) | |
4442 | int r1, r2; | |
4443 | { | |
4444 | enum reload_type r1_type = reload_when_needed[r1]; | |
4445 | enum reload_type r2_type = reload_when_needed[r2]; | |
4446 | int r1_opnum = reload_opnum[r1]; | |
4447 | int r2_opnum = reload_opnum[r2]; | |
4448 | ||
4449 | /* RELOAD_OTHER conflicts with everything except | |
4450 | RELOAD_FOR_OTHER_ADDRESS. */ | |
4451 | ||
4452 | if ((r1_type == RELOAD_OTHER && r2_type != RELOAD_FOR_OTHER_ADDRESS) | |
4453 | || (r2_type == RELOAD_OTHER && r1_type != RELOAD_FOR_OTHER_ADDRESS)) | |
4454 | return 1; | |
4455 | ||
4456 | /* Otherwise, check conflicts differently for each type. */ | |
4457 | ||
4458 | switch (r1_type) | |
4459 | { | |
4460 | case RELOAD_FOR_INPUT: | |
4461 | return (r2_type == RELOAD_FOR_INSN | |
4462 | || r2_type == RELOAD_FOR_OPERAND_ADDRESS | |
4463 | || r2_type == RELOAD_FOR_INPUT | |
4464 | || (r2_type == RELOAD_FOR_INPUT_ADDRESS && r2_opnum > r1_opnum)); | |
4465 | ||
4466 | case RELOAD_FOR_INPUT_ADDRESS: | |
4467 | return ((r2_type == RELOAD_FOR_INPUT_ADDRESS && r1_opnum == r2_opnum) | |
4468 | || (r2_type == RELOAD_FOR_INPUT && r2_opnum < r1_opnum)); | |
4469 | ||
4470 | case RELOAD_FOR_OUTPUT_ADDRESS: | |
4471 | return ((r2_type == RELOAD_FOR_OUTPUT_ADDRESS && r2_opnum == r1_opnum) | |
4472 | || (r2_type == RELOAD_FOR_OUTPUT && r2_opnum >= r1_opnum)); | |
4473 | ||
4474 | case RELOAD_FOR_OPERAND_ADDRESS: | |
4475 | return (r2_type == RELOAD_FOR_INPUT || r2_type == RELOAD_FOR_INSN | |
4476 | || r2_type == RELOAD_FOR_OPERAND_ADDRESS); | |
4477 | ||
4478 | case RELOAD_FOR_OUTPUT: | |
4479 | return (r2_type == RELOAD_FOR_INSN || r2_type == RELOAD_FOR_OUTPUT | |
4480 | || (r2_type == RELOAD_FOR_OUTPUT_ADDRESS | |
4481 | && r2_opnum >= r1_opnum)); | |
4482 | ||
4483 | case RELOAD_FOR_INSN: | |
4484 | return (r2_type == RELOAD_FOR_INPUT || r2_type == RELOAD_FOR_OUTPUT | |
4485 | || r2_type == RELOAD_FOR_INSN | |
4486 | || r2_type == RELOAD_FOR_OPERAND_ADDRESS); | |
4487 | ||
4488 | case RELOAD_FOR_OTHER_ADDRESS: | |
4489 | return r2_type == RELOAD_FOR_OTHER_ADDRESS; | |
4490 | ||
4491 | default: | |
4492 | abort (); | |
4493 | } | |
4494 | } | |
4495 | \f | |
4496 | /* Vector of reload-numbers showing the order in which the reloads should | |
4497 | be processed. */ | |
4498 | short reload_order[MAX_RELOADS]; | |
4499 | ||
4500 | /* Indexed by reload number, 1 if incoming value | |
4501 | inherited from previous insns. */ | |
4502 | char reload_inherited[MAX_RELOADS]; | |
4503 | ||
4504 | /* For an inherited reload, this is the insn the reload was inherited from, | |
4505 | if we know it. Otherwise, this is 0. */ | |
4506 | rtx reload_inheritance_insn[MAX_RELOADS]; | |
4507 | ||
4508 | /* If non-zero, this is a place to get the value of the reload, | |
4509 | rather than using reload_in. */ | |
4510 | rtx reload_override_in[MAX_RELOADS]; | |
4511 | ||
4512 | /* For each reload, the index in spill_regs of the spill register used, | |
4513 | or -1 if we did not need one of the spill registers for this reload. */ | |
4514 | int reload_spill_index[MAX_RELOADS]; | |
4515 | ||
4516 | /* Index of last register assigned as a spill register. We allocate in | |
4517 | a round-robin fashio. */ | |
4518 | ||
4519 | static int last_spill_reg = 0; | |
4520 | ||
4521 | /* Find a spill register to use as a reload register for reload R. | |
4522 | LAST_RELOAD is non-zero if this is the last reload for the insn being | |
4523 | processed. | |
4524 | ||
4525 | Set reload_reg_rtx[R] to the register allocated. | |
4526 | ||
4527 | If NOERROR is nonzero, we return 1 if successful, | |
4528 | or 0 if we couldn't find a spill reg and we didn't change anything. */ | |
4529 | ||
4530 | static int | |
4531 | allocate_reload_reg (r, insn, last_reload, noerror) | |
4532 | int r; | |
4533 | rtx insn; | |
4534 | int last_reload; | |
4535 | int noerror; | |
4536 | { | |
4537 | int i; | |
4538 | int pass; | |
4539 | int count; | |
4540 | rtx new; | |
4541 | int regno; | |
4542 | ||
4543 | /* If we put this reload ahead, thinking it is a group, | |
4544 | then insist on finding a group. Otherwise we can grab a | |
4545 | reg that some other reload needs. | |
4546 | (That can happen when we have a 68000 DATA_OR_FP_REG | |
4547 | which is a group of data regs or one fp reg.) | |
4548 | We need not be so restrictive if there are no more reloads | |
4549 | for this insn. | |
4550 | ||
4551 | ??? Really it would be nicer to have smarter handling | |
4552 | for that kind of reg class, where a problem like this is normal. | |
4553 | Perhaps those classes should be avoided for reloading | |
4554 | by use of more alternatives. */ | |
4555 | ||
4556 | int force_group = reload_nregs[r] > 1 && ! last_reload; | |
4557 | ||
4558 | /* If we want a single register and haven't yet found one, | |
4559 | take any reg in the right class and not in use. | |
4560 | If we want a consecutive group, here is where we look for it. | |
4561 | ||
4562 | We use two passes so we can first look for reload regs to | |
4563 | reuse, which are already in use for other reloads in this insn, | |
4564 | and only then use additional registers. | |
4565 | I think that maximizing reuse is needed to make sure we don't | |
4566 | run out of reload regs. Suppose we have three reloads, and | |
4567 | reloads A and B can share regs. These need two regs. | |
4568 | Suppose A and B are given different regs. | |
4569 | That leaves none for C. */ | |
4570 | for (pass = 0; pass < 2; pass++) | |
4571 | { | |
4572 | /* I is the index in spill_regs. | |
4573 | We advance it round-robin between insns to use all spill regs | |
4574 | equally, so that inherited reloads have a chance | |
4575 | of leapfrogging each other. Don't do this, however, when we have | |
4576 | group needs and failure would be fatal; if we only have a relatively | |
4577 | small number of spill registers, and more than one of them has | |
4578 | group needs, then by starting in the middle, we may end up | |
4579 | allocating the first one in such a way that we are not left with | |
4580 | sufficient groups to handle the rest. */ | |
4581 | ||
4582 | if (noerror || ! force_group) | |
4583 | i = last_spill_reg; | |
4584 | else | |
4585 | i = -1; | |
4586 | ||
4587 | for (count = 0; count < n_spills; count++) | |
4588 | { | |
4589 | int class = (int) reload_reg_class[r]; | |
4590 | ||
4591 | i = (i + 1) % n_spills; | |
4592 | ||
4593 | if (reload_reg_free_p (spill_regs[i], reload_opnum[r], | |
4594 | reload_when_needed[r]) | |
4595 | && TEST_HARD_REG_BIT (reg_class_contents[class], spill_regs[i]) | |
4596 | && HARD_REGNO_MODE_OK (spill_regs[i], reload_mode[r]) | |
4597 | /* Look first for regs to share, then for unshared. But | |
4598 | don't share regs used for inherited reloads; they are | |
4599 | the ones we want to preserve. */ | |
4600 | && (pass | |
4601 | || (TEST_HARD_REG_BIT (reload_reg_used_at_all, | |
4602 | spill_regs[i]) | |
4603 | && ! TEST_HARD_REG_BIT (reload_reg_used_for_inherit, | |
4604 | spill_regs[i])))) | |
4605 | { | |
4606 | int nr = HARD_REGNO_NREGS (spill_regs[i], reload_mode[r]); | |
4607 | /* Avoid the problem where spilling a GENERAL_OR_FP_REG | |
4608 | (on 68000) got us two FP regs. If NR is 1, | |
4609 | we would reject both of them. */ | |
4610 | if (force_group) | |
4611 | nr = CLASS_MAX_NREGS (reload_reg_class[r], reload_mode[r]); | |
4612 | /* If we need only one reg, we have already won. */ | |
4613 | if (nr == 1) | |
4614 | { | |
4615 | /* But reject a single reg if we demand a group. */ | |
4616 | if (force_group) | |
4617 | continue; | |
4618 | break; | |
4619 | } | |
4620 | /* Otherwise check that as many consecutive regs as we need | |
4621 | are available here. | |
4622 | Also, don't use for a group registers that are | |
4623 | needed for nongroups. */ | |
4624 | if (! TEST_HARD_REG_BIT (counted_for_nongroups, spill_regs[i])) | |
4625 | while (nr > 1) | |
4626 | { | |
4627 | regno = spill_regs[i] + nr - 1; | |
4628 | if (!(TEST_HARD_REG_BIT (reg_class_contents[class], regno) | |
4629 | && spill_reg_order[regno] >= 0 | |
4630 | && reload_reg_free_p (regno, reload_opnum[r], | |
4631 | reload_when_needed[r]) | |
4632 | && ! TEST_HARD_REG_BIT (counted_for_nongroups, | |
4633 | regno))) | |
4634 | break; | |
4635 | nr--; | |
4636 | } | |
4637 | if (nr == 1) | |
4638 | break; | |
4639 | } | |
4640 | } | |
4641 | ||
4642 | /* If we found something on pass 1, omit pass 2. */ | |
4643 | if (count < n_spills) | |
4644 | break; | |
4645 | } | |
4646 | ||
4647 | /* We should have found a spill register by now. */ | |
4648 | if (count == n_spills) | |
4649 | { | |
4650 | if (noerror) | |
4651 | return 0; | |
4652 | goto failure; | |
4653 | } | |
4654 | ||
4655 | /* I is the index in SPILL_REG_RTX of the reload register we are to | |
4656 | allocate. Get an rtx for it and find its register number. */ | |
4657 | ||
4658 | new = spill_reg_rtx[i]; | |
4659 | ||
4660 | if (new == 0 || GET_MODE (new) != reload_mode[r]) | |
4661 | spill_reg_rtx[i] = new | |
4662 | = gen_rtx (REG, reload_mode[r], spill_regs[i]); | |
4663 | ||
4664 | regno = true_regnum (new); | |
4665 | ||
4666 | /* Detect when the reload reg can't hold the reload mode. | |
4667 | This used to be one `if', but Sequent compiler can't handle that. */ | |
4668 | if (HARD_REGNO_MODE_OK (regno, reload_mode[r])) | |
4669 | { | |
4670 | enum machine_mode test_mode = VOIDmode; | |
4671 | if (reload_in[r]) | |
4672 | test_mode = GET_MODE (reload_in[r]); | |
4673 | /* If reload_in[r] has VOIDmode, it means we will load it | |
4674 | in whatever mode the reload reg has: to wit, reload_mode[r]. | |
4675 | We have already tested that for validity. */ | |
4676 | /* Aside from that, we need to test that the expressions | |
4677 | to reload from or into have modes which are valid for this | |
4678 | reload register. Otherwise the reload insns would be invalid. */ | |
4679 | if (! (reload_in[r] != 0 && test_mode != VOIDmode | |
4680 | && ! HARD_REGNO_MODE_OK (regno, test_mode))) | |
4681 | if (! (reload_out[r] != 0 | |
4682 | && ! HARD_REGNO_MODE_OK (regno, GET_MODE (reload_out[r])))) | |
4683 | { | |
4684 | /* The reg is OK. */ | |
4685 | last_spill_reg = i; | |
4686 | ||
4687 | /* Mark as in use for this insn the reload regs we use | |
4688 | for this. */ | |
4689 | mark_reload_reg_in_use (spill_regs[i], reload_opnum[r], | |
4690 | reload_when_needed[r], reload_mode[r]); | |
4691 | ||
4692 | reload_reg_rtx[r] = new; | |
4693 | reload_spill_index[r] = i; | |
4694 | return 1; | |
4695 | } | |
4696 | } | |
4697 | ||
4698 | /* The reg is not OK. */ | |
4699 | if (noerror) | |
4700 | return 0; | |
4701 | ||
4702 | failure: | |
4703 | if (asm_noperands (PATTERN (insn)) < 0) | |
4704 | /* It's the compiler's fault. */ | |
4705 | abort (); | |
4706 | ||
4707 | /* It's the user's fault; the operand's mode and constraint | |
4708 | don't match. Disable this reload so we don't crash in final. */ | |
4709 | error_for_asm (insn, | |
4710 | "`asm' operand constraint incompatible with operand size"); | |
4711 | reload_in[r] = 0; | |
4712 | reload_out[r] = 0; | |
4713 | reload_reg_rtx[r] = 0; | |
4714 | reload_optional[r] = 1; | |
4715 | reload_secondary_p[r] = 1; | |
4716 | ||
4717 | return 1; | |
4718 | } | |
4719 | \f | |
4720 | /* Assign hard reg targets for the pseudo-registers we must reload | |
4721 | into hard regs for this insn. | |
4722 | Also output the instructions to copy them in and out of the hard regs. | |
4723 | ||
4724 | For machines with register classes, we are responsible for | |
4725 | finding a reload reg in the proper class. */ | |
4726 | ||
4727 | static void | |
4728 | choose_reload_regs (insn, avoid_return_reg) | |
4729 | rtx insn; | |
4730 | rtx avoid_return_reg; | |
4731 | { | |
4732 | register int i, j; | |
4733 | int max_group_size = 1; | |
4734 | enum reg_class group_class = NO_REGS; | |
4735 | int inheritance; | |
4736 | ||
4737 | rtx save_reload_reg_rtx[MAX_RELOADS]; | |
4738 | char save_reload_inherited[MAX_RELOADS]; | |
4739 | rtx save_reload_inheritance_insn[MAX_RELOADS]; | |
4740 | rtx save_reload_override_in[MAX_RELOADS]; | |
4741 | int save_reload_spill_index[MAX_RELOADS]; | |
4742 | HARD_REG_SET save_reload_reg_used; | |
4743 | HARD_REG_SET save_reload_reg_used_in_input_addr[MAX_RECOG_OPERANDS]; | |
4744 | HARD_REG_SET save_reload_reg_used_in_output_addr[MAX_RECOG_OPERANDS]; | |
4745 | HARD_REG_SET save_reload_reg_used_in_input[MAX_RECOG_OPERANDS]; | |
4746 | HARD_REG_SET save_reload_reg_used_in_output[MAX_RECOG_OPERANDS]; | |
4747 | HARD_REG_SET save_reload_reg_used_in_op_addr; | |
4748 | HARD_REG_SET save_reload_reg_used_in_insn; | |
4749 | HARD_REG_SET save_reload_reg_used_in_other_addr; | |
4750 | HARD_REG_SET save_reload_reg_used_at_all; | |
4751 | ||
4752 | bzero (reload_inherited, MAX_RELOADS); | |
4753 | bzero (reload_inheritance_insn, MAX_RELOADS * sizeof (rtx)); | |
