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d7429b6a | 1 | /* Data flow analysis for GNU compiler. |
a5cad800 | 2 | Copyright (C) 1987, 88, 92-98, 1999 Free Software Foundation, Inc. |
d7429b6a RK |
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 | |
a35311b0 RK |
18 | the Free Software Foundation, 59 Temple Place - Suite 330, |
19 | Boston, MA 02111-1307, USA. */ | |
d7429b6a RK |
20 | |
21 | ||
e881bb1b RH |
22 | /* This file contains the data flow analysis pass of the compiler. It |
23 | computes data flow information which tells combine_instructions | |
24 | which insns to consider combining and controls register allocation. | |
d7429b6a | 25 | |
e881bb1b RH |
26 | Additional data flow information that is too bulky to record is |
27 | generated during the analysis, and is used at that time to create | |
28 | autoincrement and autodecrement addressing. | |
d7429b6a RK |
29 | |
30 | The first step is dividing the function into basic blocks. | |
31 | find_basic_blocks does this. Then life_analysis determines | |
32 | where each register is live and where it is dead. | |
33 | ||
34 | ** find_basic_blocks ** | |
35 | ||
e881bb1b RH |
36 | find_basic_blocks divides the current function's rtl into basic |
37 | blocks and constructs the CFG. The blocks are recorded in the | |
38 | basic_block_info array; the CFG exists in the edge structures | |
39 | referenced by the blocks. | |
d7429b6a | 40 | |
e881bb1b | 41 | find_basic_blocks also finds any unreachable loops and deletes them. |
d7429b6a RK |
42 | |
43 | ** life_analysis ** | |
44 | ||
45 | life_analysis is called immediately after find_basic_blocks. | |
46 | It uses the basic block information to determine where each | |
47 | hard or pseudo register is live. | |
48 | ||
49 | ** live-register info ** | |
50 | ||
51 | The information about where each register is live is in two parts: | |
e881bb1b | 52 | the REG_NOTES of insns, and the vector basic_block->global_live_at_start. |
d7429b6a | 53 | |
e881bb1b RH |
54 | basic_block->global_live_at_start has an element for each basic |
55 | block, and the element is a bit-vector with a bit for each hard or | |
56 | pseudo register. The bit is 1 if the register is live at the | |
57 | beginning of the basic block. | |
d7429b6a RK |
58 | |
59 | Two types of elements can be added to an insn's REG_NOTES. | |
60 | A REG_DEAD note is added to an insn's REG_NOTES for any register | |
61 | that meets both of two conditions: The value in the register is not | |
62 | needed in subsequent insns and the insn does not replace the value in | |
63 | the register (in the case of multi-word hard registers, the value in | |
64 | each register must be replaced by the insn to avoid a REG_DEAD note). | |
65 | ||
66 | In the vast majority of cases, an object in a REG_DEAD note will be | |
67 | used somewhere in the insn. The (rare) exception to this is if an | |
68 | insn uses a multi-word hard register and only some of the registers are | |
69 | needed in subsequent insns. In that case, REG_DEAD notes will be | |
70 | provided for those hard registers that are not subsequently needed. | |
71 | Partial REG_DEAD notes of this type do not occur when an insn sets | |
72 | only some of the hard registers used in such a multi-word operand; | |
73 | omitting REG_DEAD notes for objects stored in an insn is optional and | |
74 | the desire to do so does not justify the complexity of the partial | |
75 | REG_DEAD notes. | |
76 | ||
77 | REG_UNUSED notes are added for each register that is set by the insn | |
78 | but is unused subsequently (if every register set by the insn is unused | |
79 | and the insn does not reference memory or have some other side-effect, | |
80 | the insn is deleted instead). If only part of a multi-word hard | |
81 | register is used in a subsequent insn, REG_UNUSED notes are made for | |
82 | the parts that will not be used. | |
83 | ||
84 | To determine which registers are live after any insn, one can | |
85 | start from the beginning of the basic block and scan insns, noting | |
86 | which registers are set by each insn and which die there. | |
87 | ||
88 | ** Other actions of life_analysis ** | |
89 | ||
90 | life_analysis sets up the LOG_LINKS fields of insns because the | |
91 | information needed to do so is readily available. | |
92 | ||
93 | life_analysis deletes insns whose only effect is to store a value | |
94 | that is never used. | |
95 | ||
96 | life_analysis notices cases where a reference to a register as | |
97 | a memory address can be combined with a preceding or following | |
98 | incrementation or decrementation of the register. The separate | |
99 | instruction to increment or decrement is deleted and the address | |
100 | is changed to a POST_INC or similar rtx. | |
101 | ||
102 | Each time an incrementing or decrementing address is created, | |
103 | a REG_INC element is added to the insn's REG_NOTES list. | |
104 | ||
105 | life_analysis fills in certain vectors containing information about | |
106 | register usage: reg_n_refs, reg_n_deaths, reg_n_sets, reg_live_length, | |
fdb8a883 JW |
107 | reg_n_calls_crosses and reg_basic_block. |
108 | ||
109 | life_analysis sets current_function_sp_is_unchanging if the function | |
110 | doesn't modify the stack pointer. */ | |
e881bb1b RH |
111 | |
112 | /* TODO: | |
113 | ||
114 | Split out from life_analysis: | |
115 | - local property discovery (bb->local_live, bb->local_set) | |
116 | - global property computation | |
117 | - log links creation | |
118 | - pre/post modify transformation | |
119 | */ | |
d7429b6a | 120 | \f |
d7429b6a | 121 | #include "config.h" |
670ee920 | 122 | #include "system.h" |
d7429b6a RK |
123 | #include "rtl.h" |
124 | #include "basic-block.h" | |
125 | #include "insn-config.h" | |
126 | #include "regs.h" | |
127 | #include "hard-reg-set.h" | |
128 | #include "flags.h" | |
129 | #include "output.h" | |
b384405b | 130 | #include "function.h" |
3d195391 | 131 | #include "except.h" |
2e107e9e | 132 | #include "toplev.h" |
79c9824e | 133 | #include "recog.h" |
e881bb1b | 134 | #include "insn-flags.h" |
d7429b6a RK |
135 | |
136 | #include "obstack.h" | |
137 | #define obstack_chunk_alloc xmalloc | |
138 | #define obstack_chunk_free free | |
139 | ||
e881bb1b RH |
140 | |
141 | /* EXIT_IGNORE_STACK should be nonzero if, when returning from a function, | |
142 | the stack pointer does not matter. The value is tested only in | |
143 | functions that have frame pointers. | |
144 | No definition is equivalent to always zero. */ | |
145 | #ifndef EXIT_IGNORE_STACK | |
146 | #define EXIT_IGNORE_STACK 0 | |
147 | #endif | |
148 | ||
421382ac | 149 | |
7eb136d6 MM |
150 | /* The contents of the current function definition are allocated |
151 | in this obstack, and all are freed at the end of the function. | |
152 | For top-level functions, this is temporary_obstack. | |
153 | Separate obstacks are made for nested functions. */ | |
154 | ||
155 | extern struct obstack *function_obstack; | |
156 | ||
e881bb1b | 157 | /* Number of basic blocks in the current function. */ |
d7429b6a | 158 | |
e881bb1b | 159 | int n_basic_blocks; |
d7429b6a | 160 | |
e881bb1b | 161 | /* The basic block array. */ |
d7429b6a | 162 | |
e881bb1b | 163 | varray_type basic_block_info; |
d7429b6a | 164 | |
e881bb1b | 165 | /* The special entry and exit blocks. */ |
d7429b6a | 166 | |
e881bb1b RH |
167 | struct basic_block_def entry_exit_blocks[2] = |
168 | { | |
169 | { | |
170 | NULL, /* head */ | |
171 | NULL, /* end */ | |
172 | NULL, /* pred */ | |
173 | NULL, /* succ */ | |
174 | NULL, /* local_set */ | |
175 | NULL, /* global_live_at_start */ | |
176 | NULL, /* global_live_at_end */ | |
177 | NULL, /* aux */ | |
178 | ENTRY_BLOCK, /* index */ | |
179 | 0 /* loop_depth */ | |
180 | }, | |
181 | { | |
182 | NULL, /* head */ | |
183 | NULL, /* end */ | |
184 | NULL, /* pred */ | |
185 | NULL, /* succ */ | |
186 | NULL, /* local_set */ | |
187 | NULL, /* global_live_at_start */ | |
188 | NULL, /* global_live_at_end */ | |
189 | NULL, /* aux */ | |
190 | EXIT_BLOCK, /* index */ | |
191 | 0 /* loop_depth */ | |
192 | } | |
193 | }; | |
d7429b6a | 194 | |
56744d1a JL |
195 | /* Nonzero if the second flow pass has completed. */ |
196 | int flow2_completed; | |
197 | ||
d7429b6a RK |
198 | /* Maximum register number used in this function, plus one. */ |
199 | ||
200 | int max_regno; | |
201 | ||
b1f21e0a | 202 | /* Indexed by n, giving various register information */ |
d7429b6a | 203 | |
6feacd09 | 204 | varray_type reg_n_info; |
d7429b6a | 205 | |
a494747c MM |
206 | /* Size of the reg_n_info table. */ |
207 | ||
208 | unsigned int reg_n_max; | |
209 | ||
d7429b6a RK |
210 | /* Element N is the next insn that uses (hard or pseudo) register number N |
211 | within the current basic block; or zero, if there is no such insn. | |
212 | This is valid only during the final backward scan in propagate_block. */ | |
213 | ||
214 | static rtx *reg_next_use; | |
215 | ||
216 | /* Size of a regset for the current function, | |
217 | in (1) bytes and (2) elements. */ | |
218 | ||
219 | int regset_bytes; | |
220 | int regset_size; | |
221 | ||
d7429b6a | 222 | /* Regset of regs live when calls to `setjmp'-like functions happen. */ |
e881bb1b | 223 | /* ??? Does this exist only for the setjmp-clobbered warning message? */ |
d7429b6a RK |
224 | |
225 | regset regs_live_at_setjmp; | |
226 | ||
227 | /* List made of EXPR_LIST rtx's which gives pairs of pseudo registers | |
228 | that have to go in the same hard reg. | |
229 | The first two regs in the list are a pair, and the next two | |
230 | are another pair, etc. */ | |
231 | rtx regs_may_share; | |
232 | ||
d7429b6a RK |
233 | /* Depth within loops of basic block being scanned for lifetime analysis, |
234 | plus one. This is the weight attached to references to registers. */ | |
235 | ||
236 | static int loop_depth; | |
237 | ||
238 | /* During propagate_block, this is non-zero if the value of CC0 is live. */ | |
239 | ||
240 | static int cc0_live; | |
241 | ||
db3a887b | 242 | /* During propagate_block, this contains a list of all the MEMs we are |
40b5a77c JL |
243 | tracking for dead store elimination. |
244 | ||
245 | ?!? Note we leak memory by not free-ing items on this list. We need to | |
246 | write some generic routines to operate on memory lists since cse, gcse, | |
247 | loop, sched, flow and possibly other passes all need to do basically the | |
248 | same operations on these lists. */ | |
d7429b6a | 249 | |
db3a887b | 250 | static rtx mem_set_list; |
d7429b6a RK |
251 | |
252 | /* Set of registers that may be eliminable. These are handled specially | |
253 | in updating regs_ever_live. */ | |
254 | ||
255 | static HARD_REG_SET elim_reg_set; | |
256 | ||
e881bb1b RH |
257 | /* The basic block structure for every insn, indexed by uid. */ |
258 | ||
259 | varray_type basic_block_for_insn; | |
260 | ||
261 | /* The labels mentioned in non-jump rtl. Valid during find_basic_blocks. */ | |
262 | /* ??? Should probably be using LABEL_NUSES instead. It would take a | |
263 | bit of surgery to be able to use or co-opt the routines in jump. */ | |
264 | ||
265 | static rtx label_value_list; | |
266 | ||
267 | /* INSN_VOLATILE (insn) is 1 if the insn refers to anything volatile. */ | |
268 | ||
269 | #define INSN_VOLATILE(INSN) bitmap_bit_p (uid_volatile, INSN_UID (INSN)) | |
270 | #define SET_INSN_VOLATILE(INSN) bitmap_set_bit (uid_volatile, INSN_UID (INSN)) | |
271 | static bitmap uid_volatile; | |
272 | ||
d7429b6a | 273 | /* Forward declarations */ |
e881bb1b RH |
274 | static int count_basic_blocks PROTO((rtx)); |
275 | static rtx find_basic_blocks_1 PROTO((rtx, rtx*)); | |
276 | static void create_basic_block PROTO((int, rtx, rtx, rtx)); | |
277 | static void compute_bb_for_insn PROTO((varray_type, int)); | |
278 | static void clear_edges PROTO((void)); | |
279 | static void make_edges PROTO((rtx, rtx*)); | |
280 | static void make_edge PROTO((basic_block, basic_block, int)); | |
281 | static void make_label_edge PROTO((basic_block, rtx, int)); | |
282 | static void mark_critical_edges PROTO((void)); | |
283 | ||
284 | static void commit_one_edge_insertion PROTO((edge)); | |
285 | ||
421382ac | 286 | static void delete_unreachable_blocks PROTO((void)); |
e881bb1b | 287 | static void delete_eh_regions PROTO((void)); |
eeea333e | 288 | static int can_delete_note_p PROTO((rtx)); |
e881bb1b RH |
289 | static void delete_insn_chain PROTO((rtx, rtx)); |
290 | static int delete_block PROTO((basic_block)); | |
291 | static void expunge_block PROTO((basic_block)); | |
292 | static rtx flow_delete_insn PROTO((rtx)); | |
293 | static int can_delete_label_p PROTO((rtx)); | |
294 | static void merge_blocks_nomove PROTO((basic_block, basic_block)); | |
295 | static int merge_blocks PROTO((edge,basic_block,basic_block)); | |
296 | static void tidy_fallthru_edge PROTO((edge,basic_block,basic_block)); | |
297 | static void calculate_loop_depth PROTO((rtx)); | |
298 | ||
dc2ede84 BS |
299 | static int set_noop_p PROTO((rtx)); |
300 | static int noop_move_p PROTO((rtx)); | |
e881bb1b | 301 | static void notice_stack_pointer_modification PROTO ((rtx, rtx)); |
dc2ede84 BS |
302 | static void record_volatile_insns PROTO((rtx)); |
303 | static void mark_regs_live_at_end PROTO((regset)); | |
11f246f6 | 304 | static void life_analysis_1 PROTO((rtx, int, int)); |
e881bb1b RH |
305 | static void init_regset_vector PROTO ((regset *, int, |
306 | struct obstack *)); | |
307 | static void propagate_block PROTO((regset, rtx, rtx, int, | |
11f246f6 | 308 | regset, int, int)); |
e398aa80 | 309 | static int insn_dead_p PROTO((rtx, regset, int, rtx)); |
e658434c RK |
310 | static int libcall_dead_p PROTO((rtx, regset, rtx, rtx)); |
311 | static void mark_set_regs PROTO((regset, regset, rtx, | |
312 | rtx, regset)); | |
313 | static void mark_set_1 PROTO((regset, regset, rtx, | |
314 | rtx, regset)); | |
1d300e19 | 315 | #ifdef AUTO_INC_DEC |
e658434c | 316 | static void find_auto_inc PROTO((regset, rtx, rtx)); |
e658434c RK |
317 | static int try_pre_increment_1 PROTO((rtx)); |
318 | static int try_pre_increment PROTO((rtx, rtx, HOST_WIDE_INT)); | |
1d300e19 KG |
319 | #endif |
320 | static void mark_used_regs PROTO((regset, regset, rtx, int, rtx)); | |
e658434c | 321 | void dump_flow_info PROTO((FILE *)); |
e881bb1b RH |
322 | static void dump_edge_info PROTO((FILE *, edge, int)); |
323 | ||
5ece9746 JL |
324 | static int_list_ptr alloc_int_list_node PROTO ((int_list_block **)); |
325 | static int_list_ptr add_int_list_node PROTO ((int_list_block **, | |
326 | int_list **, int)); | |
e881bb1b RH |
327 | |
328 | static void add_pred_succ PROTO ((int, int, int_list_ptr *, | |
329 | int_list_ptr *, int *, int *)); | |
330 | ||
4c649323 JL |
331 | static void count_reg_sets_1 PROTO ((rtx)); |
332 | static void count_reg_sets PROTO ((rtx)); | |
333 | static void count_reg_references PROTO ((rtx)); | |
fdb8a883 | 334 | static void notice_stack_pointer_modification PROTO ((rtx, rtx)); |
15e088b2 | 335 | static void invalidate_mems_from_autoinc PROTO ((rtx)); |
34487bf8 | 336 | void verify_flow_info PROTO ((void)); |
d7429b6a | 337 | \f |
5ece9746 | 338 | /* Find basic blocks of the current function. |
e881bb1b RH |
339 | F is the first insn of the function and NREGS the number of register |
340 | numbers in use. */ | |
d7429b6a RK |
341 | |
342 | void | |
359da67d | 343 | find_basic_blocks (f, nregs, file, do_cleanup) |
d7429b6a | 344 | rtx f; |
e881bb1b RH |
345 | int nregs ATTRIBUTE_UNUSED; |
346 | FILE *file ATTRIBUTE_UNUSED; | |
359da67d | 347 | int do_cleanup; |
d7429b6a | 348 | { |
e881bb1b RH |
349 | rtx *bb_eh_end; |
350 | int max_uid; | |
d7429b6a | 351 | |
e881bb1b RH |
352 | /* Flush out existing data. */ |
353 | if (basic_block_info != NULL) | |
354 | { | |
355 | int i; | |
421382ac | 356 | |
e881bb1b | 357 | clear_edges (); |
d7429b6a | 358 | |
e881bb1b RH |
359 | /* Clear bb->aux on all extant basic blocks. We'll use this as a |
360 | tag for reuse during create_basic_block, just in case some pass | |
361 | copies around basic block notes improperly. */ | |
362 | for (i = 0; i < n_basic_blocks; ++i) | |
363 | BASIC_BLOCK (i)->aux = NULL; | |
d7429b6a | 364 | |
e881bb1b RH |
365 | VARRAY_FREE (basic_block_info); |
366 | } | |
27249135 | 367 | |
e881bb1b | 368 | n_basic_blocks = count_basic_blocks (f); |
27249135 | 369 | |
e881bb1b RH |
370 | /* Size the basic block table. The actual structures will be allocated |
371 | by find_basic_blocks_1, since we want to keep the structure pointers | |
372 | stable across calls to find_basic_blocks. */ | |
373 | /* ??? This whole issue would be much simpler if we called find_basic_blocks | |
374 | exactly once, and thereafter we don't have a single long chain of | |
375 | instructions at all until close to the end of compilation when we | |
376 | actually lay them out. */ | |
8cfe18d6 | 377 | |
e881bb1b RH |
378 | VARRAY_BB_INIT (basic_block_info, n_basic_blocks, "basic_block_info"); |
379 | ||
380 | /* An array to record the active exception region at the end of each | |
381 | basic block. It is filled in by find_basic_blocks_1 for make_edges. */ | |
382 | bb_eh_end = (rtx *) alloca (n_basic_blocks * sizeof (rtx)); | |
d7429b6a | 383 | |
e881bb1b | 384 | label_value_list = find_basic_blocks_1 (f, bb_eh_end); |
088e7160 | 385 | |
e881bb1b RH |
386 | /* Record the block to which an insn belongs. */ |
387 | /* ??? This should be done another way, by which (perhaps) a label is | |
388 | tagged directly with the basic block that it starts. It is used for | |
389 | more than that currently, but IMO that is the only valid use. */ | |
390 | ||
391 | max_uid = get_max_uid (); | |
d7429b6a | 392 | #ifdef AUTO_INC_DEC |
5ece9746 JL |
393 | /* Leave space for insns life_analysis makes in some cases for auto-inc. |
394 | These cases are rare, so we don't need too much space. */ | |
e881bb1b | 395 | max_uid += max_uid / 10; |
d7429b6a RK |
396 | #endif |
397 | ||
e881bb1b RH |
398 | VARRAY_BB_INIT (basic_block_for_insn, max_uid, "basic_block_for_insn"); |
399 | compute_bb_for_insn (basic_block_for_insn, max_uid); | |
400 | ||
401 | /* Discover the edges of our cfg. */ | |
d7429b6a | 402 | |
e881bb1b | 403 | make_edges (label_value_list, bb_eh_end); |
421382ac | 404 | |
e881bb1b | 405 | /* Delete unreachable blocks. */ |
d7429b6a | 406 | |
359da67d RH |
407 | if (do_cleanup) |
408 | delete_unreachable_blocks (); | |
e881bb1b RH |
409 | |
410 | /* Mark critical edges. */ | |
411 | ||
412 | mark_critical_edges (); | |
413 | ||
414 | /* Discover the loop depth at the start of each basic block to aid | |
415 | register allocation. */ | |
416 | calculate_loop_depth (f); | |
417 | ||
418 | /* Kill the data we won't maintain. */ | |
419 | label_value_list = 0; | |
34487bf8 RH |
420 | |
421 | #ifdef ENABLE_CHECKING | |
422 | verify_flow_info (); | |
423 | #endif | |
d7429b6a | 424 | } |
5ece9746 | 425 | |
e881bb1b | 426 | /* Count the basic blocks of the function. */ |
dc2ede84 | 427 | |
e881bb1b RH |
428 | static int |
429 | count_basic_blocks (f) | |
430 | rtx f; | |
431 | { | |
432 | register rtx insn; | |
433 | register RTX_CODE prev_code; | |
434 | register int count = 0; | |
435 | int eh_region = 0; | |
e881bb1b RH |
436 | int call_had_abnormal_edge = 0; |
437 | rtx prev_call = NULL_RTX; | |
dc2ede84 | 438 | |
e881bb1b RH |
439 | prev_code = JUMP_INSN; |
440 | for (insn = f; insn; insn = NEXT_INSN (insn)) | |
441 | { | |
442 | register RTX_CODE code = GET_CODE (insn); | |
443 | ||
e881bb1b RH |
444 | if (code == CODE_LABEL |
445 | || (GET_RTX_CLASS (code) == 'i' | |
446 | && (prev_code == JUMP_INSN | |
447 | || prev_code == BARRIER | |
448 | || (prev_code == CALL_INSN && call_had_abnormal_edge)))) | |
449 | { | |
450 | count++; | |
dc2ede84 | 451 | |
e881bb1b RH |
452 | /* If the previous insn was a call that did not create an |
453 | abnormal edge, we want to add a nop so that the CALL_INSN | |
454 | itself is not at basic_block_end. This allows us to | |
455 | easily distinguish between normal calls and those which | |
456 | create abnormal edges in the flow graph. */ | |
dc2ede84 | 457 | |
e881bb1b RH |
458 | if (count > 0 && prev_call != 0 && !call_had_abnormal_edge) |
459 | { | |
460 | rtx nop = gen_rtx_USE (VOIDmode, const0_rtx); | |
461 | emit_insn_after (nop, prev_call); | |
462 | } | |
463 | } | |
dc2ede84 | 464 | |
e881bb1b RH |
465 | /* Record whether this call created an edge. */ |
466 | if (code == CALL_INSN) | |
467 | { | |
6af57aae AM |
468 | rtx note = find_reg_note (insn, REG_EH_REGION, NULL_RTX); |
469 | int region = (note ? XINT (XEXP (note, 0), 0) : 1); | |
e881bb1b RH |
470 | prev_call = insn; |
471 | call_had_abnormal_edge = 0; | |
6af57aae AM |
472 | |
473 | /* If there is a specified EH region, we have an edge. */ | |
474 | if (eh_region && region > 0) | |
475 | call_had_abnormal_edge = 1; | |
476 | else | |
e881bb1b | 477 | { |
6af57aae AM |
478 | /* If there is a nonlocal goto label and the specified |
479 | region number isn't -1, we have an edge. (0 means | |
480 | no throw, but might have a nonlocal goto). */ | |
481 | if (nonlocal_goto_handler_labels && region >= 0) | |
e881bb1b RH |
482 | call_had_abnormal_edge = 1; |
483 | } | |
484 | } | |
485 | else if (code != NOTE) | |
486 | prev_call = NULL_RTX; | |
487 | ||
488 | if (code != NOTE) | |
489 | prev_code = code; | |
490 | else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_BEG) | |
491 | ++eh_region; | |
492 | else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_END) | |
493 | --eh_region; | |
494 | ||
e881bb1b RH |
495 | } |
496 | ||
497 | /* The rest of the compiler works a bit smoother when we don't have to | |
498 | check for the edge case of do-nothing functions with no basic blocks. */ | |
499 | if (count == 0) | |
500 | { | |
501 | emit_insn (gen_rtx_USE (VOIDmode, const0_rtx)); | |
502 | count = 1; | |
503 | } | |
504 | ||
505 | return count; | |
506 | } | |
dc2ede84 | 507 | |
d7429b6a RK |
508 | /* Find all basic blocks of the function whose first insn is F. |
509 | Store the correct data in the tables that describe the basic blocks, | |
510 | set up the chains of references for each CODE_LABEL, and | |
d7e4fe8b RS |
511 | delete any entire basic blocks that cannot be reached. |
512 | ||
e881bb1b RH |
513 | NONLOCAL_LABEL_LIST is a list of non-local labels in the function. Blocks |
514 | that are otherwise unreachable may be reachable with a non-local goto. | |
d7429b6a | 515 | |
e881bb1b RH |
516 | BB_EH_END is an array in which we record the list of exception regions |
517 | active at the end of every basic block. */ | |
8329b5ec | 518 | |
e881bb1b RH |
519 | static rtx |
520 | find_basic_blocks_1 (f, bb_eh_end) | |
521 | rtx f; | |
522 | rtx *bb_eh_end; | |
523 | { | |
524 | register rtx insn, next; | |
e881bb1b RH |
525 | int call_has_abnormal_edge = 0; |
526 | int i = 0; | |
527 | rtx bb_note = NULL_RTX; | |
528 | rtx eh_list = NULL_RTX; | |
529 | rtx label_value_list = NULL_RTX; | |
530 | rtx head = NULL_RTX; | |
531 | rtx end = NULL_RTX; | |
532 | ||
533 | /* We process the instructions in a slightly different way than we did | |
534 | previously. This is so that we see a NOTE_BASIC_BLOCK after we have | |
535 | closed out the previous block, so that it gets attached at the proper | |
536 | place. Since this form should be equivalent to the previous, | |
537 | find_basic_blocks_0 continues to use the old form as a check. */ | |
d7429b6a | 538 | |
e881bb1b RH |
539 | for (insn = f; insn; insn = next) |
540 | { | |
541 | enum rtx_code code = GET_CODE (insn); | |
d7429b6a | 542 | |
e881bb1b | 543 | next = NEXT_INSN (insn); |
d7429b6a | 544 | |
e881bb1b | 545 | if (code == CALL_INSN) |
e658434c | 546 | { |
e881bb1b | 547 | /* Record whether this call created an edge. */ |
6af57aae AM |
548 | rtx note = find_reg_note (insn, REG_EH_REGION, NULL_RTX); |
549 | int region = (note ? XINT (XEXP (note, 0), 0) : 1); | |
e881bb1b | 550 | call_has_abnormal_edge = 0; |
6af57aae AM |
551 | |
552 | /* If there is an EH region, we have an edge. */ | |
553 | if (eh_list && region > 0) | |
554 | call_has_abnormal_edge = 1; | |
555 | else | |
e658434c | 556 | { |
6af57aae AM |
557 | /* If there is a nonlocal goto label and the specified |
558 | region number isn't -1, we have an edge. (0 means | |
559 | no throw, but might have a nonlocal goto). */ | |
560 | if (nonlocal_goto_handler_labels && region >= 0) | |
e881bb1b | 561 | call_has_abnormal_edge = 1; |
5c35539b | 562 | } |
e658434c | 563 | } |
d7429b6a | 564 | |
e881bb1b | 565 | switch (code) |
e658434c | 566 | { |
e881bb1b RH |
567 | case NOTE: |
568 | { | |
569 | int kind = NOTE_LINE_NUMBER (insn); | |
570 | ||
571 | /* Keep a LIFO list of the currently active exception notes. */ | |
572 | if (kind == NOTE_INSN_EH_REGION_BEG) | |
573 | eh_list = gen_rtx_INSN_LIST (VOIDmode, insn, eh_list); | |
574 | else if (kind == NOTE_INSN_EH_REGION_END) | |
575 | eh_list = XEXP (eh_list, 1); | |
576 | ||
577 | /* Look for basic block notes with which to keep the | |
578 | basic_block_info pointers stable. Unthread the note now; | |
579 | we'll put it back at the right place in create_basic_block. | |
580 | Or not at all if we've already found a note in this block. */ | |
581 | else if (kind == NOTE_INSN_BASIC_BLOCK) | |
582 | { | |
583 | if (bb_note == NULL_RTX) | |
584 | bb_note = insn; | |
585 | next = flow_delete_insn (insn); | |
586 | } | |
e658434c | 587 | |
e881bb1b RH |
588 | break; |
589 | } | |
d7429b6a | 590 | |
e881bb1b RH |
591 | case CODE_LABEL: |
592 | /* A basic block starts at a label. If we've closed one off due | |
593 | to a barrier or some such, no need to do it again. */ | |
594 | if (head != NULL_RTX) | |
2ec1535d | 595 | { |
e881bb1b RH |
596 | /* While we now have edge lists with which other portions of |
597 | the compiler might determine a call ending a basic block | |
598 | does not imply an abnormal edge, it will be a bit before | |
599 | everything can be updated. So continue to emit a noop at | |
600 | the end of such a block. */ | |
601 | if (GET_CODE (end) == CALL_INSN) | |
602 | { | |
603 | rtx nop = gen_rtx_USE (VOIDmode, const0_rtx); | |
604 | end = emit_insn_after (nop, end); | |
605 | } | |
606 | ||
607 | bb_eh_end[i] = eh_list; | |
608 | create_basic_block (i++, head, end, bb_note); | |
