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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 | 123 | #include "rtl.h" |
6baf1cc8 | 124 | #include "tm_p.h" |
d7429b6a RK |
125 | #include "basic-block.h" |
126 | #include "insn-config.h" | |
127 | #include "regs.h" | |
128 | #include "hard-reg-set.h" | |
129 | #include "flags.h" | |
130 | #include "output.h" | |
b384405b | 131 | #include "function.h" |
3d195391 | 132 | #include "except.h" |
2e107e9e | 133 | #include "toplev.h" |
79c9824e | 134 | #include "recog.h" |
e881bb1b | 135 | #include "insn-flags.h" |
d7429b6a RK |
136 | |
137 | #include "obstack.h" | |
c5c76735 | 138 | |
d7429b6a RK |
139 | #define obstack_chunk_alloc xmalloc |
140 | #define obstack_chunk_free free | |
141 | ||
e881bb1b RH |
142 | |
143 | /* EXIT_IGNORE_STACK should be nonzero if, when returning from a function, | |
144 | the stack pointer does not matter. The value is tested only in | |
145 | functions that have frame pointers. | |
146 | No definition is equivalent to always zero. */ | |
147 | #ifndef EXIT_IGNORE_STACK | |
148 | #define EXIT_IGNORE_STACK 0 | |
149 | #endif | |
150 | ||
421382ac | 151 | |
7eb136d6 MM |
152 | /* The contents of the current function definition are allocated |
153 | in this obstack, and all are freed at the end of the function. | |
154 | For top-level functions, this is temporary_obstack. | |
155 | Separate obstacks are made for nested functions. */ | |
156 | ||
157 | extern struct obstack *function_obstack; | |
158 | ||
e881bb1b | 159 | /* Number of basic blocks in the current function. */ |
d7429b6a | 160 | |
e881bb1b | 161 | int n_basic_blocks; |
d7429b6a | 162 | |
e881bb1b | 163 | /* The basic block array. */ |
d7429b6a | 164 | |
e881bb1b | 165 | varray_type basic_block_info; |
d7429b6a | 166 | |
e881bb1b | 167 | /* The special entry and exit blocks. */ |
d7429b6a | 168 | |
e881bb1b RH |
169 | struct basic_block_def entry_exit_blocks[2] = |
170 | { | |
171 | { | |
172 | NULL, /* head */ | |
173 | NULL, /* end */ | |
174 | NULL, /* pred */ | |
175 | NULL, /* succ */ | |
176 | NULL, /* local_set */ | |
177 | NULL, /* global_live_at_start */ | |
178 | NULL, /* global_live_at_end */ | |
179 | NULL, /* aux */ | |
180 | ENTRY_BLOCK, /* index */ | |
336a6399 RH |
181 | 0, /* loop_depth */ |
182 | -1, -1 /* eh_beg, eh_end */ | |
e881bb1b RH |
183 | }, |
184 | { | |
185 | NULL, /* head */ | |
186 | NULL, /* end */ | |
187 | NULL, /* pred */ | |
188 | NULL, /* succ */ | |
189 | NULL, /* local_set */ | |
190 | NULL, /* global_live_at_start */ | |
191 | NULL, /* global_live_at_end */ | |
192 | NULL, /* aux */ | |
193 | EXIT_BLOCK, /* index */ | |
336a6399 RH |
194 | 0, /* loop_depth */ |
195 | -1, -1 /* eh_beg, eh_end */ | |
e881bb1b RH |
196 | } |
197 | }; | |
d7429b6a | 198 | |
56744d1a JL |
199 | /* Nonzero if the second flow pass has completed. */ |
200 | int flow2_completed; | |
201 | ||
d7429b6a RK |
202 | /* Maximum register number used in this function, plus one. */ |
203 | ||
204 | int max_regno; | |
205 | ||
b1f21e0a | 206 | /* Indexed by n, giving various register information */ |
d7429b6a | 207 | |
6feacd09 | 208 | varray_type reg_n_info; |
d7429b6a | 209 | |
a494747c MM |
210 | /* Size of the reg_n_info table. */ |
211 | ||
212 | unsigned int reg_n_max; | |
213 | ||
d7429b6a RK |
214 | /* Element N is the next insn that uses (hard or pseudo) register number N |
215 | within the current basic block; or zero, if there is no such insn. | |
216 | This is valid only during the final backward scan in propagate_block. */ | |
217 | ||
218 | static rtx *reg_next_use; | |
219 | ||
220 | /* Size of a regset for the current function, | |
221 | in (1) bytes and (2) elements. */ | |
222 | ||
223 | int regset_bytes; | |
224 | int regset_size; | |
225 | ||
d7429b6a | 226 | /* Regset of regs live when calls to `setjmp'-like functions happen. */ |
e881bb1b | 227 | /* ??? Does this exist only for the setjmp-clobbered warning message? */ |
d7429b6a RK |
228 | |
229 | regset regs_live_at_setjmp; | |
230 | ||
231 | /* List made of EXPR_LIST rtx's which gives pairs of pseudo registers | |
232 | that have to go in the same hard reg. | |
233 | The first two regs in the list are a pair, and the next two | |
234 | are another pair, etc. */ | |