4754 | bzero (reload_override_in, MAX_RELOADS * sizeof (rtx)); | |
4755 | ||
4756 | CLEAR_HARD_REG_SET (reload_reg_used); | |
4757 | CLEAR_HARD_REG_SET (reload_reg_used_at_all); | |
4758 | CLEAR_HARD_REG_SET (reload_reg_used_in_op_addr); | |
4759 | CLEAR_HARD_REG_SET (reload_reg_used_in_insn); | |
4760 | CLEAR_HARD_REG_SET (reload_reg_used_in_other_addr); | |
4761 | ||
4762 | for (i = 0; i < reload_n_operands; i++) | |
4763 | { | |
4764 | CLEAR_HARD_REG_SET (reload_reg_used_in_output[i]); | |
4765 | CLEAR_HARD_REG_SET (reload_reg_used_in_input[i]); | |
4766 | CLEAR_HARD_REG_SET (reload_reg_used_in_input_addr[i]); | |
4767 | CLEAR_HARD_REG_SET (reload_reg_used_in_output_addr[i]); | |
4768 | } | |
4769 | ||
4770 | #ifdef SMALL_REGISTER_CLASSES | |
4771 | /* Don't bother with avoiding the return reg | |
4772 | if we have no mandatory reload that could use it. */ | |
4773 | if (avoid_return_reg) | |
4774 | { | |
4775 | int do_avoid = 0; | |
4776 | int regno = REGNO (avoid_return_reg); | |
4777 | int nregs | |
4778 | = HARD_REGNO_NREGS (regno, GET_MODE (avoid_return_reg)); | |
4779 | int r; | |
4780 | ||
4781 | for (r = regno; r < regno + nregs; r++) | |
4782 | if (spill_reg_order[r] >= 0) | |
4783 | for (j = 0; j < n_reloads; j++) | |
4784 | if (!reload_optional[j] && reload_reg_rtx[j] == 0 | |
4785 | && (reload_in[j] != 0 || reload_out[j] != 0 | |
4786 | || reload_secondary_p[j]) | |
4787 | && | |
4788 | TEST_HARD_REG_BIT (reg_class_contents[(int) reload_reg_class[j]], r)) | |
4789 | do_avoid = 1; | |
4790 | if (!do_avoid) | |
4791 | avoid_return_reg = 0; | |
4792 | } | |
4793 | #endif /* SMALL_REGISTER_CLASSES */ | |
4794 | ||
4795 | #if 0 /* Not needed, now that we can always retry without inheritance. */ | |
4796 | /* See if we have more mandatory reloads than spill regs. | |
4797 | If so, then we cannot risk optimizations that could prevent | |
4798 | reloads from sharing one spill register. | |
4799 | ||
4800 | Since we will try finding a better register than reload_reg_rtx | |
4801 | unless it is equal to reload_in or reload_out, count such reloads. */ | |
4802 | ||
4803 | { | |
4804 | int tem = 0; | |
4805 | #ifdef SMALL_REGISTER_CLASSES | |
4806 | int tem = (avoid_return_reg != 0); | |
4807 | #endif | |
4808 | for (j = 0; j < n_reloads; j++) | |
4809 | if (! reload_optional[j] | |
4810 | && (reload_in[j] != 0 || reload_out[j] != 0 || reload_secondary_p[j]) | |
4811 | && (reload_reg_rtx[j] == 0 | |
4812 | || (! rtx_equal_p (reload_reg_rtx[j], reload_in[j]) | |
4813 | && ! rtx_equal_p (reload_reg_rtx[j], reload_out[j])))) | |
4814 | tem++; | |
4815 | if (tem > n_spills) | |
4816 | must_reuse = 1; | |
4817 | } | |
4818 | #endif | |
4819 | ||
4820 | #ifdef SMALL_REGISTER_CLASSES | |
4821 | /* Don't use the subroutine call return reg for a reload | |
4822 | if we are supposed to avoid it. */ | |
4823 | if (avoid_return_reg) | |
4824 | { | |
4825 | int regno = REGNO (avoid_return_reg); | |
4826 | int nregs | |
4827 | = HARD_REGNO_NREGS (regno, GET_MODE (avoid_return_reg)); | |
4828 | int r; | |
4829 | ||
4830 | for (r = regno; r < regno + nregs; r++) | |
4831 | if (spill_reg_order[r] >= 0) | |
4832 | SET_HARD_REG_BIT (reload_reg_used, r); | |
4833 | } | |
4834 | #endif /* SMALL_REGISTER_CLASSES */ | |
4835 | ||
4836 | /* In order to be certain of getting the registers we need, | |
4837 | we must sort the reloads into order of increasing register class. | |
4838 | Then our grabbing of reload registers will parallel the process | |
4839 | that provided the reload registers. | |
4840 | ||
4841 | Also note whether any of the reloads wants a consecutive group of regs. | |
4842 | If so, record the maximum size of the group desired and what | |
4843 | register class contains all the groups needed by this insn. */ | |
4844 | ||
4845 | for (j = 0; j < n_reloads; j++) | |
4846 | { | |
4847 | reload_order[j] = j; | |
4848 | reload_spill_index[j] = -1; | |
4849 | ||
4850 | reload_mode[j] | |
4851 | = (reload_inmode[j] == VOIDmode | |
4852 | || (GET_MODE_SIZE (reload_outmode[j]) | |
4853 | > GET_MODE_SIZE (reload_inmode[j]))) | |
4854 | ? reload_outmode[j] : reload_inmode[j]; | |
4855 | ||
4856 | reload_nregs[j] = CLASS_MAX_NREGS (reload_reg_class[j], reload_mode[j]); | |
4857 | ||
4858 | if (reload_nregs[j] > 1) | |
4859 | { | |
4860 | max_group_size = MAX (reload_nregs[j], max_group_size); | |
4861 | group_class = reg_class_superunion[(int)reload_reg_class[j]][(int)group_class]; | |
4862 | } | |
4863 | ||
4864 | /* If we have already decided to use a certain register, | |
4865 | don't use it in another way. */ | |
4866 | if (reload_reg_rtx[j]) | |
4867 | mark_reload_reg_in_use (REGNO (reload_reg_rtx[j]), reload_opnum[j], | |
4868 | reload_when_needed[j], reload_mode[j]); | |
4869 | } | |
4870 | ||
4871 | if (n_reloads > 1) | |
4872 | qsort (reload_order, n_reloads, sizeof (short), reload_reg_class_lower); | |
4873 | ||
4874 | bcopy (reload_reg_rtx, save_reload_reg_rtx, sizeof reload_reg_rtx); | |
4875 | bcopy (reload_inherited, save_reload_inherited, sizeof reload_inherited); | |
4876 | bcopy (reload_inheritance_insn, save_reload_inheritance_insn, | |
4877 | sizeof reload_inheritance_insn); | |
4878 | bcopy (reload_override_in, save_reload_override_in, | |
4879 | sizeof reload_override_in); | |
4880 | bcopy (reload_spill_index, save_reload_spill_index, | |
4881 | sizeof reload_spill_index); | |
4882 | COPY_HARD_REG_SET (save_reload_reg_used, reload_reg_used); | |
4883 | COPY_HARD_REG_SET (save_reload_reg_used_at_all, reload_reg_used_at_all); | |
4884 | COPY_HARD_REG_SET (save_reload_reg_used_in_op_addr, | |
4885 | reload_reg_used_in_op_addr); | |
4886 | COPY_HARD_REG_SET (save_reload_reg_used_in_insn, | |
4887 | reload_reg_used_in_insn); | |
4888 | COPY_HARD_REG_SET (save_reload_reg_used_in_other_addr, | |
4889 | reload_reg_used_in_other_addr); | |
4890 | ||
4891 | for (i = 0; i < reload_n_operands; i++) | |
4892 | { | |
4893 | COPY_HARD_REG_SET (save_reload_reg_used_in_output[i], | |
4894 | reload_reg_used_in_output[i]); | |
4895 | COPY_HARD_REG_SET (save_reload_reg_used_in_input[i], | |
4896 | reload_reg_used_in_input[i]); | |
4897 | COPY_HARD_REG_SET (save_reload_reg_used_in_input_addr[i], | |
4898 | reload_reg_used_in_input_addr[i]); | |
4899 | COPY_HARD_REG_SET (save_reload_reg_used_in_output_addr[i], | |
4900 | reload_reg_used_in_output_addr[i]); | |
4901 | } | |
4902 | ||
4903 | /* If -O, try first with inheritance, then turning it off. | |
4904 | If not -O, don't do inheritance. | |
4905 | Using inheritance when not optimizing leads to paradoxes | |
4906 | with fp on the 68k: fp numbers (not NaNs) fail to be equal to themselves | |
4907 | because one side of the comparison might be inherited. */ | |
4908 | ||
4909 | for (inheritance = optimize > 0; inheritance >= 0; inheritance--) | |
4910 | { | |
4911 | /* Process the reloads in order of preference just found. | |
4912 | Beyond this point, subregs can be found in reload_reg_rtx. | |
4913 | ||
4914 | This used to look for an existing reloaded home for all | |
4915 | of the reloads, and only then perform any new reloads. | |
4916 | But that could lose if the reloads were done out of reg-class order | |
4917 | because a later reload with a looser constraint might have an old | |
4918 | home in a register needed by an earlier reload with a tighter constraint. | |
4919 | ||
4920 | To solve this, we make two passes over the reloads, in the order | |
4921 | described above. In the first pass we try to inherit a reload | |
4922 | from a previous insn. If there is a later reload that needs a | |
4923 | class that is a proper subset of the class being processed, we must | |
4924 | also allocate a spill register during the first pass. | |
4925 | ||
4926 | Then make a second pass over the reloads to allocate any reloads | |
4927 | that haven't been given registers yet. */ | |
4928 | ||
4929 | CLEAR_HARD_REG_SET (reload_reg_used_for_inherit); | |
4930 | ||
4931 | for (j = 0; j < n_reloads; j++) | |
4932 | { | |
4933 | register int r = reload_order[j]; | |
4934 | ||
4935 | /* Ignore reloads that got marked inoperative. */ | |
4936 | if (reload_out[r] == 0 && reload_in[r] == 0 && ! reload_secondary_p[r]) | |
4937 | continue; | |
4938 | ||
4939 | /* If find_reloads chose a to use reload_in or reload_out as a reload | |
4940 | register, we don't need to chose one. Otherwise, try even if it found | |
4941 | one since we might save an insn if we find the value lying around. */ | |
4942 | if (reload_in[r] != 0 && reload_reg_rtx[r] != 0 | |
4943 | && (rtx_equal_p (reload_in[r], reload_reg_rtx[r]) | |
4944 | || rtx_equal_p (reload_out[r], reload_reg_rtx[r]))) | |
4945 | continue; | |
4946 | ||
4947 | #if 0 /* No longer needed for correct operation. | |
4948 | It might give better code, or might not; worth an experiment? */ | |
4949 | /* If this is an optional reload, we can't inherit from earlier insns | |
4950 | until we are sure that any non-optional reloads have been allocated. | |
4951 | The following code takes advantage of the fact that optional reloads | |
4952 | are at the end of reload_order. */ | |
4953 | if (reload_optional[r] != 0) | |
4954 | for (i = 0; i < j; i++) | |
4955 | if ((reload_out[reload_order[i]] != 0 | |
4956 | || reload_in[reload_order[i]] != 0 | |
4957 | || reload_secondary_p[reload_order[i]]) | |
4958 | && ! reload_optional[reload_order[i]] | |
4959 | && reload_reg_rtx[reload_order[i]] == 0) | |
4960 | allocate_reload_reg (reload_order[i], insn, 0, inheritance); | |
4961 | #endif | |
4962 | ||
4963 | /* First see if this pseudo is already available as reloaded | |
4964 | for a previous insn. We cannot try to inherit for reloads | |
4965 | that are smaller than the maximum number of registers needed | |
4966 | for groups unless the register we would allocate cannot be used | |
4967 | for the groups. | |
4968 | ||
4969 | We could check here to see if this is a secondary reload for | |
4970 | an object that is already in a register of the desired class. | |
4971 | This would avoid the need for the secondary reload register. | |
4972 | But this is complex because we can't easily determine what | |
4973 | objects might want to be loaded via this reload. So let a register | |
4974 | be allocated here. In `emit_reload_insns' we suppress one of the | |
4975 | loads in the case described above. */ | |
4976 | ||
4977 | if (inheritance) | |
4978 | { | |
4979 | register int regno = -1; | |
4980 | enum machine_mode mode; | |
4981 | ||
4982 | if (reload_in[r] == 0) | |
4983 | ; | |
4984 | else if (GET_CODE (reload_in[r]) == REG) | |
4985 | { | |
4986 | regno = REGNO (reload_in[r]); | |
4987 | mode = GET_MODE (reload_in[r]); | |
4988 | } | |
4989 | else if (GET_CODE (reload_in_reg[r]) == REG) | |
4990 | { | |
4991 | regno = REGNO (reload_in_reg[r]); | |
4992 | mode = GET_MODE (reload_in_reg[r]); | |
4993 | } | |
4994 | #if 0 | |
4995 | /* This won't work, since REGNO can be a pseudo reg number. | |
4996 | Also, it takes much more hair to keep track of all the things | |
4997 | that can invalidate an inherited reload of part of a pseudoreg. */ | |
4998 | else if (GET_CODE (reload_in[r]) == SUBREG | |
4999 | && GET_CODE (SUBREG_REG (reload_in[r])) == REG) | |
5000 | regno = REGNO (SUBREG_REG (reload_in[r])) + SUBREG_WORD (reload_in[r]); | |
5001 | #endif | |
5002 | ||
5003 | if (regno >= 0 && reg_last_reload_reg[regno] != 0) | |
5004 | { | |
5005 | i = spill_reg_order[REGNO (reg_last_reload_reg[regno])]; | |
5006 | ||
5007 | if (reg_reloaded_contents[i] == regno | |
5008 | && (GET_MODE_SIZE (GET_MODE (reg_last_reload_reg[regno])) | |
5009 | >= GET_MODE_SIZE (mode)) | |
5010 | && HARD_REGNO_MODE_OK (spill_regs[i], reload_mode[r]) | |
5011 | && TEST_HARD_REG_BIT (reg_class_contents[(int) reload_reg_class[r]], | |
5012 | spill_regs[i]) | |
5013 | && (reload_nregs[r] == max_group_size | |
5014 | || ! TEST_HARD_REG_BIT (reg_class_contents[(int) group_class], | |
5015 | spill_regs[i])) | |
5016 | && reload_reg_free_p (spill_regs[i], reload_opnum[r], | |
5017 | reload_when_needed[r]) | |
5018 | && reload_reg_free_before_p (spill_regs[i], | |
5019 | reload_opnum[r], | |
5020 | reload_when_needed[r])) | |
5021 | { | |
5022 | /* If a group is needed, verify that all the subsequent | |
5023 | registers still have their values intact. */ | |
5024 | int nr | |
5025 | = HARD_REGNO_NREGS (spill_regs[i], reload_mode[r]); | |
5026 | int k; | |
5027 | ||
5028 | for (k = 1; k < nr; k++) | |
5029 | if (reg_reloaded_contents[spill_reg_order[spill_regs[i] + k]] | |
5030 | != regno) | |
5031 | break; | |
5032 | ||
5033 | if (k == nr) | |
5034 | { | |
5035 | int i1; | |
5036 | ||
5037 | /* We found a register that contains the | |
5038 | value we need. If this register is the | |
5039 | same as an `earlyclobber' operand of the | |
5040 | current insn, just mark it as a place to | |
5041 | reload from since we can't use it as the | |