609 | bb_note = NULL_RTX; | |
2ec1535d | 610 | } |
e881bb1b RH |
611 | head = end = insn; |
612 | break; | |
d06c6389 | 613 | |
e881bb1b RH |
614 | case JUMP_INSN: |
615 | /* A basic block ends at a jump. */ | |
616 | if (head == NULL_RTX) | |
617 | head = insn; | |
618 | else | |
619 | { | |
620 | /* ??? Make a special check for table jumps. The way this | |
621 | happens is truely and amazingly gross. We are about to | |
622 | create a basic block that contains just a code label and | |
623 | an addr*vec jump insn. Worse, an addr_diff_vec creates | |
624 | its own natural loop. | |
5c35539b | 625 | |
e881bb1b RH |
626 | Prevent this bit of brain damage, pasting things together |
627 | correctly in make_edges. | |
2c3a56ad | 628 | |
e881bb1b RH |
629 | The correct solution involves emitting the table directly |
630 | on the tablejump instruction as a note, or JUMP_LABEL. */ | |
e658434c | 631 | |
e881bb1b RH |
632 | if (GET_CODE (PATTERN (insn)) == ADDR_VEC |
633 | || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC) | |
634 | { | |
635 | head = end = NULL; | |
636 | n_basic_blocks--; | |
637 | break; | |
638 | } | |
639 | } | |
640 | end = insn; | |
641 | goto new_bb_inclusive; | |
d7429b6a | 642 | |
e881bb1b RH |
643 | case BARRIER: |
644 | /* A basic block ends at a barrier. It may be that an unconditional | |
645 | jump already closed the basic block -- no need to do it again. */ | |
646 | if (head == NULL_RTX) | |
647 | break; | |
d7429b6a | 648 | |
e881bb1b RH |
649 | /* While we now have edge lists with which other portions of the |
650 | compiler might determine a call ending a basic block does not | |
651 | imply an abnormal edge, it will be a bit before everything can | |
652 | be updated. So continue to emit a noop at the end of such a | |
653 | block. */ | |
654 | if (GET_CODE (end) == CALL_INSN) | |
655 | { | |
656 | rtx nop = gen_rtx_USE (VOIDmode, const0_rtx); | |
657 | end = emit_insn_after (nop, end); | |
658 | } | |
659 | goto new_bb_exclusive; | |
660 | ||
661 | case CALL_INSN: | |
662 | /* A basic block ends at a call that can either throw or | |
663 | do a non-local goto. */ | |
664 | if (call_has_abnormal_edge) | |
665 | { | |
666 | new_bb_inclusive: | |
667 | if (head == NULL_RTX) | |
668 | head = insn; | |
669 | end = insn; | |
670 | ||
671 | new_bb_exclusive: | |
672 | bb_eh_end[i] = eh_list; | |
673 | create_basic_block (i++, head, end, bb_note); | |
674 | head = end = NULL_RTX; | |
675 | bb_note = NULL_RTX; | |
676 | break; | |
677 | } | |
678 | /* FALLTHRU */ | |
d7429b6a | 679 | |
e881bb1b RH |
680 | default: |
681 | if (GET_RTX_CLASS (code) == 'i') | |
682 | { | |
683 | if (head == NULL_RTX) | |
684 | head = insn; | |
685 | end = insn; | |
686 | } | |
687 | break; | |
688 | } | |
d7429b6a | 689 | |
e881bb1b | 690 | if (GET_RTX_CLASS (code) == 'i') |
d7429b6a | 691 | { |
e881bb1b | 692 | rtx note; |
421382ac | 693 | |
e881bb1b RH |
694 | /* Make a list of all labels referred to other than by jumps |
695 | (which just don't have the REG_LABEL notes). | |
2ec1535d | 696 | |
e881bb1b RH |
697 | Make a special exception for labels followed by an ADDR*VEC, |
698 | as this would be a part of the tablejump setup code. | |
421382ac | 699 | |
e881bb1b RH |
700 | Make a special exception for the eh_return_stub_label, which |
701 | we know isn't part of any otherwise visible control flow. */ | |
702 | ||
703 | for (note = REG_NOTES (insn); note; note = XEXP (note, 1)) | |
704 | if (REG_NOTE_KIND (note) == REG_LABEL) | |
705 | { | |
706 | rtx lab = XEXP (note, 0), next; | |
707 | ||
708 | if (lab == eh_return_stub_label) | |
709 | ; | |
710 | else if ((next = next_nonnote_insn (lab)) != NULL | |
711 | && GET_CODE (next) == JUMP_INSN | |
712 | && (GET_CODE (PATTERN (next)) == ADDR_VEC | |
713 | || GET_CODE (PATTERN (next)) == ADDR_DIFF_VEC)) | |
714 | ; | |
715 | else | |
716 | label_value_list | |
717 | = gen_rtx_EXPR_LIST (VOIDmode, XEXP (note, 0), | |
718 | label_value_list); | |
d7429b6a RK |
719 | } |
720 | } | |
e881bb1b | 721 | } |
d7429b6a | 722 | |
e881bb1b RH |
723 | if (head != NULL_RTX) |
724 | { | |
725 | bb_eh_end[i] = eh_list; | |
726 | create_basic_block (i++, head, end, bb_note); | |
727 | } | |
af14ce9c | 728 | |
e881bb1b RH |
729 | if (i != n_basic_blocks) |
730 | abort (); | |
af14ce9c | 731 | |
e881bb1b | 732 | return label_value_list; |
d7429b6a | 733 | } |
5ece9746 | 734 | |
e881bb1b RH |
735 | /* Create a new basic block consisting of the instructions between |
736 | HEAD and END inclusive. Reuses the note and basic block struct | |
737 | in BB_NOTE, if any. */ | |
5ece9746 | 738 | |
e881bb1b RH |
739 | static void |
740 | create_basic_block (index, head, end, bb_note) | |
741 | int index; | |
742 | rtx head, end, bb_note; | |
5ece9746 | 743 | { |
e881bb1b RH |
744 | basic_block bb; |
745 | ||
746 | if (bb_note | |
b3bf5bde | 747 | && ! RTX_INTEGRATED_P (bb_note) |
e881bb1b RH |
748 | && (bb = NOTE_BASIC_BLOCK (bb_note)) != NULL |
749 | && bb->aux == NULL) | |
5ece9746 | 750 | { |
e881bb1b RH |
751 | /* If we found an existing note, thread it back onto the chain. */ |
752 | ||
753 | if (GET_CODE (head) == CODE_LABEL) | |
754 | add_insn_after (bb_note, head); | |
755 | else | |
756 | { | |
757 | add_insn_before (bb_note, head); | |
758 | head = bb_note; | |
759 | } | |
5ece9746 | 760 | } |
e881bb1b RH |
761 | else |
762 | { | |
763 | /* Otherwise we must create a note and a basic block structure. | |
764 | Since we allow basic block structs in rtl, give the struct | |
765 | the same lifetime by allocating it off the function obstack | |
766 | rather than using malloc. */ | |
8329b5ec | 767 | |
e881bb1b RH |
768 | bb = (basic_block) obstack_alloc (function_obstack, sizeof (*bb)); |
769 | memset (bb, 0, sizeof (*bb)); | |
421382ac | 770 | |
e881bb1b RH |
771 | if (GET_CODE (head) == CODE_LABEL) |
772 | bb_note = emit_note_after (NOTE_INSN_BASIC_BLOCK, head); | |
773 | else | |
774 | { | |
775 | bb_note = emit_note_before (NOTE_INSN_BASIC_BLOCK, head); | |
776 | head = bb_note; | |
777 | } | |
778 | NOTE_BASIC_BLOCK (bb_note) = bb; | |
779 | } | |
780 | ||
eeea333e RH |
781 | /* Always include the bb note in the block. */ |
782 | if (NEXT_INSN (end) == bb_note) | |
783 | end = bb_note; | |
784 | ||
e881bb1b RH |
785 | bb->head = head; |
786 | bb->end = end; | |
787 | bb->index = index; | |
788 | BASIC_BLOCK (index) = bb; | |
789 | ||
790 | /* Tag the block so that we know it has been used when considering | |
791 | other basic block notes. */ | |
792 | bb->aux = bb; | |
421382ac | 793 | } |
e881bb1b RH |
794 | \f |
795 | /* Records the basic block struct in BB_FOR_INSN, for every instruction | |
796 | indexed by INSN_UID. MAX is the size of the array. */ | |
421382ac | 797 | |
421382ac | 798 | static void |
e881bb1b RH |
799 | compute_bb_for_insn (bb_for_insn, max) |
800 | varray_type bb_for_insn; | |
801 | int max; | |
421382ac | 802 | { |
e881bb1b | 803 | int i; |
421382ac | 804 | |
e881bb1b RH |
805 | for (i = 0; i < n_basic_blocks; ++i) |
806 | { | |
807 | basic_block bb = BASIC_BLOCK (i); | |
808 | rtx insn, end; | |
809 | ||
810 | end = bb->end; | |
811 | insn = bb->head; | |
812 | while (1) | |
813 | { | |
814 | int uid = INSN_UID (insn); | |
815 | if (uid < max) | |
816 | VARRAY_BB (bb_for_insn, uid) = bb; | |
817 | if (insn == end) | |
818 | break; | |
819 | insn = NEXT_INSN (insn); | |
820 | } | |
821 | } | |
421382ac BS |
822 | } |
823 | ||
e881bb1b | 824 | /* Free the memory associated with the edge structures. */ |
421382ac BS |
825 | |
826 | static void | |
e881bb1b | 827 | clear_edges () |
421382ac | 828 | { |
e881bb1b RH |
829 | int i; |
830 | edge n, e; | |
421382ac | 831 | |
e881bb1b | 832 | for (i = 0; i < n_basic_blocks; ++i) |
421382ac | 833 | { |
e881bb1b | 834 | basic_block bb = BASIC_BLOCK (i); |
421382ac | 835 | |
e881bb1b | 836 | for (e = bb->succ; e ; e = n) |
421382ac | 837 | { |
e881bb1b RH |
838 | n = e->succ_next; |
839 | free (e); | |
421382ac | 840 | } |
e881bb1b RH |
841 | |
842 | bb->succ = 0; | |
843 | bb->pred = 0; | |
844 | } | |
845 | ||
846 | for (e = ENTRY_BLOCK_PTR->succ; e ; e = n) | |
847 | { | |
848 | n = e->succ_next; | |
849 | free (e); | |
421382ac | 850 | } |
e881bb1b RH |
851 | |
852 | ENTRY_BLOCK_PTR->succ = 0; | |
853 | EXIT_BLOCK_PTR->pred = 0; | |
421382ac BS |
854 | } |
855 | ||
e881bb1b RH |
856 | /* Identify the edges between basic blocks. |
857 | ||
858 | NONLOCAL_LABEL_LIST is a list of non-local labels in the function. Blocks | |
859 | that are otherwise unreachable may be reachable with a non-local goto. | |
860 | ||
861 | BB_EH_END is an array indexed by basic block number in which we record | |
862 | the list of exception regions active at the end of the basic block. */ | |
863 | ||
dc2ede84 | 864 | static void |
e881bb1b RH |
865 | make_edges (label_value_list, bb_eh_end) |
866 | rtx label_value_list; | |
867 | rtx *bb_eh_end; | |
dc2ede84 | 868 | { |
e881bb1b | 869 | int i; |
1ef1bf06 | 870 | eh_nesting_info *eh_nest_info = init_eh_nesting_info (); |
e881bb1b RH |
871 | |
872 | /* Assume no computed jump; revise as we create edges. */ | |
873 | current_function_has_computed_jump = 0; | |
874 | ||
875 | /* By nature of the way these get numbered, block 0 is always the entry. */ | |
876 | make_edge (ENTRY_BLOCK_PTR, BASIC_BLOCK (0), EDGE_FALLTHRU); | |
dc2ede84 | 877 | |
e881bb1b | 878 | for (i = 0; i < n_basic_blocks; ++i) |
421382ac | 879 | { |
e881bb1b RH |
880 | basic_block bb = BASIC_BLOCK (i); |
881 | rtx insn, x, eh_list; | |
882 | enum rtx_code code; | |
4b523fc4 | 883 | int force_fallthru = 0; |
421382ac | 884 | |
e881bb1b RH |
885 | /* If we have asynchronous exceptions, scan the notes for all exception |
886 | regions active in the block. In the normal case, we only need the | |
887 | one active at the end of the block, which is bb_eh_end[i]. */ | |
421382ac | 888 | |
e881bb1b RH |
889 | eh_list = bb_eh_end[i]; |
890 | if (asynchronous_exceptions) | |
dc2ede84 | 891 | { |
e881bb1b | 892 | for (insn = bb->end; insn != bb->head; insn = PREV_INSN (insn)) |
dc2ede84 | 893 | { |
e881bb1b RH |
894 | if (GET_CODE (insn) == NOTE |
895 | && NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_END) | |
896 | eh_list = gen_rtx_INSN_LIST (VOIDmode, insn, eh_list); | |
dc2ede84 | 897 | } |
e881bb1b | 898 | } |
dc2ede84 | 899 | |
e881bb1b RH |
900 | /* Now examine the last instruction of the block, and discover the |
901 | ways we can leave the block. */ | |
902 | ||
903 | insn = bb->end; | |
904 | code = GET_CODE (insn); | |
905 | ||
906 | /* A branch. */ | |
907 | if (code == JUMP_INSN) | |
908 | { | |
909 | rtx tmp; | |
910 | ||
911 | /* ??? Recognize a tablejump and do the right thing. */ | |
912 | if ((tmp = JUMP_LABEL (insn)) != NULL_RTX | |
913 | && (tmp = NEXT_INSN (tmp)) != NULL_RTX | |
914 | && GET_CODE (tmp) == JUMP_INSN | |
915 | && (GET_CODE (PATTERN (tmp)) == ADDR_VEC | |
916 | || GET_CODE (PATTERN (tmp)) == ADDR_DIFF_VEC)) | |
917 | { | |
918 | rtvec vec; | |
919 | int j; | |
920 | ||
921 | if (GET_CODE (PATTERN (tmp)) == ADDR_VEC) | |
922 | vec = XVEC (PATTERN (tmp), 0); | |
923 | else | |
924 | vec = XVEC (PATTERN (tmp), 1); | |
925 | ||
926 | for (j = GET_NUM_ELEM (vec) - 1; j >= 0; --j) | |
927 | make_label_edge (bb, XEXP (RTVEC_ELT (vec, j), 0), 0); | |
4b523fc4 RE |
928 | |
929 | /* Some targets (eg, ARM) emit a conditional jump that also | |
930 | contains the out-of-range target. Scan for these and | |
931 | add an edge if necessary. */ | |
932 | if ((tmp = single_set (insn)) != NULL | |
933 | && SET_DEST (tmp) == pc_rtx | |
934 | && GET_CODE (SET_SRC (tmp)) == IF_THEN_ELSE | |
935 | && GET_CODE (XEXP (SET_SRC (tmp), 2)) == LABEL_REF) | |
936 | make_label_edge (bb, XEXP (XEXP (SET_SRC (tmp), 2), 0), 0); | |
937 | ||
938 | #ifdef CASE_DROPS_THROUGH | |
939 | /* Silly VAXen. The ADDR_VEC is going to be in the way of | |
940 | us naturally detecting fallthru into the next block. */ | |
941 | force_fallthru = 1; | |
942 | #endif | |
e881bb1b RH |
943 | } |
944 | ||
945 | /* If this is a computed jump, then mark it as reaching | |
946 | everything on the label_value_list and forced_labels list. */ | |
947 | else if (computed_jump_p (insn)) | |
948 | { | |
dc2ede84 | 949 | current_function_has_computed_jump = 1; |
dc2ede84 | 950 | |
e881bb1b RH |
951 | for (x = label_value_list; x; x = XEXP (x, 1)) |
952 | make_label_edge (bb, XEXP (x, 0), EDGE_ABNORMAL); | |
953 | ||
dc2ede84 | 954 | for (x = forced_labels; x; x = XEXP (x, 1)) |
e881bb1b | 955 | make_label_edge (bb, XEXP (x, 0), EDGE_ABNORMAL); |
dc2ede84 BS |
956 | } |
957 | ||
e881bb1b RH |
958 | /* Returns create an exit out. */ |
959 | else if (returnjump_p (insn)) | |
960 | make_edge (bb, EXIT_BLOCK_PTR, 0); | |
961 | ||
962 | /* Otherwise, we have a plain conditional or unconditional jump. */ | |
963 | else | |
dc2ede84 | 964 | { |
e881bb1b RH |
965 | if (! JUMP_LABEL (insn)) |
966 | abort (); | |
967 | make_label_edge (bb, JUMP_LABEL (insn), 0); | |
968 | } | |
969 | } | |
970 | ||
971 | /* If this is a CALL_INSN, then mark it as reaching the active EH | |
972 | handler for this CALL_INSN. If we're handling asynchronous | |
973 | exceptions then any insn can reach any of the active handlers. | |
b472794d | 974 | |
e881bb1b | 975 | Also mark the CALL_INSN as reaching any nonlocal goto handler. */ |
b472794d | 976 | |
a3e924fc | 977 | if (code == CALL_INSN || asynchronous_exceptions) |
e881bb1b RH |
978 | { |
979 | int is_call = (code == CALL_INSN ? EDGE_ABNORMAL_CALL : 0); | |
1ef1bf06 AM |
980 | handler_info **handler_list; |
981 | int eh_region = -1; | |
982 | int num; | |
e881bb1b | 983 | |
1ef1bf06 AM |
984 | if (eh_list) |
985 | eh_region = NOTE_BLOCK_NUMBER (XEXP (eh_list, 0)); | |
e881bb1b | 986 | |
1ef1bf06 AM |
987 | num = reachable_handlers (eh_region, eh_nest_info, |
988 | insn, &handler_list); | |
989 | for ( ; num > 0; num--) | |
e881bb1b | 990 | { |
1ef1bf06 AM |
991 | make_label_edge (bb, handler_list[num - 1]->handler_label, |
992 | EDGE_ABNORMAL | EDGE_EH | is_call); | |
e881bb1b RH |
993 | } |
994 | ||
995 | if (code == CALL_INSN && nonlocal_goto_handler_labels) | |
996 | { | |
dc2ede84 BS |
997 | /* ??? This could be made smarter: in some cases it's possible |
998 | to tell that certain calls will not do a nonlocal goto. | |
999 | ||
1000 | For example, if the nested functions that do the nonlocal | |
1001 | gotos do not have their addresses taken, then only calls to | |
1002 | those functions or to other nested functions that use them | |
1003 | could possibly do nonlocal gotos. */ | |
1ef1bf06 AM |
1004 | /* We do know that a REG_EH_REGION note with a value less |
1005 | than 0 is guaranteed not to perform a non-local goto. */ | |
1006 | rtx note = find_reg_note (insn, REG_EH_REGION, NULL_RTX); | |
1007 | if (!note || XINT (XEXP (note, 0), 0) >= 0) | |
1008 | for (x = nonlocal_goto_handler_labels; x ; x = XEXP (x, 1)) | |
1009 | make_label_edge (bb, XEXP (x, 0), | |
1010 | EDGE_ABNORMAL | EDGE_ABNORMAL_CALL); | |
dc2ede84 BS |
1011 | } |
1012 | } | |
e881bb1b RH |
1013 | |
1014 | /* We know something about the structure of the function __throw in | |
1015 | libgcc2.c. It is the only function that ever contains eh_stub | |
1016 | labels. It modifies its return address so that the last block | |
1017 | returns to one of the eh_stub labels within it. So we have to | |
1018 | make additional edges in the flow graph. */ | |
1019 | if (i + 1 == n_basic_blocks && eh_return_stub_label != 0) | |
1020 | make_label_edge (bb, eh_return_stub_label, EDGE_EH); | |
1021 | ||
1022 | /* Find out if we can drop through to the next block. */ | |
1023 | insn = next_nonnote_insn (insn); | |
4b523fc4 | 1024 | if (!insn || (i + 1 == n_basic_blocks && force_fallthru)) |
e881bb1b RH |
1025 | make_edge (bb, EXIT_BLOCK_PTR, EDGE_FALLTHRU); |
1026 | else if (i + 1 < n_basic_blocks) | |
1027 | { | |
1028 | rtx tmp = BLOCK_HEAD (i + 1); | |
1029 | if (GET_CODE (tmp) == NOTE) | |
1030 | tmp = next_nonnote_insn (tmp); | |
4b523fc4 | 1031 | if (force_fallthru || insn == tmp) |
e881bb1b RH |
1032 | make_edge (bb, BASIC_BLOCK (i + 1), EDGE_FALLTHRU); |
1033 | } | |
dc2ede84 | 1034 | } |
1ef1bf06 | 1035 | free_eh_nesting_info (eh_nest_info); |
e881bb1b RH |
1036 | } |
1037 | ||
1038 | /* Create an edge between two basic blocks. FLAGS are auxiliary information | |
1039 | about the edge that is accumulated between calls. */ | |
1040 | ||
1041 | static void | |
1042 | make_edge (src, dst, flags) | |
1043 | basic_block src, dst; | |
1044 | int flags; | |
1045 | { | |
1046 | edge e; | |
1047 | ||
1048 | /* Make sure we don't add duplicate edges. */ | |
1049 | ||
1050 | for (e = src->succ; e ; e = e->succ_next) | |
1051 | if (e->dest == dst) | |
1052 | { | |
1053 | e->flags |= flags; | |
1054 | return; | |
1055 | } | |
1056 | ||
1057 | e = (edge) xcalloc (1, sizeof (*e)); | |
1058 | ||
1059 | e->succ_next = src->succ; | |
1060 | e->pred_next = dst->pred; | |
1061 | e->src = src; | |
1062 | e->dest = dst; | |
1063 | e->flags = flags; | |
1064 | ||
1065 | src->succ = e; | |
1066 | dst->pred = e; | |
1067 | } | |
1068 | ||
1069 | /* Create an edge from a basic block to a label. */ | |
1070 | ||
1071 | static void | |
1072 | make_label_edge (src, label, flags) | |
1073 | basic_block src; | |
1074 | rtx label; | |
1075 | int flags; | |
1076 | { | |
1077 | if (GET_CODE (label) != CODE_LABEL) | |
1078 | abort (); | |
1079 | ||
1080 | /* If the label was never emitted, this insn is junk, but avoid a | |
1081 | crash trying to refer to BLOCK_FOR_INSN (label). This can happen | |
1082 | as a result of a syntax error and a diagnostic has already been | |
1083 | printed. */ | |
1084 | ||
1085 | if (INSN_UID (label) == 0) | |
1086 | return; | |
1087 | ||
1088 | make_edge (src, BLOCK_FOR_INSN (label), flags); | |
1089 | } | |
e6cfb550 | 1090 | |
e881bb1b RH |
1091 | /* Identify critical edges and set the bits appropriately. */ |
1092 | static void | |
1093 | mark_critical_edges () | |
1094 | { | |
1095 | int i, n = n_basic_blocks; | |
1096 | basic_block bb; | |
1097 | ||
1098 | /* We begin with the entry block. This is not terribly important now, | |
1099 | but could be if a front end (Fortran) implemented alternate entry | |
1100 | points. */ | |
1101 | bb = ENTRY_BLOCK_PTR; | |
1102 | i = -1; | |
1103 | ||
1104 | while (1) | |
e6cfb550 | 1105 | { |
e881bb1b RH |
1106 | edge e; |
1107 | ||
1108 | /* (1) Critical edges must have a source with multiple successors. */ | |
1109 | if (bb->succ && bb->succ->succ_next) | |
1110 | { | |
1111 | for (e = bb->succ; e ; e = e->succ_next) | |
1112 | { | |
1113 | /* (2) Critical edges must have a destination with multiple | |
1114 | predecessors. Note that we know there is at least one | |
1115 | predecessor -- the edge we followed to get here. */ | |
1116 | if (e->dest->pred->pred_next) | |
1117 | e->flags |= EDGE_CRITICAL; | |
1118 | else | |
1119 | e->flags &= ~EDGE_CRITICAL; | |
1120 | } | |
1121 | } | |
1122 | else | |
1123 | { | |
1124 | for (e = bb->succ; e ; e = e->succ_next) | |
1125 | e->flags &= ~EDGE_CRITICAL; | |
1126 | } | |
1127 | ||
1128 | if (++i >= n) | |
1129 | break; | |
1130 | bb = BASIC_BLOCK (i); | |
e6cfb550 | 1131 | } |
e881bb1b RH |
1132 | } |
1133 | \f | |
1134 | /* Split a (typically critical) edge. Return the new block. | |
1135 | Abort on abnormal edges. | |
1136 | ||
1137 | ??? The code generally expects to be called on critical edges. | |
1138 | The case of a block ending in an unconditional jump to a | |
1139 | block with multiple predecessors is not handled optimally. */ | |
1140 | ||
1141 | basic_block | |
1142 | split_edge (edge_in) | |
1143 | edge edge_in; | |
1144 | { | |
1145 | basic_block old_pred, bb, old_succ; | |
1146 | edge edge_out; | |
1147 | rtx bb_note; | |
1148 | int i; | |
1149 | ||
1150 | /* Abnormal edges cannot be split. */ | |
1151 | if ((edge_in->flags & EDGE_ABNORMAL) != 0) | |
1152 | abort (); | |
1153 | ||
1154 | old_pred = edge_in->src; | |
1155 | old_succ = edge_in->dest; | |
1156 | ||
1157 | /* Remove the existing edge from the destination's pred list. */ | |
1158 | { | |
1159 | edge *pp; | |
1160 | for (pp = &old_succ->pred; *pp != edge_in; pp = &(*pp)->pred_next) | |
1161 | continue; | |
1162 | *pp = edge_in->pred_next; | |
1e7d57a3 | 1163 | edge_in->pred_next = NULL; |
e881bb1b RH |
1164 | } |
1165 | ||
1166 | /* Create the new structures. */ | |
1167 | bb = (basic_block) obstack_alloc (function_obstack, sizeof (*bb)); | |
1168 | edge_out = (edge) xcalloc (1, sizeof (*edge_out)); | |
1169 | ||
1170 | memset (bb, 0, sizeof (*bb)); | |
1171 | bb->local_set = OBSTACK_ALLOC_REG_SET (function_obstack); | |
1172 | bb->global_live_at_start = OBSTACK_ALLOC_REG_SET (function_obstack); | |
1173 | bb->global_live_at_end = OBSTACK_ALLOC_REG_SET (function_obstack); | |
1174 | ||
1175 | /* ??? This info is likely going to be out of date very soon. */ | |
1176 | CLEAR_REG_SET (bb->local_set); | |
1177 | if (old_succ->global_live_at_start) | |
1178 | { | |
1179 | COPY_REG_SET (bb->global_live_at_start, old_succ->global_live_at_start); | |
1180 | COPY_REG_SET (bb->global_live_at_end, old_succ->global_live_at_start); | |
1181 | } | |
1182 | else | |
1183 | { | |
1184 | CLEAR_REG_SET (bb->global_live_at_start); | |
1185 | CLEAR_REG_SET (bb->global_live_at_end); | |
1186 | } | |
1187 | ||
1188 | /* Wire them up. */ | |
1189 | bb->pred = edge_in; | |
1190 | bb->succ = edge_out; | |
1e7d57a3 | 1191 | |
e881bb1b | 1192 | edge_in->dest = bb; |
1e7d57a3 JH |
1193 | edge_in->flags &= ~EDGE_CRITICAL; |
1194 | ||
1195 | edge_out->pred_next = old_succ->pred; | |
1196 | edge_out->succ_next = NULL; | |
e881bb1b RH |
1197 | edge_out->src = bb; |
1198 | edge_out->dest = old_succ; | |
1e7d57a3 JH |
1199 | edge_out->flags = EDGE_FALLTHRU; |
1200 | edge_out->probability = REG_BR_PROB_BASE; | |
1201 | ||
1202 | old_succ->pred = edge_out; | |
e881bb1b RH |
1203 | |
1204 | /* Tricky case -- if there existed a fallthru into the successor | |
1205 | (and we're not it) we must add a new unconditional jump around | |
1206 | the new block we're actually interested in. | |
1207 | ||
1208 | Further, if that edge is critical, this means a second new basic | |
1209 | block must be created to hold it. In order to simplify correct | |
1210 | insn placement, do this before we touch the existing basic block | |
1211 | ordering for the block we were really wanting. */ | |
1212 | if ((edge_in->flags & EDGE_FALLTHRU) == 0) | |
1213 | { | |
1214 | edge e; | |
1e7d57a3 | 1215 | for (e = edge_out->pred_next; e ; e = e->pred_next) |
e881bb1b RH |
1216 | if (e->flags & EDGE_FALLTHRU) |
1217 | break; | |
1218 | ||
1219 | if (e) | |
1220 | { | |
1221 | basic_block jump_block; | |
1222 | rtx pos; | |
1223 | ||
1224 | if ((e->flags & EDGE_CRITICAL) == 0) | |
1225 | { | |
1226 | /* Non critical -- we can simply add a jump to the end | |
1227 | of the existing predecessor. */ | |
1228 | jump_block = e->src; | |
e881bb1b RH |
1229 | } |
1230 | else | |
1231 | { | |
1232 | /* We need a new block to hold the jump. The simplest | |
1233 | way to do the bulk of the work here is to recursively | |
1234 | call ourselves. */ | |
1235 | jump_block = split_edge (e); | |
1236 | e = jump_block->succ; | |
e881bb1b RH |
1237 | } |
1238 | ||
1e7d57a3 JH |
1239 | /* Now add the jump insn ... */ |
1240 | pos = emit_jump_insn_after (gen_jump (old_succ->head), | |
1241 | jump_block->end); | |
e881bb1b RH |
1242 | jump_block->end = pos; |
1243 | emit_barrier_after (pos); | |
1e7d57a3 JH |
1244 | |
1245 | /* ... let jump know that label is in use, ... */ | |
a8688bd6 | 1246 | JUMP_LABEL (pos) = old_succ->head; |
1e7d57a3 | 1247 | ++LABEL_NUSES (old_succ->head); |
088e7160 | 1248 | |
e881bb1b RH |
1249 | /* ... and clear fallthru on the outgoing edge. */ |
1250 | e->flags &= ~EDGE_FALLTHRU; | |
1251 | ||
1252 | /* Continue splitting the interesting edge. */ | |
1253 | } | |
1254 | } | |
1255 | ||
1256 | /* Place the new block just in front of the successor. */ | |
1257 | VARRAY_GROW (basic_block_info, ++n_basic_blocks); | |
1258 | for (i = n_basic_blocks - 1; i > old_succ->index; --i) | |
1259 | { | |
1260 | basic_block tmp = BASIC_BLOCK (i - 1); | |
1261 | BASIC_BLOCK (i) = tmp; | |
1262 | tmp->index = i; | |
1263 | } | |
1264 | BASIC_BLOCK (i) = bb; | |
1265 | bb->index = i; | |
1266 | ||
1267 | /* Create the basic block note. */ | |
1268 | bb_note = emit_note_before (NOTE_INSN_BASIC_BLOCK, old_succ->head); | |
1269 | NOTE_BASIC_BLOCK (bb_note) = bb; | |
1270 | bb->head = bb->end = bb_note; | |
1271 | ||
1272 | /* Not quite simple -- for non-fallthru edges, we must adjust the | |
1273 | predecessor's jump instruction to target our new block. */ | |
1274 | if ((edge_in->flags & EDGE_FALLTHRU) == 0) | |
1275 | { | |
1276 | rtx tmp, insn = old_pred->end; | |
1277 | rtx old_label = old_succ->head; | |
1278 | rtx new_label = gen_label_rtx (); | |
1279 | ||
1280 | if (GET_CODE (insn) != JUMP_INSN) | |
1281 | abort (); | |
1282 | ||
1283 | /* ??? Recognize a tablejump and adjust all matching cases. */ | |
1284 | if ((tmp = JUMP_LABEL (insn)) != NULL_RTX | |
1285 | && (tmp = NEXT_INSN (tmp)) != NULL_RTX | |
1286 | && GET_CODE (tmp) == JUMP_INSN | |
1287 | && (GET_CODE (PATTERN (tmp)) == ADDR_VEC | |
1288 | || GET_CODE (PATTERN (tmp)) == ADDR_DIFF_VEC)) | |
1289 | { | |
1290 | rtvec vec; | |
1291 | int j; | |
1292 | ||
1293 | if (GET_CODE (PATTERN (tmp)) == ADDR_VEC) | |
1294 | vec = XVEC (PATTERN (tmp), 0); | |
1295 | else | |
1296 | vec = XVEC (PATTERN (tmp), 1); | |
1297 | ||
1298 | for (j = GET_NUM_ELEM (vec) - 1; j >= 0; --j) | |
1299 | if (XEXP (RTVEC_ELT (vec, j), 0) == old_label) | |
1300 | { | |
1301 | RTVEC_ELT (vec, j) = gen_rtx_LABEL_REF (VOIDmode, new_label); | |
1302 | --LABEL_NUSES (old_label); | |
1303 | ++LABEL_NUSES (new_label); | |
1304 | } | |
1305 | } | |
1306 | else | |
1307 | { | |
1308 | /* This would have indicated an abnormal edge. */ | |
1309 | if (computed_jump_p (insn)) | |
1310 | abort (); | |
1311 | ||
1312 | /* A return instruction can't be redirected. */ | |
1313 | if (returnjump_p (insn)) | |
1314 | abort (); | |
1315 | ||
1316 | /* If the insn doesn't go where we think, we're confused. */ | |
1317 | if (JUMP_LABEL (insn) != old_label) | |
1318 | abort (); | |
1319 | ||
1320 | redirect_jump (insn, new_label); | |
1321 | } | |
1322 | ||
1323 | emit_label_before (new_label, bb_note); | |