235 | rtx regs_may_share; | |
236 | ||
d7429b6a RK |
237 | /* Depth within loops of basic block being scanned for lifetime analysis, |
238 | plus one. This is the weight attached to references to registers. */ | |
239 | ||
240 | static int loop_depth; | |
241 | ||
242 | /* During propagate_block, this is non-zero if the value of CC0 is live. */ | |
243 | ||
244 | static int cc0_live; | |
245 | ||
db3a887b | 246 | /* During propagate_block, this contains a list of all the MEMs we are |
40b5a77c JL |
247 | tracking for dead store elimination. |
248 | ||
249 | ?!? Note we leak memory by not free-ing items on this list. We need to | |
250 | write some generic routines to operate on memory lists since cse, gcse, | |
251 | loop, sched, flow and possibly other passes all need to do basically the | |
252 | same operations on these lists. */ | |
d7429b6a | 253 | |
db3a887b | 254 | static rtx mem_set_list; |
d7429b6a RK |
255 | |
256 | /* Set of registers that may be eliminable. These are handled specially | |
257 | in updating regs_ever_live. */ | |
258 | ||
259 | static HARD_REG_SET elim_reg_set; | |
260 | ||
e881bb1b RH |
261 | /* The basic block structure for every insn, indexed by uid. */ |
262 | ||
263 | varray_type basic_block_for_insn; | |
264 | ||
265 | /* The labels mentioned in non-jump rtl. Valid during find_basic_blocks. */ | |
266 | /* ??? Should probably be using LABEL_NUSES instead. It would take a | |
267 | bit of surgery to be able to use or co-opt the routines in jump. */ | |
268 | ||
269 | static rtx label_value_list; | |
270 | ||
271 | /* INSN_VOLATILE (insn) is 1 if the insn refers to anything volatile. */ | |
272 | ||
273 | #define INSN_VOLATILE(INSN) bitmap_bit_p (uid_volatile, INSN_UID (INSN)) | |
274 | #define SET_INSN_VOLATILE(INSN) bitmap_set_bit (uid_volatile, INSN_UID (INSN)) | |
275 | static bitmap uid_volatile; | |
276 | ||
d7429b6a | 277 | /* Forward declarations */ |
e881bb1b | 278 | static int count_basic_blocks PROTO((rtx)); |
336a6399 | 279 | static rtx find_basic_blocks_1 PROTO((rtx)); |
e881bb1b | 280 | static void create_basic_block PROTO((int, rtx, rtx, rtx)); |
e881bb1b | 281 | static void clear_edges PROTO((void)); |
336a6399 | 282 | static void make_edges PROTO((rtx)); |
e881bb1b RH |
283 | static void make_edge PROTO((basic_block, basic_block, int)); |
284 | static void make_label_edge PROTO((basic_block, rtx, int)); | |
336a6399 RH |
285 | static void make_eh_edge PROTO((eh_nesting_info *, basic_block, |
286 | rtx, int)); | |
e881bb1b | 287 | static void mark_critical_edges PROTO((void)); |
336a6399 RH |
288 | static void move_stray_eh_region_notes PROTO((void)); |
289 | static void record_active_eh_regions PROTO((rtx)); | |
e881bb1b RH |
290 | |
291 | static void commit_one_edge_insertion PROTO((edge)); | |
292 | ||
421382ac | 293 | static void delete_unreachable_blocks PROTO((void)); |
e881bb1b | 294 | static void delete_eh_regions PROTO((void)); |
eeea333e | 295 | static int can_delete_note_p PROTO((rtx)); |
5aabad00 | 296 | static void flow_delete_insn_chain PROTO((rtx, rtx)); |
e881bb1b RH |
297 | static int delete_block PROTO((basic_block)); |
298 | static void expunge_block PROTO((basic_block)); | |
299 | static rtx flow_delete_insn PROTO((rtx)); | |
300 | static int can_delete_label_p PROTO((rtx)); | |
336a6399 RH |
301 | static int merge_blocks_move_predecessor_nojumps PROTO((basic_block, |
302 | basic_block)); | |
303 | static int merge_blocks_move_successor_nojumps PROTO((basic_block, | |
304 | basic_block)); | |
e881bb1b RH |
305 | static void merge_blocks_nomove PROTO((basic_block, basic_block)); |
306 | static int merge_blocks PROTO((edge,basic_block,basic_block)); | |
336a6399 | 307 | static void try_merge_blocks PROTO((void)); |
e881bb1b RH |
308 | static void tidy_fallthru_edge PROTO((edge,basic_block,basic_block)); |
309 | static void calculate_loop_depth PROTO((rtx)); | |
310 | ||
dc2ede84 BS |
311 | static int set_noop_p PROTO((rtx)); |
312 | static int noop_move_p PROTO((rtx)); | |
e881bb1b | 313 | static void notice_stack_pointer_modification PROTO ((rtx, rtx)); |
dc2ede84 BS |
314 | static void record_volatile_insns PROTO((rtx)); |
315 | static void mark_regs_live_at_end PROTO((regset)); | |
11f246f6 | 316 | static void life_analysis_1 PROTO((rtx, int, int)); |