5042 | reload register itself. */ | |
5043 | ||
5044 | for (i1 = 0; i1 < n_earlyclobbers; i1++) | |
5045 | if (reg_overlap_mentioned_for_reload_p | |
5046 | (reg_last_reload_reg[regno], | |
5047 | reload_earlyclobbers[i1])) | |
5048 | break; | |
5049 | ||
5050 | if (i1 != n_earlyclobbers | |
5051 | /* Don't really use the inherited spill reg | |
5052 | if we need it wider than we've got it. */ | |
5053 | || (GET_MODE_SIZE (reload_mode[r]) | |
5054 | > GET_MODE_SIZE (mode))) | |
5055 | reload_override_in[r] = reg_last_reload_reg[regno]; | |
5056 | else | |
5057 | { | |
5058 | int k; | |
5059 | /* We can use this as a reload reg. */ | |
5060 | /* Mark the register as in use for this part of | |
5061 | the insn. */ | |
5062 | mark_reload_reg_in_use (spill_regs[i], | |
5063 | reload_opnum[r], | |
5064 | reload_when_needed[r], | |
5065 | reload_mode[r]); | |
5066 | reload_reg_rtx[r] = reg_last_reload_reg[regno]; | |
5067 | reload_inherited[r] = 1; | |
5068 | reload_inheritance_insn[r] | |
5069 | = reg_reloaded_insn[i]; | |
5070 | reload_spill_index[r] = i; | |
5071 | for (k = 0; k < nr; k++) | |
5072 | SET_HARD_REG_BIT (reload_reg_used_for_inherit, | |
5073 | spill_regs[i + k]); | |
5074 | } | |
5075 | } | |
5076 | } | |
5077 | } | |
5078 | } | |
5079 | ||
5080 | /* Here's another way to see if the value is already lying around. */ | |
5081 | if (inheritance | |
5082 | && reload_in[r] != 0 | |
5083 | && ! reload_inherited[r] | |
5084 | && reload_out[r] == 0 | |
5085 | && (CONSTANT_P (reload_in[r]) | |
5086 | || GET_CODE (reload_in[r]) == PLUS | |
5087 | || GET_CODE (reload_in[r]) == REG | |
5088 | || GET_CODE (reload_in[r]) == MEM) | |
5089 | && (reload_nregs[r] == max_group_size | |
5090 | || ! reg_classes_intersect_p (reload_reg_class[r], group_class))) | |
5091 | { | |
5092 | register rtx equiv | |
5093 | = find_equiv_reg (reload_in[r], insn, reload_reg_class[r], | |
5094 | -1, NULL_PTR, 0, reload_mode[r]); | |
5095 | int regno; | |
5096 | ||
5097 | if (equiv != 0) | |
5098 | { | |
5099 | if (GET_CODE (equiv) == REG) | |
5100 | regno = REGNO (equiv); | |
5101 | else if (GET_CODE (equiv) == SUBREG) | |
5102 | { | |
5103 | /* This must be a SUBREG of a hard register. | |
5104 | Make a new REG since this might be used in an | |
5105 | address and not all machines support SUBREGs | |
5106 | there. */ | |
5107 | regno = REGNO (SUBREG_REG (equiv)) + SUBREG_WORD (equiv); | |
5108 | equiv = gen_rtx (REG, reload_mode[r], regno); | |
5109 | } | |
5110 | else | |
5111 | abort (); | |
5112 | } | |
5113 | ||
5114 | /* If we found a spill reg, reject it unless it is free | |
5115 | and of the desired class. */ | |
5116 | if (equiv != 0 | |
5117 | && ((spill_reg_order[regno] >= 0 | |
5118 | && ! reload_reg_free_before_p (regno, reload_opnum[r], | |
5119 | reload_when_needed[r])) | |
5120 | || ! TEST_HARD_REG_BIT (reg_class_contents[(int) reload_reg_class[r]], | |
5121 | regno))) | |
5122 | equiv = 0; | |
5123 | ||
5124 | if (equiv != 0 && TEST_HARD_REG_BIT (reload_reg_used_at_all, regno)) | |
5125 | equiv = 0; | |
5126 | ||
5127 | if (equiv != 0 && ! HARD_REGNO_MODE_OK (regno, reload_mode[r])) | |
5128 | equiv = 0; | |
5129 | ||
5130 | /* We found a register that contains the value we need. | |
5131 | If this register is the same as an `earlyclobber' operand | |
5132 | of the current insn, just mark it as a place to reload from | |
5133 | since we can't use it as the reload register itself. */ | |
5134 | ||
5135 | if (equiv != 0) | |
5136 | for (i = 0; i < n_earlyclobbers; i++) | |
5137 | if (reg_overlap_mentioned_for_reload_p (equiv, | |
5138 | reload_earlyclobbers[i])) | |
5139 | { | |
5140 | reload_override_in[r] = equiv; | |
5141 | equiv = 0; | |
5142 | break; | |
5143 | } | |
5144 | ||
5145 | /* JRV: If the equiv register we have found is explicitly | |
5146 | clobbered in the current insn, mark but don't use, as above. */ | |
5147 | ||
5148 | if (equiv != 0 && regno_clobbered_p (regno, insn)) | |
5149 | { | |
5150 | reload_override_in[r] = equiv; | |
5151 | equiv = 0; | |
5152 | } | |
5153 | ||
5154 | /* If we found an equivalent reg, say no code need be generated | |
5155 | to load it, and use it as our reload reg. */ | |
5156 | if (equiv != 0 && regno != HARD_FRAME_POINTER_REGNUM) | |
5157 | { | |
5158 | reload_reg_rtx[r] = equiv; | |
5159 | reload_inherited[r] = 1; | |
5160 | /* If it is a spill reg, | |
5161 | mark the spill reg as in use for this insn. */ | |
5162 | i = spill_reg_order[regno]; | |
5163 | if (i >= 0) | |
5164 | { | |
5165 | int nr = HARD_REGNO_NREGS (regno, reload_mode[r]); | |
5166 | int k; | |
5167 | mark_reload_reg_in_use (regno, reload_opnum[r], | |
5168 | reload_when_needed[r], | |
5169 | reload_mode[r]); | |
5170 | for (k = 0; k < nr; k++) | |
5171 | SET_HARD_REG_BIT (reload_reg_used_for_inherit, regno + k); | |
5172 | } | |
5173 | } | |
5174 | } | |
5175 | ||
5176 | /* If we found a register to use already, or if this is an optional | |
5177 | reload, we are done. */ | |
5178 | if (reload_reg_rtx[r] != 0 || reload_optional[r] != 0) | |
5179 | continue; | |
5180 | ||
5181 | #if 0 /* No longer needed for correct operation. Might or might not | |
5182 | give better code on the average. Want to experiment? */ | |
5183 | ||
5184 | /* See if there is a later reload that has a class different from our | |
5185 | class that intersects our class or that requires less register | |
5186 | than our reload. If so, we must allocate a register to this | |
5187 | reload now, since that reload might inherit a previous reload | |
5188 | and take the only available register in our class. Don't do this | |
5189 | for optional reloads since they will force all previous reloads | |
5190 | to be allocated. Also don't do this for reloads that have been | |
5191 | turned off. */ | |
5192 | ||
5193 | for (i = j + 1; i < n_reloads; i++) | |
5194 | { | |
5195 | int s = reload_order[i]; | |
5196 | ||
5197 | if ((reload_in[s] == 0 && reload_out[s] == 0 | |
5198 | && ! reload_secondary_p[s]) | |
5199 | || reload_optional[s]) | |
5200 | continue; | |
5201 | ||
5202 | if ((reload_reg_class[s] != reload_reg_class[r] | |
5203 | && reg_classes_intersect_p (reload_reg_class[r], | |
5204 | reload_reg_class[s])) | |
5205 | || reload_nregs[s] < reload_nregs[r]) | |
5206 | break; | |
5207 | } | |
5208 | ||
5209 | if (i == n_reloads) | |
5210 | continue; | |
5211 | ||
5212 | allocate_reload_reg (r, insn, j == n_reloads - 1, inheritance); | |
5213 | #endif | |
5214 | } | |
5215 | ||
5216 | /* Now allocate reload registers for anything non-optional that | |
5217 | didn't get one yet. */ | |
5218 | for (j = 0; j < n_reloads; j++) | |
5219 | { | |
5220 | register int r = reload_order[j]; | |
5221 | ||
5222 | /* Ignore reloads that got marked inoperative. */ | |
5223 | if (reload_out[r] == 0 && reload_in[r] == 0 && ! reload_secondary_p[r]) | |
5224 | continue; | |
5225 | ||
5226 | /* Skip reloads that already have a register allocated or are | |
5227 | optional. */ | |
5228 | if (reload_reg_rtx[r] != 0 || reload_optional[r]) | |
5229 | continue; | |
5230 | ||
5231 | if (! allocate_reload_reg (r, insn, j == n_reloads - 1, inheritance)) | |
5232 | break; | |
5233 | } | |
5234 | ||
5235 | /* If that loop got all the way, we have won. */ | |
5236 | if (j == n_reloads) | |
5237 | break; | |
5238 | ||
5239 | fail: | |
5240 | /* Loop around and try without any inheritance. */ | |
5241 | /* First undo everything done by the failed attempt | |
5242 | to allocate with inheritance. */ | |
5243 | bcopy (save_reload_reg_rtx, reload_reg_rtx, sizeof reload_reg_rtx); | |
5244 | bcopy (save_reload_inherited, reload_inherited, sizeof reload_inherited); | |
5245 | bcopy (save_reload_inheritance_insn, reload_inheritance_insn, | |
5246 | sizeof reload_inheritance_insn); | |
5247 | bcopy (save_reload_override_in, reload_override_in, | |
5248 | sizeof reload_override_in); | |
5249 | bcopy (save_reload_spill_index, reload_spill_index, | |
5250 | sizeof reload_spill_index); | |
5251 | COPY_HARD_REG_SET (reload_reg_used, save_reload_reg_used); | |
5252 | COPY_HARD_REG_SET (reload_reg_used_at_all, save_reload_reg_used_at_all); | |
5253 | COPY_HARD_REG_SET (reload_reg_used_in_op_addr, | |
5254 | save_reload_reg_used_in_op_addr); | |
5255 | COPY_HARD_REG_SET (reload_reg_used_in_insn, | |
5256 | save_reload_reg_used_in_insn); | |
5257 | COPY_HARD_REG_SET (reload_reg_used_in_other_addr, | |
5258 | save_reload_reg_used_in_other_addr); | |
5259 | ||
5260 | for (i = 0; i < reload_n_operands; i++) | |
5261 | { | |
5262 | COPY_HARD_REG_SET (reload_reg_used_in_input[i], | |
5263 | save_reload_reg_used_in_input[i]); | |
5264 | COPY_HARD_REG_SET (reload_reg_used_in_output[i], | |
5265 | save_reload_reg_used_in_output[i]); | |
5266 | COPY_HARD_REG_SET (reload_reg_used_in_input_addr[i], | |
5267 | save_reload_reg_used_in_input_addr[i]); | |
5268 | COPY_HARD_REG_SET (reload_reg_used_in_output_addr[i], | |
5269 | save_reload_reg_used_in_output_addr[i]); | |
5270 | } | |
5271 | } | |
5272 | ||
5273 | /* If we thought we could inherit a reload, because it seemed that | |
5274 | nothing else wanted the same reload register earlier in the insn, | |
5275 | verify that assumption, now that all reloads have been assigned. */ | |
5276 | ||
5277 | for (j = 0; j < n_reloads; j++) | |
5278 | { | |
5279 | register int r = reload_order[j]; | |
5280 | ||
5281 | if (reload_inherited[r] && reload_reg_rtx[r] != 0 | |
5282 | && ! reload_reg_free_before_p (true_regnum (reload_reg_rtx[r]), | |
5283 | reload_opnum[r], | |
5284 | reload_when_needed[r])) | |
5285 | reload_inherited[r] = 0; | |
5286 | ||
5287 | /* If we found a better place to reload from, | |
5288 | validate it in the same fashion, if it is a reload reg. */ | |
5289 | if (reload_override_in[r] | |
5290 | && (GET_CODE (reload_override_in[r]) == REG | |
5291 | || GET_CODE (reload_override_in[r]) == SUBREG)) | |
5292 | { | |
5293 | int regno = true_regnum (reload_override_in[r]); | |
5294 | if (spill_reg_order[regno] >= 0 | |
5295 | && ! reload_reg_free_before_p (regno, reload_opnum[r], | |
5296 | reload_when_needed[r])) | |
5297 | reload_override_in[r] = 0; | |
5298 | } | |
5299 | } | |
5300 | ||
5301 | /* Now that reload_override_in is known valid, | |
5302 | actually override reload_in. */ | |
5303 | for (j = 0; j < n_reloads; j++) | |
5304 | if (reload_override_in[j]) | |
5305 | reload_in[j] = reload_override_in[j]; | |
5306 | ||
5307 | /* If this reload won't be done because it has been cancelled or is | |
5308 | optional and not inherited, clear reload_reg_rtx so other | |
5309 | routines (such as subst_reloads) don't get confused. */ | |
5310 | for (j = 0; j < n_reloads; j++) | |
5311 | if (reload_reg_rtx[j] != 0 | |
5312 | && ((reload_optional[j] && ! reload_inherited[j]) | |
5313 | || (reload_in[j] == 0 && reload_out[j] == 0 | |
5314 | && ! reload_secondary_p[j]))) | |
5315 | { | |
5316 | int regno = true_regnum (reload_reg_rtx[j]); | |
5317 | ||
5318 | if (spill_reg_order[regno] >= 0) | |
5319 | clear_reload_reg_in_use (regno, reload_opnum[j], | |
5320 | reload_when_needed[j], reload_mode[j]); | |
5321 | reload_reg_rtx[j] = 0; | |
5322 | } | |
5323 | ||
5324 | /* Record which pseudos and which spill regs have output reloads. */ | |
5325 | for (j = 0; j < n_reloads; j++) | |
5326 | { | |
5327 | register int r = reload_order[j]; | |
5328 | ||
5329 | i = reload_spill_index[r]; | |
5330 | ||
5331 | /* I is nonneg if this reload used one of the spill regs. | |
5332 | If reload_reg_rtx[r] is 0, this is an optional reload | |
5333 | that we opted to ignore. */ | |
5334 | if (reload_out[r] != 0 && GET_CODE (reload_out[r]) == REG | |
5335 | && reload_reg_rtx[r] != 0) | |
5336 | { | |
5337 | register int nregno = REGNO (reload_out[r]); | |
5338 | int nr = 1; | |
5339 | ||
5340 | if (nregno < FIRST_PSEUDO_REGISTER) | |
5341 | nr = HARD_REGNO_NREGS (nregno, reload_mode[r]); | |
5342 | ||
5343 | while (--nr >= 0) | |
5344 | reg_has_output_reload[nregno + nr] = 1; | |
5345 | ||
5346 | if (i >= 0) | |
5347 | { | |
5348 | nr = HARD_REGNO_NREGS (spill_regs[i], reload_mode[r]); | |
5349 | while (--nr >= 0) | |
5350 | SET_HARD_REG_BIT (reg_is_output_reload, spill_regs[i] + nr); | |
5351 | } | |
5352 | ||
5353 | if (reload_when_needed[r] != RELOAD_OTHER | |
5354 | && reload_when_needed[r] != RELOAD_FOR_OUTPUT | |
5355 | && reload_when_needed[r] != RELOAD_FOR_INSN) | |
5356 | abort (); | |
5357 | } | |
5358 | } | |
5359 | } | |
5360 | \f | |
5361 | /* If SMALL_REGISTER_CLASSES are defined, we may not have merged two | |
5362 | reloads of the same item for fear that we might not have enough reload | |
5363 | registers. However, normally they will get the same reload register | |
5364 | and hence actually need not be loaded twice. | |
5365 | ||
5366 | Here we check for the most common case of this phenomenon: when we have | |