1324 | bb->head = new_label; | |
1325 | } | |
1326 | ||
e881bb1b RH |
1327 | return bb; |
1328 | } | |
1329 | ||
1330 | /* Queue instructions for insertion on an edge between two basic blocks. | |
1331 | The new instructions and basic blocks (if any) will not appear in the | |
1332 | CFG until commit_edge_insertions is called. */ | |
1333 | ||
1334 | void | |
1335 | insert_insn_on_edge (pattern, e) | |
1336 | rtx pattern; | |
1337 | edge e; | |
1338 | { | |
1339 | /* We cannot insert instructions on an abnormal critical edge. | |
1340 | It will be easier to find the culprit if we die now. */ | |
1341 | if ((e->flags & (EDGE_ABNORMAL|EDGE_CRITICAL)) | |
1342 | == (EDGE_ABNORMAL|EDGE_CRITICAL)) | |
1343 | abort (); | |
1344 | ||
1345 | if (e->insns == NULL_RTX) | |
1346 | start_sequence (); | |
1347 | else | |
1348 | push_to_sequence (e->insns); | |
1349 | ||
1350 | emit_insn (pattern); | |
1351 | ||
1352 | e->insns = get_insns (); | |
1353 | end_sequence(); | |
1354 | } | |
1355 | ||
1356 | /* Update the CFG for the instructions queued on edge E. */ | |
1357 | ||
1358 | static void | |
1359 | commit_one_edge_insertion (e) | |
1360 | edge e; | |
1361 | { | |
1362 | rtx before = NULL_RTX, after = NULL_RTX, tmp; | |
1363 | basic_block bb; | |
1364 | ||
1365 | /* Figure out where to put these things. If the destination has | |
1366 | one predecessor, insert there. Except for the exit block. */ | |
1367 | if (e->dest->pred->pred_next == NULL | |
1368 | && e->dest != EXIT_BLOCK_PTR) | |
1369 | { | |
1370 | bb = e->dest; | |
1371 | ||
1372 | /* Get the location correct wrt a code label, and "nice" wrt | |
1373 | a basic block note, and before everything else. */ | |
1374 | tmp = bb->head; | |
1375 | if (GET_CODE (tmp) == CODE_LABEL) | |
1376 | tmp = NEXT_INSN (tmp); | |
1377 | if (GET_CODE (tmp) == NOTE | |
1378 | && NOTE_LINE_NUMBER (tmp) == NOTE_INSN_BASIC_BLOCK) | |
1379 | tmp = NEXT_INSN (tmp); | |
1380 | if (tmp == bb->head) | |
1381 | before = tmp; | |
1382 | else | |
1383 | after = PREV_INSN (tmp); | |
1384 | } | |
1385 | ||
1386 | /* If the source has one successor and the edge is not abnormal, | |
1387 | insert there. Except for the entry block. */ | |
1388 | else if ((e->flags & EDGE_ABNORMAL) == 0 | |
1389 | && e->src->succ->succ_next == NULL | |
1390 | && e->src != ENTRY_BLOCK_PTR) | |
1391 | { | |
1392 | bb = e->src; | |
1393 | if (GET_CODE (bb->end) == JUMP_INSN) | |
1394 | { | |
1395 | /* ??? Is it possible to wind up with non-simple jumps? Perhaps | |
1396 | a jump with delay slots already filled? */ | |
1397 | if (! simplejump_p (bb->end)) | |
1398 | abort (); | |
1399 | ||
1400 | before = bb->end; | |
1401 | } | |
1402 | else | |
1403 | { | |
1404 | /* We'd better be fallthru, or we've lost track of what's what. */ | |
1405 | if ((e->flags & EDGE_FALLTHRU) == 0) | |
1406 | abort (); | |
1407 | ||
1408 | after = bb->end; | |
1409 | } | |
1410 | } | |
1411 | ||
1412 | /* Otherwise we must split the edge. */ | |
1413 | else | |
1414 | { | |
1415 | bb = split_edge (e); | |
1416 | after = bb->end; | |
1417 | } | |
1418 | ||
1419 | /* Now that we've found the spot, do the insertion. */ | |
1420 | tmp = e->insns; | |
1421 | e->insns = NULL_RTX; | |
a8688bd6 AM |
1422 | |
1423 | /* Set the new block number for these insns, if structure is allocated. */ | |
1424 | if (basic_block_for_insn) | |
1425 | { | |
1426 | rtx i; | |
1427 | for (i = tmp; i != NULL_RTX; i = NEXT_INSN (i)) | |
1428 | set_block_for_insn (i, bb); | |
1429 | } | |
1430 | ||
e881bb1b RH |
1431 | if (before) |
1432 | { | |
1433 | emit_insns_before (tmp, before); | |
1434 | if (before == bb->head) | |
a8688bd6 | 1435 | bb->head = tmp; |
e881bb1b RH |
1436 | } |
1437 | else | |
1438 | { | |
1439 | tmp = emit_insns_after (tmp, after); | |
1440 | if (after == bb->end) | |
1441 | bb->end = tmp; | |
1442 | } | |
1443 | } | |
1444 | ||
1445 | /* Update the CFG for all queued instructions. */ | |
1446 | ||
1447 | void | |
1448 | commit_edge_insertions () | |
1449 | { | |
1450 | int i; | |
1451 | basic_block bb; | |
1452 | ||
1453 | i = -1; | |
1454 | bb = ENTRY_BLOCK_PTR; | |
1455 | while (1) | |
1456 | { | |
1457 | edge e, next; | |
1458 | ||
1459 | for (e = bb->succ; e ; e = next) | |
1460 | { | |
1461 | next = e->succ_next; | |
1462 | if (e->insns) | |
1463 | commit_one_edge_insertion (e); | |
1464 | } | |
1465 | ||
1466 | if (++i >= n_basic_blocks) | |
1467 | break; | |
1468 | bb = BASIC_BLOCK (i); | |
1469 | } | |
1470 | } | |
1471 | \f | |
1472 | /* Delete all unreachable basic blocks. */ | |
1473 | ||
1474 | static void | |
1475 | delete_unreachable_blocks () | |
1476 | { | |
1477 | basic_block *worklist, *tos; | |
1478 | int deleted_handler; | |
1479 | edge e; | |
1480 | int i, n; | |
1481 | ||
1482 | n = n_basic_blocks; | |
1483 | tos = worklist = (basic_block *) alloca (sizeof (basic_block) * n); | |
1484 | ||
1485 | /* Use basic_block->aux as a marker. Clear them all. */ | |
1486 | ||
1487 | for (i = 0; i < n; ++i) | |
1488 | BASIC_BLOCK (i)->aux = NULL; | |
1489 | ||
1490 | /* Add our starting points to the worklist. Almost always there will | |
1491 | be only one. It isn't inconcievable that we might one day directly | |
1492 | support Fortran alternate entry points. */ | |
1493 | ||
1494 | for (e = ENTRY_BLOCK_PTR->succ; e ; e = e->succ_next) | |
aa3d4bf9 RH |
1495 | { |
1496 | *tos++ = e->dest; | |
1497 | ||
1498 | /* Mark the block with a handy non-null value. */ | |
1499 | e->dest->aux = e; | |
1500 | } | |
e881bb1b RH |
1501 | |
1502 | /* Iterate: find everything reachable from what we've already seen. */ | |
1503 | ||
1504 | while (tos != worklist) | |
1505 | { | |
1506 | basic_block b = *--tos; | |
1507 | ||
e881bb1b RH |
1508 | for (e = b->succ; e ; e = e->succ_next) |
1509 | if (!e->dest->aux) | |
aa3d4bf9 RH |
1510 | { |
1511 | *tos++ = e->dest; | |
1512 | e->dest->aux = e; | |
1513 | } | |
e881bb1b RH |
1514 | } |
1515 | ||
1516 | /* Delete all unreachable basic blocks. Count down so that we don't | |
1517 | interfere with the block renumbering that happens in delete_block. */ | |
1518 | ||
1519 | deleted_handler = 0; | |
1520 | ||
1521 | for (i = n - 1; i >= 0; --i) | |
1522 | { | |
1523 | basic_block b = BASIC_BLOCK (i); | |
1524 | ||
1525 | if (b->aux != NULL) | |
1526 | /* This block was found. Tidy up the mark. */ | |
1527 | b->aux = NULL; | |
1528 | else | |
1529 | deleted_handler |= delete_block (b); | |
1530 | } | |
1531 | ||
1532 | /* Fix up edges that now fall through, or rather should now fall through | |
1533 | but previously required a jump around now deleted blocks. Simplify | |
1534 | the search by only examining blocks numerically adjacent, since this | |
1535 | is how find_basic_blocks created them. */ | |
1536 | ||
1537 | for (i = 1; i < n_basic_blocks; ++i) | |
1538 | { | |
1539 | basic_block b = BASIC_BLOCK (i - 1); | |
1540 | basic_block c = BASIC_BLOCK (i); | |
1541 | edge s; | |
1542 | ||
abb3f0a9 JL |
1543 | /* We care about simple conditional or unconditional jumps with |
1544 | a single successor. | |
1545 | ||
1546 | If we had a conditional branch to the next instruction when | |
1547 | find_basic_blocks was called, then there will only be one | |
1548 | out edge for the block which ended with the conditional | |
1549 | branch (since we do not create duplicate edges). | |
1550 | ||
4f282ba1 JL |
1551 | Furthermore, the edge will be marked as a fallthru because we |
1552 | merge the flags for the duplicate edges. So we do not want to | |
1553 | check that the edge is not a FALLTHRU edge. */ | |
e881bb1b RH |
1554 | if ((s = b->succ) != NULL |
1555 | && s->succ_next == NULL | |
e8fe3cc3 | 1556 | && s->dest == c |
d0e80719 RH |
1557 | /* If the jump insn has side effects, we can't tidy the edge. */ |
1558 | && (GET_CODE (b->end) != JUMP_INSN | |
1559 | || onlyjump_p (b->end))) | |
e881bb1b RH |
1560 | tidy_fallthru_edge (s, b, c); |
1561 | } | |
1562 | ||
1563 | /* Attempt to merge blocks as made possible by edge removal. If a block | |
1564 | has only one successor, and the successor has only one predecessor, | |
1565 | they may be combined. */ | |
1566 | ||
1567 | for (i = 0; i < n_basic_blocks; ) | |
1568 | { | |
1569 | basic_block c, b = BASIC_BLOCK (i); | |
1570 | edge s; | |
1571 | ||
1572 | /* A loop because chains of blocks might be combineable. */ | |
1573 | while ((s = b->succ) != NULL | |
1574 | && s->succ_next == NULL | |
9a2cab6e | 1575 | && (s->flags & EDGE_EH) == 0 |
e881bb1b RH |
1576 | && (c = s->dest) != EXIT_BLOCK_PTR |
1577 | && c->pred->pred_next == NULL | |
d0e80719 RH |
1578 | /* If the jump insn has side effects, we can't kill the edge. */ |
1579 | && (GET_CODE (b->end) != JUMP_INSN | |
1580 | || onlyjump_p (b->end)) | |
e881bb1b RH |
1581 | && merge_blocks (s, b, c)) |
1582 | continue; | |
1583 | ||
1584 | /* Don't get confused by the index shift caused by deleting blocks. */ | |
1585 | i = b->index + 1; | |
1586 | } | |
1587 | ||
1588 | /* If we deleted an exception handler, we may have EH region begin/end | |
1589 | blocks to remove as well. */ | |
1590 | if (deleted_handler) | |
1591 | delete_eh_regions (); | |
1592 | } | |
1593 | ||
1594 | /* Find EH regions for which there is no longer a handler, and delete them. */ | |
1595 | ||
1596 | static void | |
1597 | delete_eh_regions () | |
1598 | { | |
1599 | rtx insn; | |
1600 | ||
1ef1bf06 AM |
1601 | update_rethrow_references (); |
1602 | ||
e881bb1b RH |
1603 | for (insn = get_insns (); insn; insn = NEXT_INSN (insn)) |
1604 | if (GET_CODE (insn) == NOTE) | |
1605 | { | |
1606 | if ((NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_BEG) || | |
1607 | (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_END)) | |
1608 | { | |
1609 | int num = CODE_LABEL_NUMBER (insn); | |
1ef1bf06 AM |
1610 | /* A NULL handler indicates a region is no longer needed, |
1611 | as long as it isn't the target of a rethrow. */ | |
1612 | if (get_first_handler (num) == NULL && ! rethrow_used (num)) | |
e881bb1b RH |
1613 | { |
1614 | NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED; | |
1615 | NOTE_SOURCE_FILE (insn) = 0; | |
1616 | } | |
1617 | } | |
1618 | } | |
1619 | } | |
1620 | ||
1621 | /* Return true if NOTE is not one of the ones that must be kept paired, | |
1622 | so that we may simply delete them. */ | |
1623 | ||
1624 | static int | |
eeea333e | 1625 | can_delete_note_p (note) |
e881bb1b RH |
1626 | rtx note; |
1627 | { | |
1628 | return (NOTE_LINE_NUMBER (note) == NOTE_INSN_DELETED | |
1629 | || NOTE_LINE_NUMBER (note) == NOTE_INSN_BASIC_BLOCK); | |
1630 | } | |
1631 | ||
1632 | /* Unlink a chain of insns between START and FINISH, leaving notes | |
1633 | that must be paired. */ | |
1634 | ||
1635 | static void | |
1636 | delete_insn_chain (start, finish) | |
1637 | rtx start, finish; | |
1638 | { | |
1639 | /* Unchain the insns one by one. It would be quicker to delete all | |
1640 | of these with a single unchaining, rather than one at a time, but | |
1641 | we need to keep the NOTE's. */ | |
1642 | ||
1643 | rtx next; | |
1644 | ||
1645 | while (1) | |
1646 | { | |
1647 | next = NEXT_INSN (start); | |
eeea333e RH |
1648 | if (GET_CODE (start) == NOTE && !can_delete_note_p (start)) |
1649 | ; | |
1650 | else if (GET_CODE (start) == CODE_LABEL && !can_delete_label_p (start)) | |
1651 | ; | |
1652 | else | |
e881bb1b RH |
1653 | next = flow_delete_insn (start); |
1654 | ||
1655 | if (start == finish) | |
1656 | break; | |
1657 | start = next; | |
1658 | } | |
1659 | } | |
1660 | ||
1661 | /* Delete the insns in a (non-live) block. We physically delete every | |
1662 | non-deleted-note insn, and update the flow graph appropriately. | |
1663 | ||
1664 | Return nonzero if we deleted an exception handler. */ | |
1665 | ||
1666 | /* ??? Preserving all such notes strikes me as wrong. It would be nice | |
1667 | to post-process the stream to remove empty blocks, loops, ranges, etc. */ | |
1668 | ||
1669 | static int | |
1670 | delete_block (b) | |
1671 | basic_block b; | |
1672 | { | |
1673 | int deleted_handler = 0; | |
1674 | rtx insn, end; | |
1675 | ||
1676 | /* If the head of this block is a CODE_LABEL, then it might be the | |
1677 | label for an exception handler which can't be reached. | |
1678 | ||
1679 | We need to remove the label from the exception_handler_label list | |
1680 | and remove the associated NOTE_EH_REGION_BEG and NOTE_EH_REGION_END | |
1681 | notes. */ | |
1682 | ||
1683 | insn = b->head; | |
088e7160 | 1684 | |
e881bb1b RH |
1685 | if (GET_CODE (insn) == CODE_LABEL) |
1686 | { | |
1687 | rtx x, *prev = &exception_handler_labels; | |
1688 | ||
1689 | for (x = exception_handler_labels; x; x = XEXP (x, 1)) | |
1690 | { | |
1691 | if (XEXP (x, 0) == insn) | |
1692 | { | |
1693 | /* Found a match, splice this label out of the EH label list. */ | |
1694 | *prev = XEXP (x, 1); | |
1695 | XEXP (x, 1) = NULL_RTX; | |
1696 | XEXP (x, 0) = NULL_RTX; | |
1697 | ||
1698 | /* Remove the handler from all regions */ | |
1699 | remove_handler (insn); | |
1700 | deleted_handler = 1; | |
1701 | break; | |
1702 | } | |
1703 | prev = &XEXP (x, 1); | |
1704 | } | |
1705 | ||
1706 | /* This label may be referenced by code solely for its value, or | |
1707 | referenced by static data, or something. We have determined | |
1708 | that it is not reachable, but cannot delete the label itself. | |
1709 | Save code space and continue to delete the balance of the block, | |
1710 | along with properly updating the cfg. */ | |
1711 | if (!can_delete_label_p (insn)) | |
1712 | { | |
1713 | /* If we've only got one of these, skip the whole deleting | |
1714 | insns thing. */ | |
1715 | if (insn == b->end) | |
1716 | goto no_delete_insns; | |
1717 | insn = NEXT_INSN (insn); | |
1718 | } | |
1719 | } | |
1720 | ||
1721 | /* Selectively unlink the insn chain. Include any BARRIER that may | |
1722 | follow the basic block. */ | |
1723 | end = next_nonnote_insn (b->end); | |
1724 | if (!end || GET_CODE (end) != BARRIER) | |
1725 | end = b->end; | |
1726 | delete_insn_chain (insn, end); | |
1727 | ||
1728 | no_delete_insns: | |
1729 | ||
1730 | /* Remove the edges into and out of this block. Note that there may | |
1731 | indeed be edges in, if we are removing an unreachable loop. */ | |
1732 | { | |
1733 | edge e, next, *q; | |
1734 | ||
1735 | for (e = b->pred; e ; e = next) | |
1736 | { | |
1737 | for (q = &e->src->succ; *q != e; q = &(*q)->succ_next) | |
1738 | continue; | |
1739 | *q = e->succ_next; | |
1740 | next = e->pred_next; | |
1741 | free (e); | |
1742 | } | |
1743 | for (e = b->succ; e ; e = next) | |
1744 | { | |
1745 | for (q = &e->dest->pred; *q != e; q = &(*q)->pred_next) | |
1746 | continue; | |
1747 | *q = e->pred_next; | |
1748 | next = e->succ_next; | |
1749 | free (e); | |
1750 | } | |
1751 | ||
1752 | b->pred = NULL; | |
1753 | b->succ = NULL; | |
1754 | } | |
1755 | ||
1756 | /* Remove the basic block from the array, and compact behind it. */ | |
1757 | expunge_block (b); | |
1758 | ||
1759 | return deleted_handler; | |
1760 | } | |
1761 | ||
1762 | /* Remove block B from the basic block array and compact behind it. */ | |
1763 | ||
1764 | static void | |
1765 | expunge_block (b) | |
1766 | basic_block b; | |
1767 | { | |
1768 | int i, n = n_basic_blocks; | |
1769 | ||
1770 | for (i = b->index; i + 1 < n; ++i) | |
1771 | { | |
1772 | basic_block x = BASIC_BLOCK (i + 1); | |
1773 | BASIC_BLOCK (i) = x; | |
1774 | x->index = i; | |
1775 | } | |
1776 | ||
1777 | basic_block_info->num_elements--; | |
1778 | n_basic_blocks--; | |
1779 | } | |
1780 | ||
1781 | /* Delete INSN by patching it out. Return the next insn. */ | |
1782 | ||
1783 | static rtx | |
1784 | flow_delete_insn (insn) | |
1785 | rtx insn; | |
1786 | { | |
1787 | rtx prev = PREV_INSN (insn); | |
1788 | rtx next = NEXT_INSN (insn); | |
1789 | ||
1790 | PREV_INSN (insn) = NULL_RTX; | |
1791 | NEXT_INSN (insn) = NULL_RTX; | |
1792 | ||
1793 | if (prev) | |
1794 | NEXT_INSN (prev) = next; | |
1795 | if (next) | |
1796 | PREV_INSN (next) = prev; | |
1797 | else | |
1798 | set_last_insn (prev); | |
e6cfb550 | 1799 | |
55a98783 JL |
1800 | if (GET_CODE (insn) == CODE_LABEL) |
1801 | remove_node_from_expr_list (insn, &nonlocal_goto_handler_labels); | |
1802 | ||
e881bb1b RH |
1803 | /* If deleting a jump, decrement the use count of the label. Deleting |
1804 | the label itself should happen in the normal course of block merging. */ | |
1805 | if (GET_CODE (insn) == JUMP_INSN && JUMP_LABEL (insn)) | |
1806 | LABEL_NUSES (JUMP_LABEL (insn))--; | |
1807 | ||
1808 | return next; | |
d7429b6a | 1809 | } |
8329b5ec | 1810 | |
e881bb1b RH |
1811 | /* True if a given label can be deleted. */ |
1812 | ||
1813 | static int | |
1814 | can_delete_label_p (label) | |
1815 | rtx label; | |
dc2ede84 | 1816 | { |
e881bb1b | 1817 | rtx x; |
dc2ede84 | 1818 | |
e881bb1b RH |
1819 | if (LABEL_PRESERVE_P (label)) |
1820 | return 0; | |
421382ac | 1821 | |
e881bb1b RH |
1822 | for (x = forced_labels; x ; x = XEXP (x, 1)) |
1823 | if (label == XEXP (x, 0)) | |
1824 | return 0; | |
1825 | for (x = label_value_list; x ; x = XEXP (x, 1)) | |
1826 | if (label == XEXP (x, 0)) | |
1827 | return 0; | |
1828 | for (x = exception_handler_labels; x ; x = XEXP (x, 1)) | |
1829 | if (label == XEXP (x, 0)) | |
1830 | return 0; | |
dc2ede84 | 1831 | |
abb3f0a9 | 1832 | /* User declared labels must be preserved. */ |
088e7160 | 1833 | if (LABEL_NAME (label) != 0) |
abb3f0a9 | 1834 | return 0; |
088e7160 | 1835 | |
e881bb1b RH |
1836 | return 1; |
1837 | } | |
421382ac | 1838 | |
e881bb1b RH |
1839 | /* Blocks A and B are to be merged into a single block. The insns |
1840 | are already contiguous, hence `nomove'. */ | |
421382ac | 1841 | |
e881bb1b RH |
1842 | static void |
1843 | merge_blocks_nomove (a, b) | |
1844 | basic_block a, b; | |
1845 | { | |
1846 | edge e; | |
f5c14c21 RH |
1847 | rtx b_head, b_end, a_end; |
1848 | int b_empty = 0; | |
1849 | ||
1850 | /* If there was a CODE_LABEL beginning B, delete it. */ | |
1851 | b_head = b->head; | |
1852 | b_end = b->end; | |
1853 | if (GET_CODE (b_head) == CODE_LABEL) | |
1854 | { | |
1855 | /* Detect basic blocks with nothing but a label. This can happen | |
1856 | in particular at the end of a function. */ | |
1857 | if (b_head == b_end) | |
1858 | b_empty = 1; | |
1859 | b_head = flow_delete_insn (b_head); | |
1860 | } | |
1861 | ||
1862 | /* Delete the basic block note. */ | |
1863 | if (GET_CODE (b_head) == NOTE | |
1864 | && NOTE_LINE_NUMBER (b_head) == NOTE_INSN_BASIC_BLOCK) | |
1865 | { | |
1866 | if (b_head == b_end) | |
1867 | b_empty = 1; | |
1868 | b_head = flow_delete_insn (b_head); | |
1869 | } | |
421382ac | 1870 | |
e881bb1b | 1871 | /* If there was a jump out of A, delete it. */ |
f5c14c21 RH |
1872 | a_end = a->end; |
1873 | if (GET_CODE (a_end) == JUMP_INSN) | |
e881bb1b | 1874 | { |
f5c14c21 | 1875 | rtx prev; |
86879c21 | 1876 | |
f5c14c21 RH |
1877 | prev = prev_nonnote_insn (a_end); |
1878 | if (!prev) | |
1879 | prev = a->head; | |
86879c21 JL |
1880 | |
1881 | #ifdef HAVE_cc0 | |
f5c14c21 RH |
1882 | /* If this was a conditional jump, we need to also delete |
1883 | the insn that set cc0. */ | |
86879c21 | 1884 | |
f5c14c21 RH |
1885 | if (prev && sets_cc0_p (prev)) |
1886 | { | |
1887 | rtx tmp = prev; | |
1888 | prev = prev_nonnote_insn (prev); | |
1889 | if (!prev) | |
1890 | prev = a->head; | |
e881bb1b | 1891 | flow_delete_insn (tmp); |
421382ac | 1892 | } |
f5c14c21 RH |
1893 | #endif |
1894 | ||
1895 | /* Note that a->head != a->end, since we should have at least a | |
1896 | bb note plus the jump, so prev != insn. */ | |
1897 | flow_delete_insn (a_end); | |
1898 | a_end = prev; | |
421382ac | 1899 | } |
421382ac | 1900 | |
e881bb1b RH |
1901 | /* By definition, there should only be one successor of A, and that is |
1902 | B. Free that edge struct. */ | |
1903 | free (a->succ); | |
1904 | ||
1905 | /* Adjust the edges out of B for the new owner. */ | |
1906 | for (e = b->succ; e ; e = e->succ_next) | |
1907 | e->src = a; | |
1908 | a->succ = b->succ; | |
1909 | ||
e881bb1b | 1910 | /* Reassociate the insns of B with A. */ |
f5c14c21 | 1911 | if (!b_empty) |
e881bb1b | 1912 | { |
f5c14c21 RH |
1913 | BLOCK_FOR_INSN (b_head) = a; |
1914 | while (b_head != b_end) | |
dc2ede84 | 1915 | { |
f5c14c21 RH |
1916 | b_head = NEXT_INSN (b_head); |
1917 | BLOCK_FOR_INSN (b_head) = a; | |
dc2ede84 | 1918 | } |
f5c14c21 | 1919 | a_end = b_head; |
e881bb1b | 1920 | } |
f5c14c21 | 1921 | a->end = a_end; |
e881bb1b RH |
1922 | |
1923 | /* Compact the basic block array. */ | |
1924 | expunge_block (b); | |
dc2ede84 BS |
1925 | } |
1926 | ||
e881bb1b RH |
1927 | /* Attempt to merge basic blocks that are potentially non-adjacent. |
1928 | Return true iff the attempt succeeded. */ | |
dc2ede84 | 1929 | |
dc2ede84 | 1930 | static int |
e881bb1b RH |
1931 | merge_blocks (e, b, c) |
1932 | edge e; | |
1933 | basic_block b, c; | |
dc2ede84 | 1934 | { |
e881bb1b RH |
1935 | /* If B has a fallthru edge to C, no need to move anything. */ |
1936 | if (!(e->flags & EDGE_FALLTHRU)) | |
1937 | { | |
1938 | /* ??? From here on out we must make sure to not munge nesting | |
1939 | of exception regions and lexical blocks. Need to think about | |
1940 | these cases before this gets implemented. */ | |
1941 | return 0; | |
1942 | ||
1943 | /* If C has an outgoing fallthru, and B does not have an incoming | |
1944 | fallthru, move B before C. The later clause is somewhat arbitrary, | |
1945 | but avoids modifying blocks other than the two we've been given. */ | |
1946 | ||
1947 | /* Otherwise, move C after B. If C had a fallthru, which doesn't | |
1948 | happen to be the physical successor to B, insert an unconditional | |
1949 | branch. If C already ended with a conditional branch, the new | |
1950 | jump must go in a new basic block D. */ | |
1951 | } | |
dc2ede84 | 1952 | |
34487bf8 RH |
1953 | /* If a label still appears somewhere and we cannot delete the label, |
1954 | then we cannot merge the blocks. The edge was tidied already. */ | |
1955 | { | |
1956 | rtx insn, stop = NEXT_INSN (c->head); | |
1957 | for (insn = NEXT_INSN (b->end); insn != stop; insn = NEXT_INSN (insn)) | |
1958 | if (GET_CODE (insn) == CODE_LABEL && !can_delete_label_p (insn)) | |
1959 | return 0; | |
1960 | } | |
421382ac | 1961 | |
e881bb1b RH |
1962 | merge_blocks_nomove (b, c); |
1963 | return 1; | |
1964 | } | |
421382ac | 1965 | |
e881bb1b RH |
1966 | /* The given edge should potentially a fallthru edge. If that is in |
1967 | fact true, delete the unconditional jump and barriers that are in | |
1968 | the way. */ | |
1969 | ||
1970 | static void | |
1971 | tidy_fallthru_edge (e, b, c) | |
1972 | edge e; | |
1973 | basic_block b, c; | |
1974 | { | |
eeea333e | 1975 | rtx q; |
e881bb1b RH |
1976 | |
1977 | /* ??? In a late-running flow pass, other folks may have deleted basic | |
1978 | blocks by nopping out blocks, leaving multiple BARRIERs between here | |
1979 | and the target label. They ought to be chastized and fixed. | |
1980 | ||
eeea333e RH |
1981 | We can also wind up with a sequence of undeletable labels between |
1982 | one block and the next. | |
dc2ede84 | 1983 | |
eeea333e RH |
1984 | So search through a sequence of barriers, labels, and notes for |
1985 | the head of block C and assert that we really do fall through. */ | |
421382ac | 1986 | |
eeea333e | 1987 | if (next_real_insn (b->end) != next_real_insn (PREV_INSN (c->head))) |
e881bb1b | 1988 | return; |
421382ac | 1989 | |
e881bb1b RH |
1990 | /* Remove what will soon cease being the jump insn from the source block. |
1991 | If block B consisted only of this single jump, turn it into a deleted | |
1992 | note. */ | |
1993 | q = b->end; | |
1994 | if (GET_CODE (q) == JUMP_INSN) | |
421382ac | 1995 | { |
86a1db60 RH |
1996 | #ifdef HAVE_cc0 |
1997 | /* If this was a conditional jump, we need to also delete | |
1998 | the insn that set cc0. */ | |
1999 | if (! simplejump_p (q) && condjump_p (q)) | |
2000 | q = PREV_INSN (q); | |
2001 | #endif | |
2002 | ||
e881bb1b RH |
2003 | if (b->head == q) |
2004 | { | |
2005 | PUT_CODE (q, NOTE); | |
2006 | NOTE_LINE_NUMBER (q) = NOTE_INSN_DELETED; | |
2007 | NOTE_SOURCE_FILE (q) = 0; | |
2008 | } | |
e3f6ee23 | 2009 | else |
e881bb1b | 2010 | b->end = q = PREV_INSN (q); |
421382ac | 2011 | } |
421382ac | 2012 | |
e881bb1b | 2013 | /* Selectively unlink the sequence. */ |
86a1db60 RH |
2014 | if (q != PREV_INSN (c->head)) |
2015 | delete_insn_chain (NEXT_INSN (q), PREV_INSN (c->head)); | |
b7f7462b | 2016 | |
e881bb1b RH |
2017 | e->flags |= EDGE_FALLTHRU; |
2018 | } | |
dc2ede84 | 2019 | |
e881bb1b RH |
2020 | /* Discover and record the loop depth at the head of each basic block. */ |
2021 | ||
2022 | static void | |
2023 | calculate_loop_depth (insns) | |
2024 | rtx insns; | |
2025 | { | |
2026 | basic_block bb; | |
2027 | rtx insn; | |
2028 | int i = 0, depth = 1; | |
dc2ede84 | 2029 | |
e881bb1b RH |
2030 | bb = BASIC_BLOCK (i); |
2031 | for (insn = insns; insn ; insn = NEXT_INSN (insn)) | |
dc2ede84 | 2032 | { |
e881bb1b RH |
2033 | if (insn == bb->head) |
2034 | { | |
2035 | bb->loop_depth = depth; | |
2036 | if (++i >= n_basic_blocks) | |
dc2ede84 | 2037 | break; |
e881bb1b RH |
2038 | bb = BASIC_BLOCK (i); |
2039 | } | |
dc2ede84 | 2040 | |
e881bb1b RH |
2041 | if (GET_CODE (insn) == NOTE) |
2042 | { | |
2043 | if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG) | |
2044 | depth++; | |
2045 | else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_END) | |
2046 | depth--; | |
2047 | ||
2048 | /* If we have LOOP_DEPTH == 0, there has been a bookkeeping error. */ | |
2049 | if (depth == 0) | |
2050 | abort (); | |
2051 | } | |
2052 | } | |
dc2ede84 | 2053 | } |
d7429b6a | 2054 | \f |
5ece9746 JL |
2055 | /* Perform data flow analysis. |
2056 | F is the first insn of the function and NREGS the number of register numbers | |
2057 | in use. */ | |
2058 | ||
2059 | void | |
11f246f6 | 2060 | life_analysis (f, nregs, file, remove_dead_code) |
5ece9746 JL |
2061 | rtx f; |
2062 | int nregs; | |
2063 | FILE *file; | |
11f246f6 | 2064 | int remove_dead_code; |
5ece9746 | 2065 | { |
5ece9746 | 2066 | #ifdef ELIMINABLE_REGS |
ecb06768 | 2067 | register size_t i; |
5ece9746 JL |
2068 | static struct {int from, to; } eliminables[] = ELIMINABLE_REGS; |
2069 | #endif | |
2070 | ||