e881bb1b RH |
317 | static void init_regset_vector PROTO ((regset *, int, |
318 | struct obstack *)); | |
319 | static void propagate_block PROTO((regset, rtx, rtx, int, | |
11f246f6 | 320 | regset, int, int)); |
e398aa80 | 321 | static int insn_dead_p PROTO((rtx, regset, int, rtx)); |
e658434c RK |
322 | static int libcall_dead_p PROTO((rtx, regset, rtx, rtx)); |
323 | static void mark_set_regs PROTO((regset, regset, rtx, | |
324 | rtx, regset)); | |
325 | static void mark_set_1 PROTO((regset, regset, rtx, | |
326 | rtx, regset)); | |
1d300e19 | 327 | #ifdef AUTO_INC_DEC |
e658434c | 328 | static void find_auto_inc PROTO((regset, rtx, rtx)); |
e658434c RK |
329 | static int try_pre_increment_1 PROTO((rtx)); |
330 | static int try_pre_increment PROTO((rtx, rtx, HOST_WIDE_INT)); | |
1d300e19 KG |
331 | #endif |
332 | static void mark_used_regs PROTO((regset, regset, rtx, int, rtx)); | |
e658434c | 333 | void dump_flow_info PROTO((FILE *)); |
e881bb1b RH |
334 | static void dump_edge_info PROTO((FILE *, edge, int)); |
335 | ||
5ece9746 JL |
336 | static int_list_ptr alloc_int_list_node PROTO ((int_list_block **)); |
337 | static int_list_ptr add_int_list_node PROTO ((int_list_block **, | |
338 | int_list **, int)); | |
e881bb1b RH |
339 | |
340 | static void add_pred_succ PROTO ((int, int, int_list_ptr *, | |
341 | int_list_ptr *, int *, int *)); | |
342 | ||
4c649323 JL |
343 | static void count_reg_sets_1 PROTO ((rtx)); |
344 | static void count_reg_sets PROTO ((rtx)); | |
345 | static void count_reg_references PROTO ((rtx)); | |
fdb8a883 | 346 | static void notice_stack_pointer_modification PROTO ((rtx, rtx)); |
15e088b2 | 347 | static void invalidate_mems_from_autoinc PROTO ((rtx)); |
f2a1bc02 BM |
348 | static void maybe_remove_dead_notes PROTO ((rtx, rtx, rtx, rtx, |
349 | rtx, rtx)); | |
350 | static int maybe_add_dead_note_use PROTO ((rtx, rtx)); | |
351 | static int maybe_add_dead_note PROTO ((rtx, rtx, rtx)); | |
352 | static int sets_reg_or_subreg PROTO ((rtx, rtx)); | |
353 | static void update_n_sets PROTO ((rtx, int)); | |
354 | static void new_insn_dead_notes PROTO ((rtx, rtx, rtx, rtx, rtx, rtx)); | |
34487bf8 | 355 | void verify_flow_info PROTO ((void)); |
d7429b6a | 356 | \f |
5ece9746 | 357 | /* Find basic blocks of the current function. |
e881bb1b RH |
358 | F is the first insn of the function and NREGS the number of register |
359 | numbers in use. */ | |
d7429b6a RK |
360 | |
361 | void | |
359da67d | 362 | find_basic_blocks (f, nregs, file, do_cleanup) |
d7429b6a | 363 | rtx f; |
e881bb1b RH |
364 | int nregs ATTRIBUTE_UNUSED; |
365 | FILE *file ATTRIBUTE_UNUSED; | |
359da67d | 366 | int do_cleanup; |
d7429b6a | 367 | { |
e881bb1b | 368 | int max_uid; |
d7429b6a | 369 | |
e881bb1b RH |
370 | /* Flush out existing data. */ |
371 | if (basic_block_info != NULL) | |
372 | { | |
373 | int i; | |
421382ac | 374 | |
e881bb1b | 375 | clear_edges (); |
d7429b6a | 376 | |
e881bb1b RH |
377 | /* Clear bb->aux on all extant basic blocks. We'll use this as a |
378 | tag for reuse during create_basic_block, just in case some pass | |
379 | copies around basic block notes improperly. */ | |
380 | for (i = 0; i < n_basic_blocks; ++i) | |
381 | BASIC_BLOCK (i)->aux = NULL; | |
d7429b6a | 382 | |
e881bb1b RH |
383 | VARRAY_FREE (basic_block_info); |
384 | } | |
27249135 | 385 | |
e881bb1b | 386 | n_basic_blocks = count_basic_blocks (f); |
27249135 | 387 | |
e881bb1b RH |
388 | /* Size the basic block table. The actual structures will be allocated |
389 | by find_basic_blocks_1, since we want to keep the structure pointers | |
390 | stable across calls to find_basic_blocks. */ | |
391 | /* ??? This whole issue would be much simpler if we called find_basic_blocks | |
392 | exactly once, and thereafter we don't have a single long chain of | |
393 | instructions at all until close to the end of compilation when we | |
394 | actually lay them out. */ | |
8cfe18d6 | 395 | |
e881bb1b RH |
396 | VARRAY_BB_INIT (basic_block_info, n_basic_blocks, "basic_block_info"); |
397 | ||
336a6399 | 398 | label_value_list = find_basic_blocks_1 (f); |
088e7160 | 399 | |
e881bb1b RH |
400 | /* Record the block to which an insn belongs. */ |
401 | /* ??? This should be done another way, by which (perhaps) a label is | |