5367 | a number of reloads for the same object, each of which were allocated | |
5368 | the same reload_reg_rtx, that reload_reg_rtx is not used for any other | |
5369 | reload, and is not modified in the insn itself. If we find such, | |
5370 | merge all the reloads and set the resulting reload to RELOAD_OTHER. | |
5371 | This will not increase the number of spill registers needed and will | |
5372 | prevent redundant code. */ | |
5373 | ||
5374 | #ifdef SMALL_REGISTER_CLASSES | |
5375 | ||
5376 | static void | |
5377 | merge_assigned_reloads (insn) | |
5378 | rtx insn; | |
5379 | { | |
5380 | int i, j; | |
5381 | ||
5382 | /* Scan all the reloads looking for ones that only load values and | |
5383 | are not already RELOAD_OTHER and ones whose reload_reg_rtx are | |
5384 | assigned and not modified by INSN. */ | |
5385 | ||
5386 | for (i = 0; i < n_reloads; i++) | |
5387 | { | |
5388 | if (reload_in[i] == 0 || reload_when_needed[i] == RELOAD_OTHER | |
5389 | || reload_out[i] != 0 || reload_reg_rtx[i] == 0 | |
5390 | || reg_set_p (reload_reg_rtx[i], insn)) | |
5391 | continue; | |
5392 | ||
5393 | /* Look at all other reloads. Ensure that the only use of this | |
5394 | reload_reg_rtx is in a reload that just loads the same value | |
5395 | as we do. Note that any secondary reloads must be of the identical | |
5396 | class since the values, modes, and result registers are the | |
5397 | same, so we need not do anything with any secondary reloads. */ | |
5398 | ||
5399 | for (j = 0; j < n_reloads; j++) | |
5400 | { | |
5401 | if (i == j || reload_reg_rtx[j] == 0 | |
5402 | || ! reg_overlap_mentioned_p (reload_reg_rtx[j], | |
5403 | reload_reg_rtx[i])) | |
5404 | continue; | |
5405 | ||
5406 | /* If the reload regs aren't exactly the same (e.g, different modes) | |
5407 | or if the values are different, we can't merge anything with this | |
5408 | reload register. */ | |
5409 | ||
5410 | if (! rtx_equal_p (reload_reg_rtx[i], reload_reg_rtx[j]) | |
5411 | || reload_out[j] != 0 || reload_in[j] == 0 | |
5412 | || ! rtx_equal_p (reload_in[i], reload_in[j])) | |
5413 | break; | |
5414 | } | |
5415 | ||
5416 | /* If all is OK, merge the reloads. Only set this to RELOAD_OTHER if | |
5417 | we, in fact, found any matching reloads. */ | |
5418 | ||
5419 | if (j == n_reloads) | |
5420 | { | |
5421 | for (j = 0; j < n_reloads; j++) | |
5422 | if (i != j && reload_reg_rtx[j] != 0 | |
5423 | && rtx_equal_p (reload_reg_rtx[i], reload_reg_rtx[j])) | |
5424 | { | |
5425 | reload_when_needed[i] = RELOAD_OTHER; | |
5426 | reload_in[j] = 0; | |
5427 | transfer_replacements (i, j); | |
5428 | } | |
5429 | ||
5430 | /* If this is now RELOAD_OTHER, look for any reloads that load | |
5431 | parts of this operand and set them to RELOAD_FOR_OTHER_ADDRESS | |
5432 | if they were for inputs, RELOAD_OTHER for outputs. Note that | |
5433 | this test is equivalent to looking for reloads for this operand | |
5434 | number. */ | |
5435 | ||
5436 | if (reload_when_needed[i] == RELOAD_OTHER) | |
5437 | for (j = 0; j < n_reloads; j++) | |
5438 | if (reload_in[j] != 0 | |
5439 | && reload_when_needed[i] != RELOAD_OTHER | |
5440 | && reg_overlap_mentioned_for_reload_p (reload_in[j], | |
5441 | reload_in[i])) | |
5442 | reload_when_needed[j] | |
5443 | = reload_when_needed[i] == RELOAD_FOR_INPUT_ADDRESS | |
5444 | ? RELOAD_FOR_OTHER_ADDRESS : RELOAD_OTHER; | |
5445 | } | |
5446 | } | |
5447 | } | |
5448 | #endif /* SMALL_RELOAD_CLASSES */ | |
5449 | \f | |
5450 | /* Output insns to reload values in and out of the chosen reload regs. */ | |
5451 | ||
5452 | static void | |
5453 | emit_reload_insns (insn) | |
5454 | rtx insn; | |
5455 | { | |
5456 | register int j; | |
5457 | rtx input_reload_insns[MAX_RECOG_OPERANDS]; | |
5458 | rtx other_input_address_reload_insns = 0; | |
5459 | rtx other_input_reload_insns = 0; | |
5460 | rtx input_address_reload_insns[MAX_RECOG_OPERANDS]; | |
5461 | rtx output_reload_insns[MAX_RECOG_OPERANDS]; | |
5462 | rtx output_address_reload_insns[MAX_RECOG_OPERANDS]; | |
5463 | rtx operand_reload_insns = 0; | |
5464 | rtx following_insn = NEXT_INSN (insn); | |
5465 | rtx before_insn = insn; | |
5466 | int special; | |
5467 | /* Values to be put in spill_reg_store are put here first. */ | |
5468 | rtx new_spill_reg_store[FIRST_PSEUDO_REGISTER]; | |
5469 | ||
5470 | for (j = 0; j < reload_n_operands; j++) | |
5471 | input_reload_insns[j] = input_address_reload_insns[j] | |
5472 | = output_reload_insns[j] = output_address_reload_insns[j] = 0; | |
5473 | ||
5474 | /* Now output the instructions to copy the data into and out of the | |
5475 | reload registers. Do these in the order that the reloads were reported, | |
5476 | since reloads of base and index registers precede reloads of operands | |
5477 | and the operands may need the base and index registers reloaded. */ | |
5478 | ||
5479 | for (j = 0; j < n_reloads; j++) | |
5480 | { | |
5481 | register rtx old; | |
5482 | rtx oldequiv_reg = 0; | |
5483 | rtx store_insn = 0; | |
5484 | ||
5485 | old = reload_in[j]; | |
5486 | if (old != 0 && ! reload_inherited[j] | |
5487 | && ! rtx_equal_p (reload_reg_rtx[j], old) | |
5488 | && reload_reg_rtx[j] != 0) | |
5489 | { | |
5490 | register rtx reloadreg = reload_reg_rtx[j]; | |
5491 | rtx oldequiv = 0; | |
5492 | enum machine_mode mode; | |
5493 | rtx *where; | |
5494 | ||
5495 | /* Determine the mode to reload in. | |
5496 | This is very tricky because we have three to choose from. | |
5497 | There is the mode the insn operand wants (reload_inmode[J]). | |
5498 | There is the mode of the reload register RELOADREG. | |
5499 | There is the intrinsic mode of the operand, which we could find | |
5500 | by stripping some SUBREGs. | |
5501 | It turns out that RELOADREG's mode is irrelevant: | |
5502 | we can change that arbitrarily. | |
5503 | ||
5504 | Consider (SUBREG:SI foo:QI) as an operand that must be SImode; | |
5505 | then the reload reg may not support QImode moves, so use SImode. | |
5506 | If foo is in memory due to spilling a pseudo reg, this is safe, | |
5507 | because the QImode value is in the least significant part of a | |
5508 | slot big enough for a SImode. If foo is some other sort of | |
5509 | memory reference, then it is impossible to reload this case, | |
5510 | so previous passes had better make sure this never happens. | |
5511 | ||
5512 | Then consider a one-word union which has SImode and one of its | |
5513 | members is a float, being fetched as (SUBREG:SF union:SI). | |
5514 | We must fetch that as SFmode because we could be loading into | |
5515 | a float-only register. In this case OLD's mode is correct. | |
5516 | ||
5517 | Consider an immediate integer: it has VOIDmode. Here we need | |
5518 | to get a mode from something else. | |
5519 | ||
5520 | In some cases, there is a fourth mode, the operand's | |
5521 | containing mode. If the insn specifies a containing mode for | |
5522 | this operand, it overrides all others. | |
5523 | ||
5524 | I am not sure whether the algorithm here is always right, | |
5525 | but it does the right things in those cases. */ | |
5526 | ||
5527 | mode = GET_MODE (old); | |
5528 | if (mode == VOIDmode) | |
5529 | mode = reload_inmode[j]; | |
5530 | ||
5531 | #ifdef SECONDARY_INPUT_RELOAD_CLASS | |
5532 | /* If we need a secondary register for this operation, see if | |
5533 | the value is already in a register in that class. Don't | |
5534 | do this if the secondary register will be used as a scratch | |
5535 | register. */ | |
5536 | ||
5537 | if (reload_secondary_in_reload[j] >= 0 | |
5538 | && reload_secondary_in_icode[j] == CODE_FOR_nothing | |
5539 | && optimize) | |
5540 | oldequiv | |
5541 | = find_equiv_reg (old, insn, | |
5542 | reload_reg_class[reload_secondary_in_reload[j]], | |
5543 | -1, NULL_PTR, 0, mode); | |
5544 | #endif | |
5545 | ||
5546 | /* If reloading from memory, see if there is a register | |
5547 | that already holds the same value. If so, reload from there. | |
5548 | We can pass 0 as the reload_reg_p argument because | |
5549 | any other reload has either already been emitted, | |
5550 | in which case find_equiv_reg will see the reload-insn, | |
5551 | or has yet to be emitted, in which case it doesn't matter | |
5552 | because we will use this equiv reg right away. */ | |
5553 | ||
5554 | if (oldequiv == 0 && optimize | |
5555 | && (GET_CODE (old) == MEM | |
5556 | || (GET_CODE (old) == REG | |
5557 | && REGNO (old) >= FIRST_PSEUDO_REGISTER | |
5558 | && reg_renumber[REGNO (old)] < 0))) | |
5559 | oldequiv = find_equiv_reg (old, insn, ALL_REGS, | |
5560 | -1, NULL_PTR, 0, mode); | |
5561 | ||
5562 | if (oldequiv) | |
5563 | { | |
5564 | int regno = true_regnum (oldequiv); | |
5565 | ||
5566 | /* If OLDEQUIV is a spill register, don't use it for this | |
5567 | if any other reload needs it at an earlier stage of this insn | |
5568 | or at this stage. */ | |
5569 | if (spill_reg_order[regno] >= 0 | |
5570 | && (! reload_reg_free_p (regno, reload_opnum[j], | |
5571 | reload_when_needed[j]) | |
5572 | || ! reload_reg_free_before_p (regno, reload_opnum[j], | |
5573 | reload_when_needed[j]))) | |
5574 | oldequiv = 0; | |
5575 | ||
5576 | /* If OLDEQUIV is not a spill register, | |
5577 | don't use it if any other reload wants it. */ | |
5578 | if (spill_reg_order[regno] < 0) | |
5579 | { | |
5580 | int k; | |
5581 | for (k = 0; k < n_reloads; k++) | |
5582 | if (reload_reg_rtx[k] != 0 && k != j | |
5583 | && reg_overlap_mentioned_for_reload_p (reload_reg_rtx[k], | |
5584 | oldequiv)) | |
5585 | { | |
5586 | oldequiv = 0; | |
5587 | break; | |
5588 | } | |
5589 | } | |
5590 | ||
5591 | /* If it is no cheaper to copy from OLDEQUIV into the | |
5592 | reload register than it would be to move from memory, | |
5593 | don't use it. Likewise, if we need a secondary register | |
5594 | or memory. */ | |
5595 | ||
5596 | if (oldequiv != 0 | |
5597 | && ((REGNO_REG_CLASS (regno) != reload_reg_class[j] | |
5598 | && (REGISTER_MOVE_COST (REGNO_REG_CLASS (regno), | |
5599 | reload_reg_class[j]) | |
5600 | >= MEMORY_MOVE_COST (mode))) | |
5601 | #ifdef SECONDARY_INPUT_RELOAD_CLASS | |
5602 | || (SECONDARY_INPUT_RELOAD_CLASS (reload_reg_class[j], | |
5603 | mode, oldequiv) | |
5604 | != NO_REGS) | |
5605 | #endif | |
5606 | #ifdef SECONDARY_MEMORY_NEEDED | |
5607 | || SECONDARY_MEMORY_NEEDED (reload_reg_class[j], | |
5608 | REGNO_REG_CLASS (regno), | |
5609 | mode) | |
5610 | #endif | |
5611 | )) | |
5612 | oldequiv = 0; | |
5613 | } | |
5614 | ||
5615 | if (oldequiv == 0) | |
5616 | oldequiv = old; | |
5617 | else if (GET_CODE (oldequiv) == REG) | |
5618 | oldequiv_reg = oldequiv; | |
5619 | else if (GET_CODE (oldequiv) == SUBREG) | |
5620 | oldequiv_reg = SUBREG_REG (oldequiv); | |
5621 | ||
5622 | /* If we are reloading from a register that was recently stored in | |
5623 | with an output-reload, see if we can prove there was | |
5624 | actually no need to store the old value in it. */ | |
5625 | ||
5626 | if (optimize && GET_CODE (oldequiv) == REG | |
5627 | && REGNO (oldequiv) < FIRST_PSEUDO_REGISTER | |
5628 | && spill_reg_order[REGNO (oldequiv)] >= 0 | |
5629 | && spill_reg_store[reload_spill_index[REGNO (oldequiv)]] != 0 | |
5630 | && find_reg_note (insn, REG_DEAD, reload_in[j]) | |
5631 | /* This is unsafe if operand occurs more than once in current | |
5632 | insn. Perhaps some occurrences weren't reloaded. */ | |
5633 | && count_occurrences (PATTERN (insn), reload_in[j]) == 1 | |
5634 | && spill_reg_store[spill_reg_order[REGNO (oldequiv)]] != 0) | |
5635 | delete_output_reload | |
5636 | (insn, j, spill_reg_store[spill_reg_order[REGNO (oldequiv)]]); | |
5637 | ||
5638 | /* Encapsulate both RELOADREG and OLDEQUIV into that mode, | |
5639 | then load RELOADREG from OLDEQUIV. Note that we cannot use | |
5640 | gen_lowpart_common since it can do the wrong thing when | |
5641 | RELOADREG has a multi-word mode. Note that RELOADREG | |
5642 | must always be a REG here. */ | |
5643 | ||
5644 | if (GET_MODE (reloadreg) != mode) | |
5645 | reloadreg = gen_rtx (REG, mode, REGNO (reloadreg)); | |
5646 | while (GET_CODE (oldequiv) == SUBREG && GET_MODE (oldequiv) != mode) | |
5647 | oldequiv = SUBREG_REG (oldequiv); | |
5648 | if (GET_MODE (oldequiv) != VOIDmode | |
5649 | && mode != GET_MODE (oldequiv)) | |
5650 | oldequiv = gen_rtx (SUBREG, mode, oldequiv, 0); | |
5651 | ||
5652 | /* Switch to the right place to emit the reload insns. */ | |
5653 | switch (reload_when_needed[j]) | |
5654 | { | |
5655 | case RELOAD_OTHER: | |
5656 | where = &other_input_reload_insns; | |
5657 | break; | |
5658 | case RELOAD_FOR_INPUT: | |
5659 | where = &input_reload_insns[reload_opnum[j]]; | |
5660 | break; | |
5661 | case RELOAD_FOR_INPUT_ADDRESS: | |
5662 | where = &input_address_reload_insns[reload_opnum[j]]; | |
5663 | break; | |
5664 | case RELOAD_FOR_OUTPUT_ADDRESS: | |