2071 | /* Record which registers will be eliminated. We use this in | |
2072 | mark_used_regs. */ | |
2073 | ||
2074 | CLEAR_HARD_REG_SET (elim_reg_set); | |
2075 | ||
2076 | #ifdef ELIMINABLE_REGS | |
2077 | for (i = 0; i < sizeof eliminables / sizeof eliminables[0]; i++) | |
2078 | SET_HARD_REG_BIT (elim_reg_set, eliminables[i].from); | |
2079 | #else | |
2080 | SET_HARD_REG_BIT (elim_reg_set, FRAME_POINTER_REGNUM); | |
2081 | #endif | |
2082 | ||
e881bb1b RH |
2083 | /* Allocate a bitmap to be filled in by record_volatile_insns. */ |
2084 | uid_volatile = BITMAP_ALLOCA (); | |
2085 | ||
db3a887b CB |
2086 | /* We want alias analysis information for local dead store elimination. */ |
2087 | init_alias_analysis (); | |
11f246f6 | 2088 | life_analysis_1 (f, nregs, remove_dead_code); |
db3a887b CB |
2089 | end_alias_analysis (); |
2090 | ||
5ece9746 JL |
2091 | if (file) |
2092 | dump_flow_info (file); | |
2093 | ||
e881bb1b | 2094 | BITMAP_FREE (uid_volatile); |
5ece9746 JL |
2095 | free_basic_block_vars (1); |
2096 | } | |
2097 | ||
2098 | /* Free the variables allocated by find_basic_blocks. | |
2099 | ||
e881bb1b | 2100 | KEEP_HEAD_END_P is non-zero if basic_block_info is not to be freed. */ |
5ece9746 JL |
2101 | |
2102 | void | |
2103 | free_basic_block_vars (keep_head_end_p) | |
2104 | int keep_head_end_p; | |
2105 | { | |
e881bb1b | 2106 | if (basic_block_for_insn) |
5ece9746 | 2107 | { |
e881bb1b RH |
2108 | VARRAY_FREE (basic_block_for_insn); |
2109 | basic_block_for_insn = NULL; | |
5ece9746 JL |
2110 | } |
2111 | ||
e881bb1b | 2112 | if (! keep_head_end_p) |
5ece9746 | 2113 | { |
e881bb1b RH |
2114 | clear_edges (); |
2115 | VARRAY_FREE (basic_block_info); | |
2116 | n_basic_blocks = 0; | |
359da67d RH |
2117 | |
2118 | ENTRY_BLOCK_PTR->aux = NULL; | |
2119 | ENTRY_BLOCK_PTR->global_live_at_end = NULL; | |
2120 | EXIT_BLOCK_PTR->aux = NULL; | |
2121 | EXIT_BLOCK_PTR->global_live_at_start = NULL; | |
5ece9746 JL |
2122 | } |
2123 | } | |
2124 | ||
dc2ede84 BS |
2125 | /* Return nonzero if the destination of SET equals the source. */ |
2126 | static int | |
2127 | set_noop_p (set) | |
2128 | rtx set; | |
2129 | { | |
2130 | rtx src = SET_SRC (set); | |
2131 | rtx dst = SET_DEST (set); | |
2132 | if (GET_CODE (src) == REG && GET_CODE (dst) == REG | |
2133 | && REGNO (src) == REGNO (dst)) | |
2134 | return 1; | |
2135 | if (GET_CODE (src) != SUBREG || GET_CODE (dst) != SUBREG | |
2136 | || SUBREG_WORD (src) != SUBREG_WORD (dst)) | |
2137 | return 0; | |
2138 | src = SUBREG_REG (src); | |
2139 | dst = SUBREG_REG (dst); | |
2140 | if (GET_CODE (src) == REG && GET_CODE (dst) == REG | |
2141 | && REGNO (src) == REGNO (dst)) | |
2142 | return 1; | |
2143 | return 0; | |
2144 | } | |
2145 | ||
2146 | /* Return nonzero if an insn consists only of SETs, each of which only sets a | |
2147 | value to itself. */ | |
2148 | static int | |
2149 | noop_move_p (insn) | |
2150 | rtx insn; | |
2151 | { | |
2152 | rtx pat = PATTERN (insn); | |
2153 | ||
2154 | /* Insns carrying these notes are useful later on. */ | |
2155 | if (find_reg_note (insn, REG_EQUAL, NULL_RTX)) | |
2156 | return 0; | |
2157 | ||
2158 | if (GET_CODE (pat) == SET && set_noop_p (pat)) | |
2159 | return 1; | |
2160 | ||
2161 | if (GET_CODE (pat) == PARALLEL) | |
2162 | { | |
2163 | int i; | |
2164 | /* If nothing but SETs of registers to themselves, | |
2165 | this insn can also be deleted. */ | |
2166 | for (i = 0; i < XVECLEN (pat, 0); i++) | |
2167 | { | |
2168 | rtx tem = XVECEXP (pat, 0, i); | |
2169 | ||
2170 | if (GET_CODE (tem) == USE | |
2171 | || GET_CODE (tem) == CLOBBER) | |
2172 | continue; | |
2173 | ||
2174 | if (GET_CODE (tem) != SET || ! set_noop_p (tem)) | |
2175 | return 0; | |
2176 | } | |
2177 | ||
2178 | return 1; | |
2179 | } | |
2180 | return 0; | |
2181 | } | |
2182 | ||
fdb8a883 JW |
2183 | static void |
2184 | notice_stack_pointer_modification (x, pat) | |
2185 | rtx x; | |
2186 | rtx pat ATTRIBUTE_UNUSED; | |
2187 | { | |
2188 | if (x == stack_pointer_rtx | |
2189 | /* The stack pointer is only modified indirectly as the result | |
2190 | of a push until later in flow. See the comments in rtl.texi | |
2191 | regarding Embedded Side-Effects on Addresses. */ | |
2192 | || (GET_CODE (x) == MEM | |
2193 | && (GET_CODE (XEXP (x, 0)) == PRE_DEC | |
2194 | || GET_CODE (XEXP (x, 0)) == PRE_INC | |
2195 | || GET_CODE (XEXP (x, 0)) == POST_DEC | |
2196 | || GET_CODE (XEXP (x, 0)) == POST_INC) | |
2197 | && XEXP (XEXP (x, 0), 0) == stack_pointer_rtx)) | |
2198 | current_function_sp_is_unchanging = 0; | |
2199 | } | |
2200 | ||
dc2ede84 BS |
2201 | /* Record which insns refer to any volatile memory |
2202 | or for any reason can't be deleted just because they are dead stores. | |
fdb8a883 JW |
2203 | Also, delete any insns that copy a register to itself. |
2204 | And see if the stack pointer is modified. */ | |
dc2ede84 BS |
2205 | static void |
2206 | record_volatile_insns (f) | |
2207 | rtx f; | |
2208 | { | |
2209 | rtx insn; | |
2210 | for (insn = f; insn; insn = NEXT_INSN (insn)) | |
2211 | { | |
2212 | enum rtx_code code1 = GET_CODE (insn); | |
2213 | if (code1 == CALL_INSN) | |
e881bb1b | 2214 | SET_INSN_VOLATILE (insn); |
dc2ede84 BS |
2215 | else if (code1 == INSN || code1 == JUMP_INSN) |
2216 | { | |
2217 | if (GET_CODE (PATTERN (insn)) != USE | |
2218 | && volatile_refs_p (PATTERN (insn))) | |
e881bb1b | 2219 | SET_INSN_VOLATILE (insn); |
dc2ede84 BS |
2220 | |
2221 | /* A SET that makes space on the stack cannot be dead. | |
2222 | (Such SETs occur only for allocating variable-size data, | |
2223 | so they will always have a PLUS or MINUS according to the | |
2224 | direction of stack growth.) | |
2225 | Even if this function never uses this stack pointer value, | |
2226 | signal handlers do! */ | |
2227 | else if (code1 == INSN && GET_CODE (PATTERN (insn)) == SET | |
2228 | && SET_DEST (PATTERN (insn)) == stack_pointer_rtx | |
2229 | #ifdef STACK_GROWS_DOWNWARD | |
2230 | && GET_CODE (SET_SRC (PATTERN (insn))) == MINUS | |
2231 | #else | |
2232 | && GET_CODE (SET_SRC (PATTERN (insn))) == PLUS | |
2233 | #endif | |
2234 | && XEXP (SET_SRC (PATTERN (insn)), 0) == stack_pointer_rtx) | |
e881bb1b | 2235 | SET_INSN_VOLATILE (insn); |
dc2ede84 BS |
2236 | |
2237 | /* Delete (in effect) any obvious no-op moves. */ | |
2238 | else if (noop_move_p (insn)) | |
2239 | { | |
2240 | PUT_CODE (insn, NOTE); | |
2241 | NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED; | |
2242 | NOTE_SOURCE_FILE (insn) = 0; | |
2243 | } | |
2244 | } | |
fdb8a883 JW |
2245 | |
2246 | /* Check if insn modifies the stack pointer. */ | |
2247 | if ( current_function_sp_is_unchanging | |
2248 | && GET_RTX_CLASS (GET_CODE (insn)) == 'i') | |
2249 | note_stores (PATTERN (insn), notice_stack_pointer_modification); | |
dc2ede84 BS |
2250 | } |
2251 | } | |
2252 | ||
2253 | /* Mark those regs which are needed at the end of the function as live | |
2254 | at the end of the last basic block. */ | |
2255 | static void | |
2256 | mark_regs_live_at_end (set) | |
2257 | regset set; | |
2258 | { | |
2259 | int i; | |
2260 | ||
e881bb1b RH |
2261 | /* If exiting needs the right stack value, consider the stack pointer |
2262 | live at the end of the function. */ | |
dc2ede84 BS |
2263 | if (! EXIT_IGNORE_STACK |
2264 | || (! FRAME_POINTER_REQUIRED | |
2265 | && ! current_function_calls_alloca | |
fdb8a883 JW |
2266 | && flag_omit_frame_pointer) |
2267 | || current_function_sp_is_unchanging) | |
e881bb1b RH |
2268 | { |
2269 | SET_REGNO_REG_SET (set, STACK_POINTER_REGNUM); | |
2270 | } | |
dc2ede84 | 2271 | |
e881bb1b | 2272 | /* Mark the frame pointer if needed at the end of the function. If |
dc2ede84 BS |
2273 | we end up eliminating it, it will be removed from the live list |
2274 | of each basic block by reload. */ | |
2275 | ||
e4b8a413 JW |
2276 | if (! reload_completed || frame_pointer_needed) |
2277 | { | |
2278 | SET_REGNO_REG_SET (set, FRAME_POINTER_REGNUM); | |
dc2ede84 | 2279 | #if FRAME_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM |
e4b8a413 JW |
2280 | /* If they are different, also mark the hard frame pointer as live */ |
2281 | SET_REGNO_REG_SET (set, HARD_FRAME_POINTER_REGNUM); | |
dc2ede84 | 2282 | #endif |
e4b8a413 | 2283 | } |
dc2ede84 | 2284 | |
e881bb1b | 2285 | /* Mark all global registers, and all registers used by the epilogue |
dc2ede84 BS |
2286 | as being live at the end of the function since they may be |
2287 | referenced by our caller. */ | |
2288 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
2289 | if (global_regs[i] | |
2290 | #ifdef EPILOGUE_USES | |
2291 | || EPILOGUE_USES (i) | |
2292 | #endif | |
2293 | ) | |
2294 | SET_REGNO_REG_SET (set, i); | |
e881bb1b RH |
2295 | |
2296 | /* ??? Mark function return value here rather than as uses. */ | |
dc2ede84 BS |
2297 | } |
2298 | ||
d7429b6a RK |
2299 | /* Determine which registers are live at the start of each |
2300 | basic block of the function whose first insn is F. | |
2301 | NREGS is the number of registers used in F. | |
2302 | We allocate the vector basic_block_live_at_start | |
2303 | and the regsets that it points to, and fill them with the data. | |
2304 | regset_size and regset_bytes are also set here. */ | |
2305 | ||
2306 | static void | |
11f246f6 | 2307 | life_analysis_1 (f, nregs, remove_dead_code) |
d7429b6a RK |
2308 | rtx f; |
2309 | int nregs; | |
11f246f6 | 2310 | int remove_dead_code; |
d7429b6a | 2311 | { |
d7429b6a RK |
2312 | int first_pass; |
2313 | int changed; | |
d7429b6a | 2314 | register int i; |
6764d250 | 2315 | char save_regs_ever_live[FIRST_PSEUDO_REGISTER]; |
e881bb1b | 2316 | regset *new_live_at_end; |
d7429b6a RK |
2317 | |
2318 | struct obstack flow_obstack; | |
2319 | ||
2320 | gcc_obstack_init (&flow_obstack); | |
2321 | ||
2322 | max_regno = nregs; | |
2323 | ||
d7429b6a RK |
2324 | /* Allocate and zero out many data structures |
2325 | that will record the data from lifetime analysis. */ | |
2326 | ||
359da67d RH |
2327 | allocate_reg_life_data (); |
2328 | allocate_bb_life_data (); | |
d7429b6a RK |
2329 | |
2330 | reg_next_use = (rtx *) alloca (nregs * sizeof (rtx)); | |
e881bb1b | 2331 | memset (reg_next_use, 0, nregs * sizeof (rtx)); |
d7429b6a | 2332 | |
e881bb1b | 2333 | /* Set up regset-vectors used internally within this function. |
d7429b6a RK |
2334 | Their meanings are documented above, with their declarations. */ |
2335 | ||
e881bb1b RH |
2336 | new_live_at_end = (regset *) alloca ((n_basic_blocks + 1) * sizeof (regset)); |
2337 | init_regset_vector (new_live_at_end, n_basic_blocks + 1, &flow_obstack); | |
4c9a05bc | 2338 | |
e881bb1b RH |
2339 | /* Stick these vectors into the AUX field of the basic block, so that |
2340 | we don't have to keep going through the index. */ | |
d7429b6a | 2341 | |
e881bb1b RH |
2342 | for (i = 0; i < n_basic_blocks; ++i) |
2343 | BASIC_BLOCK (i)->aux = new_live_at_end[i]; | |
2344 | ENTRY_BLOCK_PTR->aux = new_live_at_end[i]; | |
d7429b6a | 2345 | |
fdb8a883 JW |
2346 | /* Assume that the stack pointer is unchanging if alloca hasn't been used. |
2347 | This will be cleared by record_volatile_insns if it encounters an insn | |
2348 | which modifies the stack pointer. */ | |
2349 | current_function_sp_is_unchanging = !current_function_calls_alloca; | |
2350 | ||
dc2ede84 | 2351 | record_volatile_insns (f); |
fe0f9c4b RK |
2352 | |
2353 | if (n_basic_blocks > 0) | |
2354 | { | |
e881bb1b RH |
2355 | regset theend; |
2356 | register edge e; | |
2357 | ||
2358 | theend = EXIT_BLOCK_PTR->global_live_at_start; | |
2359 | mark_regs_live_at_end (theend); | |
2360 | ||
2361 | /* Propogate this exit data to each of EXIT's predecessors. */ | |
2362 | for (e = EXIT_BLOCK_PTR->pred; e ; e = e->pred_next) | |
2363 | { | |
2364 | COPY_REG_SET (e->src->global_live_at_end, theend); | |
2365 | COPY_REG_SET ((regset) e->src->aux, theend); | |
2366 | } | |
dc2ede84 | 2367 | } |
d7429b6a | 2368 | |
e881bb1b RH |
2369 | /* The post-reload life analysis have (on a global basis) the same registers |
2370 | live as was computed by reload itself. | |
2371 | ||
2372 | Otherwise elimination offsets and such may be incorrect. | |
2373 | ||
2374 | Reload will make some registers as live even though they do not appear | |
2375 | in the rtl. */ | |
2376 | if (reload_completed) | |
2377 | memcpy (save_regs_ever_live, regs_ever_live, sizeof (regs_ever_live)); | |
2378 | memset (regs_ever_live, 0, sizeof regs_ever_live); | |
2379 | ||
d7429b6a RK |
2380 | /* Propagate life info through the basic blocks |
2381 | around the graph of basic blocks. | |
2382 | ||
2383 | This is a relaxation process: each time a new register | |
2384 | is live at the end of the basic block, we must scan the block | |
2385 | to determine which registers are, as a consequence, live at the beginning | |
2386 | of that block. These registers must then be marked live at the ends | |
2387 | of all the blocks that can transfer control to that block. | |
2388 | The process continues until it reaches a fixed point. */ | |
2389 | ||
2390 | first_pass = 1; | |
2391 | changed = 1; | |
2392 | while (changed) | |
2393 | { | |
2394 | changed = 0; | |
2395 | for (i = n_basic_blocks - 1; i >= 0; i--) | |
2396 | { | |
e881bb1b | 2397 | basic_block bb = BASIC_BLOCK (i); |
d7429b6a RK |
2398 | int consider = first_pass; |
2399 | int must_rescan = first_pass; | |
2400 | register int j; | |
2401 | ||
2402 | if (!first_pass) | |
2403 | { | |
2404 | /* Set CONSIDER if this block needs thinking about at all | |
2405 | (that is, if the regs live now at the end of it | |
2406 | are not the same as were live at the end of it when | |
2407 | we last thought about it). | |
2408 | Set must_rescan if it needs to be thought about | |
2409 | instruction by instruction (that is, if any additional | |
2410 | reg that is live at the end now but was not live there before | |
2411 | is one of the significant regs of this basic block). */ | |
2412 | ||
b5835272 | 2413 | EXECUTE_IF_AND_COMPL_IN_REG_SET |
e881bb1b | 2414 | ((regset) bb->aux, bb->global_live_at_end, 0, j, |
b5835272 RK |
2415 | { |
2416 | consider = 1; | |
e881bb1b | 2417 | if (REGNO_REG_SET_P (bb->local_set, j)) |
b5835272 RK |
2418 | { |
2419 | must_rescan = 1; | |
2420 | goto done; | |
2421 | } | |
2422 | }); | |
916b1701 | 2423 | done: |
d7429b6a RK |
2424 | if (! consider) |
2425 | continue; | |
2426 | } | |
2427 | ||
2428 | /* The live_at_start of this block may be changing, | |
2429 | so another pass will be required after this one. */ | |
2430 | changed = 1; | |
2431 | ||
2432 | if (! must_rescan) | |
2433 | { | |
2434 | /* No complete rescan needed; | |
2435 | just record those variables newly known live at end | |
2436 | as live at start as well. */ | |
e881bb1b RH |
2437 | IOR_AND_COMPL_REG_SET (bb->global_live_at_start, |
2438 | (regset) bb->aux, | |
2439 | bb->global_live_at_end); | |
916b1701 | 2440 | |
e881bb1b RH |
2441 | IOR_AND_COMPL_REG_SET (bb->global_live_at_end, |
2442 | (regset) bb->aux, | |
2443 | bb->global_live_at_end); | |
d7429b6a RK |
2444 | } |
2445 | else | |
2446 | { | |
2447 | /* Update the basic_block_live_at_start | |
2448 | by propagation backwards through the block. */ | |
e881bb1b RH |
2449 | COPY_REG_SET (bb->global_live_at_end, (regset) bb->aux); |
2450 | COPY_REG_SET (bb->global_live_at_start, | |
2451 | bb->global_live_at_end); | |
2452 | propagate_block (bb->global_live_at_start, | |
2453 | bb->head, bb->end, 0, | |
2454 | first_pass ? bb->local_set : (regset) 0, | |
11f246f6 | 2455 | i, remove_dead_code); |
d7429b6a RK |
2456 | } |
2457 | ||
e881bb1b | 2458 | /* Update the new_live_at_end's of the block's predecessors. */ |
d7429b6a | 2459 | { |
e881bb1b | 2460 | register edge e; |
af14ce9c | 2461 | |
e881bb1b RH |
2462 | for (e = bb->pred; e ; e = e->pred_next) |
2463 | IOR_REG_SET ((regset) e->src->aux, bb->global_live_at_start); | |
d7429b6a | 2464 | } |
e881bb1b | 2465 | |
d7429b6a RK |
2466 | #ifdef USE_C_ALLOCA |
2467 | alloca (0); | |
2468 | #endif | |
2469 | } | |
2470 | first_pass = 0; | |
2471 | } | |
2472 | ||
2473 | /* The only pseudos that are live at the beginning of the function are | |
2474 | those that were not set anywhere in the function. local-alloc doesn't | |
2475 | know how to handle these correctly, so mark them as not local to any | |
2476 | one basic block. */ | |
2477 | ||
2478 | if (n_basic_blocks > 0) | |
e881bb1b | 2479 | EXECUTE_IF_SET_IN_REG_SET (BASIC_BLOCK (0)->global_live_at_start, |
916b1701 MM |
2480 | FIRST_PSEUDO_REGISTER, i, |
2481 | { | |
2482 | REG_BASIC_BLOCK (i) = REG_BLOCK_GLOBAL; | |
2483 | }); | |
d7429b6a | 2484 | |
e881bb1b RH |
2485 | /* Now the life information is accurate. Make one more pass over each |
2486 | basic block to delete dead stores, create autoincrement addressing | |
2487 | and record how many times each register is used, is set, or dies. */ | |
d7429b6a | 2488 | |
d7429b6a RK |
2489 | for (i = 0; i < n_basic_blocks; i++) |
2490 | { | |
e881bb1b RH |
2491 | basic_block bb = BASIC_BLOCK (i); |
2492 | ||
2493 | /* We start with global_live_at_end to determine which stores are | |
2494 | dead. This process is destructive, and we wish to preserve the | |
2495 | contents of global_live_at_end for posterity. Fortunately, | |
2496 | new_live_at_end, due to the way we converged on a solution, | |
2497 | contains a duplicate of global_live_at_end that we can kill. */ | |
11f246f6 | 2498 | propagate_block ((regset) bb->aux, bb->head, bb->end, 1, (regset) 0, i, remove_dead_code); |
e881bb1b | 2499 | |
d7429b6a RK |
2500 | #ifdef USE_C_ALLOCA |
2501 | alloca (0); | |
2502 | #endif | |
2503 | } | |
2504 | ||
e881bb1b RH |
2505 | /* We have a problem with any pseudoreg that lives across the setjmp. |
2506 | ANSI says that if a user variable does not change in value between | |
2507 | the setjmp and the longjmp, then the longjmp preserves it. This | |
2508 | includes longjmp from a place where the pseudo appears dead. | |
d7429b6a RK |
2509 | (In principle, the value still exists if it is in scope.) |
2510 | If the pseudo goes in a hard reg, some other value may occupy | |
2511 | that hard reg where this pseudo is dead, thus clobbering the pseudo. | |
2512 | Conclusion: such a pseudo must not go in a hard reg. */ | |
916b1701 MM |
2513 | EXECUTE_IF_SET_IN_REG_SET (regs_live_at_setjmp, |
2514 | FIRST_PSEUDO_REGISTER, i, | |
2515 | { | |
2516 | if (regno_reg_rtx[i] != 0) | |
2517 | { | |
2518 | REG_LIVE_LENGTH (i) = -1; | |
2519 | REG_BASIC_BLOCK (i) = -1; | |
2520 | } | |
2521 | }); | |
d7429b6a | 2522 | |
6764d250 BS |
2523 | /* Restore regs_ever_live that was provided by reload. */ |
2524 | if (reload_completed) | |
e881bb1b | 2525 | memcpy (regs_ever_live, save_regs_ever_live, sizeof (regs_ever_live)); |
67f0e213 | 2526 | |
e881bb1b | 2527 | free_regset_vector (new_live_at_end, n_basic_blocks); |
5f4f0e22 | 2528 | obstack_free (&flow_obstack, NULL_PTR); |
e881bb1b RH |
2529 | |
2530 | for (i = 0; i < n_basic_blocks; ++i) | |
2531 | BASIC_BLOCK (i)->aux = NULL; | |
2532 | ENTRY_BLOCK_PTR->aux = NULL; | |
d7429b6a RK |
2533 | } |
2534 | \f | |
2535 | /* Subroutines of life analysis. */ | |
2536 | ||
2537 | /* Allocate the permanent data structures that represent the results | |
2538 | of life analysis. Not static since used also for stupid life analysis. */ | |
2539 | ||
2540 | void | |
359da67d | 2541 | allocate_bb_life_data () |
d7429b6a RK |
2542 | { |
2543 | register int i; | |
d7429b6a | 2544 | |
e881bb1b RH |
2545 | for (i = 0; i < n_basic_blocks; i++) |
2546 | { | |
2547 | basic_block bb = BASIC_BLOCK (i); | |
2548 | ||
2549 | bb->local_set = OBSTACK_ALLOC_REG_SET (function_obstack); | |
2550 | bb->global_live_at_start = OBSTACK_ALLOC_REG_SET (function_obstack); | |
2551 | bb->global_live_at_end = OBSTACK_ALLOC_REG_SET (function_obstack); | |
2552 | } | |
2553 | ||
2554 | ENTRY_BLOCK_PTR->global_live_at_end | |
2555 | = OBSTACK_ALLOC_REG_SET (function_obstack); | |
2556 | EXIT_BLOCK_PTR->global_live_at_start | |
2557 | = OBSTACK_ALLOC_REG_SET (function_obstack); | |
d7429b6a | 2558 | |
7eb136d6 | 2559 | regs_live_at_setjmp = OBSTACK_ALLOC_REG_SET (function_obstack); |
359da67d RH |
2560 | } |
2561 | ||
2562 | void | |
2563 | allocate_reg_life_data () | |
2564 | { | |
2565 | int i; | |
2566 | ||
2567 | /* Recalculate the register space, in case it has grown. Old style | |
2568 | vector oriented regsets would set regset_{size,bytes} here also. */ | |
2569 | allocate_reg_info (max_regno, FALSE, FALSE); | |
2570 | ||
2571 | /* Because both reg_scan and flow_analysis want to set up the REG_N_SETS | |
2572 | information, explicitly reset it here. The allocation should have | |
2573 | already happened on the previous reg_scan pass. Make sure in case | |
2574 | some more registers were allocated. */ | |
2575 | for (i = 0; i < max_regno; i++) | |
2576 | REG_N_SETS (i) = 0; | |
d7429b6a RK |
2577 | } |
2578 | ||
67f0e213 RK |
2579 | /* Make each element of VECTOR point at a regset. The vector has |
2580 | NELTS elements, and space is allocated from the ALLOC_OBSTACK | |
2581 | obstack. */ | |
d7429b6a | 2582 | |
04821e98 | 2583 | static void |
67f0e213 | 2584 | init_regset_vector (vector, nelts, alloc_obstack) |
d7429b6a | 2585 | regset *vector; |
d7429b6a | 2586 | int nelts; |
7eb136d6 | 2587 | struct obstack *alloc_obstack; |
d7429b6a RK |
2588 | { |
2589 | register int i; | |
d7429b6a RK |
2590 | |
2591 | for (i = 0; i < nelts; i++) | |
2592 | { | |
7eb136d6 MM |
2593 | vector[i] = OBSTACK_ALLOC_REG_SET (alloc_obstack); |
2594 | CLEAR_REG_SET (vector[i]); | |
d7429b6a RK |
2595 | } |
2596 | } | |
e658434c | 2597 | |
67f0e213 RK |
2598 | /* Release any additional space allocated for each element of VECTOR point |
2599 | other than the regset header itself. The vector has NELTS elements. */ | |
2600 | ||
2601 | void | |
2602 | free_regset_vector (vector, nelts) | |
2603 | regset *vector; | |
2604 | int nelts; | |
2605 | { | |
2606 | register int i; | |
2607 | ||
2608 | for (i = 0; i < nelts; i++) | |
2609 | FREE_REG_SET (vector[i]); | |
2610 | } | |
2611 | ||
d7429b6a RK |
2612 | /* Compute the registers live at the beginning of a basic block |
2613 | from those live at the end. | |
2614 | ||
2615 | When called, OLD contains those live at the end. | |
2616 | On return, it contains those live at the beginning. | |
2617 | FIRST and LAST are the first and last insns of the basic block. | |
2618 | ||
2619 | FINAL is nonzero if we are doing the final pass which is not | |
2620 | for computing the life info (since that has already been done) | |
2621 | but for acting on it. On this pass, we delete dead stores, | |
2622 | set up the logical links and dead-variables lists of instructions, | |
2623 | and merge instructions for autoincrement and autodecrement addresses. | |
2624 | ||
2625 | SIGNIFICANT is nonzero only the first time for each basic block. | |
2626 | If it is nonzero, it points to a regset in which we store | |
2627 | a 1 for each register that is set within the block. | |
2628 | ||
2629 | BNUM is the number of the basic block. */ | |
2630 | ||
2631 | static void | |
11f246f6 | 2632 | propagate_block (old, first, last, final, significant, bnum, remove_dead_code) |
d7429b6a RK |
2633 | register regset old; |
2634 | rtx first; | |
2635 | rtx last; | |
2636 | int final; | |
2637 | regset significant; | |
2638 | int bnum; | |
11f246f6 | 2639 | int remove_dead_code; |
d7429b6a RK |
2640 | { |
2641 | register rtx insn; | |
2642 | rtx prev; | |
2643 | regset live; | |
2644 | regset dead; | |
2645 | ||
e881bb1b RH |
2646 | /* Find the loop depth for this block. Ignore loop level changes in the |
2647 | middle of the basic block -- for register allocation purposes, the | |
2648 | important uses will be in the blocks wholely contained within the loop | |
2649 | not in the loop pre-header or post-trailer. */ | |
2650 | loop_depth = BASIC_BLOCK (bnum)->loop_depth; | |
d7429b6a | 2651 | |
7eb136d6 MM |
2652 | dead = ALLOCA_REG_SET (); |
2653 | live = ALLOCA_REG_SET (); | |
d7429b6a RK |
2654 | |
2655 | cc0_live = 0; | |
db3a887b | 2656 | mem_set_list = NULL_RTX; |
d7429b6a | 2657 | |
d7429b6a RK |
2658 | if (final) |
2659 | { | |
916b1701 | 2660 | register int i; |
d7429b6a | 2661 | |
d7429b6a | 2662 | /* Process the regs live at the end of the block. |
f8dd7f98 | 2663 | Mark them as not local to any one basic block. */ |
916b1701 MM |
2664 | EXECUTE_IF_SET_IN_REG_SET (old, 0, i, |
2665 | { | |
2666 | REG_BASIC_BLOCK (i) = REG_BLOCK_GLOBAL; | |
916b1701 | 2667 | }); |
d7429b6a RK |
2668 | } |
2669 | ||
2670 | /* Scan the block an insn at a time from end to beginning. */ | |
2671 | ||
2672 | for (insn = last; ; insn = prev) | |
2673 | { | |
2674 | prev = PREV_INSN (insn); | |
2675 | ||
8329b5ec | 2676 | if (GET_CODE (insn) == NOTE) |
d7429b6a | 2677 | { |
8329b5ec DE |
2678 | /* If this is a call to `setjmp' et al, |
2679 | warn if any non-volatile datum is live. */ | |
2680 | ||
2681 | if (final && NOTE_LINE_NUMBER (insn) == NOTE_INSN_SETJMP) | |
916b1701 | 2682 | IOR_REG_SET (regs_live_at_setjmp, old); |
d7429b6a RK |
2683 | } |
2684 | ||
2685 | /* Update the life-status of regs for this insn. | |
2686 | First DEAD gets which regs are set in this insn | |
2687 | then LIVE gets which regs are used in this insn. | |
2688 | Then the regs live before the insn | |
2689 | are those live after, with DEAD regs turned off, | |
2690 | and then LIVE regs turned on. */ | |
2691 | ||
8329b5ec | 2692 | else if (GET_RTX_CLASS (GET_CODE (insn)) == 'i') |
d7429b6a RK |
2693 | { |
2694 | register int i; | |
5f4f0e22 | 2695 | rtx note = find_reg_note (insn, REG_RETVAL, NULL_RTX); |
11f246f6 JH |
2696 | int insn_is_dead = 0; |
2697 | int libcall_is_dead = 0; | |
2698 | ||
2699 | if (remove_dead_code) | |
2700 | { | |
2701 | insn_is_dead = (insn_dead_p (PATTERN (insn), old, 0, REG_NOTES (insn)) | |
2702 | /* Don't delete something that refers to volatile storage! */ | |
2703 | && ! INSN_VOLATILE (insn)); | |
2704 | libcall_is_dead = (insn_is_dead && note != 0 | |
2705 | && libcall_dead_p (PATTERN (insn), old, note, insn)); | |
2706 | } | |
d7429b6a RK |
2707 | |
2708 | /* If an instruction consists of just dead store(s) on final pass, | |
2709 | "delete" it by turning it into a NOTE of type NOTE_INSN_DELETED. | |
2710 | We could really delete it with delete_insn, but that | |
2711 | can cause trouble for first or last insn in a basic block. */ | |