402 | tagged directly with the basic block that it starts. It is used for | |
403 | more than that currently, but IMO that is the only valid use. */ | |
404 | ||
405 | max_uid = get_max_uid (); | |
d7429b6a | 406 | #ifdef AUTO_INC_DEC |
5ece9746 JL |
407 | /* Leave space for insns life_analysis makes in some cases for auto-inc. |
408 | These cases are rare, so we don't need too much space. */ | |
e881bb1b | 409 | max_uid += max_uid / 10; |
d7429b6a RK |
410 | #endif |
411 | ||
2307e372 | 412 | compute_bb_for_insn (max_uid); |
e881bb1b RH |
413 | |
414 | /* Discover the edges of our cfg. */ | |
d7429b6a | 415 | |
336a6399 RH |
416 | record_active_eh_regions (f); |
417 | make_edges (label_value_list); | |
421382ac | 418 | |
336a6399 | 419 | /* Delete unreachable blocks, then merge blocks when possible. */ |
d7429b6a | 420 | |
359da67d | 421 | if (do_cleanup) |
336a6399 RH |
422 | { |
423 | delete_unreachable_blocks (); | |
424 | move_stray_eh_region_notes (); | |
425 | record_active_eh_regions (f); | |
426 | try_merge_blocks (); | |
427 | } | |
e881bb1b RH |
428 | |
429 | /* Mark critical edges. */ | |
430 | ||
431 | mark_critical_edges (); | |
432 | ||
433 | /* Discover the loop depth at the start of each basic block to aid | |
434 | register allocation. */ | |
435 | calculate_loop_depth (f); | |
436 | ||
437 | /* Kill the data we won't maintain. */ | |
438 | label_value_list = 0; | |
34487bf8 RH |
439 | |
440 | #ifdef ENABLE_CHECKING | |
441 | verify_flow_info (); | |
442 | #endif | |
d7429b6a | 443 | } |
5ece9746 | 444 | |
e881bb1b | 445 | /* Count the basic blocks of the function. */ |
dc2ede84 | 446 | |
e881bb1b RH |
447 | static int |
448 | count_basic_blocks (f) | |
449 | rtx f; | |
450 | { | |
451 | register rtx insn; | |
452 | register RTX_CODE prev_code; | |
453 | register int count = 0; | |
454 | int eh_region = 0; | |
e881bb1b RH |
455 | int call_had_abnormal_edge = 0; |
456 | rtx prev_call = NULL_RTX; | |
dc2ede84 | 457 | |
e881bb1b RH |
458 | prev_code = JUMP_INSN; |
459 | for (insn = f; insn; insn = NEXT_INSN (insn)) | |
460 | { | |
461 | register RTX_CODE code = GET_CODE (insn); | |
462 | ||
e881bb1b RH |
463 | if (code == CODE_LABEL |
464 | || (GET_RTX_CLASS (code) == 'i' | |
465 | && (prev_code == JUMP_INSN | |
466 | || prev_code == BARRIER | |
467 | || (prev_code == CALL_INSN && call_had_abnormal_edge)))) | |
468 | { | |
469 | count++; | |
dc2ede84 | 470 | |
e881bb1b RH |
471 | /* If the previous insn was a call that did not create an |
472 | abnormal edge, we want to add a nop so that the CALL_INSN | |
473 | itself is not at basic_block_end. This allows us to | |
474 | easily distinguish between normal calls and those which | |
475 | create abnormal edges in the flow graph. */ | |
dc2ede84 | 476 | |
e881bb1b RH |
477 | if (count > 0 && prev_call != 0 && !call_had_abnormal_edge) |
478 | { | |
479 | rtx nop = gen_rtx_USE (VOIDmode, const0_rtx); | |
480 | emit_insn_after (nop, prev_call); | |
481 | } | |
482 | } | |
dc2ede84 | 483 | |
e881bb1b RH |
484 | /* Record whether this call created an edge. */ |
485 | if (code == CALL_INSN) | |
486 | { | |
6af57aae | 487 | rtx note = find_reg_note (insn, REG_EH_REGION, NULL_RTX); |
ef178af3 | 488 | int region = (note ? XWINT (XEXP (note, 0), 0) : 1); |
e881bb1b RH |
489 | prev_call = insn; |
490 | call_had_abnormal_edge = 0; | |
6af57aae AM |
491 | |
492 | /* If there is a specified EH region, we have an edge. */ | |
493 | if (eh_region && region > 0) | |
494 | call_had_abnormal_edge = 1; | |
495 | else | |
e881bb1b | 496 | { |
6af57aae AM |
497 | /* If there is a nonlocal goto label and the specified |
498 | region number isn't -1, we have an edge. (0 means | |
499 | no throw, but might have a nonlocal goto). */ | |
500 | if (nonlocal_goto_handler_labels && region >= 0) | |
e881bb1b RH |
501 | call_had_abnormal_edge = 1; |
502 | } | |
503 | } | |
504 | else if (code != NOTE) | |
505 | prev_call = NULL_RTX; | |
506 | ||
507 | if (code != NOTE) | |
508 | prev_code = code; | |
509 | else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_BEG) | |
510 | ++eh_region; | |
511 | else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_END) | |
512 | --eh_region; | |
513 | ||
e881bb1b RH |
514 | } |