5665 | where = &output_address_reload_insns[reload_opnum[j]]; | |
5666 | break; | |
5667 | case RELOAD_FOR_OPERAND_ADDRESS: | |
5668 | where = &operand_reload_insns; | |
5669 | break; | |
5670 | case RELOAD_FOR_OTHER_ADDRESS: | |
5671 | where = &other_input_address_reload_insns; | |
5672 | break; | |
5673 | default: | |
5674 | abort (); | |
5675 | } | |
5676 | ||
5677 | push_to_sequence (*where); | |
5678 | special = 0; | |
5679 | ||
5680 | /* Auto-increment addresses must be reloaded in a special way. */ | |
5681 | if (GET_CODE (oldequiv) == POST_INC | |
5682 | || GET_CODE (oldequiv) == POST_DEC | |
5683 | || GET_CODE (oldequiv) == PRE_INC | |
5684 | || GET_CODE (oldequiv) == PRE_DEC) | |
5685 | { | |
5686 | /* We are not going to bother supporting the case where a | |
5687 | incremented register can't be copied directly from | |
5688 | OLDEQUIV since this seems highly unlikely. */ | |
5689 | if (reload_secondary_in_reload[j] >= 0) | |
5690 | abort (); | |
5691 | /* Prevent normal processing of this reload. */ | |
5692 | special = 1; | |
5693 | /* Output a special code sequence for this case. */ | |
5694 | inc_for_reload (reloadreg, oldequiv, reload_inc[j]); | |
5695 | } | |
5696 | ||
5697 | /* If we are reloading a pseudo-register that was set by the previous | |
5698 | insn, see if we can get rid of that pseudo-register entirely | |
5699 | by redirecting the previous insn into our reload register. */ | |
5700 | ||
5701 | else if (optimize && GET_CODE (old) == REG | |
5702 | && REGNO (old) >= FIRST_PSEUDO_REGISTER | |
5703 | && dead_or_set_p (insn, old) | |
5704 | /* This is unsafe if some other reload | |
5705 | uses the same reg first. */ | |
5706 | && reload_reg_free_before_p (REGNO (reloadreg), | |
5707 | reload_opnum[j], | |
5708 | reload_when_needed[j])) | |
5709 | { | |
5710 | rtx temp = PREV_INSN (insn); | |
5711 | while (temp && GET_CODE (temp) == NOTE) | |
5712 | temp = PREV_INSN (temp); | |
5713 | if (temp | |
5714 | && GET_CODE (temp) == INSN | |
5715 | && GET_CODE (PATTERN (temp)) == SET | |
5716 | && SET_DEST (PATTERN (temp)) == old | |
5717 | /* Make sure we can access insn_operand_constraint. */ | |
5718 | && asm_noperands (PATTERN (temp)) < 0 | |
5719 | /* This is unsafe if prev insn rejects our reload reg. */ | |
5720 | && constraint_accepts_reg_p (insn_operand_constraint[recog_memoized (temp)][0], | |
5721 | reloadreg) | |
5722 | /* This is unsafe if operand occurs more than once in current | |
5723 | insn. Perhaps some occurrences aren't reloaded. */ | |
5724 | && count_occurrences (PATTERN (insn), old) == 1 | |
5725 | /* Don't risk splitting a matching pair of operands. */ | |
5726 | && ! reg_mentioned_p (old, SET_SRC (PATTERN (temp)))) | |
5727 | { | |
5728 | /* Store into the reload register instead of the pseudo. */ | |
5729 | SET_DEST (PATTERN (temp)) = reloadreg; | |
5730 | /* If these are the only uses of the pseudo reg, | |
5731 | pretend for GDB it lives in the reload reg we used. */ | |
5732 | if (reg_n_deaths[REGNO (old)] == 1 | |
5733 | && reg_n_sets[REGNO (old)] == 1) | |
5734 | { | |
5735 | reg_renumber[REGNO (old)] = REGNO (reload_reg_rtx[j]); | |
5736 | alter_reg (REGNO (old), -1); | |
5737 | } | |
5738 | special = 1; | |
5739 | } | |
5740 | } | |
5741 | ||
5742 | /* We can't do that, so output an insn to load RELOADREG. */ | |
5743 | ||
5744 | if (! special) | |
5745 | { | |
5746 | #ifdef SECONDARY_INPUT_RELOAD_CLASS | |
5747 | rtx second_reload_reg = 0; | |
5748 | enum insn_code icode; | |
5749 | ||
5750 | /* If we have a secondary reload, pick up the secondary register | |
5751 | and icode, if any. If OLDEQUIV and OLD are different or | |
5752 | if this is an in-out reload, recompute whether or not we | |
5753 | still need a secondary register and what the icode should | |
5754 | be. If we still need a secondary register and the class or | |
5755 | icode is different, go back to reloading from OLD if using | |
5756 | OLDEQUIV means that we got the wrong type of register. We | |
5757 | cannot have different class or icode due to an in-out reload | |
5758 | because we don't make such reloads when both the input and | |
5759 | output need secondary reload registers. */ | |
5760 | ||
5761 | if (reload_secondary_in_reload[j] >= 0) | |
5762 | { | |
5763 | int secondary_reload = reload_secondary_in_reload[j]; | |
5764 | rtx real_oldequiv = oldequiv; | |
5765 | rtx real_old = old; | |
5766 | ||
5767 | /* If OLDEQUIV is a pseudo with a MEM, get the real MEM | |
5768 | and similarly for OLD. | |
5769 | See comments in get_secondary_reload in reload.c. */ | |
5770 | if (GET_CODE (oldequiv) == REG | |
5771 | && REGNO (oldequiv) >= FIRST_PSEUDO_REGISTER | |
5772 | && reg_equiv_mem[REGNO (oldequiv)] != 0) | |
5773 | real_oldequiv = reg_equiv_mem[REGNO (oldequiv)]; | |
5774 | ||
5775 | if (GET_CODE (old) == REG | |
5776 | && REGNO (old) >= FIRST_PSEUDO_REGISTER | |
5777 | && reg_equiv_mem[REGNO (old)] != 0) | |
5778 | real_old = reg_equiv_mem[REGNO (old)]; | |
5779 | ||
5780 | second_reload_reg = reload_reg_rtx[secondary_reload]; | |
5781 | icode = reload_secondary_in_icode[j]; | |
5782 | ||
5783 | if ((old != oldequiv && ! rtx_equal_p (old, oldequiv)) | |
5784 | || (reload_in[j] != 0 && reload_out[j] != 0)) | |
5785 | { | |
5786 | enum reg_class new_class | |
5787 | = SECONDARY_INPUT_RELOAD_CLASS (reload_reg_class[j], | |
5788 | mode, real_oldequiv); | |
5789 | ||
5790 | if (new_class == NO_REGS) | |
5791 | second_reload_reg = 0; | |
5792 | else | |
5793 | { | |
5794 | enum insn_code new_icode; | |
5795 | enum machine_mode new_mode; | |
5796 | ||
5797 | if (! TEST_HARD_REG_BIT (reg_class_contents[(int) new_class], | |
5798 | REGNO (second_reload_reg))) | |
5799 | oldequiv = old, real_oldequiv = real_old; | |
5800 | else | |
5801 | { | |
5802 | new_icode = reload_in_optab[(int) mode]; | |
5803 | if (new_icode != CODE_FOR_nothing | |
5804 | && ((insn_operand_predicate[(int) new_icode][0] | |
5805 | && ! ((*insn_operand_predicate[(int) new_icode][0]) | |
5806 | (reloadreg, mode))) | |
5807 | || (insn_operand_predicate[(int) new_icode][1] | |
5808 | && ! ((*insn_operand_predicate[(int) new_icode][1]) | |
5809 | (real_oldequiv, mode))))) | |
5810 | new_icode = CODE_FOR_nothing; | |
5811 | ||
5812 | if (new_icode == CODE_FOR_nothing) | |
5813 | new_mode = mode; | |
5814 | else | |
5815 | new_mode = insn_operand_mode[(int) new_icode][2]; | |
5816 | ||
5817 | if (GET_MODE (second_reload_reg) != new_mode) | |
5818 | { | |
5819 | if (!HARD_REGNO_MODE_OK (REGNO (second_reload_reg), | |
5820 | new_mode)) | |
5821 | oldequiv = old, real_oldequiv = real_old; | |
5822 | else | |
5823 | second_reload_reg | |
5824 | = gen_rtx (REG, new_mode, | |
5825 | REGNO (second_reload_reg)); | |
5826 | } | |
5827 | } | |
5828 | } | |
5829 | } | |
5830 | ||
5831 | /* If we still need a secondary reload register, check | |
5832 | to see if it is being used as a scratch or intermediate | |
5833 | register and generate code appropriately. If we need | |
5834 | a scratch register, use REAL_OLDEQUIV since the form of | |
5835 | the insn may depend on the actual address if it is | |
5836 | a MEM. */ | |
5837 | ||
5838 | if (second_reload_reg) | |
5839 | { | |
5840 | if (icode != CODE_FOR_nothing) | |
5841 | { | |
5842 | emit_insn (GEN_FCN (icode) (reloadreg, real_oldequiv, | |
5843 | second_reload_reg)); | |
5844 | special = 1; | |
5845 | } | |
5846 | else | |
5847 | { | |
5848 | /* See if we need a scratch register to load the | |
5849 | intermediate register (a tertiary reload). */ | |
5850 | enum insn_code tertiary_icode | |
5851 | = reload_secondary_in_icode[secondary_reload]; | |
5852 | ||
5853 | if (tertiary_icode != CODE_FOR_nothing) | |
5854 | { | |
5855 | rtx third_reload_reg | |
5856 | = reload_reg_rtx[reload_secondary_in_reload[secondary_reload]]; | |
5857 | ||
5858 | emit_insn ((GEN_FCN (tertiary_icode) | |
5859 | (second_reload_reg, real_oldequiv, | |
5860 | third_reload_reg))); | |
5861 | } | |
5862 | else | |
5863 | gen_input_reload (second_reload_reg, oldequiv, | |
5864 | reload_opnum[j], | |
5865 | reload_when_needed[j]); | |
5866 | ||
5867 | oldequiv = second_reload_reg; | |
5868 | } | |
5869 | } | |
5870 | } | |
5871 | #endif | |
5872 | ||
5873 | if (! special && ! rtx_equal_p (reloadreg, oldequiv)) | |
5874 | gen_input_reload (reloadreg, oldequiv, reload_opnum[j], | |
5875 | reload_when_needed[j]); | |
5876 | ||
5877 | #if defined(SECONDARY_INPUT_RELOAD_CLASS) && defined(PRESERVE_DEATH_INFO_REGNO_P) | |
5878 | /* We may have to make a REG_DEAD note for the secondary reload | |
5879 | register in the insns we just made. Find the last insn that | |
5880 | mentioned the register. */ | |
5881 | if (! special && second_reload_reg | |
5882 | && PRESERVE_DEATH_INFO_REGNO_P (REGNO (second_reload_reg))) | |
5883 | { | |
5884 | rtx prev; | |
5885 | ||
5886 | for (prev = get_last_insn (); prev; | |
5887 | prev = PREV_INSN (prev)) | |
5888 | if (GET_RTX_CLASS (GET_CODE (prev) == 'i') | |
5889 | && reg_overlap_mentioned_for_reload_p (second_reload_reg, | |
5890 | PATTERN (prev))) | |
5891 | { | |
5892 | REG_NOTES (prev) = gen_rtx (EXPR_LIST, REG_DEAD, | |
5893 | second_reload_reg, | |
5894 | REG_NOTES (prev)); | |
5895 | break; | |
5896 | } | |
5897 | } | |
5898 | #endif | |
5899 | } | |
5900 | ||
5901 | /* End this sequence. */ | |
5902 | *where = get_insns (); | |
5903 | end_sequence (); | |
5904 | } | |
5905 | ||
5906 | /* Add a note saying the input reload reg | |
5907 | dies in this insn, if anyone cares. */ | |
5908 | #ifdef PRESERVE_DEATH_INFO_REGNO_P | |
5909 | if (old != 0 | |
5910 | && reload_reg_rtx[j] != old | |
5911 | && reload_reg_rtx[j] != 0 | |
5912 | && reload_out[j] == 0 | |
5913 | && ! reload_inherited[j] | |
5914 | && PRESERVE_DEATH_INFO_REGNO_P (REGNO (reload_reg_rtx[j]))) | |
5915 | { | |
5916 | register rtx reloadreg = reload_reg_rtx[j]; | |
5917 | ||
5918 | #if 0 | |
5919 | /* We can't abort here because we need to support this for sched.c. | |
5920 | It's not terrible to miss a REG_DEAD note, but we should try | |
5921 | to figure out how to do this correctly. */ | |
5922 | /* The code below is incorrect for address-only reloads. */ | |
5923 | if (reload_when_needed[j] != RELOAD_OTHER | |
5924 | && reload_when_needed[j] != RELOAD_FOR_INPUT) | |
5925 | abort (); | |
5926 | #endif | |
5927 | ||
5928 | /* Add a death note to this insn, for an input reload. */ | |
5929 | ||
5930 | if ((reload_when_needed[j] == RELOAD_OTHER | |
5931 | || reload_when_needed[j] == RELOAD_FOR_INPUT) | |
5932 | && ! dead_or_set_p (insn, reloadreg)) | |
5933 | REG_NOTES (insn) | |
5934 | = gen_rtx (EXPR_LIST, REG_DEAD, | |
5935 | reloadreg, REG_NOTES (insn)); | |
5936 | } | |
5937 | ||
5938 | /* When we inherit a reload, the last marked death of the reload reg | |
5939 | may no longer really be a death. */ | |
5940 | if (reload_reg_rtx[j] != 0 | |
5941 | && PRESERVE_DEATH_INFO_REGNO_P (REGNO (reload_reg_rtx[j])) | |
5942 | && reload_inherited[j]) | |
5943 | { | |
5944 | /* Handle inheriting an output reload. | |
5945 | Remove the death note from the output reload insn. */ | |
5946 | if (reload_spill_index[j] >= 0 | |
5947 | && GET_CODE (reload_in[j]) == REG | |
5948 | && spill_reg_store[reload_spill_index[j]] != 0 | |
5949 | && find_regno_note (spill_reg_store[reload_spill_index[j]], | |
5950 | REG_DEAD, REGNO (reload_reg_rtx[j]))) | |
5951 | remove_death (REGNO (reload_reg_rtx[j]), | |
5952 | spill_reg_store[reload_spill_index[j]]); | |
5953 | /* Likewise for input reloads that were inherited. */ | |
5954 | else if (reload_spill_index[j] >= 0 | |
5955 | && GET_CODE (reload_in[j]) == REG | |
5956 | && spill_reg_store[reload_spill_index[j]] == 0 | |
5957 | && reload_inheritance_insn[j] != 0 | |
5958 | && find_regno_note (reload_inheritance_insn[j], REG_DEAD, | |
5959 | REGNO (reload_reg_rtx[j]))) | |
5960 | remove_death (REGNO (reload_reg_rtx[j]), | |
5961 | reload_inheritance_insn[j]); | |
5962 | else | |
5963 | { | |
5964 | rtx prev; | |
5965 | ||
5966 | /* We got this register from find_equiv_reg. | |
5967 | Search back for its last death note and get rid of it. | |
5968 | But don't search back too far. | |
5969 | Don't go past a place where this reg is set, | |
5970 | since a death note before that remains valid. */ | |
5971 | for (prev = PREV_INSN (insn); | |
5972 | prev && GET_CODE (prev) != CODE_LABEL; | |
5973 | prev = PREV_INSN (prev)) | |
5974 | if (GET_RTX_CLASS (GET_CODE (prev)) == 'i' | |
5975 | && dead_or_set_p (prev, reload_reg_rtx[j])) | |
5976 | { | |
5977 | if (find_regno_note (prev, REG_DEAD, | |
5978 | REGNO (reload_reg_rtx[j]))) | |
5979 | remove_death (REGNO (reload_reg_rtx[j]), prev); | |
5980 | break; | |
5981 | } | |
5982 | } | |
5983 | } | |
5984 | ||
5985 | /* We might have used find_equiv_reg above to choose an alternate | |
5986 | place from which to reload. If so, and it died, we need to remove | |