b590bbfd | 2712 | if (final && insn_is_dead) |
d7429b6a RK |
2713 | { |
2714 | PUT_CODE (insn, NOTE); | |
2715 | NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED; | |
2716 | NOTE_SOURCE_FILE (insn) = 0; | |
2717 | ||
e5df1ea3 RK |
2718 | /* CC0 is now known to be dead. Either this insn used it, |
2719 | in which case it doesn't anymore, or clobbered it, | |
2720 | so the next insn can't use it. */ | |
2721 | cc0_live = 0; | |
2722 | ||
d7429b6a RK |
2723 | /* If this insn is copying the return value from a library call, |
2724 | delete the entire library call. */ | |
2725 | if (libcall_is_dead) | |
2726 | { | |
2727 | rtx first = XEXP (note, 0); | |
2728 | rtx p = insn; | |
2729 | while (INSN_DELETED_P (first)) | |
2730 | first = NEXT_INSN (first); | |
2731 | while (p != first) | |
2732 | { | |
2733 | p = PREV_INSN (p); | |
2734 | PUT_CODE (p, NOTE); | |
2735 | NOTE_LINE_NUMBER (p) = NOTE_INSN_DELETED; | |
2736 | NOTE_SOURCE_FILE (p) = 0; | |
2737 | } | |
2738 | } | |
2739 | goto flushed; | |
2740 | } | |
2741 | ||
916b1701 MM |
2742 | CLEAR_REG_SET (dead); |
2743 | CLEAR_REG_SET (live); | |
d7429b6a RK |
2744 | |
2745 | /* See if this is an increment or decrement that can be | |
2746 | merged into a following memory address. */ | |
2747 | #ifdef AUTO_INC_DEC | |
2748 | { | |
956d6950 JL |
2749 | register rtx x = single_set (insn); |
2750 | ||
d7429b6a | 2751 | /* Does this instruction increment or decrement a register? */ |
6764d250 BS |
2752 | if (!reload_completed |
2753 | && final && x != 0 | |
d7429b6a RK |
2754 | && GET_CODE (SET_DEST (x)) == REG |
2755 | && (GET_CODE (SET_SRC (x)) == PLUS | |
2756 | || GET_CODE (SET_SRC (x)) == MINUS) | |
2757 | && XEXP (SET_SRC (x), 0) == SET_DEST (x) | |
2758 | && GET_CODE (XEXP (SET_SRC (x), 1)) == CONST_INT | |
2759 | /* Ok, look for a following memory ref we can combine with. | |
2760 | If one is found, change the memory ref to a PRE_INC | |
2761 | or PRE_DEC, cancel this insn, and return 1. | |
2762 | Return 0 if nothing has been done. */ | |
2763 | && try_pre_increment_1 (insn)) | |
2764 | goto flushed; | |
2765 | } | |
2766 | #endif /* AUTO_INC_DEC */ | |
2767 | ||
2768 | /* If this is not the final pass, and this insn is copying the | |
2769 | value of a library call and it's dead, don't scan the | |
2770 | insns that perform the library call, so that the call's | |
2771 | arguments are not marked live. */ | |
2772 | if (libcall_is_dead) | |
2773 | { | |
2774 | /* Mark the dest reg as `significant'. */ | |
5f4f0e22 | 2775 | mark_set_regs (old, dead, PATTERN (insn), NULL_RTX, significant); |
d7429b6a RK |
2776 | |
2777 | insn = XEXP (note, 0); | |
2778 | prev = PREV_INSN (insn); | |
2779 | } | |
2780 | else if (GET_CODE (PATTERN (insn)) == SET | |
2781 | && SET_DEST (PATTERN (insn)) == stack_pointer_rtx | |
2782 | && GET_CODE (SET_SRC (PATTERN (insn))) == PLUS | |
2783 | && XEXP (SET_SRC (PATTERN (insn)), 0) == stack_pointer_rtx | |
2784 | && GET_CODE (XEXP (SET_SRC (PATTERN (insn)), 1)) == CONST_INT) | |
2785 | /* We have an insn to pop a constant amount off the stack. | |
2786 | (Such insns use PLUS regardless of the direction of the stack, | |
2787 | and any insn to adjust the stack by a constant is always a pop.) | |
2788 | These insns, if not dead stores, have no effect on life. */ | |
2789 | ; | |
2790 | else | |
2791 | { | |
f8dd7f98 BS |
2792 | /* Any regs live at the time of a call instruction |
2793 | must not go in a register clobbered by calls. | |
2794 | Find all regs now live and record this for them. */ | |
2795 | ||
2796 | if (GET_CODE (insn) == CALL_INSN && final) | |
2797 | EXECUTE_IF_SET_IN_REG_SET (old, 0, i, | |
2798 | { | |
2799 | REG_N_CALLS_CROSSED (i)++; | |
2800 | }); | |
2801 | ||
d7429b6a RK |
2802 | /* LIVE gets the regs used in INSN; |
2803 | DEAD gets those set by it. Dead insns don't make anything | |
2804 | live. */ | |
2805 | ||
5f4f0e22 CH |
2806 | mark_set_regs (old, dead, PATTERN (insn), |
2807 | final ? insn : NULL_RTX, significant); | |
d7429b6a RK |
2808 | |
2809 | /* If an insn doesn't use CC0, it becomes dead since we | |
2810 | assume that every insn clobbers it. So show it dead here; | |
2811 | mark_used_regs will set it live if it is referenced. */ | |
2812 | cc0_live = 0; | |
2813 | ||
2814 | if (! insn_is_dead) | |
2815 | mark_used_regs (old, live, PATTERN (insn), final, insn); | |
2816 | ||
2817 | /* Sometimes we may have inserted something before INSN (such as | |
2818 | a move) when we make an auto-inc. So ensure we will scan | |
2819 | those insns. */ | |
2820 | #ifdef AUTO_INC_DEC | |
2821 | prev = PREV_INSN (insn); | |
2822 | #endif | |
2823 | ||
2824 | if (! insn_is_dead && GET_CODE (insn) == CALL_INSN) | |
2825 | { | |
2826 | register int i; | |
2827 | ||
6b67ec08 RK |
2828 | rtx note; |
2829 | ||
2830 | for (note = CALL_INSN_FUNCTION_USAGE (insn); | |
2831 | note; | |
2832 | note = XEXP (note, 1)) | |
2833 | if (GET_CODE (XEXP (note, 0)) == USE) | |
2834 | mark_used_regs (old, live, SET_DEST (XEXP (note, 0)), | |
2835 | final, insn); | |
2836 | ||
d7429b6a | 2837 | /* Each call clobbers all call-clobbered regs that are not |
e4329280 | 2838 | global or fixed. Note that the function-value reg is a |
d7429b6a RK |
2839 | call-clobbered reg, and mark_set_regs has already had |
2840 | a chance to handle it. */ | |
2841 | ||
2842 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
e4329280 RK |
2843 | if (call_used_regs[i] && ! global_regs[i] |
2844 | && ! fixed_regs[i]) | |
916b1701 | 2845 | SET_REGNO_REG_SET (dead, i); |
d7429b6a RK |
2846 | |
2847 | /* The stack ptr is used (honorarily) by a CALL insn. */ | |
916b1701 | 2848 | SET_REGNO_REG_SET (live, STACK_POINTER_REGNUM); |
d7429b6a RK |
2849 | |
2850 | /* Calls may also reference any of the global registers, | |
2851 | so they are made live. */ | |
d7429b6a RK |
2852 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) |
2853 | if (global_regs[i]) | |
9b316aa2 | 2854 | mark_used_regs (old, live, |
38a448ca | 2855 | gen_rtx_REG (reg_raw_mode[i], i), |
9b316aa2 | 2856 | final, insn); |
d7429b6a RK |
2857 | |
2858 | /* Calls also clobber memory. */ | |
db3a887b | 2859 | mem_set_list = NULL_RTX; |
d7429b6a RK |
2860 | } |
2861 | ||
2862 | /* Update OLD for the registers used or set. */ | |
916b1701 MM |
2863 | AND_COMPL_REG_SET (old, dead); |
2864 | IOR_REG_SET (old, live); | |
d7429b6a | 2865 | |
d7429b6a RK |
2866 | } |
2867 | ||
f8dd7f98 BS |
2868 | /* On final pass, update counts of how many insns each reg is live |
2869 | at. */ | |
d7429b6a | 2870 | if (final) |
f8dd7f98 BS |
2871 | EXECUTE_IF_SET_IN_REG_SET (old, 0, i, |
2872 | { REG_LIVE_LENGTH (i)++; }); | |
d7429b6a RK |
2873 | } |
2874 | flushed: ; | |
2875 | if (insn == first) | |
2876 | break; | |
2877 | } | |
2878 | ||
67f0e213 RK |
2879 | FREE_REG_SET (dead); |
2880 | FREE_REG_SET (live); | |
d7429b6a RK |
2881 | } |
2882 | \f | |
2883 | /* Return 1 if X (the body of an insn, or part of it) is just dead stores | |
2884 | (SET expressions whose destinations are registers dead after the insn). | |
2885 | NEEDED is the regset that says which regs are alive after the insn. | |
2886 | ||
e398aa80 R |
2887 | Unless CALL_OK is non-zero, an insn is needed if it contains a CALL. |
2888 | ||
2889 | If X is the entire body of an insn, NOTES contains the reg notes | |
2890 | pertaining to the insn. */ | |
d7429b6a RK |
2891 | |
2892 | static int | |
e398aa80 | 2893 | insn_dead_p (x, needed, call_ok, notes) |
d7429b6a RK |
2894 | rtx x; |
2895 | regset needed; | |
2896 | int call_ok; | |
e398aa80 | 2897 | rtx notes ATTRIBUTE_UNUSED; |
d7429b6a | 2898 | { |
e5e809f4 JL |
2899 | enum rtx_code code = GET_CODE (x); |
2900 | ||
e398aa80 R |
2901 | #ifdef AUTO_INC_DEC |
2902 | /* If flow is invoked after reload, we must take existing AUTO_INC | |
2903 | expresions into account. */ | |
2904 | if (reload_completed) | |
2905 | { | |
2906 | for ( ; notes; notes = XEXP (notes, 1)) | |
2907 | { | |
2908 | if (REG_NOTE_KIND (notes) == REG_INC) | |
2909 | { | |
2910 | int regno = REGNO (XEXP (notes, 0)); | |
2911 | ||
2912 | /* Don't delete insns to set global regs. */ | |
2913 | if ((regno < FIRST_PSEUDO_REGISTER && global_regs[regno]) | |
2914 | || REGNO_REG_SET_P (needed, regno)) | |
2915 | return 0; | |
2916 | } | |
2917 | } | |
2918 | } | |
2919 | #endif | |
2920 | ||
d7429b6a RK |
2921 | /* If setting something that's a reg or part of one, |
2922 | see if that register's altered value will be live. */ | |
2923 | ||
2924 | if (code == SET) | |
2925 | { | |
e5e809f4 JL |
2926 | rtx r = SET_DEST (x); |
2927 | ||
d7429b6a RK |
2928 | /* A SET that is a subroutine call cannot be dead. */ |
2929 | if (! call_ok && GET_CODE (SET_SRC (x)) == CALL) | |
2930 | return 0; | |
2931 | ||
2932 | #ifdef HAVE_cc0 | |
2933 | if (GET_CODE (r) == CC0) | |
2934 | return ! cc0_live; | |
2935 | #endif | |
2936 | ||
db3a887b CB |
2937 | if (GET_CODE (r) == MEM && ! MEM_VOLATILE_P (r)) |
2938 | { | |
2939 | rtx temp; | |
2940 | /* Walk the set of memory locations we are currently tracking | |
2941 | and see if one is an identical match to this memory location. | |
2942 | If so, this memory write is dead (remember, we're walking | |
2943 | backwards from the end of the block to the start. */ | |
2944 | temp = mem_set_list; | |
2945 | while (temp) | |
2946 | { | |
2947 | if (rtx_equal_p (XEXP (temp, 0), r)) | |
2948 | return 1; | |
2949 | temp = XEXP (temp, 1); | |
2950 | } | |
2951 | } | |
d7429b6a | 2952 | |
e5e809f4 JL |
2953 | while (GET_CODE (r) == SUBREG || GET_CODE (r) == STRICT_LOW_PART |
2954 | || GET_CODE (r) == ZERO_EXTRACT) | |
d7429b6a RK |
2955 | r = SUBREG_REG (r); |
2956 | ||
2957 | if (GET_CODE (r) == REG) | |
2958 | { | |
e5e809f4 | 2959 | int regno = REGNO (r); |
d7429b6a | 2960 | |
d8c8b8e3 | 2961 | /* Don't delete insns to set global regs. */ |
d7429b6a RK |
2962 | if ((regno < FIRST_PSEUDO_REGISTER && global_regs[regno]) |
2963 | /* Make sure insns to set frame pointer aren't deleted. */ | |
e4b8a413 JW |
2964 | || (regno == FRAME_POINTER_REGNUM |
2965 | && (! reload_completed || frame_pointer_needed)) | |
73a187c1 | 2966 | #if FRAME_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM |
e4b8a413 JW |
2967 | || (regno == HARD_FRAME_POINTER_REGNUM |
2968 | && (! reload_completed || frame_pointer_needed)) | |
73a187c1 | 2969 | #endif |
d7e4fe8b RS |
2970 | #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM |
2971 | /* Make sure insns to set arg pointer are never deleted | |
2972 | (if the arg pointer isn't fixed, there will be a USE for | |
0f41302f | 2973 | it, so we can treat it normally). */ |
d7e4fe8b RS |
2974 | || (regno == ARG_POINTER_REGNUM && fixed_regs[regno]) |
2975 | #endif | |
916b1701 | 2976 | || REGNO_REG_SET_P (needed, regno)) |
d7429b6a RK |
2977 | return 0; |
2978 | ||
2979 | /* If this is a hard register, verify that subsequent words are | |
2980 | not needed. */ | |
2981 | if (regno < FIRST_PSEUDO_REGISTER) | |
2982 | { | |
2983 | int n = HARD_REGNO_NREGS (regno, GET_MODE (r)); | |
2984 | ||
2985 | while (--n > 0) | |
916b1701 | 2986 | if (REGNO_REG_SET_P (needed, regno+n)) |
d7429b6a RK |
2987 | return 0; |
2988 | } | |
2989 | ||
2990 | return 1; | |
2991 | } | |
2992 | } | |
e5e809f4 | 2993 | |
d7429b6a RK |
2994 | /* If performing several activities, |
2995 | insn is dead if each activity is individually dead. | |
2996 | Also, CLOBBERs and USEs can be ignored; a CLOBBER or USE | |
2997 | that's inside a PARALLEL doesn't make the insn worth keeping. */ | |
2998 | else if (code == PARALLEL) | |
2999 | { | |
e5e809f4 JL |
3000 | int i = XVECLEN (x, 0); |
3001 | ||
d7429b6a | 3002 | for (i--; i >= 0; i--) |
e5e809f4 JL |
3003 | if (GET_CODE (XVECEXP (x, 0, i)) != CLOBBER |
3004 | && GET_CODE (XVECEXP (x, 0, i)) != USE | |
e398aa80 | 3005 | && ! insn_dead_p (XVECEXP (x, 0, i), needed, call_ok, NULL_RTX)) |
e5e809f4 JL |
3006 | return 0; |
3007 | ||
d7429b6a RK |
3008 | return 1; |
3009 | } | |
e5e809f4 JL |
3010 | |
3011 | /* A CLOBBER of a pseudo-register that is dead serves no purpose. That | |
3012 | is not necessarily true for hard registers. */ | |
3013 | else if (code == CLOBBER && GET_CODE (XEXP (x, 0)) == REG | |
3014 | && REGNO (XEXP (x, 0)) >= FIRST_PSEUDO_REGISTER | |
3015 | && ! REGNO_REG_SET_P (needed, REGNO (XEXP (x, 0)))) | |
3016 | return 1; | |
3017 | ||
3018 | /* We do not check other CLOBBER or USE here. An insn consisting of just | |
3019 | a CLOBBER or just a USE should not be deleted. */ | |
d7429b6a RK |
3020 | return 0; |
3021 | } | |
3022 | ||
3023 | /* If X is the pattern of the last insn in a libcall, and assuming X is dead, | |
3024 | return 1 if the entire library call is dead. | |
3025 | This is true if X copies a register (hard or pseudo) | |
3026 | and if the hard return reg of the call insn is dead. | |
3027 | (The caller should have tested the destination of X already for death.) | |
3028 | ||
3029 | If this insn doesn't just copy a register, then we don't | |
3030 | have an ordinary libcall. In that case, cse could not have | |
3031 | managed to substitute the source for the dest later on, | |
3032 | so we can assume the libcall is dead. | |
3033 | ||
3034 | NEEDED is the bit vector of pseudoregs live before this insn. | |
3035 | NOTE is the REG_RETVAL note of the insn. INSN is the insn itself. */ | |
3036 | ||
3037 | static int | |
3038 | libcall_dead_p (x, needed, note, insn) | |
3039 | rtx x; | |
3040 | regset needed; | |
3041 | rtx note; | |
3042 | rtx insn; | |
3043 | { | |
3044 | register RTX_CODE code = GET_CODE (x); | |
3045 | ||
3046 | if (code == SET) | |
3047 | { | |
3048 | register rtx r = SET_SRC (x); | |
3049 | if (GET_CODE (r) == REG) | |
3050 | { | |
3051 | rtx call = XEXP (note, 0); | |
e398aa80 | 3052 | rtx call_pat; |
d7429b6a RK |
3053 | register int i; |
3054 | ||
3055 | /* Find the call insn. */ | |
3056 | while (call != insn && GET_CODE (call) != CALL_INSN) | |
3057 | call = NEXT_INSN (call); | |
3058 | ||
3059 | /* If there is none, do nothing special, | |
3060 | since ordinary death handling can understand these insns. */ | |
3061 | if (call == insn) | |
3062 | return 0; | |
3063 | ||
3064 | /* See if the hard reg holding the value is dead. | |
3065 | If this is a PARALLEL, find the call within it. */ | |
e398aa80 R |
3066 | call_pat = PATTERN (call); |
3067 | if (GET_CODE (call_pat) == PARALLEL) | |
d7429b6a | 3068 | { |
e398aa80 R |
3069 | for (i = XVECLEN (call_pat, 0) - 1; i >= 0; i--) |
3070 | if (GET_CODE (XVECEXP (call_pat, 0, i)) == SET | |
3071 | && GET_CODE (SET_SRC (XVECEXP (call_pat, 0, i))) == CALL) | |
d7429b6a RK |
3072 | break; |
3073 | ||
761a5bcd JW |
3074 | /* This may be a library call that is returning a value |
3075 | via invisible pointer. Do nothing special, since | |
3076 | ordinary death handling can understand these insns. */ | |
d7429b6a | 3077 | if (i < 0) |
761a5bcd | 3078 | return 0; |
d7429b6a | 3079 | |
e398aa80 | 3080 | call_pat = XVECEXP (call_pat, 0, i); |
d7429b6a RK |
3081 | } |
3082 | ||
e398aa80 | 3083 | return insn_dead_p (call_pat, needed, 1, REG_NOTES (call)); |
d7429b6a RK |
3084 | } |
3085 | } | |
3086 | return 1; | |
3087 | } | |
3088 | ||
bd80fbde RH |
3089 | /* Return 1 if register REGNO was used before it was set, i.e. if it is |
3090 | live at function entry. Don't count global register variables, variables | |
3091 | in registers that can be used for function arg passing, or variables in | |
3092 | fixed hard registers. */ | |
d7429b6a RK |
3093 | |
3094 | int | |
3095 | regno_uninitialized (regno) | |
3096 | int regno; | |
3097 | { | |
b0b7b46a | 3098 | if (n_basic_blocks == 0 |
6a45254e | 3099 | || (regno < FIRST_PSEUDO_REGISTER |
bd80fbde RH |
3100 | && (global_regs[regno] |
3101 | || fixed_regs[regno] | |
3102 | || FUNCTION_ARG_REGNO_P (regno)))) | |
d7429b6a RK |
3103 | return 0; |
3104 | ||
e881bb1b | 3105 | return REGNO_REG_SET_P (BASIC_BLOCK (0)->global_live_at_start, regno); |
d7429b6a RK |
3106 | } |
3107 | ||
3108 | /* 1 if register REGNO was alive at a place where `setjmp' was called | |
3109 | and was set more than once or is an argument. | |
3110 | Such regs may be clobbered by `longjmp'. */ | |
3111 | ||
3112 | int | |
3113 | regno_clobbered_at_setjmp (regno) | |
3114 | int regno; | |
3115 | { | |
3116 | if (n_basic_blocks == 0) | |
3117 | return 0; | |
3118 | ||
b1f21e0a | 3119 | return ((REG_N_SETS (regno) > 1 |
e881bb1b | 3120 | || REGNO_REG_SET_P (BASIC_BLOCK (0)->global_live_at_start, regno)) |
916b1701 | 3121 | && REGNO_REG_SET_P (regs_live_at_setjmp, regno)); |
d7429b6a RK |
3122 | } |
3123 | \f | |
15e088b2 JL |
3124 | /* INSN references memory, possibly using autoincrement addressing modes. |
3125 | Find any entries on the mem_set_list that need to be invalidated due | |
3126 | to an address change. */ | |
3127 | static void | |
3128 | invalidate_mems_from_autoinc (insn) | |
3129 | rtx insn; | |
3130 | { | |
3131 | rtx note = REG_NOTES (insn); | |
3132 | for (note = REG_NOTES (insn); note; note = XEXP (note, 1)) | |
3133 | { | |
3134 | if (REG_NOTE_KIND (note) == REG_INC) | |
3135 | { | |
3136 | rtx temp = mem_set_list; | |
3137 | rtx prev = NULL_RTX; | |
3138 | ||
3139 | while (temp) | |
3140 | { | |
3141 | if (reg_overlap_mentioned_p (XEXP (note, 0), XEXP (temp, 0))) | |
3142 | { | |
3143 | /* Splice temp out of list. */ | |
3144 | if (prev) | |
3145 | XEXP (prev, 1) = XEXP (temp, 1); | |
3146 | else | |
3147 | mem_set_list = XEXP (temp, 1); | |
3148 | } | |
3149 | else | |
3150 | prev = temp; | |
3151 | temp = XEXP (temp, 1); | |
3152 | } | |
3153 | } | |
3154 | } | |
3155 | } | |
3156 | ||
d7429b6a RK |
3157 | /* Process the registers that are set within X. |
3158 | Their bits are set to 1 in the regset DEAD, | |
3159 | because they are dead prior to this insn. | |
3160 | ||
3161 | If INSN is nonzero, it is the insn being processed | |
3162 | and the fact that it is nonzero implies this is the FINAL pass | |
3163 | in propagate_block. In this case, various info about register | |
3164 | usage is stored, LOG_LINKS fields of insns are set up. */ | |
3165 | ||
d7429b6a RK |
3166 | static void |
3167 | mark_set_regs (needed, dead, x, insn, significant) | |
3168 | regset needed; | |
3169 | regset dead; | |
3170 | rtx x; | |
3171 | rtx insn; | |
3172 | regset significant; | |
3173 | { | |
3174 | register RTX_CODE code = GET_CODE (x); | |
3175 | ||
3176 | if (code == SET || code == CLOBBER) | |
3177 | mark_set_1 (needed, dead, x, insn, significant); | |
3178 | else if (code == PARALLEL) | |
3179 | { | |
3180 | register int i; | |
3181 | for (i = XVECLEN (x, 0) - 1; i >= 0; i--) | |
3182 | { | |
3183 | code = GET_CODE (XVECEXP (x, 0, i)); | |
3184 | if (code == SET || code == CLOBBER) | |
3185 | mark_set_1 (needed, dead, XVECEXP (x, 0, i), insn, significant); | |
3186 | } | |
3187 | } | |
3188 | } | |
3189 | ||
3190 | /* Process a single SET rtx, X. */ | |
3191 | ||
3192 | static void | |
3193 | mark_set_1 (needed, dead, x, insn, significant) | |
3194 | regset needed; | |
3195 | regset dead; | |
3196 | rtx x; | |
3197 | rtx insn; | |
3198 | regset significant; | |
3199 | { | |
3200 | register int regno; | |
3201 | register rtx reg = SET_DEST (x); | |
3202 | ||
86465af7 DM |
3203 | /* Some targets place small structures in registers for |
3204 | return values of functions. We have to detect this | |
3205 | case specially here to get correct flow information. */ | |
3206 | if (GET_CODE (reg) == PARALLEL | |
3207 | && GET_MODE (reg) == BLKmode) | |
3208 | { | |
3209 | register int i; | |
3210 | ||
3211 | for (i = XVECLEN (reg, 0) - 1; i >= 0; i--) | |
3212 | mark_set_1 (needed, dead, XVECEXP (reg, 0, i), insn, significant); | |
3213 | return; | |
3214 | } | |
3215 | ||
d7429b6a RK |
3216 | /* Modifying just one hardware register of a multi-reg value |
3217 | or just a byte field of a register | |
3218 | does not mean the value from before this insn is now dead. | |
3219 | But it does mean liveness of that register at the end of the block | |
3220 | is significant. | |
3221 | ||
3222 | Within mark_set_1, however, we treat it as if the register is | |
3223 | indeed modified. mark_used_regs will, however, also treat this | |
3224 | register as being used. Thus, we treat these insns as setting a | |
3225 | new value for the register as a function of its old value. This | |
3226 | cases LOG_LINKS to be made appropriately and this will help combine. */ | |
3227 | ||
3228 | while (GET_CODE (reg) == SUBREG || GET_CODE (reg) == ZERO_EXTRACT | |
3229 | || GET_CODE (reg) == SIGN_EXTRACT | |
3230 | || GET_CODE (reg) == STRICT_LOW_PART) | |
3231 | reg = XEXP (reg, 0); | |
3232 | ||
db3a887b CB |
3233 | /* If this set is a MEM, then it kills any aliased writes. |
3234 | If this set is a REG, then it kills any MEMs which use the reg. */ | |
d7429b6a | 3235 | if (GET_CODE (reg) == MEM |
db3a887b CB |
3236 | || GET_CODE (reg) == REG) |
3237 | { | |
3238 | rtx temp = mem_set_list; | |
3239 | rtx prev = NULL_RTX; | |
3240 | ||
3241 | while (temp) | |
3242 | { | |
3243 | if ((GET_CODE (reg) == MEM | |
3244 | && output_dependence (XEXP (temp, 0), reg)) | |
3245 | || (GET_CODE (reg) == REG | |
3246 | && reg_overlap_mentioned_p (reg, XEXP (temp, 0)))) | |
3247 | { | |
3248 | /* Splice this entry out of the list. */ | |
3249 | if (prev) | |
3250 | XEXP (prev, 1) = XEXP (temp, 1); | |
3251 | else | |
3252 | mem_set_list = XEXP (temp, 1); | |
3253 | } | |
3254 | else | |
3255 | prev = temp; | |
3256 | temp = XEXP (temp, 1); | |
3257 | } | |
3258 | } | |
15e088b2 JL |
3259 | |
3260 | /* If the memory reference had embedded side effects (autoincrement | |
3261 | address modes. Then we may need to kill some entries on the | |
3262 | memory set list. */ | |
3263 | if (insn && GET_CODE (reg) == MEM) | |
3264 | invalidate_mems_from_autoinc (insn); | |
3265 | ||
d7429b6a | 3266 | if (GET_CODE (reg) == MEM && ! side_effects_p (reg) |
3ce7c5a2 JL |
3267 | /* We do not know the size of a BLKmode store, so we do not track |
3268 | them for redundant store elimination. */ | |
3269 | && GET_MODE (reg) != BLKmode | |
d7429b6a RK |
3270 | /* There are no REG_INC notes for SP, so we can't assume we'll see |
3271 | everything that invalidates it. To be safe, don't eliminate any | |
3272 | stores though SP; none of them should be redundant anyway. */ | |
3273 | && ! reg_mentioned_p (stack_pointer_rtx, reg)) | |
db3a887b | 3274 | mem_set_list = gen_rtx_EXPR_LIST (VOIDmode, reg, mem_set_list); |
d7429b6a RK |
3275 | |
3276 | if (GET_CODE (reg) == REG | |
e4b8a413 JW |
3277 | && (regno = REGNO (reg), ! (regno == FRAME_POINTER_REGNUM |
3278 | && (! reload_completed || frame_pointer_needed))) | |
73a187c1 | 3279 | #if FRAME_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM |
e4b8a413 JW |
3280 | && ! (regno == HARD_FRAME_POINTER_REGNUM |
3281 | && (! reload_completed || frame_pointer_needed)) | |
73a187c1 | 3282 | #endif |
d7e4fe8b RS |
3283 | #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM |
3284 | && ! (regno == ARG_POINTER_REGNUM && fixed_regs[regno]) | |
3285 | #endif | |
d7429b6a RK |
3286 | && ! (regno < FIRST_PSEUDO_REGISTER && global_regs[regno])) |
3287 | /* && regno != STACK_POINTER_REGNUM) -- let's try without this. */ | |
3288 | { | |
916b1701 MM |
3289 | int some_needed = REGNO_REG_SET_P (needed, regno); |
3290 | int some_not_needed = ! some_needed; | |
d7429b6a RK |
3291 | |
3292 | /* Mark it as a significant register for this basic block. */ | |
3293 | if (significant) | |
916b1701 | 3294 | SET_REGNO_REG_SET (significant, regno); |
d7429b6a | 3295 | |
38e01259 | 3296 | /* Mark it as dead before this insn. */ |
916b1701 | 3297 | SET_REGNO_REG_SET (dead, regno); |
d7429b6a RK |
3298 | |
3299 | /* A hard reg in a wide mode may really be multiple registers. | |
3300 | If so, mark all of them just like the first. */ | |
3301 | if (regno < FIRST_PSEUDO_REGISTER) | |
3302 | { | |
3303 | int n; | |
3304 | ||
3305 | /* Nothing below is needed for the stack pointer; get out asap. | |
3306 | Eg, log links aren't needed, since combine won't use them. */ | |
3307 | if (regno == STACK_POINTER_REGNUM) | |
3308 | return; | |
3309 | ||
3310 | n = HARD_REGNO_NREGS (regno, GET_MODE (reg)); | |
3311 | while (--n > 0) | |
3312 | { | |
916b1701 MM |
3313 | int regno_n = regno + n; |
3314 | int needed_regno = REGNO_REG_SET_P (needed, regno_n); | |
d7429b6a | 3315 | if (significant) |
916b1701 | 3316 | SET_REGNO_REG_SET (significant, regno_n); |
cb9e8ad1 | 3317 | |
916b1701 MM |
3318 | SET_REGNO_REG_SET (dead, regno_n); |
3319 | some_needed |= needed_regno; | |
3320 | some_not_needed |= ! needed_regno; | |
d7429b6a RK |
3321 | } |
3322 | } | |
3323 | /* Additional data to record if this is the final pass. */ | |
3324 | if (insn) | |
3325 | { | |
3326 | register rtx y = reg_next_use[regno]; | |
3327 | register int blocknum = BLOCK_NUM (insn); | |
3328 | ||
3329 | /* If this is a hard reg, record this function uses the reg. */ | |
3330 | ||
3331 | if (regno < FIRST_PSEUDO_REGISTER) | |
3332 | { | |
3333 | register int i; | |
3334 | int endregno = regno + HARD_REGNO_NREGS (regno, GET_MODE (reg)); | |
3335 | ||
3336 | for (i = regno; i < endregno; i++) | |
3337 | { | |
93514916 JW |
3338 | /* The next use is no longer "next", since a store |
3339 | intervenes. */ | |
3340 | reg_next_use[i] = 0; | |
3341 | ||
d7429b6a | 3342 | regs_ever_live[i] = 1; |
b1f21e0a | 3343 | REG_N_SETS (i)++; |
d7429b6a RK |
3344 | } |
3345 | } | |
3346 | else | |
3347 | { | |
93514916 JW |
3348 | /* The next use is no longer "next", since a store |
3349 | intervenes. */ | |
3350 | reg_next_use[regno] = 0; | |
3351 | ||
d7429b6a RK |
3352 | /* Keep track of which basic blocks each reg appears in. */ |
3353 | ||
b1f21e0a MM |
3354 | if (REG_BASIC_BLOCK (regno) == REG_BLOCK_UNKNOWN) |
3355 | REG_BASIC_BLOCK (regno) = blocknum; | |
3356 | else if (REG_BASIC_BLOCK (regno) != blocknum) | |
3357 | REG_BASIC_BLOCK (regno) = REG_BLOCK_GLOBAL; | |
d7429b6a RK |
3358 | |
3359 | /* Count (weighted) references, stores, etc. This counts a | |
3360 | register twice if it is modified, but that is correct. */ | |
b1f21e0a | 3361 | REG_N_SETS (regno)++; |
d7429b6a | 3362 | |
b1f21e0a | 3363 | REG_N_REFS (regno) += loop_depth; |
d7429b6a RK |
3364 | |
3365 | /* The insns where a reg is live are normally counted | |
3366 | elsewhere, but we want the count to include the insn | |