515 | ||
516 | /* The rest of the compiler works a bit smoother when we don't have to | |
517 | check for the edge case of do-nothing functions with no basic blocks. */ | |
518 | if (count == 0) | |
519 | { | |
520 | emit_insn (gen_rtx_USE (VOIDmode, const0_rtx)); | |
521 | count = 1; | |
522 | } | |
523 | ||
524 | return count; | |
525 | } | |
dc2ede84 | 526 | |
d7429b6a | 527 | /* Find all basic blocks of the function whose first insn is F. |
d7429b6a | 528 | |
336a6399 RH |
529 | Collect and return a list of labels whose addresses are taken. This |
530 | will be used in make_edges for use with computed gotos. */ | |
8329b5ec | 531 | |
e881bb1b | 532 | static rtx |
336a6399 | 533 | find_basic_blocks_1 (f) |
e881bb1b | 534 | rtx f; |
e881bb1b RH |
535 | { |
536 | register rtx insn, next; | |
e881bb1b RH |
537 | int call_has_abnormal_edge = 0; |
538 | int i = 0; | |
539 | rtx bb_note = NULL_RTX; | |
540 | rtx eh_list = NULL_RTX; | |
541 | rtx label_value_list = NULL_RTX; | |
542 | rtx head = NULL_RTX; | |
543 | rtx end = NULL_RTX; | |
544 | ||
545 | /* We process the instructions in a slightly different way than we did | |
546 | previously. This is so that we see a NOTE_BASIC_BLOCK after we have | |
547 | closed out the previous block, so that it gets attached at the proper | |
548 | place. Since this form should be equivalent to the previous, | |
336a6399 | 549 | count_basic_blocks continues to use the old form as a check. */ |
d7429b6a | 550 | |
e881bb1b RH |
551 | for (insn = f; insn; insn = next) |
552 | { | |
553 | enum rtx_code code = GET_CODE (insn); | |
d7429b6a | 554 | |
e881bb1b | 555 | next = NEXT_INSN (insn); |
d7429b6a | 556 | |
e881bb1b | 557 | if (code == CALL_INSN) |
e658434c | 558 | { |
e881bb1b | 559 | /* Record whether this call created an edge. */ |
6af57aae | 560 | rtx note = find_reg_note (insn, REG_EH_REGION, NULL_RTX); |
ef178af3 | 561 | int region = (note ? XWINT (XEXP (note, 0), 0) : 1); |
e881bb1b | 562 | call_has_abnormal_edge = 0; |
6af57aae AM |
563 | |
564 | /* If there is an EH region, we have an edge. */ | |
565 | if (eh_list && region > 0) | |
566 | call_has_abnormal_edge = 1; | |
567 | else | |
e658434c | 568 | { |
6af57aae AM |
569 | /* If there is a nonlocal goto label and the specified |
570 | region number isn't -1, we have an edge. (0 means | |
571 | no throw, but might have a nonlocal goto). */ | |
572 | if (nonlocal_goto_handler_labels && region >= 0) | |
e881bb1b | 573 | call_has_abnormal_edge = 1; |
5c35539b | 574 | } |
e658434c | 575 | } |
d7429b6a | 576 | |
e881bb1b | 577 | switch (code) |
e658434c | 578 | { |
e881bb1b RH |
579 | case NOTE: |
580 | { | |
581 | int kind = NOTE_LINE_NUMBER (insn); | |
582 | ||
583 | /* Keep a LIFO list of the currently active exception notes. */ | |
584 | if (kind == NOTE_INSN_EH_REGION_BEG) | |
336a6399 | 585 | eh_list = alloc_INSN_LIST (insn, eh_list); |
e881bb1b | 586 | else if (kind == NOTE_INSN_EH_REGION_END) |
336a6399 RH |
587 | { |
588 | rtx t = eh_list; | |
589 | eh_list = XEXP (eh_list, 1); | |
590 | free_INSN_LIST_node (t); | |
591 | } | |
e881bb1b RH |
592 | |
593 | /* Look for basic block notes with which to keep the | |
594 | basic_block_info pointers stable. Unthread the note now; | |
595 | we'll put it back at the right place in create_basic_block. | |
596 | Or not at all if we've already found a note in this block. */ | |
597 | else if (kind == NOTE_INSN_BASIC_BLOCK) | |
598 | { | |
599 | if (bb_note == NULL_RTX) | |
600 | bb_note = insn; | |
601 | next = flow_delete_insn (insn); | |
602 | } | |
e658434c | 603 | |
e881bb1b RH |
604 | break; |
605 | } | |
d7429b6a | 606 | |
e881bb1b RH |
607 | case CODE_LABEL: |
608 | /* A basic block starts at a label. If we've closed one off due | |
609 | to a barrier or some such, no need to do it again. */ | |
610 | if (head != NULL_RTX) | |
2ec1535d | 611 | { |
e881bb1b RH |
612 | /* While we now have edge lists with which other portions of |
613 | the compiler might determine a call ending a basic block | |
614 | does not imply an abnormal edge, it will be a bit before | |
615 | everything can be updated. So continue to emit a noop at | |
616 | the end of such a block. */ | |
617 | if (GET_CODE (end) == CALL_INSN) | |
618 | { | |
619 | rtx nop = gen_rtx_USE (VOIDmode, const0_rtx); | |