5987 | that death and move it to one of the insns we just made. */ | |
5988 | ||
5989 | if (oldequiv_reg != 0 | |
5990 | && PRESERVE_DEATH_INFO_REGNO_P (true_regnum (oldequiv_reg))) | |
5991 | { | |
5992 | rtx prev, prev1; | |
5993 | ||
5994 | for (prev = PREV_INSN (insn); prev && GET_CODE (prev) != CODE_LABEL; | |
5995 | prev = PREV_INSN (prev)) | |
5996 | if (GET_RTX_CLASS (GET_CODE (prev)) == 'i' | |
5997 | && dead_or_set_p (prev, oldequiv_reg)) | |
5998 | { | |
5999 | if (find_regno_note (prev, REG_DEAD, REGNO (oldequiv_reg))) | |
6000 | { | |
6001 | for (prev1 = this_reload_insn; | |
6002 | prev1; prev1 = PREV_INSN (prev1)) | |
6003 | if (GET_RTX_CLASS (GET_CODE (prev1) == 'i') | |
6004 | && reg_overlap_mentioned_for_reload_p (oldequiv_reg, | |
6005 | PATTERN (prev1))) | |
6006 | { | |
6007 | REG_NOTES (prev1) = gen_rtx (EXPR_LIST, REG_DEAD, | |
6008 | oldequiv_reg, | |
6009 | REG_NOTES (prev1)); | |
6010 | break; | |
6011 | } | |
6012 | remove_death (REGNO (oldequiv_reg), prev); | |
6013 | } | |
6014 | break; | |
6015 | } | |
6016 | } | |
6017 | #endif | |
6018 | ||
6019 | /* If we are reloading a register that was recently stored in with an | |
6020 | output-reload, see if we can prove there was | |
6021 | actually no need to store the old value in it. */ | |
6022 | ||
6023 | if (optimize && reload_inherited[j] && reload_spill_index[j] >= 0 | |
6024 | && reload_in[j] != 0 | |
6025 | && GET_CODE (reload_in[j]) == REG | |
6026 | #if 0 | |
6027 | /* There doesn't seem to be any reason to restrict this to pseudos | |
6028 | and doing so loses in the case where we are copying from a | |
6029 | register of the wrong class. */ | |
6030 | && REGNO (reload_in[j]) >= FIRST_PSEUDO_REGISTER | |
6031 | #endif | |
6032 | && spill_reg_store[reload_spill_index[j]] != 0 | |
6033 | /* This is unsafe if some other reload uses the same reg first. */ | |
6034 | && reload_reg_free_before_p (spill_regs[reload_spill_index[j]], | |
6035 | reload_opnum[j], reload_when_needed[j]) | |
6036 | && dead_or_set_p (insn, reload_in[j]) | |
6037 | /* This is unsafe if operand occurs more than once in current | |
6038 | insn. Perhaps some occurrences weren't reloaded. */ | |
6039 | && count_occurrences (PATTERN (insn), reload_in[j]) == 1) | |
6040 | delete_output_reload (insn, j, | |
6041 | spill_reg_store[reload_spill_index[j]]); | |
6042 | ||
6043 | /* Input-reloading is done. Now do output-reloading, | |
6044 | storing the value from the reload-register after the main insn | |
6045 | if reload_out[j] is nonzero. | |
6046 | ||
6047 | ??? At some point we need to support handling output reloads of | |
6048 | JUMP_INSNs or insns that set cc0. */ | |
6049 | old = reload_out[j]; | |
6050 | if (old != 0 | |
6051 | && reload_reg_rtx[j] != old | |
6052 | && reload_reg_rtx[j] != 0) | |
6053 | { | |
6054 | register rtx reloadreg = reload_reg_rtx[j]; | |
6055 | register rtx second_reloadreg = 0; | |
6056 | rtx note, p; | |
6057 | enum machine_mode mode; | |
6058 | int special = 0; | |
6059 | ||
6060 | /* An output operand that dies right away does need a reload, | |
6061 | but need not be copied from it. Show the new location in the | |
6062 | REG_UNUSED note. */ | |
6063 | if ((GET_CODE (old) == REG || GET_CODE (old) == SCRATCH) | |
6064 | && (note = find_reg_note (insn, REG_UNUSED, old)) != 0) | |
6065 | { | |
6066 | XEXP (note, 0) = reload_reg_rtx[j]; | |
6067 | continue; | |
6068 | } | |
6069 | else if (GET_CODE (old) == SCRATCH) | |
6070 | /* If we aren't optimizing, there won't be a REG_UNUSED note, | |
6071 | but we don't want to make an output reload. */ | |
6072 | continue; | |
6073 | ||
6074 | #if 0 | |
6075 | /* Strip off of OLD any size-increasing SUBREGs such as | |
6076 | (SUBREG:SI foo:QI 0). */ | |
6077 | ||
6078 | while (GET_CODE (old) == SUBREG && SUBREG_WORD (old) == 0 | |
6079 | && (GET_MODE_SIZE (GET_MODE (old)) | |
6080 | > GET_MODE_SIZE (GET_MODE (SUBREG_REG (old))))) | |
6081 | old = SUBREG_REG (old); | |
6082 | #endif | |
6083 | ||
6084 | /* If is a JUMP_INSN, we can't support output reloads yet. */ | |
6085 | if (GET_CODE (insn) == JUMP_INSN) | |
6086 | abort (); | |
6087 | ||
6088 | push_to_sequence (output_reload_insns[reload_opnum[j]]); | |
6089 | ||
6090 | /* Determine the mode to reload in. | |
6091 | See comments above (for input reloading). */ | |
6092 | ||
6093 | mode = GET_MODE (old); | |
6094 | if (mode == VOIDmode) | |
6095 | { | |
6096 | /* VOIDmode should never happen for an output. */ | |
6097 | if (asm_noperands (PATTERN (insn)) < 0) | |
6098 | /* It's the compiler's fault. */ | |
6099 | abort (); | |
6100 | error_for_asm (insn, "output operand is constant in `asm'"); | |
6101 | /* Prevent crash--use something we know is valid. */ | |
6102 | mode = word_mode; | |
6103 | old = gen_rtx (REG, mode, REGNO (reloadreg)); | |
6104 | } | |
6105 | ||
6106 | if (GET_MODE (reloadreg) != mode) | |
6107 | reloadreg = gen_rtx (REG, mode, REGNO (reloadreg)); | |
6108 | ||
6109 | #ifdef SECONDARY_OUTPUT_RELOAD_CLASS | |
6110 | ||
6111 | /* If we need two reload regs, set RELOADREG to the intermediate | |
6112 | one, since it will be stored into OUT. We might need a secondary | |
6113 | register only for an input reload, so check again here. */ | |
6114 | ||
6115 | if (reload_secondary_out_reload[j] >= 0) | |
6116 | { | |
6117 | rtx real_old = old; | |
6118 | ||
6119 | if (GET_CODE (old) == REG && REGNO (old) >= FIRST_PSEUDO_REGISTER | |
6120 | && reg_equiv_mem[REGNO (old)] != 0) | |
6121 | real_old = reg_equiv_mem[REGNO (old)]; | |
6122 | ||
6123 | if((SECONDARY_OUTPUT_RELOAD_CLASS (reload_reg_class[j], | |
6124 | mode, real_old) | |
6125 | != NO_REGS)) | |
6126 | { | |
6127 | second_reloadreg = reloadreg; | |
6128 | reloadreg = reload_reg_rtx[reload_secondary_out_reload[j]]; | |
6129 | ||
6130 | /* See if RELOADREG is to be used as a scratch register | |
6131 | or as an intermediate register. */ | |
6132 | if (reload_secondary_out_icode[j] != CODE_FOR_nothing) | |
6133 | { | |
6134 | emit_insn ((GEN_FCN (reload_secondary_out_icode[j]) | |
6135 | (real_old, second_reloadreg, reloadreg))); | |
6136 | special = 1; | |
6137 | } | |
6138 | else | |
6139 | { | |
6140 | /* See if we need both a scratch and intermediate reload | |
6141 | register. */ | |
6142 | int secondary_reload = reload_secondary_out_reload[j]; | |
6143 | enum insn_code tertiary_icode | |
6144 | = reload_secondary_out_icode[secondary_reload]; | |
6145 | rtx pat; | |
6146 | ||
6147 | if (GET_MODE (reloadreg) != mode) | |
6148 | reloadreg = gen_rtx (REG, mode, REGNO (reloadreg)); | |
6149 | ||
6150 | if (tertiary_icode != CODE_FOR_nothing) | |
6151 | { | |
6152 | rtx third_reloadreg | |
6153 | = reload_reg_rtx[reload_secondary_out_reload[secondary_reload]]; | |
6154 | pat = (GEN_FCN (tertiary_icode) | |
6155 | (reloadreg, second_reloadreg, third_reloadreg)); | |
6156 | } | |
6157 | #ifdef SECONDARY_MEMORY_NEEDED | |
6158 | /* If we need a memory location to do the move, do it that way. */ | |
6159 | else if (GET_CODE (reloadreg) == REG | |
6160 | && REGNO (reloadreg) < FIRST_PSEUDO_REGISTER | |
6161 | && SECONDARY_MEMORY_NEEDED (REGNO_REG_CLASS (REGNO (reloadreg)), | |
6162 | REGNO_REG_CLASS (REGNO (second_reloadreg)), | |
6163 | GET_MODE (second_reloadreg))) | |
6164 | { | |
6165 | /* Get the memory to use and rewrite both registers | |
6166 | to its mode. */ | |
6167 | rtx loc | |
6168 | = get_secondary_mem (reloadreg, | |
6169 | GET_MODE (second_reloadreg), | |
6170 | reload_opnum[j], | |
6171 | reload_when_needed[j]); | |
6172 | rtx tmp_reloadreg; | |
6173 | ||
6174 | if (GET_MODE (loc) != GET_MODE (second_reloadreg)) | |
6175 | second_reloadreg = gen_rtx (REG, GET_MODE (loc), | |
6176 | REGNO (second_reloadreg)); | |
6177 | ||
6178 | if (GET_MODE (loc) != GET_MODE (reloadreg)) | |
6179 | tmp_reloadreg = gen_rtx (REG, GET_MODE (loc), | |
6180 | REGNO (reloadreg)); | |
6181 | else | |
6182 | tmp_reloadreg = reloadreg; | |
6183 | ||
6184 | emit_move_insn (loc, second_reloadreg); | |
6185 | pat = gen_move_insn (tmp_reloadreg, loc); | |
6186 | } | |
6187 | #endif | |
6188 | else | |
6189 | pat = gen_move_insn (reloadreg, second_reloadreg); | |
6190 | ||
6191 | emit_insn (pat); | |
6192 | } | |
6193 | } | |
6194 | } | |
6195 | #endif | |
6196 | ||
6197 | /* Output the last reload insn. */ | |
6198 | if (! special) | |
6199 | { | |
6200 | #ifdef SECONDARY_MEMORY_NEEDED | |
6201 | /* If we need a memory location to do the move, do it that way. */ | |
6202 | if (GET_CODE (old) == REG && REGNO (old) < FIRST_PSEUDO_REGISTER | |
6203 | && SECONDARY_MEMORY_NEEDED (REGNO_REG_CLASS (REGNO (old)), | |
6204 | REGNO_REG_CLASS (REGNO (reloadreg)), | |
6205 | GET_MODE (reloadreg))) | |
6206 | { | |
6207 | /* Get the memory to use and rewrite both registers to | |
6208 | its mode. */ | |
6209 | rtx loc = get_secondary_mem (old, GET_MODE (reloadreg), | |
6210 | reload_opnum[j], | |
6211 | reload_when_needed[j]); | |
6212 | ||
6213 | if (GET_MODE (loc) != GET_MODE (reloadreg)) | |
6214 | reloadreg = gen_rtx (REG, GET_MODE (loc), | |
6215 | REGNO (reloadreg)); | |
6216 | ||
6217 | if (GET_MODE (loc) != GET_MODE (old)) | |
6218 | old = gen_rtx (REG, GET_MODE (loc), REGNO (old)); | |
6219 | ||
6220 | emit_insn (gen_move_insn (loc, reloadreg)); | |
6221 | emit_insn (gen_move_insn (old, loc)); | |
6222 | } | |
6223 | else | |
6224 | #endif | |
6225 | emit_insn (gen_move_insn (old, reloadreg)); | |
6226 | } | |
6227 | ||
6228 | #ifdef PRESERVE_DEATH_INFO_REGNO_P | |
6229 | /* If final will look at death notes for this reg, | |
6230 | put one on the last output-reload insn to use it. Similarly | |
6231 | for any secondary register. */ | |
6232 | if (PRESERVE_DEATH_INFO_REGNO_P (REGNO (reloadreg))) | |
6233 | for (p = get_last_insn (); p; p = PREV_INSN (p)) | |
6234 | if (GET_RTX_CLASS (GET_CODE (p)) == 'i' | |
6235 | && reg_overlap_mentioned_for_reload_p (reloadreg, | |
6236 | PATTERN (p))) | |
6237 | REG_NOTES (p) = gen_rtx (EXPR_LIST, REG_DEAD, | |
6238 | reloadreg, REG_NOTES (p)); | |
6239 | ||
6240 | #ifdef SECONDARY_OUTPUT_RELOAD_CLASS | |
6241 | if (! special | |
6242 | && PRESERVE_DEATH_INFO_REGNO_P (REGNO (second_reloadreg))) | |
6243 | for (p = get_last_insn (); p; p = PREV_INSN (p)) | |
6244 | if (GET_RTX_CLASS (GET_CODE (p)) == 'i' | |
6245 | && reg_overlap_mentioned_for_reload_p (second_reloadreg, | |
6246 | PATTERN (p))) | |
6247 | REG_NOTES (p) = gen_rtx (EXPR_LIST, REG_DEAD, | |
6248 | second_reloadreg, REG_NOTES (p)); | |
6249 | #endif | |
6250 | #endif | |
6251 | /* Look at all insns we emitted, just to be safe. */ | |
6252 | for (p = get_insns (); p; p = NEXT_INSN (p)) | |
6253 | if (GET_RTX_CLASS (GET_CODE (p)) == 'i') | |
6254 | { | |
6255 | /* If this output reload doesn't come from a spill reg, | |
6256 | clear any memory of reloaded copies of the pseudo reg. | |
6257 | If this output reload comes from a spill reg, | |
6258 | reg_has_output_reload will make this do nothing. */ | |
6259 | note_stores (PATTERN (p), forget_old_reloads_1); | |
6260 | ||
6261 | if (reg_mentioned_p (reload_reg_rtx[j], PATTERN (p))) | |
6262 | store_insn = p; | |
6263 | } | |
6264 | ||
6265 | output_reload_insns[reload_opnum[j]] = get_insns (); | |
6266 | end_sequence (); | |
6267 | ||
6268 | } | |
6269 | ||
6270 | if (reload_spill_index[j] >= 0) | |
6271 | new_spill_reg_store[reload_spill_index[j]] = store_insn; | |
6272 | } | |
6273 | ||
6274 | /* Now write all the insns we made for reloads in the order expected by | |
6275 | the allocation functions. Prior to the insn being reloaded, we write | |
6276 | the following reloads: | |
6277 | ||
6278 | RELOAD_FOR_OTHER_ADDRESS reloads for input addresses. | |
6279 | ||
6280 | RELOAD_OTHER reloads. | |
6281 | ||
6282 | For each operand, any RELOAD_FOR_INPUT_ADDRESS reloads followed by | |
6283 | the RELOAD_FOR_INPUT reload for the operand. | |
6284 | ||
6285 | RELOAD_FOR_OPERAND_ADDRESS reloads. | |
6286 | ||
6287 | After the insn being reloaded, we write the following: | |
6288 | ||
6289 | For each operand, any RELOAD_FOR_OUTPUT_ADDRESS reload followed by | |
6290 | the RELOAD_FOR_OUTPUT reload for that operand. */ | |
6291 | ||
6292 | emit_insns_before (other_input_address_reload_insns, before_insn); | |
6293 | emit_insns_before (other_input_reload_insns, before_insn); | |
6294 | ||
6295 | for (j = 0; j < reload_n_operands; j++) | |
6296 | { | |
6297 | emit_insns_before (input_address_reload_insns[j], before_insn); | |
6298 | emit_insns_before (input_reload_insns[j], before_insn); | |
6299 | } | |
6300 | ||
6301 | emit_insns_before (operand_reload_insns, before_insn); | |
6302 | ||
6303 | for (j = 0; j < reload_n_operands; j++) | |
6304 | { | |
6305 | emit_insns_before (output_address_reload_insns[j], following_insn); | |
6306 | emit_insns_before (output_reload_insns[j], following_insn); | |
6307 | } | |
6308 | ||
6309 | /* Move death notes from INSN | |