3367 | where the reg is set, and the normal counting mechanism | |
3368 | would not count it. */ | |
b1f21e0a | 3369 | REG_LIVE_LENGTH (regno)++; |
d7429b6a RK |
3370 | } |
3371 | ||
cb9e8ad1 | 3372 | if (! some_not_needed) |
d7429b6a RK |
3373 | { |
3374 | /* Make a logical link from the next following insn | |
3375 | that uses this register, back to this insn. | |
3376 | The following insns have already been processed. | |
3377 | ||
3378 | We don't build a LOG_LINK for hard registers containing | |
3379 | in ASM_OPERANDs. If these registers get replaced, | |
3380 | we might wind up changing the semantics of the insn, | |
3381 | even if reload can make what appear to be valid assignments | |
3382 | later. */ | |
3383 | if (y && (BLOCK_NUM (y) == blocknum) | |
3384 | && (regno >= FIRST_PSEUDO_REGISTER | |
3385 | || asm_noperands (PATTERN (y)) < 0)) | |
3386 | LOG_LINKS (y) | |
38a448ca | 3387 | = gen_rtx_INSN_LIST (VOIDmode, insn, LOG_LINKS (y)); |
d7429b6a RK |
3388 | } |
3389 | else if (! some_needed) | |
3390 | { | |
3391 | /* Note that dead stores have already been deleted when possible | |
3392 | If we get here, we have found a dead store that cannot | |
3393 | be eliminated (because the same insn does something useful). | |
3394 | Indicate this by marking the reg being set as dying here. */ | |
3395 | REG_NOTES (insn) | |
38a448ca | 3396 | = gen_rtx_EXPR_LIST (REG_UNUSED, reg, REG_NOTES (insn)); |
b1f21e0a | 3397 | REG_N_DEATHS (REGNO (reg))++; |
d7429b6a RK |
3398 | } |
3399 | else | |
3400 | { | |
3401 | /* This is a case where we have a multi-word hard register | |
3402 | and some, but not all, of the words of the register are | |
3403 | needed in subsequent insns. Write REG_UNUSED notes | |
3404 | for those parts that were not needed. This case should | |
3405 | be rare. */ | |
3406 | ||
3407 | int i; | |
3408 | ||
3409 | for (i = HARD_REGNO_NREGS (regno, GET_MODE (reg)) - 1; | |
3410 | i >= 0; i--) | |
916b1701 | 3411 | if (!REGNO_REG_SET_P (needed, regno + i)) |
d7429b6a | 3412 | REG_NOTES (insn) |
38a448ca RH |
3413 | = gen_rtx_EXPR_LIST (REG_UNUSED, |
3414 | gen_rtx_REG (reg_raw_mode[regno + i], | |
3415 | regno + i), | |
3416 | REG_NOTES (insn)); | |
d7429b6a RK |
3417 | } |
3418 | } | |
3419 | } | |
8244fc4f RS |
3420 | else if (GET_CODE (reg) == REG) |
3421 | reg_next_use[regno] = 0; | |
d7429b6a RK |
3422 | |
3423 | /* If this is the last pass and this is a SCRATCH, show it will be dying | |
3424 | here and count it. */ | |
3425 | else if (GET_CODE (reg) == SCRATCH && insn != 0) | |
3426 | { | |
3427 | REG_NOTES (insn) | |
38a448ca | 3428 | = gen_rtx_EXPR_LIST (REG_UNUSED, reg, REG_NOTES (insn)); |
d7429b6a RK |
3429 | } |
3430 | } | |
3431 | \f | |
3432 | #ifdef AUTO_INC_DEC | |
3433 | ||
3434 | /* X is a MEM found in INSN. See if we can convert it into an auto-increment | |
3435 | reference. */ | |
3436 | ||
3437 | static void | |
3438 | find_auto_inc (needed, x, insn) | |
3439 | regset needed; | |
3440 | rtx x; | |
3441 | rtx insn; | |
3442 | { | |
3443 | rtx addr = XEXP (x, 0); | |
e658434c | 3444 | HOST_WIDE_INT offset = 0; |
05ed5d57 | 3445 | rtx set; |
d7429b6a RK |
3446 | |
3447 | /* Here we detect use of an index register which might be good for | |
3448 | postincrement, postdecrement, preincrement, or predecrement. */ | |
3449 | ||
3450 | if (GET_CODE (addr) == PLUS && GET_CODE (XEXP (addr, 1)) == CONST_INT) | |
3451 | offset = INTVAL (XEXP (addr, 1)), addr = XEXP (addr, 0); | |
3452 | ||
3453 | if (GET_CODE (addr) == REG) | |
3454 | { | |
3455 | register rtx y; | |
3456 | register int size = GET_MODE_SIZE (GET_MODE (x)); | |
3457 | rtx use; | |
3458 | rtx incr; | |
3459 | int regno = REGNO (addr); | |
3460 | ||
3461 | /* Is the next use an increment that might make auto-increment? */ | |
05ed5d57 RK |
3462 | if ((incr = reg_next_use[regno]) != 0 |
3463 | && (set = single_set (incr)) != 0 | |
3464 | && GET_CODE (set) == SET | |
d7429b6a RK |
3465 | && BLOCK_NUM (incr) == BLOCK_NUM (insn) |
3466 | /* Can't add side effects to jumps; if reg is spilled and | |
3467 | reloaded, there's no way to store back the altered value. */ | |
3468 | && GET_CODE (insn) != JUMP_INSN | |
05ed5d57 | 3469 | && (y = SET_SRC (set), GET_CODE (y) == PLUS) |
d7429b6a RK |
3470 | && XEXP (y, 0) == addr |
3471 | && GET_CODE (XEXP (y, 1)) == CONST_INT | |
940da324 JL |
3472 | && ((HAVE_POST_INCREMENT |
3473 | && (INTVAL (XEXP (y, 1)) == size && offset == 0)) | |
3474 | || (HAVE_POST_DECREMENT | |
3475 | && (INTVAL (XEXP (y, 1)) == - size && offset == 0)) | |
3476 | || (HAVE_PRE_INCREMENT | |
3477 | && (INTVAL (XEXP (y, 1)) == size && offset == size)) | |
3478 | || (HAVE_PRE_DECREMENT | |
3479 | && (INTVAL (XEXP (y, 1)) == - size && offset == - size))) | |
d7429b6a RK |
3480 | /* Make sure this reg appears only once in this insn. */ |
3481 | && (use = find_use_as_address (PATTERN (insn), addr, offset), | |
3482 | use != 0 && use != (rtx) 1)) | |
3483 | { | |
05ed5d57 | 3484 | rtx q = SET_DEST (set); |
7280c2a4 RK |
3485 | enum rtx_code inc_code = (INTVAL (XEXP (y, 1)) == size |
3486 | ? (offset ? PRE_INC : POST_INC) | |
3487 | : (offset ? PRE_DEC : POST_DEC)); | |
d7429b6a RK |
3488 | |
3489 | if (dead_or_set_p (incr, addr)) | |
7280c2a4 RK |
3490 | { |
3491 | /* This is the simple case. Try to make the auto-inc. If | |
3492 | we can't, we are done. Otherwise, we will do any | |
3493 | needed updates below. */ | |
3494 | if (! validate_change (insn, &XEXP (x, 0), | |
38a448ca | 3495 | gen_rtx_fmt_e (inc_code, Pmode, addr), |
7280c2a4 RK |
3496 | 0)) |
3497 | return; | |
3498 | } | |
5175ad37 DE |
3499 | else if (GET_CODE (q) == REG |
3500 | /* PREV_INSN used here to check the semi-open interval | |
3501 | [insn,incr). */ | |
b24884cd JL |
3502 | && ! reg_used_between_p (q, PREV_INSN (insn), incr) |
3503 | /* We must also check for sets of q as q may be | |
3504 | a call clobbered hard register and there may | |
3505 | be a call between PREV_INSN (insn) and incr. */ | |
3506 | && ! reg_set_between_p (q, PREV_INSN (insn), incr)) | |
d7429b6a | 3507 | { |
5175ad37 | 3508 | /* We have *p followed sometime later by q = p+size. |
d7429b6a | 3509 | Both p and q must be live afterward, |
9ec36da5 | 3510 | and q is not used between INSN and its assignment. |
d7429b6a RK |
3511 | Change it to q = p, ...*q..., q = q+size. |
3512 | Then fall into the usual case. */ | |
3513 | rtx insns, temp; | |
e881bb1b | 3514 | basic_block bb; |
d7429b6a RK |
3515 | |
3516 | start_sequence (); | |
3517 | emit_move_insn (q, addr); | |
3518 | insns = get_insns (); | |
3519 | end_sequence (); | |
3520 | ||
e881bb1b | 3521 | bb = BLOCK_FOR_INSN (insn); |
d7429b6a | 3522 | for (temp = insns; temp; temp = NEXT_INSN (temp)) |
e881bb1b | 3523 | set_block_for_insn (temp, bb); |
d7429b6a | 3524 | |
7280c2a4 RK |
3525 | /* If we can't make the auto-inc, or can't make the |
3526 | replacement into Y, exit. There's no point in making | |
3527 | the change below if we can't do the auto-inc and doing | |
3528 | so is not correct in the pre-inc case. */ | |
3529 | ||
3530 | validate_change (insn, &XEXP (x, 0), | |
38a448ca | 3531 | gen_rtx_fmt_e (inc_code, Pmode, q), |
7280c2a4 RK |
3532 | 1); |
3533 | validate_change (incr, &XEXP (y, 0), q, 1); | |
3534 | if (! apply_change_group ()) | |
3535 | return; | |
3536 | ||
3537 | /* We now know we'll be doing this change, so emit the | |
3538 | new insn(s) and do the updates. */ | |
d7429b6a | 3539 | emit_insns_before (insns, insn); |
e8b641a1 | 3540 | |
e881bb1b RH |
3541 | if (BLOCK_FOR_INSN (insn)->head == insn) |
3542 | BLOCK_FOR_INSN (insn)->head = insns; | |
e8b641a1 | 3543 | |
d7429b6a RK |
3544 | /* INCR will become a NOTE and INSN won't contain a |
3545 | use of ADDR. If a use of ADDR was just placed in | |
3546 | the insn before INSN, make that the next use. | |
3547 | Otherwise, invalidate it. */ | |
3548 | if (GET_CODE (PREV_INSN (insn)) == INSN | |
3549 | && GET_CODE (PATTERN (PREV_INSN (insn))) == SET | |
3550 | && SET_SRC (PATTERN (PREV_INSN (insn))) == addr) | |
3551 | reg_next_use[regno] = PREV_INSN (insn); | |
3552 | else | |
3553 | reg_next_use[regno] = 0; | |
3554 | ||
3555 | addr = q; | |
3556 | regno = REGNO (q); | |
d7429b6a RK |
3557 | |
3558 | /* REGNO is now used in INCR which is below INSN, but | |
3559 | it previously wasn't live here. If we don't mark | |
3560 | it as needed, we'll put a REG_DEAD note for it | |
3561 | on this insn, which is incorrect. */ | |
916b1701 | 3562 | SET_REGNO_REG_SET (needed, regno); |
d7429b6a RK |
3563 | |
3564 | /* If there are any calls between INSN and INCR, show | |
3565 | that REGNO now crosses them. */ | |
3566 | for (temp = insn; temp != incr; temp = NEXT_INSN (temp)) | |
3567 | if (GET_CODE (temp) == CALL_INSN) | |
b1f21e0a | 3568 | REG_N_CALLS_CROSSED (regno)++; |
d7429b6a | 3569 | } |
02df8aba RK |
3570 | else |
3571 | return; | |
d7429b6a | 3572 | |
7280c2a4 RK |
3573 | /* If we haven't returned, it means we were able to make the |
3574 | auto-inc, so update the status. First, record that this insn | |
3575 | has an implicit side effect. */ | |
3576 | ||
3577 | REG_NOTES (insn) | |
38a448ca | 3578 | = gen_rtx_EXPR_LIST (REG_INC, addr, REG_NOTES (insn)); |
7280c2a4 RK |
3579 | |
3580 | /* Modify the old increment-insn to simply copy | |
3581 | the already-incremented value of our register. */ | |
3582 | if (! validate_change (incr, &SET_SRC (set), addr, 0)) | |
3583 | abort (); | |
3584 | ||
3585 | /* If that makes it a no-op (copying the register into itself) delete | |
3586 | it so it won't appear to be a "use" and a "set" of this | |
3587 | register. */ | |
3588 | if (SET_DEST (set) == addr) | |
d7429b6a | 3589 | { |
7280c2a4 RK |
3590 | PUT_CODE (incr, NOTE); |
3591 | NOTE_LINE_NUMBER (incr) = NOTE_INSN_DELETED; | |
3592 | NOTE_SOURCE_FILE (incr) = 0; | |
3593 | } | |
d7429b6a | 3594 | |
7280c2a4 RK |
3595 | if (regno >= FIRST_PSEUDO_REGISTER) |
3596 | { | |
3597 | /* Count an extra reference to the reg. When a reg is | |
3598 | incremented, spilling it is worse, so we want to make | |
3599 | that less likely. */ | |
b1f21e0a | 3600 | REG_N_REFS (regno) += loop_depth; |
7280c2a4 RK |
3601 | |
3602 | /* Count the increment as a setting of the register, | |
3603 | even though it isn't a SET in rtl. */ | |
b1f21e0a | 3604 | REG_N_SETS (regno)++; |
d7429b6a RK |
3605 | } |
3606 | } | |
3607 | } | |
3608 | } | |
3609 | #endif /* AUTO_INC_DEC */ | |
3610 | \f | |
3611 | /* Scan expression X and store a 1-bit in LIVE for each reg it uses. | |
3612 | This is done assuming the registers needed from X | |
3613 | are those that have 1-bits in NEEDED. | |
3614 | ||
3615 | On the final pass, FINAL is 1. This means try for autoincrement | |
3616 | and count the uses and deaths of each pseudo-reg. | |
3617 | ||
3618 | INSN is the containing instruction. If INSN is dead, this function is not | |
3619 | called. */ | |
3620 | ||
3621 | static void | |
3622 | mark_used_regs (needed, live, x, final, insn) | |
3623 | regset needed; | |
3624 | regset live; | |
3625 | rtx x; | |
d7429b6a | 3626 | int final; |
e658434c | 3627 | rtx insn; |
d7429b6a RK |
3628 | { |
3629 | register RTX_CODE code; | |
3630 | register int regno; | |
3631 | int i; | |
3632 | ||
3633 | retry: | |
3634 | code = GET_CODE (x); | |
3635 | switch (code) | |
3636 | { | |
3637 | case LABEL_REF: | |
3638 | case SYMBOL_REF: | |
3639 | case CONST_INT: | |
3640 | case CONST: | |
3641 | case CONST_DOUBLE: | |
3642 | case PC: | |
d7429b6a RK |
3643 | case ADDR_VEC: |
3644 | case ADDR_DIFF_VEC: | |
d7429b6a RK |
3645 | return; |
3646 | ||
3647 | #ifdef HAVE_cc0 | |
3648 | case CC0: | |
3649 | cc0_live = 1; | |
3650 | return; | |
3651 | #endif | |
3652 | ||
2f1553a4 RK |
3653 | case CLOBBER: |
3654 | /* If we are clobbering a MEM, mark any registers inside the address | |
3655 | as being used. */ | |
3656 | if (GET_CODE (XEXP (x, 0)) == MEM) | |
3657 | mark_used_regs (needed, live, XEXP (XEXP (x, 0), 0), final, insn); | |
3658 | return; | |
3659 | ||
d7429b6a | 3660 | case MEM: |
7eb136d6 MM |
3661 | /* Invalidate the data for the last MEM stored, but only if MEM is |
3662 | something that can be stored into. */ | |
3663 | if (GET_CODE (XEXP (x, 0)) == SYMBOL_REF | |
3664 | && CONSTANT_POOL_ADDRESS_P (XEXP (x, 0))) | |
db3a887b | 3665 | ; /* needn't clear the memory set list */ |
7eb136d6 | 3666 | else |
db3a887b CB |
3667 | { |
3668 | rtx temp = mem_set_list; | |
3669 | rtx prev = NULL_RTX; | |
3670 | ||
3671 | while (temp) | |
3672 | { | |
063cd522 | 3673 | if (anti_dependence (XEXP (temp, 0), x)) |
db3a887b CB |
3674 | { |
3675 | /* Splice temp out of the list. */ | |
3676 | if (prev) | |
3677 | XEXP (prev, 1) = XEXP (temp, 1); | |
3678 | else | |
3679 | mem_set_list = XEXP (temp, 1); | |
3680 | } | |
3681 | else | |
3682 | prev = temp; | |
3683 | temp = XEXP (temp, 1); | |
3684 | } | |
3685 | } | |
d7429b6a | 3686 | |
15e088b2 JL |
3687 | /* If the memory reference had embedded side effects (autoincrement |
3688 | address modes. Then we may need to kill some entries on the | |
3689 | memory set list. */ | |
3690 | if (insn) | |
3691 | invalidate_mems_from_autoinc (insn); | |
3692 | ||
d7429b6a RK |
3693 | #ifdef AUTO_INC_DEC |
3694 | if (final) | |
3695 | find_auto_inc (needed, x, insn); | |
3696 | #endif | |
3697 | break; | |
3698 | ||
80f8f04a RK |
3699 | case SUBREG: |
3700 | if (GET_CODE (SUBREG_REG (x)) == REG | |
3701 | && REGNO (SUBREG_REG (x)) >= FIRST_PSEUDO_REGISTER | |
3702 | && (GET_MODE_SIZE (GET_MODE (x)) | |
88285acf | 3703 | != GET_MODE_SIZE (GET_MODE (SUBREG_REG (x))))) |
b1f21e0a | 3704 | REG_CHANGES_SIZE (REGNO (SUBREG_REG (x))) = 1; |
80f8f04a RK |
3705 | |
3706 | /* While we're here, optimize this case. */ | |
3707 | x = SUBREG_REG (x); | |
3708 | ||
e100a3bb | 3709 | /* In case the SUBREG is not of a register, don't optimize */ |
ce79abf3 | 3710 | if (GET_CODE (x) != REG) |
e100a3bb MM |
3711 | { |
3712 | mark_used_regs (needed, live, x, final, insn); | |
3713 | return; | |
3714 | } | |
ce79abf3 | 3715 | |
0f41302f | 3716 | /* ... fall through ... */ |
80f8f04a | 3717 | |
d7429b6a RK |
3718 | case REG: |
3719 | /* See a register other than being set | |
3720 | => mark it as needed. */ | |
3721 | ||
3722 | regno = REGNO (x); | |
3723 | { | |
67f0e213 RK |
3724 | int some_needed = REGNO_REG_SET_P (needed, regno); |
3725 | int some_not_needed = ! some_needed; | |
d7429b6a | 3726 | |
916b1701 | 3727 | SET_REGNO_REG_SET (live, regno); |
cb9e8ad1 | 3728 | |
d7429b6a RK |
3729 | /* A hard reg in a wide mode may really be multiple registers. |
3730 | If so, mark all of them just like the first. */ | |
3731 | if (regno < FIRST_PSEUDO_REGISTER) | |
3732 | { | |
3733 | int n; | |
3734 | ||
d7e4fe8b | 3735 | /* For stack ptr or fixed arg pointer, |
d7429b6a RK |
3736 | nothing below can be necessary, so waste no more time. */ |
3737 | if (regno == STACK_POINTER_REGNUM | |
73a187c1 | 3738 | #if FRAME_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM |
e4b8a413 JW |
3739 | || (regno == HARD_FRAME_POINTER_REGNUM |
3740 | && (! reload_completed || frame_pointer_needed)) | |
73a187c1 | 3741 | #endif |
d7e4fe8b RS |
3742 | #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM |
3743 | || (regno == ARG_POINTER_REGNUM && fixed_regs[regno]) | |
3744 | #endif | |
e4b8a413 JW |
3745 | || (regno == FRAME_POINTER_REGNUM |
3746 | && (! reload_completed || frame_pointer_needed))) | |
d7429b6a RK |
3747 | { |
3748 | /* If this is a register we are going to try to eliminate, | |
3749 | don't mark it live here. If we are successful in | |
3750 | eliminating it, it need not be live unless it is used for | |
3751 | pseudos, in which case it will have been set live when | |
3752 | it was allocated to the pseudos. If the register will not | |
3753 | be eliminated, reload will set it live at that point. */ | |
3754 | ||
3755 | if (! TEST_HARD_REG_BIT (elim_reg_set, regno)) | |
3756 | regs_ever_live[regno] = 1; | |
3757 | return; | |
3758 | } | |
3759 | /* No death notes for global register variables; | |
3760 | their values are live after this function exits. */ | |
3761 | if (global_regs[regno]) | |
d8c8b8e3 RS |
3762 | { |
3763 | if (final) | |
3764 | reg_next_use[regno] = insn; | |
3765 | return; | |
3766 | } | |
d7429b6a RK |
3767 | |
3768 | n = HARD_REGNO_NREGS (regno, GET_MODE (x)); | |
3769 | while (--n > 0) | |
3770 | { | |
916b1701 MM |
3771 | int regno_n = regno + n; |
3772 | int needed_regno = REGNO_REG_SET_P (needed, regno_n); | |
cb9e8ad1 | 3773 | |
916b1701 MM |
3774 | SET_REGNO_REG_SET (live, regno_n); |
3775 | some_needed |= needed_regno; | |
931c6c7a | 3776 | some_not_needed |= ! needed_regno; |
d7429b6a RK |
3777 | } |
3778 | } | |
3779 | if (final) | |
3780 | { | |
3781 | /* Record where each reg is used, so when the reg | |
3782 | is set we know the next insn that uses it. */ | |
3783 | ||
3784 | reg_next_use[regno] = insn; | |
3785 | ||
3786 | if (regno < FIRST_PSEUDO_REGISTER) | |
3787 | { | |
3788 | /* If a hard reg is being used, | |
3789 | record that this function does use it. */ | |
3790 | ||
3791 | i = HARD_REGNO_NREGS (regno, GET_MODE (x)); | |
3792 | if (i == 0) | |
3793 | i = 1; | |
3794 | do | |
3795 | regs_ever_live[regno + --i] = 1; | |
3796 | while (i > 0); | |
3797 | } | |
3798 | else | |
3799 | { | |
3800 | /* Keep track of which basic block each reg appears in. */ | |
3801 | ||
3802 | register int blocknum = BLOCK_NUM (insn); | |
3803 | ||
b1f21e0a MM |
3804 | if (REG_BASIC_BLOCK (regno) == REG_BLOCK_UNKNOWN) |
3805 | REG_BASIC_BLOCK (regno) = blocknum; | |
3806 | else if (REG_BASIC_BLOCK (regno) != blocknum) | |
3807 | REG_BASIC_BLOCK (regno) = REG_BLOCK_GLOBAL; | |
d7429b6a RK |
3808 | |
3809 | /* Count (weighted) number of uses of each reg. */ | |
3810 | ||
b1f21e0a | 3811 | REG_N_REFS (regno) += loop_depth; |
d7429b6a RK |
3812 | } |
3813 | ||
3814 | /* Record and count the insns in which a reg dies. | |
3815 | If it is used in this insn and was dead below the insn | |
3816 | then it dies in this insn. If it was set in this insn, | |
3817 | we do not make a REG_DEAD note; likewise if we already | |
3818 | made such a note. */ | |
3819 | ||
cb9e8ad1 | 3820 | if (some_not_needed |
d7429b6a RK |
3821 | && ! dead_or_set_p (insn, x) |
3822 | #if 0 | |
3823 | && (regno >= FIRST_PSEUDO_REGISTER || ! fixed_regs[regno]) | |
3824 | #endif | |
3825 | ) | |
3826 | { | |
ab28041e JW |
3827 | /* Check for the case where the register dying partially |
3828 | overlaps the register set by this insn. */ | |
3829 | if (regno < FIRST_PSEUDO_REGISTER | |
3830 | && HARD_REGNO_NREGS (regno, GET_MODE (x)) > 1) | |
3831 | { | |
480eac3b | 3832 | int n = HARD_REGNO_NREGS (regno, GET_MODE (x)); |
ab28041e JW |
3833 | while (--n >= 0) |
3834 | some_needed |= dead_or_set_regno_p (insn, regno + n); | |
3835 | } | |
3836 | ||
d7429b6a RK |
3837 | /* If none of the words in X is needed, make a REG_DEAD |
3838 | note. Otherwise, we must make partial REG_DEAD notes. */ | |
3839 | if (! some_needed) | |
3840 | { | |
3841 | REG_NOTES (insn) | |
38a448ca | 3842 | = gen_rtx_EXPR_LIST (REG_DEAD, x, REG_NOTES (insn)); |
b1f21e0a | 3843 | REG_N_DEATHS (regno)++; |
d7429b6a RK |
3844 | } |
3845 | else | |
3846 | { | |
3847 | int i; | |
3848 | ||
3849 | /* Don't make a REG_DEAD note for a part of a register | |
3850 | that is set in the insn. */ | |
3851 | ||
3852 | for (i = HARD_REGNO_NREGS (regno, GET_MODE (x)) - 1; | |
3853 | i >= 0; i--) | |
916b1701 | 3854 | if (!REGNO_REG_SET_P (needed, regno + i) |
d7429b6a RK |
3855 | && ! dead_or_set_regno_p (insn, regno + i)) |
3856 | REG_NOTES (insn) | |
38a448ca RH |
3857 | = gen_rtx_EXPR_LIST (REG_DEAD, |
3858 | gen_rtx_REG (reg_raw_mode[regno + i], | |
3859 | regno + i), | |
3860 | REG_NOTES (insn)); | |
d7429b6a RK |
3861 | } |
3862 | } | |
3863 | } | |
3864 | } | |
3865 | return; | |
3866 | ||
3867 | case SET: | |
3868 | { | |
3869 | register rtx testreg = SET_DEST (x); | |
3870 | int mark_dest = 0; | |
3871 | ||
3872 | /* If storing into MEM, don't show it as being used. But do | |
3873 | show the address as being used. */ | |
3874 | if (GET_CODE (testreg) == MEM) | |
3875 | { | |
3876 | #ifdef AUTO_INC_DEC | |
3877 | if (final) | |
3878 | find_auto_inc (needed, testreg, insn); | |
3879 | #endif | |
3880 | mark_used_regs (needed, live, XEXP (testreg, 0), final, insn); | |
3881 | mark_used_regs (needed, live, SET_SRC (x), final, insn); | |
3882 | return; | |
3883 | } | |
3884 | ||
3885 | /* Storing in STRICT_LOW_PART is like storing in a reg | |
3886 | in that this SET might be dead, so ignore it in TESTREG. | |
3887 | but in some other ways it is like using the reg. | |
3888 | ||
3889 | Storing in a SUBREG or a bit field is like storing the entire | |
3890 | register in that if the register's value is not used | |
3891 | then this SET is not needed. */ | |
3892 | while (GET_CODE (testreg) == STRICT_LOW_PART | |
3893 | || GET_CODE (testreg) == ZERO_EXTRACT | |
3894 | || GET_CODE (testreg) == SIGN_EXTRACT | |
3895 | || GET_CODE (testreg) == SUBREG) | |
3896 | { | |
88285acf RK |
3897 | if (GET_CODE (testreg) == SUBREG |
3898 | && GET_CODE (SUBREG_REG (testreg)) == REG | |
3899 | && REGNO (SUBREG_REG (testreg)) >= FIRST_PSEUDO_REGISTER | |
3900 | && (GET_MODE_SIZE (GET_MODE (testreg)) | |
3901 | != GET_MODE_SIZE (GET_MODE (SUBREG_REG (testreg))))) | |
b1f21e0a | 3902 | REG_CHANGES_SIZE (REGNO (SUBREG_REG (testreg))) = 1; |
88285acf | 3903 | |
d7429b6a RK |
3904 | /* Modifying a single register in an alternate mode |
3905 | does not use any of the old value. But these other | |
3906 | ways of storing in a register do use the old value. */ | |
3907 | if (GET_CODE (testreg) == SUBREG | |
3908 | && !(REG_SIZE (SUBREG_REG (testreg)) > REG_SIZE (testreg))) | |
3909 | ; | |
3910 | else | |
3911 | mark_dest = 1; | |
3912 | ||
3913 | testreg = XEXP (testreg, 0); | |
3914 | } | |
3915 | ||
3916 | /* If this is a store into a register, | |
3917 | recursively scan the value being stored. */ | |
3918 | ||
86465af7 DM |
3919 | if ((GET_CODE (testreg) == PARALLEL |
3920 | && GET_MODE (testreg) == BLKmode) | |
3921 | || (GET_CODE (testreg) == REG | |
e4b8a413 JW |
3922 | && (regno = REGNO (testreg), ! (regno == FRAME_POINTER_REGNUM |
3923 | && (! reload_completed || frame_pointer_needed))) | |
73a187c1 | 3924 | #if FRAME_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM |
e4b8a413 JW |
3925 | && ! (regno == HARD_FRAME_POINTER_REGNUM |
3926 | && (! reload_completed || frame_pointer_needed)) | |
73a187c1 | 3927 | #endif |
d7e4fe8b | 3928 | #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM |
86465af7 | 3929 | && ! (regno == ARG_POINTER_REGNUM && fixed_regs[regno]) |
d7e4fe8b | 3930 | #endif |
86465af7 | 3931 | )) |
d8c8b8e3 RS |
3932 | /* We used to exclude global_regs here, but that seems wrong. |
3933 | Storing in them is like storing in mem. */ | |
d7429b6a RK |
3934 | { |
3935 | mark_used_regs (needed, live, SET_SRC (x), final, insn); | |
3936 | if (mark_dest) | |
3937 | mark_used_regs (needed, live, SET_DEST (x), final, insn); | |
3938 | return; | |
3939 | } | |
3940 | } | |
3941 | break; | |
3942 | ||
3943 | case RETURN: | |
3944 | /* If exiting needs the right stack value, consider this insn as | |
3945 | using the stack pointer. In any event, consider it as using | |
632c9d9e | 3946 | all global registers and all registers used by return. */ |
d7429b6a | 3947 | if (! EXIT_IGNORE_STACK |
0200b5ed JL |
3948 | || (! FRAME_POINTER_REQUIRED |
3949 | && ! current_function_calls_alloca | |
bfc5000a JL |
3950 | && flag_omit_frame_pointer) |
3951 | || current_function_sp_is_unchanging) | |
916b1701 | 3952 | SET_REGNO_REG_SET (live, STACK_POINTER_REGNUM); |
d7429b6a RK |
3953 | |
3954 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
632c9d9e MS |
3955 | if (global_regs[i] |
3956 | #ifdef EPILOGUE_USES | |
3957 | || EPILOGUE_USES (i) | |
3958 | #endif | |
3959 | ) | |
916b1701 | 3960 | SET_REGNO_REG_SET (live, i); |
d7429b6a | 3961 | break; |
e9a25f70 | 3962 | |
40b5a77c JL |
3963 | case ASM_OPERANDS: |
3964 | case UNSPEC_VOLATILE: | |
3965 | case TRAP_IF: | |
3966 | case ASM_INPUT: | |
3967 | { | |
3968 | /* Traditional and volatile asm instructions must be considered to use | |
3969 | and clobber all hard registers, all pseudo-registers and all of | |
3970 | memory. So must TRAP_IF and UNSPEC_VOLATILE operations. | |
3971 | ||
3972 | Consider for instance a volatile asm that changes the fpu rounding | |
3973 | mode. An insn should not be moved across this even if it only uses | |
3974 | pseudo-regs because it might give an incorrectly rounded result. | |
3975 | ||
3976 | ?!? Unfortunately, marking all hard registers as live causes massive | |
3977 | problems for the register allocator and marking all pseudos as live | |
3978 | creates mountains of uninitialized variable warnings. | |
3979 | ||
3980 | So for now, just clear the memory set list and mark any regs | |
3981 | we can find in ASM_OPERANDS as used. */ | |
3982 | if (code != ASM_OPERANDS || MEM_VOLATILE_P (x)) | |
3983 | mem_set_list = NULL_RTX; | |
3984 | ||
3985 | /* For all ASM_OPERANDS, we must traverse the vector of input operands. | |
3986 | We can not just fall through here since then we would be confused | |
3987 | by the ASM_INPUT rtx inside ASM_OPERANDS, which do not indicate | |
3988 | traditional asms unlike their normal usage. */ | |
3989 | if (code == ASM_OPERANDS) | |
3990 | { | |
3991 | int j; | |
3992 | ||
3993 | for (j = 0; j < ASM_OPERANDS_INPUT_LENGTH (x); j++) | |
3994 | mark_used_regs (needed, live, ASM_OPERANDS_INPUT (x, j), | |
3995 | final, insn); | |
3996 | } | |
3997 | break; | |
3998 | } | |
3999 | ||
4000 | ||
e9a25f70 JL |
4001 | default: |
4002 | break; | |
d7429b6a RK |
4003 | } |
4004 | ||
4005 | /* Recursively scan the operands of this expression. */ | |
4006 | ||
4007 | { | |
4008 | register char *fmt = GET_RTX_FORMAT (code); | |
4009 | register int i; | |
4010 | ||
4011 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
4012 | { | |
4013 | if (fmt[i] == 'e') | |
4014 | { | |
4015 | /* Tail recursive case: save a function call level. */ | |
4016 | if (i == 0) | |
4017 | { | |
4018 | x = XEXP (x, 0); | |
4019 | goto retry; | |
4020 | } | |
4021 | mark_used_regs (needed, live, XEXP (x, i), final, insn); | |
4022 | } | |
4023 | else if (fmt[i] == 'E') | |
4024 | { | |
4025 | register int j; | |