620 | end = emit_insn_after (nop, end); | |
621 | } | |
622 | ||
e881bb1b RH |
623 | create_basic_block (i++, head, end, bb_note); |
624 | bb_note = NULL_RTX; | |
2ec1535d | 625 | } |
e881bb1b RH |
626 | head = end = insn; |
627 | break; | |
d06c6389 | 628 | |
e881bb1b RH |
629 | case JUMP_INSN: |
630 | /* A basic block ends at a jump. */ | |
631 | if (head == NULL_RTX) | |
632 | head = insn; | |
633 | else | |
634 | { | |
635 | /* ??? Make a special check for table jumps. The way this | |
636 | happens is truely and amazingly gross. We are about to | |
637 | create a basic block that contains just a code label and | |
638 | an addr*vec jump insn. Worse, an addr_diff_vec creates | |
639 | its own natural loop. | |
5c35539b | 640 | |
e881bb1b RH |
641 | Prevent this bit of brain damage, pasting things together |
642 | correctly in make_edges. | |
2c3a56ad | 643 | |
e881bb1b RH |
644 | The correct solution involves emitting the table directly |
645 | on the tablejump instruction as a note, or JUMP_LABEL. */ | |
e658434c | 646 | |
e881bb1b RH |
647 | if (GET_CODE (PATTERN (insn)) == ADDR_VEC |
648 | || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC) | |
649 | { | |
650 | head = end = NULL; | |
651 | n_basic_blocks--; | |
652 | break; | |
653 | } | |
654 | } | |
655 | end = insn; | |
656 | goto new_bb_inclusive; | |
d7429b6a | 657 | |
e881bb1b RH |
658 | case BARRIER: |
659 | /* A basic block ends at a barrier. It may be that an unconditional | |
660 | jump already closed the basic block -- no need to do it again. */ | |
661 | if (head == NULL_RTX) | |
662 | break; | |
d7429b6a | 663 | |
e881bb1b RH |
664 | /* While we now have edge lists with which other portions of the |
665 | compiler might determine a call ending a basic block does not | |
666 | imply an abnormal edge, it will be a bit before everything can | |
667 | be updated. So continue to emit a noop at the end of such a | |
668 | block. */ | |
669 | if (GET_CODE (end) == CALL_INSN) | |
670 | { | |
671 | rtx nop = gen_rtx_USE (VOIDmode, const0_rtx); | |
672 | end = emit_insn_after (nop, end); | |
673 | } | |
674 | goto new_bb_exclusive; | |
675 | ||
676 | case CALL_INSN: | |
677 | /* A basic block ends at a call that can either throw or | |
678 | do a non-local goto. */ | |
679 | if (call_has_abnormal_edge) | |
680 | { | |
681 | new_bb_inclusive: | |
682 | if (head == NULL_RTX) | |
683 | head = insn; | |
684 | end = insn; | |
685 | ||
686 | new_bb_exclusive: | |
e881bb1b RH |
687 | create_basic_block (i++, head, end, bb_note); |
688 | head = end = NULL_RTX; | |
689 | bb_note = NULL_RTX; | |
690 | break; | |
691 | } | |
692 | /* FALLTHRU */ | |
d7429b6a | 693 | |
e881bb1b RH |
694 | default: |
695 | if (GET_RTX_CLASS (code) == 'i') | |
696 | { | |
697 | if (head == NULL_RTX) | |
698 | head = insn; | |
699 | end = insn; | |
700 | } | |
701 | break; | |
702 | } | |
d7429b6a | 703 | |
e881bb1b | 704 | if (GET_RTX_CLASS (code) == 'i') |
d7429b6a | 705 | { |
e881bb1b | 706 | rtx note; |
421382ac | 707 | |
e881bb1b RH |
708 | /* Make a list of all labels referred to other than by jumps |
709 | (which just don't have the REG_LABEL notes). | |
2ec1535d | 710 | |
e881bb1b RH |
711 | Make a special exception for labels followed by an ADDR*VEC, |
712 | as this would be a part of the tablejump setup code. | |
421382ac | 713 | |
e881bb1b RH |
714 | Make a special exception for the eh_return_stub_label, which |
715 | we know isn't part of any otherwise visible control flow. */ | |
716 | ||
717 | for (note = REG_NOTES (insn); note; note = XEXP (note, 1)) | |
718 | if (REG_NOTE_KIND (note) == REG_LABEL) | |
719 | { | |
720 | rtx lab = XEXP (note, 0), next; | |
721 | ||
722 | if (lab == eh_return_stub_label) | |
723 | ; | |
724 | else if ((next = next_nonnote_insn (lab)) != NULL | |
725 | && GET_CODE (next) == JUMP_INSN | |
726 | && (GET_CODE (PATTERN (next)) == ADDR_VEC | |
727 | || GET_CODE (PATTERN (next)) == ADDR_DIFF_VEC)) | |
728 | ; | |
729 | else | |
730 | label_value_list | |
731 | = gen_rtx_EXPR_LIST (VOIDmode, XEXP (note, 0), | |
732 | label_value_list); | |
d7429b6a RK |
733 | } |
734 | } | |
e881bb1b | 735 | } |
d7429b6a | 736 | |
e881bb1b | 737 | if (head != NULL_RTX) |
336a6399 | 738 | create_basic_block (i++, head, end, bb_note); |