6310 | to output-operand-address and output reload insns. */ | |
6311 | #ifdef PRESERVE_DEATH_INFO_REGNO_P | |
6312 | { | |
6313 | rtx insn1; | |
6314 | /* Loop over those insns, last ones first. */ | |
6315 | for (insn1 = PREV_INSN (following_insn); insn1 != insn; | |
6316 | insn1 = PREV_INSN (insn1)) | |
6317 | if (GET_CODE (insn1) == INSN && GET_CODE (PATTERN (insn1)) == SET) | |
6318 | { | |
6319 | rtx source = SET_SRC (PATTERN (insn1)); | |
6320 | rtx dest = SET_DEST (PATTERN (insn1)); | |
6321 | ||
6322 | /* The note we will examine next. */ | |
6323 | rtx reg_notes = REG_NOTES (insn); | |
6324 | /* The place that pointed to this note. */ | |
6325 | rtx *prev_reg_note = ®_NOTES (insn); | |
6326 | ||
6327 | /* If the note is for something used in the source of this | |
6328 | reload insn, or in the output address, move the note. */ | |
6329 | while (reg_notes) | |
6330 | { | |
6331 | rtx next_reg_notes = XEXP (reg_notes, 1); | |
6332 | if (REG_NOTE_KIND (reg_notes) == REG_DEAD | |
6333 | && GET_CODE (XEXP (reg_notes, 0)) == REG | |
6334 | && ((GET_CODE (dest) != REG | |
6335 | && reg_overlap_mentioned_for_reload_p (XEXP (reg_notes, 0), | |
6336 | dest)) | |
6337 | || reg_overlap_mentioned_for_reload_p (XEXP (reg_notes, 0), | |
6338 | source))) | |
6339 | { | |
6340 | *prev_reg_note = next_reg_notes; | |
6341 | XEXP (reg_notes, 1) = REG_NOTES (insn1); | |
6342 | REG_NOTES (insn1) = reg_notes; | |
6343 | } | |
6344 | else | |
6345 | prev_reg_note = &XEXP (reg_notes, 1); | |
6346 | ||
6347 | reg_notes = next_reg_notes; | |
6348 | } | |
6349 | } | |
6350 | } | |
6351 | #endif | |
6352 | ||
6353 | /* For all the spill regs newly reloaded in this instruction, | |
6354 | record what they were reloaded from, so subsequent instructions | |
6355 | can inherit the reloads. | |
6356 | ||
6357 | Update spill_reg_store for the reloads of this insn. | |
6358 | Copy the elements that were updated in the loop above. */ | |
6359 | ||
6360 | for (j = 0; j < n_reloads; j++) | |
6361 | { | |
6362 | register int r = reload_order[j]; | |
6363 | register int i = reload_spill_index[r]; | |
6364 | ||
6365 | /* I is nonneg if this reload used one of the spill regs. | |
6366 | If reload_reg_rtx[r] is 0, this is an optional reload | |
6367 | that we opted to ignore. | |
6368 | ||
6369 | Also ignore reloads that don't reach the end of the insn, | |
6370 | since we will eventually see the one that does. */ | |
6371 | ||
6372 | if (i >= 0 && reload_reg_rtx[r] != 0 | |
6373 | && reload_reg_reaches_end_p (spill_regs[i], reload_opnum[r], | |
6374 | reload_when_needed[r])) | |
6375 | { | |
6376 | /* First, clear out memory of what used to be in this spill reg. | |
6377 | If consecutive registers are used, clear them all. */ | |
6378 | int nr | |
6379 | = HARD_REGNO_NREGS (spill_regs[i], GET_MODE (reload_reg_rtx[r])); | |
6380 | int k; | |
6381 | ||
6382 | for (k = 0; k < nr; k++) | |
6383 | { | |
6384 | reg_reloaded_contents[spill_reg_order[spill_regs[i] + k]] = -1; | |
6385 | reg_reloaded_insn[spill_reg_order[spill_regs[i] + k]] = 0; | |
6386 | } | |
6387 | ||
6388 | /* Maybe the spill reg contains a copy of reload_out. */ | |
6389 | if (reload_out[r] != 0 && GET_CODE (reload_out[r]) == REG) | |
6390 | { | |
6391 | register int nregno = REGNO (reload_out[r]); | |
6392 | int nnr = (nregno >= FIRST_PSEUDO_REGISTER ? 1 | |
6393 | : HARD_REGNO_NREGS (nregno, | |
6394 | GET_MODE (reload_reg_rtx[r]))); | |
6395 | ||
6396 | spill_reg_store[i] = new_spill_reg_store[i]; | |
6397 | reg_last_reload_reg[nregno] = reload_reg_rtx[r]; | |
6398 | ||
6399 | /* If NREGNO is a hard register, it may occupy more than | |
6400 | one register. If it does, say what is in the | |
6401 | rest of the registers assuming that both registers | |
6402 | agree on how many words the object takes. If not, | |
6403 | invalidate the subsequent registers. */ | |
6404 | ||
6405 | if (nregno < FIRST_PSEUDO_REGISTER) | |
6406 | for (k = 1; k < nnr; k++) | |
6407 | reg_last_reload_reg[nregno + k] | |
6408 | = (nr == nnr ? gen_rtx (REG, | |
6409 | reg_raw_mode[REGNO (reload_reg_rtx[r]) + k], | |
6410 | REGNO (reload_reg_rtx[r]) + k) | |
6411 | : 0); | |
6412 | ||
6413 | /* Now do the inverse operation. */ | |
6414 | for (k = 0; k < nr; k++) | |
6415 | { | |
6416 | reg_reloaded_contents[spill_reg_order[spill_regs[i] + k]] | |
6417 | = (nregno >= FIRST_PSEUDO_REGISTER || nr != nnr ? nregno | |
6418 | : nregno + k); | |
6419 | reg_reloaded_insn[spill_reg_order[spill_regs[i] + k]] = insn; | |
6420 | } | |
6421 | } | |
6422 | ||
6423 | /* Maybe the spill reg contains a copy of reload_in. Only do | |
6424 | something if there will not be an output reload for | |
6425 | the register being reloaded. */ | |
6426 | else if (reload_out[r] == 0 | |
6427 | && reload_in[r] != 0 | |
6428 | && ((GET_CODE (reload_in[r]) == REG | |
6429 | && ! reg_has_output_reload[REGNO (reload_in[r])] | |
6430 | || (GET_CODE (reload_in_reg[r]) == REG | |
6431 | && ! reg_has_output_reload[REGNO (reload_in_reg[r])])))) | |
6432 | { | |
6433 | register int nregno; | |
6434 | int nnr; | |
6435 | ||
6436 | if (GET_CODE (reload_in[r]) == REG) | |
6437 | nregno = REGNO (reload_in[r]); | |
6438 | else | |
6439 | nregno = REGNO (reload_in_reg[r]); | |
6440 | ||
6441 | nnr = (nregno >= FIRST_PSEUDO_REGISTER ? 1 | |
6442 | : HARD_REGNO_NREGS (nregno, | |
6443 | GET_MODE (reload_reg_rtx[r]))); | |
6444 | ||
6445 | reg_last_reload_reg[nregno] = reload_reg_rtx[r]; | |
6446 | ||
6447 | if (nregno < FIRST_PSEUDO_REGISTER) | |
6448 | for (k = 1; k < nnr; k++) | |
6449 | reg_last_reload_reg[nregno + k] | |
6450 | = (nr == nnr ? gen_rtx (REG, | |
6451 | reg_raw_mode[REGNO (reload_reg_rtx[r]) + k], | |
6452 | REGNO (reload_reg_rtx[r]) + k) | |
6453 | : 0); | |
6454 | ||
6455 | /* Unless we inherited this reload, show we haven't | |
6456 | recently done a store. */ | |
6457 | if (! reload_inherited[r]) | |
6458 | spill_reg_store[i] = 0; | |
6459 | ||
6460 | for (k = 0; k < nr; k++) | |
6461 | { | |
6462 | reg_reloaded_contents[spill_reg_order[spill_regs[i] + k]] | |
6463 | = (nregno >= FIRST_PSEUDO_REGISTER || nr != nnr ? nregno | |
6464 | : nregno + k); | |
6465 | reg_reloaded_insn[spill_reg_order[spill_regs[i] + k]] | |
6466 | = insn; | |
6467 | } | |
6468 | } | |
6469 | } | |
6470 | ||
6471 | /* The following if-statement was #if 0'd in 1.34 (or before...). | |
6472 | It's reenabled in 1.35 because supposedly nothing else | |
6473 | deals with this problem. */ | |
6474 | ||
6475 | /* If a register gets output-reloaded from a non-spill register, | |
6476 | that invalidates any previous reloaded copy of it. | |
6477 | But forget_old_reloads_1 won't get to see it, because | |
6478 | it thinks only about the original insn. So invalidate it here. */ | |
6479 | if (i < 0 && reload_out[r] != 0 && GET_CODE (reload_out[r]) == REG) | |
6480 | { | |
6481 | register int nregno = REGNO (reload_out[r]); | |
6482 | int num_regs = HARD_REGNO_NREGS (nregno, GET_MODE (reload_out[r])); | |
6483 | ||
6484 | while (num_regs-- > 0) | |
6485 | reg_last_reload_reg[nregno + num_regs] = 0; | |
6486 | } | |
6487 | } | |
6488 | } | |
6489 | \f | |
6490 | /* Emit code to perform an input reload of IN to RELOADREG. IN is from | |
6491 | operand OPNUM with reload type TYPE. | |
6492 | ||
6493 | Returns first insn emitted. */ | |
6494 | ||
6495 | rtx | |
6496 | gen_input_reload (reloadreg, in, opnum, type) | |
6497 | rtx reloadreg; | |
6498 | rtx in; | |
6499 | int opnum; | |
6500 | enum reload_type type; | |
6501 | { | |
6502 | rtx last = get_last_insn (); | |
6503 | ||
6504 | /* How to do this reload can get quite tricky. Normally, we are being | |
6505 | asked to reload a simple operand, such as a MEM, a constant, or a pseudo | |
6506 | register that didn't get a hard register. In that case we can just | |
6507 | call emit_move_insn. | |
6508 | ||
6509 | We can also be asked to reload a PLUS that adds a register or a MEM to | |
6510 | another register, constant or MEM. This can occur during frame pointer | |
6511 | elimination and while reloading addresses. This case is handled by | |
6512 | trying to emit a single insn to perform the add. If it is not valid, | |
6513 | we use a two insn sequence. | |
6514 | ||
6515 | Finally, we could be called to handle an 'o' constraint by putting | |
6516 | an address into a register. In that case, we first try to do this | |
6517 | with a named pattern of "reload_load_address". If no such pattern | |
6518 | exists, we just emit a SET insn and hope for the best (it will normally | |
6519 | be valid on machines that use 'o'). | |
6520 | ||
6521 | This entire process is made complex because reload will never | |
6522 | process the insns we generate here and so we must ensure that | |
6523 | they will fit their constraints and also by the fact that parts of | |
6524 | IN might be being reloaded separately and replaced with spill registers. | |
6525 | Because of this, we are, in some sense, just guessing the right approach | |
6526 | here. The one listed above seems to work. | |
6527 | ||
6528 | ??? At some point, this whole thing needs to be rethought. */ | |
6529 | ||
6530 | if (GET_CODE (in) == PLUS | |
6531 | && (GET_CODE (XEXP (in, 0)) == REG | |
6532 | || GET_CODE (XEXP (in, 0)) == MEM) | |
6533 | && (GET_CODE (XEXP (in, 1)) == REG | |
6534 | || CONSTANT_P (XEXP (in, 1)) | |
6535 | || GET_CODE (XEXP (in, 1)) == MEM)) | |
6536 | { | |
6537 | /* We need to compute the sum of a register or a MEM and another | |
6538 | register, constant, or MEM, and put it into the reload | |
6539 | register. The best possible way of doing this is if the machine | |
6540 | has a three-operand ADD insn that accepts the required operands. | |
6541 | ||
6542 | The simplest approach is to try to generate such an insn and see if it | |
6543 | is recognized and matches its constraints. If so, it can be used. | |
6544 | ||
6545 | It might be better not to actually emit the insn unless it is valid, | |
6546 | but we need to pass the insn as an operand to `recog' and | |
6547 | `insn_extract' and it is simpler to emit and then delete the insn if | |
6548 | not valid than to dummy things up. */ | |
6549 | ||
6550 | rtx op0, op1, tem, insn; | |
6551 | int code; | |
6552 | ||
6553 | op0 = find_replacement (&XEXP (in, 0)); | |
6554 | op1 = find_replacement (&XEXP (in, 1)); | |
6555 | ||
6556 | /* Since constraint checking is strict, commutativity won't be | |
6557 | checked, so we need to do that here to avoid spurious failure | |
6558 | if the add instruction is two-address and the second operand | |
6559 | of the add is the same as the reload reg, which is frequently | |
6560 | the case. If the insn would be A = B + A, rearrange it so | |
6561 | it will be A = A + B as constrain_operands expects. */ | |
6562 | ||
6563 | if (GET_CODE (XEXP (in, 1)) == REG | |
6564 | && REGNO (reloadreg) == REGNO (XEXP (in, 1))) | |
6565 | tem = op0, op0 = op1, op1 = tem; | |
6566 | ||
6567 | if (op0 != XEXP (in, 0) || op1 != XEXP (in, 1)) | |
6568 | in = gen_rtx (PLUS, GET_MODE (in), op0, op1); | |
6569 | ||
6570 | insn = emit_insn (gen_rtx (SET, VOIDmode, reloadreg, in)); | |
6571 | code = recog_memoized (insn); | |
6572 | ||
6573 | if (code >= 0) | |
6574 | { | |
6575 | insn_extract (insn); | |
6576 | /* We want constrain operands to treat this insn strictly in | |
6577 | its validity determination, i.e., the way it would after reload | |
6578 | has completed. */ | |
6579 | if (constrain_operands (code, 1)) | |
6580 | return insn; | |
6581 | } | |
6582 | ||
6583 | delete_insns_since (last); | |
6584 | ||
6585 | /* If that failed, we must use a conservative two-insn sequence. | |
6586 | use move to copy constant, MEM, or pseudo register to the reload | |
6587 | register since "move" will be able to handle an arbitrary operand, | |
6588 | unlike add which can't, in general. Then add the registers. | |
6589 | ||
6590 | If there is another way to do this for a specific machine, a | |
6591 | DEFINE_PEEPHOLE should be specified that recognizes the sequence | |
6592 | we emit below. */ | |
6593 | ||
6594 | if (CONSTANT_P (op1) || GET_CODE (op1) == MEM | |
6595 | || (GET_CODE (op1) == REG | |
6596 | && REGNO (op1) >= FIRST_PSEUDO_REGISTER)) | |
6597 | tem = op0, op0 = op1, op1 = tem; | |
6598 | ||
6599 | emit_insn (gen_move_insn (reloadreg, op0)); | |
6600 | ||
6601 | /* If OP0 and OP1 are the same, we can use RELOADREG for OP1. | |
6602 | This fixes a problem on the 32K where the stack pointer cannot | |
6603 | be used as an operand of an add insn. */ | |
6604 | ||
6605 | if (rtx_equal_p (op0, op1)) | |
6606 | op1 = reloadreg; | |
6607 | ||
6608 | insn = emit_insn (gen_add2_insn (reloadreg, op1)); | |
6609 | ||
6610 | /* If that failed, copy the address register to the reload register. | |
6611 | Then add the constant to the reload register. */ | |
6612 | ||
6613 | code = recog_memoized (insn); | |
6614 | ||