4026 | for (j = 0; j < XVECLEN (x, i); j++) | |
4027 | mark_used_regs (needed, live, XVECEXP (x, i, j), final, insn); | |
4028 | } | |
4029 | } | |
4030 | } | |
4031 | } | |
4032 | \f | |
4033 | #ifdef AUTO_INC_DEC | |
4034 | ||
4035 | static int | |
4036 | try_pre_increment_1 (insn) | |
4037 | rtx insn; | |
4038 | { | |
4039 | /* Find the next use of this reg. If in same basic block, | |
4040 | make it do pre-increment or pre-decrement if appropriate. */ | |
956d6950 | 4041 | rtx x = single_set (insn); |
5f4f0e22 | 4042 | HOST_WIDE_INT amount = ((GET_CODE (SET_SRC (x)) == PLUS ? 1 : -1) |
d7429b6a RK |
4043 | * INTVAL (XEXP (SET_SRC (x), 1))); |
4044 | int regno = REGNO (SET_DEST (x)); | |
4045 | rtx y = reg_next_use[regno]; | |
4046 | if (y != 0 | |
4047 | && BLOCK_NUM (y) == BLOCK_NUM (insn) | |
89861c38 | 4048 | /* Don't do this if the reg dies, or gets set in y; a standard addressing |
0f41302f | 4049 | mode would be better. */ |
89861c38 | 4050 | && ! dead_or_set_p (y, SET_DEST (x)) |
956d6950 | 4051 | && try_pre_increment (y, SET_DEST (x), amount)) |
d7429b6a RK |
4052 | { |
4053 | /* We have found a suitable auto-increment | |
4054 | and already changed insn Y to do it. | |
4055 | So flush this increment-instruction. */ | |
4056 | PUT_CODE (insn, NOTE); | |
4057 | NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED; | |
4058 | NOTE_SOURCE_FILE (insn) = 0; | |
4059 | /* Count a reference to this reg for the increment | |
4060 | insn we are deleting. When a reg is incremented. | |
4061 | spilling it is worse, so we want to make that | |
4062 | less likely. */ | |
4063 | if (regno >= FIRST_PSEUDO_REGISTER) | |
4064 | { | |
b1f21e0a MM |
4065 | REG_N_REFS (regno) += loop_depth; |
4066 | REG_N_SETS (regno)++; | |
d7429b6a RK |
4067 | } |
4068 | return 1; | |
4069 | } | |
4070 | return 0; | |
4071 | } | |
4072 | ||
4073 | /* Try to change INSN so that it does pre-increment or pre-decrement | |
4074 | addressing on register REG in order to add AMOUNT to REG. | |
4075 | AMOUNT is negative for pre-decrement. | |
4076 | Returns 1 if the change could be made. | |
4077 | This checks all about the validity of the result of modifying INSN. */ | |
4078 | ||
4079 | static int | |
4080 | try_pre_increment (insn, reg, amount) | |
4081 | rtx insn, reg; | |
5f4f0e22 | 4082 | HOST_WIDE_INT amount; |
d7429b6a RK |
4083 | { |
4084 | register rtx use; | |
4085 | ||
4086 | /* Nonzero if we can try to make a pre-increment or pre-decrement. | |
4087 | For example, addl $4,r1; movl (r1),... can become movl +(r1),... */ | |
4088 | int pre_ok = 0; | |
4089 | /* Nonzero if we can try to make a post-increment or post-decrement. | |
4090 | For example, addl $4,r1; movl -4(r1),... can become movl (r1)+,... | |
4091 | It is possible for both PRE_OK and POST_OK to be nonzero if the machine | |
4092 | supports both pre-inc and post-inc, or both pre-dec and post-dec. */ | |
4093 | int post_ok = 0; | |
4094 | ||
4095 | /* Nonzero if the opportunity actually requires post-inc or post-dec. */ | |
4096 | int do_post = 0; | |
4097 | ||
4098 | /* From the sign of increment, see which possibilities are conceivable | |
4099 | on this target machine. */ | |
940da324 | 4100 | if (HAVE_PRE_INCREMENT && amount > 0) |
d7429b6a | 4101 | pre_ok = 1; |
940da324 | 4102 | if (HAVE_POST_INCREMENT && amount > 0) |
d7429b6a | 4103 | post_ok = 1; |
d7429b6a | 4104 | |
940da324 | 4105 | if (HAVE_PRE_DECREMENT && amount < 0) |
d7429b6a | 4106 | pre_ok = 1; |
940da324 | 4107 | if (HAVE_POST_DECREMENT && amount < 0) |
d7429b6a | 4108 | post_ok = 1; |
d7429b6a RK |
4109 | |
4110 | if (! (pre_ok || post_ok)) | |
4111 | return 0; | |
4112 | ||
4113 | /* It is not safe to add a side effect to a jump insn | |
4114 | because if the incremented register is spilled and must be reloaded | |
4115 | there would be no way to store the incremented value back in memory. */ | |
4116 | ||
4117 | if (GET_CODE (insn) == JUMP_INSN) | |
4118 | return 0; | |
4119 | ||
4120 | use = 0; | |
4121 | if (pre_ok) | |
4122 | use = find_use_as_address (PATTERN (insn), reg, 0); | |
4123 | if (post_ok && (use == 0 || use == (rtx) 1)) | |
4124 | { | |
4125 | use = find_use_as_address (PATTERN (insn), reg, -amount); | |
4126 | do_post = 1; | |
4127 | } | |
4128 | ||
4129 | if (use == 0 || use == (rtx) 1) | |
4130 | return 0; | |
4131 | ||
4132 | if (GET_MODE_SIZE (GET_MODE (use)) != (amount > 0 ? amount : - amount)) | |
4133 | return 0; | |
4134 | ||
a0fbc3a9 SC |
4135 | /* See if this combination of instruction and addressing mode exists. */ |
4136 | if (! validate_change (insn, &XEXP (use, 0), | |
38a448ca RH |
4137 | gen_rtx_fmt_e (amount > 0 |
4138 | ? (do_post ? POST_INC : PRE_INC) | |
4139 | : (do_post ? POST_DEC : PRE_DEC), | |
4140 | Pmode, reg), 0)) | |
a0fbc3a9 | 4141 | return 0; |
d7429b6a RK |
4142 | |
4143 | /* Record that this insn now has an implicit side effect on X. */ | |
38a448ca | 4144 | REG_NOTES (insn) = gen_rtx_EXPR_LIST (REG_INC, reg, REG_NOTES (insn)); |
d7429b6a RK |
4145 | return 1; |
4146 | } | |
4147 | ||
4148 | #endif /* AUTO_INC_DEC */ | |
4149 | \f | |
4150 | /* Find the place in the rtx X where REG is used as a memory address. | |
4151 | Return the MEM rtx that so uses it. | |
4152 | If PLUSCONST is nonzero, search instead for a memory address equivalent to | |
4153 | (plus REG (const_int PLUSCONST)). | |
4154 | ||
4155 | If such an address does not appear, return 0. | |
4156 | If REG appears more than once, or is used other than in such an address, | |
4157 | return (rtx)1. */ | |
4158 | ||
8c660648 | 4159 | rtx |
d7429b6a RK |
4160 | find_use_as_address (x, reg, plusconst) |
4161 | register rtx x; | |
4162 | rtx reg; | |
e658434c | 4163 | HOST_WIDE_INT plusconst; |
d7429b6a RK |
4164 | { |
4165 | enum rtx_code code = GET_CODE (x); | |
4166 | char *fmt = GET_RTX_FORMAT (code); | |
4167 | register int i; | |
4168 | register rtx value = 0; | |
4169 | register rtx tem; | |
4170 | ||
4171 | if (code == MEM && XEXP (x, 0) == reg && plusconst == 0) | |
4172 | return x; | |
4173 | ||
4174 | if (code == MEM && GET_CODE (XEXP (x, 0)) == PLUS | |
4175 | && XEXP (XEXP (x, 0), 0) == reg | |
4176 | && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT | |
4177 | && INTVAL (XEXP (XEXP (x, 0), 1)) == plusconst) | |
4178 | return x; | |
4179 | ||
4180 | if (code == SIGN_EXTRACT || code == ZERO_EXTRACT) | |
4181 | { | |
4182 | /* If REG occurs inside a MEM used in a bit-field reference, | |
4183 | that is unacceptable. */ | |
4184 | if (find_use_as_address (XEXP (x, 0), reg, 0) != 0) | |
6fa5c106 | 4185 | return (rtx) (HOST_WIDE_INT) 1; |
d7429b6a RK |
4186 | } |
4187 | ||
4188 | if (x == reg) | |
6fa5c106 | 4189 | return (rtx) (HOST_WIDE_INT) 1; |
d7429b6a RK |
4190 | |
4191 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
4192 | { | |
4193 | if (fmt[i] == 'e') | |
4194 | { | |
4195 | tem = find_use_as_address (XEXP (x, i), reg, plusconst); | |
4196 | if (value == 0) | |
4197 | value = tem; | |
4198 | else if (tem != 0) | |
6fa5c106 | 4199 | return (rtx) (HOST_WIDE_INT) 1; |
d7429b6a RK |
4200 | } |
4201 | if (fmt[i] == 'E') | |
4202 | { | |
4203 | register int j; | |
4204 | for (j = XVECLEN (x, i) - 1; j >= 0; j--) | |
4205 | { | |
4206 | tem = find_use_as_address (XVECEXP (x, i, j), reg, plusconst); | |
4207 | if (value == 0) | |
4208 | value = tem; | |
4209 | else if (tem != 0) | |
6fa5c106 | 4210 | return (rtx) (HOST_WIDE_INT) 1; |
d7429b6a RK |
4211 | } |
4212 | } | |
4213 | } | |
4214 | ||
4215 | return value; | |
4216 | } | |
4217 | \f | |
4218 | /* Write information about registers and basic blocks into FILE. | |
4219 | This is part of making a debugging dump. */ | |
4220 | ||
4221 | void | |
4222 | dump_flow_info (file) | |
4223 | FILE *file; | |
4224 | { | |
4225 | register int i; | |
4226 | static char *reg_class_names[] = REG_CLASS_NAMES; | |
4227 | ||
4228 | fprintf (file, "%d registers.\n", max_regno); | |
d7429b6a | 4229 | for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++) |
b1f21e0a | 4230 | if (REG_N_REFS (i)) |
d7429b6a | 4231 | { |
e4600702 | 4232 | enum reg_class class, altclass; |
d7429b6a | 4233 | fprintf (file, "\nRegister %d used %d times across %d insns", |
b1f21e0a MM |
4234 | i, REG_N_REFS (i), REG_LIVE_LENGTH (i)); |
4235 | if (REG_BASIC_BLOCK (i) >= 0) | |
4236 | fprintf (file, " in block %d", REG_BASIC_BLOCK (i)); | |
6fc4610b MM |
4237 | if (REG_N_SETS (i)) |
4238 | fprintf (file, "; set %d time%s", REG_N_SETS (i), | |
4239 | (REG_N_SETS (i) == 1) ? "" : "s"); | |
4240 | if (REG_USERVAR_P (regno_reg_rtx[i])) | |
4241 | fprintf (file, "; user var"); | |
b1f21e0a MM |
4242 | if (REG_N_DEATHS (i) != 1) |
4243 | fprintf (file, "; dies in %d places", REG_N_DEATHS (i)); | |
4244 | if (REG_N_CALLS_CROSSED (i) == 1) | |
d7429b6a | 4245 | fprintf (file, "; crosses 1 call"); |
b1f21e0a MM |
4246 | else if (REG_N_CALLS_CROSSED (i)) |
4247 | fprintf (file, "; crosses %d calls", REG_N_CALLS_CROSSED (i)); | |
d7429b6a RK |
4248 | if (PSEUDO_REGNO_BYTES (i) != UNITS_PER_WORD) |
4249 | fprintf (file, "; %d bytes", PSEUDO_REGNO_BYTES (i)); | |
4250 | class = reg_preferred_class (i); | |
e4600702 RK |
4251 | altclass = reg_alternate_class (i); |
4252 | if (class != GENERAL_REGS || altclass != ALL_REGS) | |
d7429b6a | 4253 | { |
e4600702 RK |
4254 | if (altclass == ALL_REGS || class == ALL_REGS) |
4255 | fprintf (file, "; pref %s", reg_class_names[(int) class]); | |
4256 | else if (altclass == NO_REGS) | |
d7429b6a RK |
4257 | fprintf (file, "; %s or none", reg_class_names[(int) class]); |
4258 | else | |
e4600702 RK |
4259 | fprintf (file, "; pref %s, else %s", |
4260 | reg_class_names[(int) class], | |
4261 | reg_class_names[(int) altclass]); | |
d7429b6a RK |
4262 | } |
4263 | if (REGNO_POINTER_FLAG (i)) | |
4264 | fprintf (file, "; pointer"); | |
4265 | fprintf (file, ".\n"); | |
4266 | } | |
e881bb1b | 4267 | |
d7429b6a | 4268 | fprintf (file, "\n%d basic blocks.\n", n_basic_blocks); |
e881bb1b RH |
4269 | for (i = 0; i < n_basic_blocks; i++) |
4270 | { | |
4271 | register basic_block bb = BASIC_BLOCK (i); | |
4272 | register int regno; | |
4273 | register edge e; | |
4274 | ||
4275 | fprintf (file, "\nBasic block %d: first insn %d, last %d.\n", | |
4276 | i, INSN_UID (bb->head), INSN_UID (bb->end)); | |
4277 | ||
4278 | fprintf (file, "Predecessors: "); | |
4279 | for (e = bb->pred; e ; e = e->pred_next) | |
4280 | dump_edge_info (file, e, 0); | |
4281 | ||
4282 | fprintf (file, "\nSuccessors: "); | |
4283 | for (e = bb->succ; e ; e = e->succ_next) | |
4284 | dump_edge_info (file, e, 1); | |
4285 | ||
4286 | fprintf (file, "\nRegisters live at start:"); | |
4287 | if (bb->global_live_at_start) | |
4288 | { | |
4289 | for (regno = 0; regno < max_regno; regno++) | |
4290 | if (REGNO_REG_SET_P (bb->global_live_at_start, regno)) | |
4291 | fprintf (file, " %d", regno); | |
4292 | } | |
4293 | else | |
4294 | fprintf (file, " n/a"); | |
4295 | ||
4296 | fprintf (file, "\nRegisters live at end:"); | |
4297 | if (bb->global_live_at_end) | |
4298 | { | |
4299 | for (regno = 0; regno < max_regno; regno++) | |
4300 | if (REGNO_REG_SET_P (bb->global_live_at_end, regno)) | |
4301 | fprintf (file, " %d", regno); | |
4302 | } | |
4303 | else | |
4304 | fprintf (file, " n/a"); | |
4305 | ||
4306 | putc('\n', file); | |
4307 | } | |
4308 | ||
4309 | putc('\n', file); | |
4310 | } | |
4311 | ||
4312 | static void | |
4313 | dump_edge_info (file, e, do_succ) | |
4314 | FILE *file; | |
4315 | edge e; | |
4316 | int do_succ; | |
4317 | { | |
4318 | basic_block side = (do_succ ? e->dest : e->src); | |
4319 | ||
4320 | if (side == ENTRY_BLOCK_PTR) | |
4321 | fputs (" ENTRY", file); | |
4322 | else if (side == EXIT_BLOCK_PTR) | |
4323 | fputs (" EXIT", file); | |
4324 | else | |
4325 | fprintf (file, " %d", side->index); | |
4326 | ||
4327 | if (e->flags) | |
4328 | { | |
4329 | static char * bitnames[] = { | |
4330 | "fallthru", "crit", "ab", "abcall", "eh", "fake" | |
4331 | }; | |
4332 | int comma = 0; | |
4333 | int i, flags = e->flags; | |
4334 | ||
4335 | fputc (' ', file); | |
4336 | fputc ('(', file); | |
4337 | for (i = 0; flags; i++) | |
4338 | if (flags & (1 << i)) | |
4339 | { | |
4340 | flags &= ~(1 << i); | |
4341 | ||
4342 | if (comma) | |
4343 | fputc (',', file); | |
4344 | if (i < (int)(sizeof (bitnames) / sizeof (*bitnames))) | |
4345 | fputs (bitnames[i], file); | |
4346 | else | |
4347 | fprintf (file, "%d", i); | |
4348 | comma = 1; | |
4349 | } | |
4350 | fputc (')', file); | |
4351 | } | |
d7429b6a | 4352 | } |
3e28fe44 MM |
4353 | |
4354 | \f | |
4355 | /* Like print_rtl, but also print out live information for the start of each | |
4356 | basic block. */ | |
4357 | ||
4358 | void | |
4359 | print_rtl_with_bb (outf, rtx_first) | |
4360 | FILE *outf; | |
4361 | rtx rtx_first; | |
4362 | { | |
4363 | register rtx tmp_rtx; | |
4364 | ||
4365 | if (rtx_first == 0) | |
4366 | fprintf (outf, "(nil)\n"); | |
3e28fe44 MM |
4367 | else |
4368 | { | |
e881bb1b | 4369 | int i; |
3e28fe44 MM |
4370 | enum bb_state { NOT_IN_BB, IN_ONE_BB, IN_MULTIPLE_BB }; |
4371 | int max_uid = get_max_uid (); | |
54ea1de9 KG |
4372 | basic_block *start = (basic_block *) |
4373 | alloca (max_uid * sizeof (basic_block)); | |
4374 | basic_block *end = (basic_block *) | |
4375 | alloca (max_uid * sizeof (basic_block)); | |
2a92c071 GS |
4376 | enum bb_state *in_bb_p = (enum bb_state *) |
4377 | alloca (max_uid * sizeof (enum bb_state)); | |
3e28fe44 | 4378 | |
e881bb1b RH |
4379 | memset (start, 0, max_uid * sizeof (basic_block)); |
4380 | memset (end, 0, max_uid * sizeof (basic_block)); | |
4381 | memset (in_bb_p, 0, max_uid * sizeof (enum bb_state)); | |
3e28fe44 | 4382 | |
e881bb1b | 4383 | for (i = n_basic_blocks - 1; i >= 0; i--) |
3e28fe44 | 4384 | { |
e881bb1b | 4385 | basic_block bb = BASIC_BLOCK (i); |
3e28fe44 | 4386 | rtx x; |
e881bb1b RH |
4387 | |
4388 | start[INSN_UID (bb->head)] = bb; | |
4389 | end[INSN_UID (bb->end)] = bb; | |
4390 | for (x = bb->head; x != NULL_RTX; x = NEXT_INSN (x)) | |
3e28fe44 | 4391 | { |
e881bb1b RH |
4392 | enum bb_state state = IN_MULTIPLE_BB; |
4393 | if (in_bb_p[INSN_UID(x)] == NOT_IN_BB) | |
4394 | state = IN_ONE_BB; | |
4395 | in_bb_p[INSN_UID(x)] = state; | |
4396 | ||
4397 | if (x == bb->end) | |
3e28fe44 MM |
4398 | break; |
4399 | } | |
4400 | } | |
4401 | ||
4402 | for (tmp_rtx = rtx_first; NULL != tmp_rtx; tmp_rtx = NEXT_INSN (tmp_rtx)) | |
4403 | { | |
b707b450 | 4404 | int did_output; |
e881bb1b | 4405 | basic_block bb; |
b707b450 | 4406 | |
e881bb1b | 4407 | if ((bb = start[INSN_UID (tmp_rtx)]) != NULL) |
3e28fe44 MM |
4408 | { |
4409 | fprintf (outf, ";; Start of basic block %d, registers live:", | |
e881bb1b | 4410 | bb->index); |
3e28fe44 | 4411 | |
e881bb1b | 4412 | EXECUTE_IF_SET_IN_REG_SET (bb->global_live_at_start, 0, i, |
3e28fe44 MM |
4413 | { |
4414 | fprintf (outf, " %d", i); | |
4415 | if (i < FIRST_PSEUDO_REGISTER) | |
4416 | fprintf (outf, " [%s]", | |
4417 | reg_names[i]); | |
4418 | }); | |
4419 | putc ('\n', outf); | |
4420 | } | |
4421 | ||
ab87f8c8 | 4422 | if (in_bb_p[INSN_UID(tmp_rtx)] == NOT_IN_BB |
3e28fe44 | 4423 | && GET_CODE (tmp_rtx) != NOTE |
ab87f8c8 JL |
4424 | && GET_CODE (tmp_rtx) != BARRIER |
4425 | && ! obey_regdecls) | |
3e28fe44 | 4426 | fprintf (outf, ";; Insn is not within a basic block\n"); |
e881bb1b | 4427 | else if (in_bb_p[INSN_UID(tmp_rtx)] == IN_MULTIPLE_BB) |
3e28fe44 MM |
4428 | fprintf (outf, ";; Insn is in multiple basic blocks\n"); |
4429 | ||
b707b450 | 4430 | did_output = print_rtl_single (outf, tmp_rtx); |
3e28fe44 | 4431 | |
e881bb1b RH |
4432 | if ((bb = end[INSN_UID (tmp_rtx)]) != NULL) |
4433 | fprintf (outf, ";; End of basic block %d\n", bb->index); | |
3e28fe44 | 4434 | |
b707b450 | 4435 | if (did_output) |
9ec36da5 | 4436 | putc ('\n', outf); |
3e28fe44 MM |
4437 | } |
4438 | } | |
4439 | } | |
5ece9746 JL |
4440 | |
4441 | \f | |
4442 | /* Integer list support. */ | |
4443 | ||
4444 | /* Allocate a node from list *HEAD_PTR. */ | |
4445 | ||
4446 | static int_list_ptr | |
4447 | alloc_int_list_node (head_ptr) | |
4448 | int_list_block **head_ptr; | |
4449 | { | |
4450 | struct int_list_block *first_blk = *head_ptr; | |
4451 | ||
4452 | if (first_blk == NULL || first_blk->nodes_left <= 0) | |
4453 | { | |
4454 | first_blk = (struct int_list_block *) xmalloc (sizeof (struct int_list_block)); | |
4455 | first_blk->nodes_left = INT_LIST_NODES_IN_BLK; | |
4456 | first_blk->next = *head_ptr; | |
4457 | *head_ptr = first_blk; | |
4458 | } | |
4459 | ||
4460 | first_blk->nodes_left--; | |
4461 | return &first_blk->nodes[first_blk->nodes_left]; | |
4462 | } | |
4463 | ||
4464 | /* Pointer to head of predecessor/successor block list. */ | |
4465 | static int_list_block *pred_int_list_blocks; | |
4466 | ||
4467 | /* Add a new node to integer list LIST with value VAL. | |
4468 | LIST is a pointer to a list object to allow for different implementations. | |
4469 | If *LIST is initially NULL, the list is empty. | |
4470 | The caller must not care whether the element is added to the front or | |
4471 | to the end of the list (to allow for different implementations). */ | |
4472 | ||
4473 | static int_list_ptr | |
4474 | add_int_list_node (blk_list, list, val) | |
4475 | int_list_block **blk_list; | |
4476 | int_list **list; | |
4477 | int val; | |
4478 | { | |
4479 | int_list_ptr p = alloc_int_list_node (blk_list); | |
4480 | ||
4481 | p->val = val; | |
4482 | p->next = *list; | |
4483 | *list = p; | |
4484 | return p; | |
4485 | } | |
4486 | ||
4487 | /* Free the blocks of lists at BLK_LIST. */ | |
4488 | ||
4489 | void | |
4490 | free_int_list (blk_list) | |
4491 | int_list_block **blk_list; | |
4492 | { | |
4493 | int_list_block *p, *next; | |
4494 | ||
4495 | for (p = *blk_list; p != NULL; p = next) | |
4496 | { | |
4497 | next = p->next; | |
4498 | free (p); | |
4499 | } | |
4500 | ||
4501 | /* Mark list as empty for the next function we compile. */ | |
4502 | *blk_list = NULL; | |
4503 | } | |
4504 | \f | |
4505 | /* Predecessor/successor computation. */ | |
4506 | ||
4507 | /* Mark PRED_BB a precessor of SUCC_BB, | |
4508 | and conversely SUCC_BB a successor of PRED_BB. */ | |
4509 | ||
4510 | static void | |
4511 | add_pred_succ (pred_bb, succ_bb, s_preds, s_succs, num_preds, num_succs) | |
4512 | int pred_bb; | |
4513 | int succ_bb; | |
4514 | int_list_ptr *s_preds; | |
4515 | int_list_ptr *s_succs; | |
4516 | int *num_preds; | |
4517 | int *num_succs; | |
4518 | { | |
4519 | if (succ_bb != EXIT_BLOCK) | |
4520 | { | |
4521 | add_int_list_node (&pred_int_list_blocks, &s_preds[succ_bb], pred_bb); | |
4522 | num_preds[succ_bb]++; | |
4523 | } | |
4524 | if (pred_bb != ENTRY_BLOCK) | |
4525 | { | |
4526 | add_int_list_node (&pred_int_list_blocks, &s_succs[pred_bb], succ_bb); | |
4527 | num_succs[pred_bb]++; | |
4528 | } | |
4529 | } | |
4530 | ||
e881bb1b RH |
4531 | /* Convert edge lists into pred/succ lists for backward compatibility. */ |
4532 | ||
743bb12d | 4533 | void |
5ece9746 JL |
4534 | compute_preds_succs (s_preds, s_succs, num_preds, num_succs) |
4535 | int_list_ptr *s_preds; | |
4536 | int_list_ptr *s_succs; | |
4537 | int *num_preds; | |
4538 | int *num_succs; | |
4539 | { | |
e881bb1b RH |
4540 | int i, n = n_basic_blocks; |
4541 | edge e; | |
5ece9746 | 4542 | |
e881bb1b RH |
4543 | memset (s_preds, 0, n_basic_blocks * sizeof (int_list_ptr)); |
4544 | memset (s_succs, 0, n_basic_blocks * sizeof (int_list_ptr)); | |
4545 | memset (num_preds, 0, n_basic_blocks * sizeof (int)); | |
4546 | memset (num_succs, 0, n_basic_blocks * sizeof (int)); | |
5ece9746 | 4547 | |
e881bb1b | 4548 | for (i = 0; i < n; ++i) |
5ece9746 | 4549 | { |
e881bb1b RH |
4550 | basic_block bb = BASIC_BLOCK (i); |
4551 | ||
4552 | for (e = bb->succ; e ; e = e->succ_next) | |
4553 | add_pred_succ (i, e->dest->index, s_preds, s_succs, | |
4554 | num_preds, num_succs); | |
5ece9746 JL |
4555 | } |
4556 | ||
e881bb1b RH |
4557 | for (e = ENTRY_BLOCK_PTR->succ; e ; e = e->succ_next) |
4558 | add_pred_succ (ENTRY_BLOCK, e->dest->index, s_preds, s_succs, | |
4559 | num_preds, num_succs); | |
5ece9746 JL |
4560 | } |
4561 | ||
4562 | void | |
421382ac | 4563 | dump_bb_data (file, preds, succs, live_info) |
5ece9746 JL |
4564 | FILE *file; |
4565 | int_list_ptr *preds; | |
4566 | int_list_ptr *succs; | |
421382ac | 4567 | int live_info; |
5ece9746 JL |
4568 | { |
4569 | int bb; | |
4570 | int_list_ptr p; | |
4571 | ||
4572 | fprintf (file, "BB data\n\n"); | |
4573 | for (bb = 0; bb < n_basic_blocks; bb++) | |
4574 | { | |
4575 | fprintf (file, "BB %d, start %d, end %d\n", bb, | |
4576 | INSN_UID (BLOCK_HEAD (bb)), INSN_UID (BLOCK_END (bb))); | |
4577 | fprintf (file, " preds:"); | |
4578 | for (p = preds[bb]; p != NULL; p = p->next) | |
4579 | { | |
4580 | int pred_bb = INT_LIST_VAL (p); | |
4581 | if (pred_bb == ENTRY_BLOCK) | |
4582 | fprintf (file, " entry"); | |
4583 | else | |
4584 | fprintf (file, " %d", pred_bb); | |
4585 | } | |
4586 | fprintf (file, "\n"); | |
4587 | fprintf (file, " succs:"); | |
4588 | for (p = succs[bb]; p != NULL; p = p->next) | |
4589 | { | |
4590 | int succ_bb = INT_LIST_VAL (p); | |
4591 | if (succ_bb == EXIT_BLOCK) | |
4592 | fprintf (file, " exit"); | |
4593 | else | |
4594 | fprintf (file, " %d", succ_bb); | |
4595 | } | |
421382ac BS |
4596 | if (live_info) |
4597 | { | |
4598 | int regno; | |
4599 | fprintf (file, "\nRegisters live at start:"); | |
4600 | for (regno = 0; regno < max_regno; regno++) | |
e881bb1b | 4601 | if (REGNO_REG_SET_P (BASIC_BLOCK (bb)->global_live_at_start, regno)) |
421382ac BS |
4602 | fprintf (file, " %d", regno); |
4603 | fprintf (file, "\n"); | |
4604 | } | |
5ece9746 JL |
4605 | fprintf (file, "\n"); |
4606 | } | |
4607 | fprintf (file, "\n"); | |
4608 | } | |
4609 | ||
4610 | /* Free basic block data storage. */ | |
4611 | ||
4612 | void | |
4613 | free_bb_mem () | |
4614 | { | |
4615 | free_int_list (&pred_int_list_blocks); | |
4616 | } | |
5e89e58b | 4617 | |
5ece9746 JL |
4618 | /* Compute dominator relationships. */ |
4619 | void | |
4620 | compute_dominators (dominators, post_dominators, s_preds, s_succs) | |
4621 | sbitmap *dominators; | |
4622 | sbitmap *post_dominators; | |
4623 | int_list_ptr *s_preds; | |
4624 | int_list_ptr *s_succs; | |
4625 | { | |
4626 | int bb, changed, passes; | |
4627 | sbitmap *temp_bitmap; | |
4628 | ||
4629 | temp_bitmap = sbitmap_vector_alloc (n_basic_blocks, n_basic_blocks); | |
4630 | sbitmap_vector_ones (dominators, n_basic_blocks); | |
4631 | sbitmap_vector_ones (post_dominators, n_basic_blocks); | |
4632 | sbitmap_vector_zero (temp_bitmap, n_basic_blocks); | |
4633 | ||
4634 | sbitmap_zero (dominators[0]); | |
4635 | SET_BIT (dominators[0], 0); | |
4636 | ||
e881bb1b RH |
4637 | sbitmap_zero (post_dominators[n_basic_blocks - 1]); |
4638 | SET_BIT (post_dominators[n_basic_blocks - 1], 0); | |
5ece9746 JL |
4639 | |
4640 | passes = 0; | |
4641 | changed = 1; | |
4642 | while (changed) | |
4643 | { | |
4644 | changed = 0; | |
4645 | for (bb = 1; bb < n_basic_blocks; bb++) | |
4646 | { | |
4647 | sbitmap_intersect_of_predecessors (temp_bitmap[bb], dominators, | |
4648 | bb, s_preds); | |
4649 | SET_BIT (temp_bitmap[bb], bb); | |
4650 | changed |= sbitmap_a_and_b (dominators[bb], | |
4651 | dominators[bb], | |
4652 | temp_bitmap[bb]); | |
4653 | sbitmap_intersect_of_successors (temp_bitmap[bb], post_dominators, | |
4654 | bb, s_succs); | |
4655 | SET_BIT (temp_bitmap[bb], bb); | |
4656 | changed |= sbitmap_a_and_b (post_dominators[bb], | |
4657 | post_dominators[bb], | |
4658 | temp_bitmap[bb]); | |
4659 | } | |
4660 | passes++; | |
4661 | } | |
4662 | ||
4663 | free (temp_bitmap); | |
4664 | } | |
4c649323 | 4665 | |
422d0fb0 RH |
4666 | /* Given DOMINATORS, compute the immediate dominators into IDOM. */ |
4667 | ||
4668 | void | |
4669 | compute_immediate_dominators (idom, dominators) | |
4670 | int *idom; | |
4671 | sbitmap *dominators; | |
4672 | { | |
4673 | sbitmap *tmp; | |
4674 | int b; | |
4675 | ||
4676 | tmp = sbitmap_vector_alloc (n_basic_blocks, n_basic_blocks); | |
4677 | ||
4678 | /* Begin with tmp(n) = dom(n) - { n }. */ | |
4679 | for (b = n_basic_blocks; --b >= 0; ) | |
4680 | { | |
4681 | sbitmap_copy (tmp[b], dominators[b]); | |
4682 | RESET_BIT (tmp[b], b); | |
4683 | } | |
4684 | ||
4685 | /* Subtract out all of our dominator's dominators. */ | |
4686 | for (b = n_basic_blocks; --b >= 0; ) | |
4687 | { | |
4688 | sbitmap tmp_b = tmp[b]; | |
4689 | int s; | |
4690 | ||
4691 | for (s = n_basic_blocks; --s >= 0; ) | |
4692 | if (TEST_BIT (tmp_b, s)) | |
4693 | sbitmap_difference (tmp_b, tmp_b, tmp[s]); | |
4694 | } | |
4695 | ||
4696 | /* Find the one bit set in the bitmap and put it in the output array. */ | |
4697 | for (b = n_basic_blocks; --b >= 0; ) | |
4698 | { | |
4699 | int t; | |
4700 | EXECUTE_IF_SET_IN_SBITMAP (tmp[b], 0, t, { idom[b] = t; }); | |
4701 | } | |
4702 | ||
4703 | sbitmap_vector_free (tmp); | |
4704 | } | |
4705 | ||
4c649323 JL |
4706 | /* Count for a single SET rtx, X. */ |
4707 | ||
4708 | static void | |
4709 | count_reg_sets_1 (x) | |
4710 | rtx x; | |
4711 | { | |
4712 | register int regno; | |
4713 | register rtx reg = SET_DEST (x); | |
4714 | ||
4715 | /* Find the register that's set/clobbered. */ | |
4716 | while (GET_CODE (reg) == SUBREG || GET_CODE (reg) == ZERO_EXTRACT | |
4717 | || GET_CODE (reg) == SIGN_EXTRACT | |
4718 | || GET_CODE (reg) == STRICT_LOW_PART) | |
4719 | reg = XEXP (reg, 0); | |
4720 | ||
86465af7 DM |
4721 | if (GET_CODE (reg) == PARALLEL |
4722 | && GET_MODE (reg) == BLKmode) | |
4723 | { | |
4724 | register int i; | |
4725 | for (i = XVECLEN (reg, 0) - 1; i >= 0; i--) | |
4726 | count_reg_sets_1 (XVECEXP (reg, 0, i)); | |
4727 | return; | |
4728 | } | |
4729 | ||
4c649323 JL |
4730 | if (GET_CODE (reg) == REG) |
4731 | { | |
4732 | regno = REGNO (reg); | |
4733 | if (regno >= FIRST_PSEUDO_REGISTER) | |
4734 | { | |
4735 | /* Count (weighted) references, stores, etc. This counts a | |
4736 | register twice if it is modified, but that is correct. */ | |
4737 | REG_N_SETS (regno)++; | |
4738 | ||
4739 | REG_N_REFS (regno) += loop_depth; | |
4740 | } | |
4741 | } | |
4742 | } | |
4743 | ||
4744 | /* Increment REG_N_SETS for each SET or CLOBBER found in X; also increment | |
4745 | REG_N_REFS by the current loop depth for each SET or CLOBBER found. */ | |
4746 | ||