af14ce9c | 739 | |
e881bb1b RH |
740 | if (i != n_basic_blocks) |
741 | abort (); | |
af14ce9c | 742 | |
e881bb1b | 743 | return label_value_list; |
d7429b6a | 744 | } |
5ece9746 | 745 | |
e881bb1b RH |
746 | /* Create a new basic block consisting of the instructions between |
747 | HEAD and END inclusive. Reuses the note and basic block struct | |
748 | in BB_NOTE, if any. */ | |
5ece9746 | 749 | |
e881bb1b RH |
750 | static void |
751 | create_basic_block (index, head, end, bb_note) | |
752 | int index; | |
753 | rtx head, end, bb_note; | |
5ece9746 | 754 | { |
e881bb1b RH |
755 | basic_block bb; |
756 | ||
757 | if (bb_note | |
b3bf5bde | 758 | && ! RTX_INTEGRATED_P (bb_note) |
e881bb1b RH |
759 | && (bb = NOTE_BASIC_BLOCK (bb_note)) != NULL |
760 | && bb->aux == NULL) | |
5ece9746 | 761 | { |
e881bb1b RH |
762 | /* If we found an existing note, thread it back onto the chain. */ |
763 | ||
764 | if (GET_CODE (head) == CODE_LABEL) | |
765 | add_insn_after (bb_note, head); | |
766 | else | |
767 | { | |
768 | add_insn_before (bb_note, head); | |
769 | head = bb_note; | |
770 | } | |
5ece9746 | 771 | } |
e881bb1b RH |
772 | else |
773 | { | |
774 | /* Otherwise we must create a note and a basic block structure. | |
775 | Since we allow basic block structs in rtl, give the struct | |
776 | the same lifetime by allocating it off the function obstack | |
777 | rather than using malloc. */ | |
8329b5ec | 778 | |
e881bb1b RH |
779 | bb = (basic_block) obstack_alloc (function_obstack, sizeof (*bb)); |
780 | memset (bb, 0, sizeof (*bb)); | |
421382ac | 781 | |
e881bb1b RH |
782 | if (GET_CODE (head) == CODE_LABEL) |
783 | bb_note = emit_note_after (NOTE_INSN_BASIC_BLOCK, head); | |
784 | else | |
785 | { | |
786 | bb_note = emit_note_before (NOTE_INSN_BASIC_BLOCK, head); | |
787 | head = bb_note; | |
788 | } | |
789 | NOTE_BASIC_BLOCK (bb_note) = bb; | |
790 | } | |
791 | ||
eeea333e RH |
792 | /* Always include the bb note in the block. */ |
793 | if (NEXT_INSN (end) == bb_note) | |
794 | end = bb_note; | |
795 | ||
e881bb1b RH |
796 | bb->head = head; |
797 | bb->end = end; | |
798 | bb->index = index; | |
799 | BASIC_BLOCK (index) = bb; | |
800 | ||
801 | /* Tag the block so that we know it has been used when considering | |
802 | other basic block notes. */ | |
803 | bb->aux = bb; | |
421382ac | 804 | } |
e881bb1b RH |
805 | \f |
806 | /* Records the basic block struct in BB_FOR_INSN, for every instruction | |
807 | indexed by INSN_UID. MAX is the size of the array. */ | |
421382ac | 808 | |
2307e372 RH |
809 | void |
810 | compute_bb_for_insn (max) | |
e881bb1b | 811 | int max; |
421382ac | 812 | { |
e881bb1b | 813 | int i; |
421382ac | 814 | |
2307e372 RH |
815 | VARRAY_BB_INIT (basic_block_for_insn, max, "basic_block_for_insn"); |
816 | ||
e881bb1b RH |
817 | for (i = 0; i < n_basic_blocks; ++i) |
818 | { | |
819 | basic_block bb = BASIC_BLOCK (i); | |
820 | rtx insn, end; | |
821 | ||
822 | end = bb->end; | |
823 | insn = bb->head; | |
824 | while (1) | |
825 | { | |
826 | int uid = INSN_UID (insn); | |
827 | if (uid < max) | |
2307e372 | 828 | VARRAY_BB (basic_block_for_insn, uid) = bb; |
e881bb1b RH |
829 | if (insn == end) |
830 | break; | |
831 | insn = NEXT_INSN (insn); | |
832 | } | |
833 | } | |
421382ac BS |
834 | } |
835 | ||
e881bb1b | 836 | /* Free the memory associated with the edge structures. */ |
421382ac BS |
837 | |
838 | static void | |
e881bb1b | 839 | clear_edges () |
421382ac | 840 | { |
e881bb1b RH |
841 | int i; |
842 | edge n, e; | |
421382ac | 843 | |
e881bb1b | 844 | for (i = 0; i < n_basic_blocks; ++i) |
421382ac | 845 | { |
e881bb1b | 846 | basic_block bb = BASIC_BLOCK (i); |
421382ac | 847 | |
e881bb1b | 848 | for (e = bb->succ; e ; e = n) |
421382ac | 849 | { |
e881bb1b RH |
850 | n = e->succ_next; |
851 | free (e); | |
421382ac | 852 | } |
e881bb1b RH |
853 | |
854 | bb->succ = 0; | |
855 | bb->pred = 0; | |
856 | } | |
857 | ||
858 | for (e = ENTRY_BLOCK_PTR->succ; e ; e = n) | |
859 | { | |
860 | n = e->succ_next; | |
861 | free (e); | |
421382ac | 862 | } |
e881bb1b RH |
863 | |
864 | ENTRY_BLOCK_PTR->succ = 0; | |
865 | EXIT_BLOCK_PTR->pred = 0; | |
421382ac BS |
866 | } |
867 | ||
e881bb1b RH |
868 | /* Identify the edges between basic blocks. |