6615 | if (code >= 0) | |
6616 | { | |
6617 | insn_extract (insn); | |
6618 | /* We want constrain operands to treat this insn strictly in | |
6619 | its validity determination, i.e., the way it would after reload | |
6620 | has completed. */ | |
6621 | if (constrain_operands (code, 1)) | |
6622 | return insn; | |
6623 | } | |
6624 | ||
6625 | delete_insns_since (last); | |
6626 | ||
6627 | emit_insn (gen_move_insn (reloadreg, op1)); | |
6628 | emit_insn (gen_add2_insn (reloadreg, op0)); | |
6629 | } | |
6630 | ||
6631 | #ifdef SECONDARY_MEMORY_NEEDED | |
6632 | /* If we need a memory location to do the move, do it that way. */ | |
6633 | else if (GET_CODE (in) == REG && REGNO (in) < FIRST_PSEUDO_REGISTER | |
6634 | && SECONDARY_MEMORY_NEEDED (REGNO_REG_CLASS (REGNO (in)), | |
6635 | REGNO_REG_CLASS (REGNO (reloadreg)), | |
6636 | GET_MODE (reloadreg))) | |
6637 | { | |
6638 | /* Get the memory to use and rewrite both registers to its mode. */ | |
6639 | rtx loc = get_secondary_mem (in, GET_MODE (reloadreg), opnum, type); | |
6640 | ||
6641 | if (GET_MODE (loc) != GET_MODE (reloadreg)) | |
6642 | reloadreg = gen_rtx (REG, GET_MODE (loc), REGNO (reloadreg)); | |
6643 | ||
6644 | if (GET_MODE (loc) != GET_MODE (in)) | |
6645 | in = gen_rtx (REG, GET_MODE (loc), REGNO (in)); | |
6646 | ||
6647 | emit_insn (gen_move_insn (loc, in)); | |
6648 | emit_insn (gen_move_insn (reloadreg, loc)); | |
6649 | } | |
6650 | #endif | |
6651 | ||
6652 | /* If IN is a simple operand, use gen_move_insn. */ | |
6653 | else if (GET_RTX_CLASS (GET_CODE (in)) == 'o' || GET_CODE (in) == SUBREG) | |
6654 | emit_insn (gen_move_insn (reloadreg, in)); | |
6655 | ||
6656 | #ifdef HAVE_reload_load_address | |
6657 | else if (HAVE_reload_load_address) | |
6658 | emit_insn (gen_reload_load_address (reloadreg, in)); | |
6659 | #endif | |
6660 | ||
6661 | /* Otherwise, just write (set REGLOADREG IN) and hope for the best. */ | |
6662 | else | |
6663 | emit_insn (gen_rtx (SET, VOIDmode, reloadreg, in)); | |
6664 | ||
6665 | /* Return the first insn emitted. | |
6666 | We can not just return get_last_insn, because there may have | |
6667 | been multiple instructions emitted. Also note that gen_move_insn may | |
6668 | emit more than one insn itself, so we can not assume that there is one | |
6669 | insn emitted per emit_insn_before call. */ | |
6670 | ||
6671 | return last ? NEXT_INSN (last) : get_insns (); | |
6672 | } | |
6673 | \f | |
6674 | /* Delete a previously made output-reload | |
6675 | whose result we now believe is not needed. | |
6676 | First we double-check. | |
6677 | ||
6678 | INSN is the insn now being processed. | |
6679 | OUTPUT_RELOAD_INSN is the insn of the output reload. | |
6680 | J is the reload-number for this insn. */ | |
6681 | ||
6682 | static void | |
6683 | delete_output_reload (insn, j, output_reload_insn) | |
6684 | rtx insn; | |
6685 | int j; | |
6686 | rtx output_reload_insn; | |
6687 | { | |
6688 | register rtx i1; | |
6689 | ||
6690 | /* Get the raw pseudo-register referred to. */ | |
6691 | ||
6692 | rtx reg = reload_in[j]; | |
6693 | while (GET_CODE (reg) == SUBREG) | |
6694 | reg = SUBREG_REG (reg); | |
6695 | ||
6696 | /* If the pseudo-reg we are reloading is no longer referenced | |
6697 | anywhere between the store into it and here, | |
6698 | and no jumps or labels intervene, then the value can get | |
6699 | here through the reload reg alone. | |
6700 | Otherwise, give up--return. */ | |
6701 | for (i1 = NEXT_INSN (output_reload_insn); | |
6702 | i1 != insn; i1 = NEXT_INSN (i1)) | |
6703 | { | |
6704 | if (GET_CODE (i1) == CODE_LABEL || GET_CODE (i1) == JUMP_INSN) | |
6705 | return; | |
6706 | if ((GET_CODE (i1) == INSN || GET_CODE (i1) == CALL_INSN) | |
6707 | && reg_mentioned_p (reg, PATTERN (i1))) | |
6708 | return; | |
6709 | } | |
6710 | ||
6711 | if (cannot_omit_stores[REGNO (reg)]) | |
6712 | return; | |
6713 | ||
6714 | /* If this insn will store in the pseudo again, | |
6715 | the previous store can be removed. */ | |
6716 | if (reload_out[j] == reload_in[j]) | |
6717 | delete_insn (output_reload_insn); | |
6718 | ||
6719 | /* See if the pseudo reg has been completely replaced | |
6720 | with reload regs. If so, delete the store insn | |
6721 | and forget we had a stack slot for the pseudo. */ | |
6722 | else if (reg_n_deaths[REGNO (reg)] == 1 | |
6723 | && reg_basic_block[REGNO (reg)] >= 0 | |
6724 | && find_regno_note (insn, REG_DEAD, REGNO (reg))) | |
6725 | { | |
6726 | rtx i2; | |
6727 | ||
6728 | /* We know that it was used only between here | |
6729 | and the beginning of the current basic block. | |
6730 | (We also know that the last use before INSN was | |
6731 | the output reload we are thinking of deleting, but never mind that.) | |
6732 | Search that range; see if any ref remains. */ | |
6733 | for (i2 = PREV_INSN (insn); i2; i2 = PREV_INSN (i2)) | |
6734 | { | |
6735 | rtx set = single_set (i2); | |
6736 | ||
6737 | /* Uses which just store in the pseudo don't count, | |
6738 | since if they are the only uses, they are dead. */ | |
6739 | if (set != 0 && SET_DEST (set) == reg) | |
6740 | continue; | |
6741 | if (GET_CODE (i2) == CODE_LABEL | |
6742 | || GET_CODE (i2) == JUMP_INSN) | |
6743 | break; | |
6744 | if ((GET_CODE (i2) == INSN || GET_CODE (i2) == CALL_INSN) | |
6745 | && reg_mentioned_p (reg, PATTERN (i2))) | |
6746 | /* Some other ref remains; | |
6747 | we can't do anything. */ | |
6748 | return; | |
6749 | } | |
6750 | ||
6751 | /* Delete the now-dead stores into this pseudo. */ | |
6752 | for (i2 = PREV_INSN (insn); i2; i2 = PREV_INSN (i2)) | |
6753 | { | |
6754 | rtx set = single_set (i2); | |
6755 | ||
6756 | if (set != 0 && SET_DEST (set) == reg) | |
6757 | delete_insn (i2); | |
6758 | if (GET_CODE (i2) == CODE_LABEL | |
6759 | || GET_CODE (i2) == JUMP_INSN) | |
6760 | break; | |
6761 | } | |
6762 | ||
6763 | /* For the debugging info, | |
6764 | say the pseudo lives in this reload reg. */ | |
6765 | reg_renumber[REGNO (reg)] = REGNO (reload_reg_rtx[j]); | |
6766 | alter_reg (REGNO (reg), -1); | |
6767 | } | |
6768 | } | |
6769 | \f | |
6770 | /* Output reload-insns to reload VALUE into RELOADREG. | |
6771 | VALUE is an autoincrement or autodecrement RTX whose operand | |
6772 | is a register or memory location; | |
6773 | so reloading involves incrementing that location. | |
6774 | ||
6775 | INC_AMOUNT is the number to increment or decrement by (always positive). | |
6776 | This cannot be deduced from VALUE. */ | |
6777 | ||
6778 | static void | |
6779 | inc_for_reload (reloadreg, value, inc_amount) | |
6780 | rtx reloadreg; | |
6781 | rtx value; | |
6782 | int inc_amount; | |
6783 | { | |
6784 | /* REG or MEM to be copied and incremented. */ | |
6785 | rtx incloc = XEXP (value, 0); | |
6786 | /* Nonzero if increment after copying. */ | |
6787 | int post = (GET_CODE (value) == POST_DEC || GET_CODE (value) == POST_INC); | |
6788 | rtx last; | |
6789 | rtx inc; | |
6790 | rtx add_insn; | |
6791 | int code; | |
6792 | ||
6793 | /* No hard register is equivalent to this register after | |
6794 | inc/dec operation. If REG_LAST_RELOAD_REG were non-zero, | |
6795 | we could inc/dec that register as well (maybe even using it for | |
6796 | the source), but I'm not sure it's worth worrying about. */ | |
6797 | if (GET_CODE (incloc) == REG) | |
6798 | reg_last_reload_reg[REGNO (incloc)] = 0; | |
6799 | ||
6800 | if (GET_CODE (value) == PRE_DEC || GET_CODE (value) == POST_DEC) | |
6801 | inc_amount = - inc_amount; | |
6802 | ||
6803 | inc = GEN_INT (inc_amount); | |
6804 | ||
6805 | /* If this is post-increment, first copy the location to the reload reg. */ | |
6806 | if (post) | |
6807 | emit_insn (gen_move_insn (reloadreg, incloc)); | |
6808 | ||
6809 | /* See if we can directly increment INCLOC. Use a method similar to that | |
6810 | in gen_input_reload. */ | |
6811 | ||
6812 | last = get_last_insn (); | |
6813 | add_insn = emit_insn (gen_rtx (SET, VOIDmode, incloc, | |
6814 | gen_rtx (PLUS, GET_MODE (incloc), | |
6815 | incloc, inc))); | |
6816 | ||
6817 | code = recog_memoized (add_insn); | |
6818 | if (code >= 0) | |
6819 | { | |
6820 | insn_extract (add_insn); | |
6821 | if (constrain_operands (code, 1)) | |
6822 | { | |
6823 | /* If this is a pre-increment and we have incremented the value | |
6824 | where it lives, copy the incremented value to RELOADREG to | |
6825 | be used as an address. */ | |
6826 | ||
6827 | if (! post) | |
6828 | emit_insn (gen_move_insn (reloadreg, incloc)); | |
6829 | ||
6830 | return; | |
6831 | } | |
6832 | } | |
6833 | ||
6834 | delete_insns_since (last); | |
6835 | ||
6836 | /* If couldn't do the increment directly, must increment in RELOADREG. | |
6837 | The way we do this depends on whether this is pre- or post-increment. | |
6838 | For pre-increment, copy INCLOC to the reload register, increment it | |
6839 | there, then save back. */ | |
6840 | ||
6841 | if (! post) | |
6842 | { | |
6843 | emit_insn (gen_move_insn (reloadreg, incloc)); | |
6844 | emit_insn (gen_add2_insn (reloadreg, inc)); | |
6845 | emit_insn (gen_move_insn (incloc, reloadreg)); | |
6846 | } | |
6847 | else | |
6848 | { | |
6849 | /* Postincrement. | |
6850 | Because this might be a jump insn or a compare, and because RELOADREG | |
6851 | may not be available after the insn in an input reload, we must do | |
6852 | the incrementation before the insn being reloaded for. | |
6853 | ||
6854 | We have already copied INCLOC to RELOADREG. Increment the copy in | |
6855 | RELOADREG, save that back, then decrement RELOADREG so it has | |
6856 | the original value. */ | |
6857 | ||
6858 | emit_insn (gen_add2_insn (reloadreg, inc)); | |
6859 | emit_insn (gen_move_insn (incloc, reloadreg)); | |
6860 | emit_insn (gen_add2_insn (reloadreg, GEN_INT (-inc_amount))); | |
6861 | } | |
6862 | ||
6863 | return; | |
6864 | } | |
6865 | \f | |
6866 | /* Return 1 if we are certain that the constraint-string STRING allows | |
6867 | the hard register REG. Return 0 if we can't be sure of this. */ | |
6868 | ||
6869 | static int | |
6870 | constraint_accepts_reg_p (string, reg) | |
6871 | char *string; | |
6872 | rtx reg; | |
6873 | { | |
6874 | int value = 0; | |
6875 | int regno = true_regnum (reg); | |
6876 | int c; | |
6877 | ||
6878 | /* Initialize for first alternative. */ | |
6879 | value = 0; | |
6880 | /* Check that each alternative contains `g' or `r'. */ | |
6881 | while (1) | |
6882 | switch (c = *string++) | |
6883 | { | |
6884 | case 0: | |
6885 | /* If an alternative lacks `g' or `r', we lose. */ | |
6886 | return value; | |
6887 | case ',': | |
6888 | /* If an alternative lacks `g' or `r', we lose. */ | |
6889 | if (value == 0) | |
6890 | return 0; | |
6891 | /* Initialize for next alternative. */ | |
6892 | value = 0; | |
6893 | break; | |
6894 | case 'g': | |
6895 | case 'r': | |
6896 | /* Any general reg wins for this alternative. */ | |
6897 | if (TEST_HARD_REG_BIT (reg_class_contents[(int) GENERAL_REGS], regno)) | |
6898 | value = 1; | |
6899 | break; | |
6900 | default: | |
6901 | /* Any reg in specified class wins for this alternative. */ | |
6902 | { | |
6903 | enum reg_class class = REG_CLASS_FROM_LETTER (c); | |
6904 | ||
6905 | if (TEST_HARD_REG_BIT (reg_class_contents[(int) class], regno)) | |
6906 | value = 1; | |
6907 | } | |
6908 | } | |
6909 | } | |
6910 | \f | |
6911 | /* Return the number of places FIND appears within X, but don't count | |
6912 | an occurrence if some SET_DEST is FIND. */ | |
6913 | ||
6914 | static int | |
6915 | count_occurrences (x, find) | |
6916 | register rtx x, find; | |
6917 | { | |
6918 | register int i, j; | |
6919 | register enum rtx_code code; | |
6920 | register char *format_ptr; | |
6921 | int count; | |
6922 | ||
6923 | if (x == find) | |
6924 | return 1; | |
6925 | if (x == 0) | |
6926 | return 0; | |
6927 | ||
6928 | code = GET_CODE (x); | |
6929 | ||
6930 | switch (code) | |
6931 | { | |
6932 | case REG: | |
6933 | case QUEUED: | |
6934 | case CONST_INT: | |
6935 | case CONST_DOUBLE: | |
6936 | case SYMBOL_REF: | |
6937 | case CODE_LABEL: | |
6938 | case PC: | |
6939 | case CC0: | |
6940 | return 0; | |
6941 | ||
6942 | case SET: | |
6943 | if (SET_DEST (x) == find) | |
6944 | return count_occurrences (SET_SRC (x), find); | |
6945 | break; | |
6946 | } | |
6947 | ||
6948 | format_ptr = GET_RTX_FORMAT (code); | |
6949 | count = 0; | |
6950 | ||
6951 | for (i = 0; i < GET_RTX_LENGTH (code); i++) | |
6952 | { | |
6953 | switch (*format_ptr++) | |
6954 | { | |
6955 | case 'e': | |
6956 | count += count_occurrences (XEXP (x, i), find); | |
6957 | break; | |
6958 | ||
6959 | case 'E': | |
6960 | if (XVEC (x, i) != NULL) | |
6961 | { | |
6962 | for (j = 0; j < XVECLEN (x, i); j++) | |
6963 | count += count_occurrences (XVECEXP (x, i, j), find); | |
6964 | } | |
6965 | break; | |
6966 | } | |
6967 | } | |
6968 | return count; | |
6969 | } |