4747 | static void | |
4748 | count_reg_sets (x) | |
4749 | rtx x; | |
4750 | { | |
4751 | register RTX_CODE code = GET_CODE (x); | |
4752 | ||
4753 | if (code == SET || code == CLOBBER) | |
4754 | count_reg_sets_1 (x); | |
4755 | else if (code == PARALLEL) | |
4756 | { | |
4757 | register int i; | |
4758 | for (i = XVECLEN (x, 0) - 1; i >= 0; i--) | |
4759 | { | |
4760 | code = GET_CODE (XVECEXP (x, 0, i)); | |
4761 | if (code == SET || code == CLOBBER) | |
4762 | count_reg_sets_1 (XVECEXP (x, 0, i)); | |
4763 | } | |
4764 | } | |
4765 | } | |
4766 | ||
4767 | /* Increment REG_N_REFS by the current loop depth each register reference | |
4768 | found in X. */ | |
4769 | ||
4770 | static void | |
4771 | count_reg_references (x) | |
4772 | rtx x; | |
4773 | { | |
4774 | register RTX_CODE code; | |
4c649323 JL |
4775 | |
4776 | retry: | |
4777 | code = GET_CODE (x); | |
4778 | switch (code) | |
4779 | { | |
4780 | case LABEL_REF: | |
4781 | case SYMBOL_REF: | |
4782 | case CONST_INT: | |
4783 | case CONST: | |
4784 | case CONST_DOUBLE: | |
4785 | case PC: | |
4786 | case ADDR_VEC: | |
4787 | case ADDR_DIFF_VEC: | |
4788 | case ASM_INPUT: | |
4789 | return; | |
4790 | ||
4791 | #ifdef HAVE_cc0 | |
4792 | case CC0: | |
4793 | return; | |
4794 | #endif | |
4795 | ||
4796 | case CLOBBER: | |
4797 | /* If we are clobbering a MEM, mark any registers inside the address | |
4798 | as being used. */ | |
4799 | if (GET_CODE (XEXP (x, 0)) == MEM) | |
4800 | count_reg_references (XEXP (XEXP (x, 0), 0)); | |
4801 | return; | |
4802 | ||
4803 | case SUBREG: | |
4804 | /* While we're here, optimize this case. */ | |
4805 | x = SUBREG_REG (x); | |
4806 | ||
4807 | /* In case the SUBREG is not of a register, don't optimize */ | |
4808 | if (GET_CODE (x) != REG) | |
4809 | { | |
4810 | count_reg_references (x); | |
4811 | return; | |
4812 | } | |
4813 | ||
4814 | /* ... fall through ... */ | |
4815 | ||
4816 | case REG: | |
4817 | if (REGNO (x) >= FIRST_PSEUDO_REGISTER) | |
4818 | REG_N_REFS (REGNO (x)) += loop_depth; | |
4819 | return; | |
4820 | ||
4821 | case SET: | |
4822 | { | |
4823 | register rtx testreg = SET_DEST (x); | |
4824 | int mark_dest = 0; | |
4825 | ||
4826 | /* If storing into MEM, don't show it as being used. But do | |
4827 | show the address as being used. */ | |
4828 | if (GET_CODE (testreg) == MEM) | |
4829 | { | |
4830 | count_reg_references (XEXP (testreg, 0)); | |
4831 | count_reg_references (SET_SRC (x)); | |
4832 | return; | |
4833 | } | |
4834 | ||
4835 | /* Storing in STRICT_LOW_PART is like storing in a reg | |
4836 | in that this SET might be dead, so ignore it in TESTREG. | |
4837 | but in some other ways it is like using the reg. | |
4838 | ||
4839 | Storing in a SUBREG or a bit field is like storing the entire | |
4840 | register in that if the register's value is not used | |
4841 | then this SET is not needed. */ | |
4842 | while (GET_CODE (testreg) == STRICT_LOW_PART | |
4843 | || GET_CODE (testreg) == ZERO_EXTRACT | |
4844 | || GET_CODE (testreg) == SIGN_EXTRACT | |
4845 | || GET_CODE (testreg) == SUBREG) | |
4846 | { | |
4847 | /* Modifying a single register in an alternate mode | |
4848 | does not use any of the old value. But these other | |
4849 | ways of storing in a register do use the old value. */ | |
4850 | if (GET_CODE (testreg) == SUBREG | |
4851 | && !(REG_SIZE (SUBREG_REG (testreg)) > REG_SIZE (testreg))) | |
4852 | ; | |
4853 | else | |
4854 | mark_dest = 1; | |
4855 | ||
4856 | testreg = XEXP (testreg, 0); | |
4857 | } | |
4858 | ||
4859 | /* If this is a store into a register, | |
4860 | recursively scan the value being stored. */ | |
4861 | ||
86465af7 DM |
4862 | if ((GET_CODE (testreg) == PARALLEL |
4863 | && GET_MODE (testreg) == BLKmode) | |
4864 | || GET_CODE (testreg) == REG) | |
4c649323 JL |
4865 | { |
4866 | count_reg_references (SET_SRC (x)); | |
4867 | if (mark_dest) | |
4868 | count_reg_references (SET_DEST (x)); | |
4869 | return; | |
4870 | } | |
4871 | } | |
4872 | break; | |
4873 | ||
4874 | default: | |
4875 | break; | |
4876 | } | |
4877 | ||
4878 | /* Recursively scan the operands of this expression. */ | |
4879 | ||
4880 | { | |
4881 | register char *fmt = GET_RTX_FORMAT (code); | |
4882 | register int i; | |
4883 | ||
4884 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
4885 | { | |
4886 | if (fmt[i] == 'e') | |
4887 | { | |
4888 | /* Tail recursive case: save a function call level. */ | |
4889 | if (i == 0) | |
4890 | { | |
4891 | x = XEXP (x, 0); | |
4892 | goto retry; | |
4893 | } | |
4894 | count_reg_references (XEXP (x, i)); | |
4895 | } | |
4896 | else if (fmt[i] == 'E') | |
4897 | { | |
4898 | register int j; | |
4899 | for (j = 0; j < XVECLEN (x, i); j++) | |
4900 | count_reg_references (XVECEXP (x, i, j)); | |
4901 | } | |
4902 | } | |
4903 | } | |
4904 | } | |
4905 | ||
4906 | /* Recompute register set/reference counts immediately prior to register | |
4907 | allocation. | |
4908 | ||
4909 | This avoids problems with set/reference counts changing to/from values | |
4910 | which have special meanings to the register allocators. | |
4911 | ||
4912 | Additionally, the reference counts are the primary component used by the | |
4913 | register allocators to prioritize pseudos for allocation to hard regs. | |
4914 | More accurate reference counts generally lead to better register allocation. | |
4915 | ||
213c4983 R |
4916 | F is the first insn to be scanned. |
4917 | LOOP_STEP denotes how much loop_depth should be incremented per | |
4918 | loop nesting level in order to increase the ref count more for references | |
4919 | in a loop. | |
4920 | ||
4c649323 JL |
4921 | It might be worthwhile to update REG_LIVE_LENGTH, REG_BASIC_BLOCK and |
4922 | possibly other information which is used by the register allocators. */ | |
4923 | ||
762a1d90 | 4924 | void |
213c4983 | 4925 | recompute_reg_usage (f, loop_step) |
4c649323 | 4926 | rtx f; |
213c4983 | 4927 | int loop_step; |
4c649323 JL |
4928 | { |
4929 | rtx insn; | |
4930 | int i, max_reg; | |
4931 | ||
4932 | /* Clear out the old data. */ | |
4933 | max_reg = max_reg_num (); | |
4934 | for (i = FIRST_PSEUDO_REGISTER; i < max_reg; i++) | |
4935 | { | |
4936 | REG_N_SETS (i) = 0; | |
4937 | REG_N_REFS (i) = 0; | |
4938 | } | |
4939 | ||
4940 | /* Scan each insn in the chain and count how many times each register is | |
4941 | set/used. */ | |
4942 | loop_depth = 1; | |
4943 | for (insn = f; insn; insn = NEXT_INSN (insn)) | |
4944 | { | |
4945 | /* Keep track of loop depth. */ | |
4946 | if (GET_CODE (insn) == NOTE) | |
4947 | { | |
4948 | /* Look for loop boundaries. */ | |
4949 | if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_END) | |
213c4983 | 4950 | loop_depth -= loop_step; |
4c649323 | 4951 | else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG) |
213c4983 | 4952 | loop_depth += loop_step; |
4c649323 JL |
4953 | |
4954 | /* If we have LOOP_DEPTH == 0, there has been a bookkeeping error. | |
4955 | Abort now rather than setting register status incorrectly. */ | |
4956 | if (loop_depth == 0) | |
4957 | abort (); | |
4958 | } | |
4959 | else if (GET_RTX_CLASS (GET_CODE (insn)) == 'i') | |
4960 | { | |
4961 | rtx links; | |
4962 | ||
4963 | /* This call will increment REG_N_SETS for each SET or CLOBBER | |
4964 | of a register in INSN. It will also increment REG_N_REFS | |
4965 | by the loop depth for each set of a register in INSN. */ | |
4966 | count_reg_sets (PATTERN (insn)); | |
4967 | ||
4968 | /* count_reg_sets does not detect autoincrement address modes, so | |
4969 | detect them here by looking at the notes attached to INSN. */ | |
4970 | for (links = REG_NOTES (insn); links; links = XEXP (links, 1)) | |
4971 | { | |
4972 | if (REG_NOTE_KIND (links) == REG_INC) | |
4973 | /* Count (weighted) references, stores, etc. This counts a | |
4974 | register twice if it is modified, but that is correct. */ | |
4975 | REG_N_SETS (REGNO (XEXP (links, 0)))++; | |
4976 | } | |
4977 | ||
4978 | /* This call will increment REG_N_REFS by the current loop depth for | |
4979 | each reference to a register in INSN. */ | |
4980 | count_reg_references (PATTERN (insn)); | |
4981 | ||
4982 | /* count_reg_references will not include counts for arguments to | |
4983 | function calls, so detect them here by examining the | |
4984 | CALL_INSN_FUNCTION_USAGE data. */ | |
4985 | if (GET_CODE (insn) == CALL_INSN) | |
4986 | { | |
4987 | rtx note; | |
4988 | ||
4989 | for (note = CALL_INSN_FUNCTION_USAGE (insn); | |
4990 | note; | |
4991 | note = XEXP (note, 1)) | |
4992 | if (GET_CODE (XEXP (note, 0)) == USE) | |
4993 | count_reg_references (SET_DEST (XEXP (note, 0))); | |
4994 | } | |
4995 | } | |
4996 | } | |
4997 | } | |
e881bb1b RH |
4998 | |
4999 | /* Record INSN's block as BB. */ | |
5000 | ||
5001 | void | |
5002 | set_block_for_insn (insn, bb) | |
5003 | rtx insn; | |
5004 | basic_block bb; | |
5005 | { | |
5006 | size_t uid = INSN_UID (insn); | |
5007 | if (uid >= basic_block_for_insn->num_elements) | |
5008 | { | |
5009 | int new_size; | |
5010 | ||
5011 | /* Add one-eighth the size so we don't keep calling xrealloc. */ | |
5012 | new_size = uid + (uid + 7) / 8; | |
5013 | ||
5014 | VARRAY_GROW (basic_block_for_insn, new_size); | |
5015 | } | |
5016 | VARRAY_BB (basic_block_for_insn, uid) = bb; | |
5017 | } | |
5018 | ||
5019 | /* Record INSN's block number as BB. */ | |
5020 | /* ??? This has got to go. */ | |
5021 | ||
5022 | void | |
5023 | set_block_num (insn, bb) | |
5024 | rtx insn; | |
5025 | int bb; | |
5026 | { | |
5027 | set_block_for_insn (insn, BASIC_BLOCK (bb)); | |
5028 | } | |
34487bf8 RH |
5029 | \f |
5030 | /* Verify the CFG consistency. This function check some CFG invariants and | |
5031 | aborts when something is wrong. Hope that this function will help to | |
5032 | convert many optimization passes to preserve CFG consistent. | |
5033 | ||
5034 | Currently it does following checks: | |
5035 | ||
5036 | - test head/end pointers | |
5037 | - overlapping of basic blocks | |
5038 | - edge list corectness | |
5039 | - headers of basic blocks (the NOTE_INSN_BASIC_BLOCK note) | |
5040 | - tails of basic blocks (ensure that boundary is necesary) | |
5041 | - scans body of the basic block for JUMP_INSN, CODE_LABEL | |
5042 | and NOTE_INSN_BASIC_BLOCK | |
5043 | - check that all insns are in the basic blocks | |
5044 | (except the switch handling code, barriers and notes) | |
5045 | ||
5046 | In future it can be extended check a lot of other stuff as well | |
5047 | (reachability of basic blocks, life information, etc. etc.). */ | |
5048 | ||
5049 | void | |
5050 | verify_flow_info () | |
5051 | { | |
5052 | const int max_uid = get_max_uid (); | |
5053 | const rtx rtx_first = get_insns (); | |
5054 | basic_block *bb_info; | |
5055 | rtx x; | |
5056 | int i; | |
5057 | ||
5058 | bb_info = (basic_block *) alloca (max_uid * sizeof (basic_block)); | |
5059 | memset (bb_info, 0, max_uid * sizeof (basic_block)); | |
5060 | ||
5061 | /* First pass check head/end pointers and set bb_info array used by | |
5062 | later passes. */ | |
5063 | for (i = n_basic_blocks - 1; i >= 0; i--) | |
5064 | { | |
5065 | basic_block bb = BASIC_BLOCK (i); | |
5066 | ||
5067 | /* Check the head pointer and make sure that it is pointing into | |
5068 | insn list. */ | |
5069 | for (x = rtx_first; x != NULL_RTX; x = NEXT_INSN (x)) | |
5070 | if (x == bb->head) | |
5071 | break; | |
5072 | if (!x) | |
5073 | { | |
5074 | fatal ("verify_flow_info: Head insn %d for block %d not found in the insn stream.\n", | |
5075 | INSN_UID (bb->head), bb->index); | |
5076 | } | |
5077 | ||
5078 | /* Check the end pointer and make sure that it is pointing into | |
5079 | insn list. */ | |
5080 | for (x = bb->head; x != NULL_RTX; x = NEXT_INSN (x)) | |
5081 | { | |
5082 | if (bb_info[INSN_UID (x)] != NULL) | |
5083 | { | |
5084 | fatal ("verify_flow_info: Insn %d is in multiple basic blocks (%d and %d)", | |
5085 | INSN_UID (x), bb->index, bb_info[INSN_UID (x)]->index); | |
5086 | } | |
5087 | bb_info[INSN_UID (x)] = bb; | |
5088 | ||
5089 | if (x == bb->end) | |
5090 | break; | |
5091 | } | |
5092 | if (!x) | |
5093 | { | |
5094 | fatal ("verify_flow_info: End insn %d for block %d not found in the insn stream.\n", | |
5095 | INSN_UID (bb->end), bb->index); | |
5096 | } | |
5097 | } | |
5098 | ||
5099 | /* Now check the basic blocks (boundaries etc.) */ | |
5100 | for (i = n_basic_blocks - 1; i >= 0; i--) | |
5101 | { | |
5102 | basic_block bb = BASIC_BLOCK (i); | |
5103 | /* Check corectness of edge lists */ | |
5104 | edge e; | |
5105 | ||
5106 | e = bb->succ; | |
5107 | while (e) | |
5108 | { | |
5109 | if (e->src != bb) | |
5110 | { | |
5111 | fprintf (stderr, "verify_flow_info: Basic block %d succ edge is corrupted\n", | |
5112 | bb->index); | |
5113 | fprintf (stderr, "Predecessor: "); | |
5114 | dump_edge_info (stderr, e, 0); | |
5115 | fprintf (stderr, "\nSuccessor: "); | |
5116 | dump_edge_info (stderr, e, 1); | |
5117 | fflush (stderr); | |
5118 | abort (); | |
5119 | } | |
5120 | if (e->dest != EXIT_BLOCK_PTR) | |
5121 | { | |
5122 | edge e2 = e->dest->pred; | |
5123 | while (e2 && e2 != e) | |
5124 | e2 = e2->pred_next; | |
5125 | if (!e2) | |
5126 | { | |
5127 | fatal ("verify_flow_info: Basic block %i edge lists are corrupted\n", | |
5128 | bb->index); | |
5129 | } | |
5130 | } | |
5131 | e = e->succ_next; | |
5132 | } | |
5133 | ||
5134 | e = bb->pred; | |
5135 | while (e) | |
5136 | { | |
5137 | if (e->dest != bb) | |
5138 | { | |
5139 | fprintf (stderr, "verify_flow_info: Basic block %d pred edge is corrupted\n", | |
5140 | bb->index); | |
5141 | fprintf (stderr, "Predecessor: "); | |
5142 | dump_edge_info (stderr, e, 0); | |
5143 | fprintf (stderr, "\nSuccessor: "); | |
5144 | dump_edge_info (stderr, e, 1); | |
5145 | fflush (stderr); | |
5146 | abort (); | |
5147 | } | |
5148 | if (e->src != ENTRY_BLOCK_PTR) | |
5149 | { | |
5150 | edge e2 = e->src->succ; | |
5151 | while (e2 && e2 != e) | |
5152 | e2 = e2->succ_next; | |
5153 | if (!e2) | |
5154 | { | |
5155 | fatal ("verify_flow_info: Basic block %i edge lists are corrupted\n", | |
5156 | bb->index); | |
5157 | } | |
5158 | } | |
5159 | e = e->pred_next; | |
5160 | } | |
5161 | ||
5162 | /* OK pointers are correct. Now check the header of basic | |
5163 | block. It ought to contain optional CODE_LABEL followed | |
5164 | by NOTE_BASIC_BLOCK. */ | |
5165 | x = bb->head; | |
5166 | if (GET_CODE (x) == CODE_LABEL) | |
5167 | { | |
5168 | if (bb->end == x) | |
5169 | { | |
5170 | fatal ("verify_flow_info: Basic block contains only CODE_LABEL and no NOTE_INSN_BASIC_BLOCK note\n"); | |
5171 | } | |
5172 | x = NEXT_INSN (x); | |
5173 | } | |
5174 | if (GET_CODE (x) != NOTE | |
5175 | || NOTE_LINE_NUMBER (x) != NOTE_INSN_BASIC_BLOCK | |
5176 | || NOTE_BASIC_BLOCK (x) != bb) | |
5177 | { | |
5178 | fatal ("verify_flow_info: NOTE_INSN_BASIC_BLOCK is missing for block %d\n", | |
5179 | bb->index); | |
5180 | } | |
5181 | ||
5182 | if (bb->end == x) | |
5183 | { | |
5184 | /* Do checks for empty blocks here */ | |
5185 | } | |
5186 | else | |
5187 | { | |
5188 | x = NEXT_INSN (x); | |
5189 | while (x) | |
5190 | { | |
5191 | if (GET_CODE (x) == NOTE | |
5192 | && NOTE_LINE_NUMBER (x) == NOTE_INSN_BASIC_BLOCK) | |
5193 | { | |
5194 | fatal ("verify_flow_info: NOTE_INSN_BASIC_BLOCK %d in the middle of basic block %d\n", | |
5195 | INSN_UID (x), bb->index); | |
5196 | } | |
5197 | ||
5198 | if (x == bb->end) | |
5199 | break; | |
5200 | ||
5201 | if (GET_CODE (x) == JUMP_INSN | |
5202 | || GET_CODE (x) == CODE_LABEL | |
5203 | || GET_CODE (x) == BARRIER) | |
5204 | { | |
5205 | fatal_insn ("verify_flow_info: Incorrect insn in the middle of basic block %d\n", | |
5206 | x, bb->index); | |
5207 | } | |
5208 | ||
5209 | x = NEXT_INSN (x); | |
5210 | } | |
5211 | } | |
5212 | } | |
5213 | ||
5214 | x = rtx_first; | |
5215 | while (x) | |
5216 | { | |
5217 | if (!bb_info[INSN_UID (x)]) | |
5218 | { | |
5219 | switch (GET_CODE (x)) | |
5220 | { | |
5221 | case BARRIER: | |
5222 | case NOTE: | |
5223 | break; | |
5224 | ||
5225 | case CODE_LABEL: | |
5226 | /* An addr_vec is placed outside any block block. */ | |
5227 | if (NEXT_INSN (x) | |
5228 | && GET_CODE (NEXT_INSN (x)) == JUMP_INSN | |
5229 | && (GET_CODE (PATTERN (NEXT_INSN (x))) == ADDR_DIFF_VEC | |
5230 | || GET_CODE (PATTERN (NEXT_INSN (x))) == ADDR_VEC)) | |
5231 | { | |
5232 | x = NEXT_INSN (x); | |
5233 | } | |
5234 | ||
5235 | /* But in any case, non-deletable labels can appear anywhere. */ | |
5236 | break; | |
5237 | ||
5238 | default: | |
5239 | fatal_insn ("verify_flow_info: Insn outside basic block\n", x); | |
5240 | } | |
5241 | } | |
5242 | ||
5243 | x = NEXT_INSN (x); | |
5244 | } | |
5245 | } | |
410538ea AM |
5246 | \f |
5247 | /* Functions to access an edge list with a vector representation. | |
5248 | Enough data is kept such that given an index number, the | |
5249 | pred and succ that edge reprsents can be determined, or | |
5250 | given a pred and a succ, it's index number can be returned. | |
5251 | This allows algorithms which comsume a lot of memory to | |
5252 | represent the normally full matrix of edge (pred,succ) with a | |
5253 | single indexed vector, edge (EDGE_INDEX (pred, succ)), with no | |
5254 | wasted space in the client code due to sparse flow graphs. */ | |
5255 | ||
5256 | /* This functions initializes the edge list. Basically the entire | |
5257 | flowgraph is processed, and all edges are assigned a number, | |
5258 | and the data structure is filed in. */ | |
5259 | struct edge_list * | |
5260 | create_edge_list () | |
5261 | { | |
5262 | struct edge_list *elist; | |
5263 | edge e; | |
5264 | int num_edges; | |
5265 | int x,y; | |
5266 | int_list_ptr ptr; | |
5267 | int block_count; | |
5268 | ||
5269 | block_count = n_basic_blocks + 2; /* Include the entry and exit blocks. */ | |
5270 | ||
5271 | num_edges = 0; | |
5272 | ||
5273 | /* Determine the number of edges in the flow graph by counting successor | |
5274 | edges on each basic block. */ | |
5275 | for (x = 0; x < n_basic_blocks; x++) | |
5276 | { | |
5277 | basic_block bb = BASIC_BLOCK (x); | |
5278 | ||
5279 | for (e = bb->succ; e; e = e->succ_next) | |
5280 | num_edges++; | |
5281 | } | |
5282 | /* Don't forget successors of the entry block. */ | |
5283 | for (e = ENTRY_BLOCK_PTR->succ; e; e = e->succ_next) | |
5284 | num_edges++; | |
5285 | ||
57ad4479 | 5286 | elist = xmalloc (sizeof (struct edge_list)); |
410538ea AM |
5287 | elist->num_blocks = block_count; |
5288 | elist->num_edges = num_edges; | |
57ad4479 | 5289 | elist->index_to_edge = xmalloc (sizeof (edge) * num_edges); |
410538ea AM |
5290 | |
5291 | num_edges = 0; | |
5292 | ||
5293 | /* Follow successors of the entry block, and register these edges. */ | |
5294 | for (e = ENTRY_BLOCK_PTR->succ; e; e = e->succ_next) | |
5295 | { | |
5296 | elist->index_to_edge[num_edges] = e; | |
5297 | num_edges++; | |
5298 | } | |
5299 | ||
5300 | for (x = 0; x < n_basic_blocks; x++) | |
5301 | { | |
5302 | basic_block bb = BASIC_BLOCK (x); | |
5303 | ||
5304 | /* Follow all successors of blocks, and register these edges. */ | |
5305 | for (e = bb->succ; e; e = e->succ_next) | |
5306 | { | |
5307 | elist->index_to_edge[num_edges] = e; | |
5308 | num_edges++; | |
5309 | } | |
5310 | } | |
5311 | return elist; | |
5312 | } | |
5313 | ||
5314 | /* This function free's memory associated with an edge list. */ | |
5315 | void | |
5316 | free_edge_list (elist) | |
5317 | struct edge_list *elist; | |
5318 | { | |
5319 | if (elist) | |
5320 | { | |
5321 | free (elist->index_to_edge); | |
5322 | free (elist); | |
5323 | } | |
5324 | } | |
5325 | ||
5326 | /* This function provides debug output showing an edge list. */ | |
5327 | void | |
5328 | print_edge_list (f, elist) | |
5329 | FILE *f; | |
5330 | struct edge_list *elist; | |
5331 | { | |
5332 | int x; | |
5333 | fprintf(f, "Compressed edge list, %d BBs + entry & exit, and %d edges\n", | |
5334 | elist->num_blocks - 2, elist->num_edges); | |
5335 | ||
5336 | for (x = 0; x < elist->num_edges; x++) | |
5337 | { | |
5338 | fprintf (f, " %-4d - edge(", x); | |
5339 | if (INDEX_EDGE_PRED_BB (elist, x) == ENTRY_BLOCK_PTR) | |
5340 | fprintf (f,"entry,"); | |
5341 | else | |
5342 | fprintf (f,"%d,", INDEX_EDGE_PRED_BB (elist, x)->index); | |
5343 | ||
5344 | if (INDEX_EDGE_SUCC_BB (elist, x) == EXIT_BLOCK_PTR) | |
5345 | fprintf (f,"exit)\n"); | |
5346 | else | |
5347 | fprintf (f,"%d)\n", INDEX_EDGE_SUCC_BB (elist, x)->index); | |
5348 | } | |
5349 | } | |
5350 | ||
5351 | /* This function provides an internal consistancy check of an edge list, | |
5352 | verifying that all edges are present, and that there are no | |
5353 | extra edges. */ | |
5354 | void | |
5355 | verify_edge_list (f, elist) | |
5356 | FILE *f; | |
5357 | struct edge_list *elist; | |
5358 | { | |
5359 | int x, pred, succ, index; | |
5360 | int_list_ptr ptr; | |
5361 | int flawed = 0; | |
5362 | edge e; | |
5363 | ||
5364 | for (x = 0; x < n_basic_blocks; x++) | |
5365 | { | |
5366 | basic_block bb = BASIC_BLOCK (x); | |
5367 | ||
5368 | for (e = bb->succ; e; e = e->succ_next) | |
5369 | { | |
5370 | pred = e->src->index; | |
5371 | succ = e->dest->index; | |
5372 | index = EDGE_INDEX (elist, pred, succ); | |
5373 | if (index == EDGE_INDEX_NO_EDGE) | |
5374 | { | |
5375 | fprintf (f, "*p* No index for edge from %d to %d\n",pred, succ); | |
5376 | continue; | |
5377 | } | |
5378 | if (INDEX_EDGE_PRED_BB (elist, index)->index != pred) | |
5379 | fprintf (f, "*p* Pred for index %d should be %d not %d\n", | |
5380 | index, pred, INDEX_EDGE_PRED_BB (elist, index)->index); | |
5381 | if (INDEX_EDGE_SUCC_BB (elist, index)->index != succ) | |
5382 | fprintf (f, "*p* Succ for index %d should be %d not %d\n", | |
5383 | index, succ, INDEX_EDGE_SUCC_BB (elist, index)->index); | |
5384 | } | |
5385 | } | |
5386 | for (e = ENTRY_BLOCK_PTR->succ; e; e = e->succ_next) | |
5387 | { | |
5388 | pred = e->src->index; | |
5389 | succ = e->dest->index; | |
5390 | index = EDGE_INDEX (elist, pred, succ); | |
5391 | if (index == EDGE_INDEX_NO_EDGE) | |
5392 | { | |
5393 | fprintf (f, "*p* No index for edge from %d to %d\n",pred, succ); | |
5394 | continue; | |
5395 | } | |
5396 | if (INDEX_EDGE_PRED_BB (elist, index)->index != pred) | |
5397 | fprintf (f, "*p* Pred for index %d should be %d not %d\n", | |
5398 | index, pred, INDEX_EDGE_PRED_BB (elist, index)->index); | |
5399 | if (INDEX_EDGE_SUCC_BB (elist, index)->index != succ) | |
5400 | fprintf (f, "*p* Succ for index %d should be %d not %d\n", | |
5401 | index, succ, INDEX_EDGE_SUCC_BB (elist, index)->index); | |
5402 | } | |
5403 | /* We've verified that all the edges are in the list, no lets make sure | |
5404 | there are no spurious edges in the list. */ | |
5405 | ||
5406 | for (pred = 0 ; pred < n_basic_blocks; pred++) | |
5407 | for (succ = 0 ; succ < n_basic_blocks; succ++) | |
5408 | { | |
5409 | basic_block p = BASIC_BLOCK (pred); | |
5410 | basic_block s = BASIC_BLOCK (succ); | |
5411 | ||
5412 | int found_edge = 0; | |
5413 | ||
5414 | for (e = p->succ; e; e = e->succ_next) | |
5415 | if (e->dest == s) | |
5416 | { | |
5417 | found_edge = 1; | |
5418 | break; | |
5419 | } | |
5420 | for (e = s->pred; e; e = e->pred_next) | |
5421 | if (e->src == p) | |
5422 | { | |
5423 | found_edge = 1; | |
5424 | break; | |
5425 | } | |
5426 | if (EDGE_INDEX (elist, pred, succ) == EDGE_INDEX_NO_EDGE | |
5427 | && found_edge != 0) | |
5428 | fprintf (f, "*** Edge (%d, %d) appears to not have an index\n", | |
5429 | pred, succ); | |
5430 | if (EDGE_INDEX (elist, pred, succ) != EDGE_INDEX_NO_EDGE | |
5431 | && found_edge == 0) | |
5432 | fprintf (f, "*** Edge (%d, %d) has index %d, but there is no edge\n", | |
5433 | pred, succ, EDGE_INDEX (elist, pred, succ)); | |
5434 | } | |
5435 | for (succ = 0 ; succ < n_basic_blocks; succ++) | |
5436 | { | |
5437 | basic_block p = ENTRY_BLOCK_PTR; | |
5438 | basic_block s = BASIC_BLOCK (succ); | |
5439 | ||
5440 | int found_edge = 0; | |
5441 | ||
5442 | for (e = p->succ; e; e = e->succ_next) | |
5443 | if (e->dest == s) | |
5444 | { | |
5445 | found_edge = 1; | |
5446 | break; | |
5447 | } | |
5448 | for (e = s->pred; e; e = e->pred_next) | |
5449 | if (e->src == p) | |
5450 | { | |
5451 | found_edge = 1; | |
5452 | break; | |
5453 | } | |
5454 | if (EDGE_INDEX (elist, ENTRY_BLOCK, succ) == EDGE_INDEX_NO_EDGE | |
5455 | && found_edge != 0) | |
5456 | fprintf (f, "*** Edge (entry, %d) appears to not have an index\n", | |
5457 | succ); | |
5458 | if (EDGE_INDEX (elist, ENTRY_BLOCK, succ) != EDGE_INDEX_NO_EDGE | |
5459 | && found_edge == 0) | |
5460 | fprintf (f, "*** Edge (entry, %d) has index %d, but no edge exists\n", | |
5461 | succ, EDGE_INDEX (elist, ENTRY_BLOCK, succ)); | |
5462 | } | |
5463 | for (pred = 0 ; pred < n_basic_blocks; pred++) | |
5464 | { | |
5465 | basic_block p = BASIC_BLOCK (pred); | |
5466 | basic_block s = EXIT_BLOCK_PTR; | |
5467 | ||
5468 | int found_edge = 0; | |
5469 | ||
5470 | for (e = p->succ; e; e = e->succ_next) | |
5471 | if (e->dest == s) | |
5472 | { | |
5473 | found_edge = 1; | |
5474 | break; | |
5475 | } | |
5476 | for (e = s->pred; e; e = e->pred_next) | |
5477 | if (e->src == p) | |
5478 | { | |
5479 | found_edge = 1; | |
5480 | break; | |
5481 | } | |
5482 | if (EDGE_INDEX (elist, pred, EXIT_BLOCK) == EDGE_INDEX_NO_EDGE | |
5483 | && found_edge != 0) | |
5484 | fprintf (f, "*** Edge (%d, exit) appears to not have an index\n", | |
5485 | pred); | |
5486 | if (EDGE_INDEX (elist, pred, EXIT_BLOCK) != EDGE_INDEX_NO_EDGE | |
5487 | && found_edge == 0) | |
5488 | fprintf (f, "*** Edge (%d, exit) has index %d, but no edge exists\n", | |
5489 | pred, EDGE_INDEX (elist, pred, EXIT_BLOCK)); | |
5490 | } | |
5491 | } | |
5492 | ||
5493 | /* This routine will determine what, if any, edge there is between | |
5494 | a specified predecessor and successor. */ | |
5495 | ||
5496 | int | |
5497 | find_edge_index (edge_list, pred, succ) | |
5498 | struct edge_list *edge_list; | |
5499 | int pred, succ; | |
5500 | { | |
5501 | int x; | |
5502 | for (x = 0; x < NUM_EDGES (edge_list); x++) | |
5503 | { | |
5504 | if (INDEX_EDGE_PRED_BB (edge_list, x)->index == pred | |
5505 | && INDEX_EDGE_SUCC_BB (edge_list, x)->index == succ) | |
5506 | return x; | |
5507 | } | |
5508 | return (EDGE_INDEX_NO_EDGE); | |
5509 | } | |
5510 |