869 | ||
870 | NONLOCAL_LABEL_LIST is a list of non-local labels in the function. Blocks | |
871 | that are otherwise unreachable may be reachable with a non-local goto. | |
872 | ||
873 | BB_EH_END is an array indexed by basic block number in which we record | |
874 | the list of exception regions active at the end of the basic block. */ | |
875 | ||
dc2ede84 | 876 | static void |
336a6399 | 877 | make_edges (label_value_list) |
e881bb1b | 878 | rtx label_value_list; |
dc2ede84 | 879 | { |
e881bb1b | 880 | int i; |
1ef1bf06 | 881 | eh_nesting_info *eh_nest_info = init_eh_nesting_info (); |
e881bb1b RH |
882 | |
883 | /* Assume no computed jump; revise as we create edges. */ | |
884 | current_function_has_computed_jump = 0; | |
885 | ||
886 | /* By nature of the way these get numbered, block 0 is always the entry. */ | |
887 | make_edge (ENTRY_BLOCK_PTR, BASIC_BLOCK (0), EDGE_FALLTHRU); | |
dc2ede84 | 888 | |
e881bb1b | 889 | for (i = 0; i < n_basic_blocks; ++i) |
421382ac | 890 | { |
e881bb1b | 891 | basic_block bb = BASIC_BLOCK (i); |
336a6399 | 892 | rtx insn, x; |
e881bb1b | 893 | enum rtx_code code; |
4b523fc4 | 894 | int force_fallthru = 0; |
421382ac | 895 | |
336a6399 | 896 | /* Examine the last instruction of the block, and discover the |
e881bb1b RH |
897 | ways we can leave the block. */ |
898 | ||
899 | insn = bb->end; | |
900 | code = GET_CODE (insn); | |
901 | ||
902 | /* A branch. */ | |
903 | if (code == JUMP_INSN) | |
904 | { | |
905 | rtx tmp; | |
906 | ||
907 | /* ??? Recognize a tablejump and do the right thing. */ | |
908 | if ((tmp = JUMP_LABEL (insn)) != NULL_RTX | |
909 | && (tmp = NEXT_INSN (tmp)) != NULL_RTX | |
910 | && GET_CODE (tmp) == JUMP_INSN | |
911 | && (GET_CODE (PATTERN (tmp)) == ADDR_VEC | |
912 | || GET_CODE (PATTERN (tmp)) == ADDR_DIFF_VEC)) | |
913 | { | |
914 | rtvec vec; | |
915 | int j; | |
916 | ||
917 | if (GET_CODE (PATTERN (tmp)) == ADDR_VEC) | |
918 | vec = XVEC (PATTERN (tmp), 0); | |
919 | else | |
920 | vec = XVEC (PATTERN (tmp), 1); | |
921 | ||
922 | for (j = GET_NUM_ELEM (vec) - 1; j >= 0; --j) | |
923 | make_label_edge (bb, XEXP (RTVEC_ELT (vec, j), 0), 0); | |
4b523fc4 RE |
924 | |
925 | /* Some targets (eg, ARM) emit a conditional jump that also | |
926 | contains the out-of-range target. Scan for these and | |
927 | add an edge if necessary. */ | |
928 | if ((tmp = single_set (insn)) != NULL | |
929 | && SET_DEST (tmp) == pc_rtx | |
930 | && GET_CODE (SET_SRC (tmp)) == IF_THEN_ELSE | |
931 | && GET_CODE (XEXP (SET_SRC (tmp), 2)) == LABEL_REF) | |
932 | make_label_edge (bb, XEXP (XEXP (SET_SRC (tmp), 2), 0), 0); | |
933 | ||
934 | #ifdef CASE_DROPS_THROUGH | |
935 | /* Silly VAXen. The ADDR_VEC is going to be in the way of | |
936 | us naturally detecting fallthru into the next block. */ | |
937 | force_fallthru = 1; | |
938 | #endif | |
e881bb1b RH |
939 | } |
940 | ||
941 | /* If this is a computed jump, then mark it as reaching | |
942 | everything on the label_value_list and forced_labels list. */ | |
943 | else if (computed_jump_p (insn)) | |
944 | { | |
dc2ede84 | 945 | current_function_has_computed_jump = 1; |
dc2ede84 | 946 | |
e881bb1b RH |
947 | for (x = label_value_list; x; x = XEXP (x, 1)) |
948 | make_label_edge (bb, XEXP (x, 0), EDGE_ABNORMAL); | |
949 | ||
dc2ede84 | 950 | for (x = forced_labels; x; x = XEXP (x, 1)) |
e881bb1b | 951 | make_label_edge (bb, XEXP (x, 0), EDGE_ABNORMAL); |
dc2ede84 BS |
952 | } |
953 | ||
e881bb1b RH |
954 | /* Returns create an exit out. */ |
955 | else if (returnjump_p (insn)) | |
956 | make_edge (bb, EXIT_BLOCK_PTR, 0); | |
957 | ||
958 | /* Otherwise, we have a plain conditional or unconditional jump. */ | |
959 | else | |
dc2ede84 | 960 | { |
e881bb1b RH |
961 | if (! JUMP_LABEL (insn)) |
962 | abort (); | |
963 | make_label_edge (bb, JUMP_LABEL (insn), 0); | |
964 | } | |
965 | } | |
966 | ||
967 | /* If this is a CALL_INSN, then mark it as reaching the active EH | |
968 | handler for this CALL_INSN. If we're handling asynchronous | |
969 | exceptions then any insn can reach any of the active handlers. | |
b472794d | 970 | |
e881bb1b | 971 | Also mark the CALL_INSN as reaching any nonlocal goto handler. */ |
b472794d | 972 | |
a3e924fc | 973 | if (code == CALL_INSN || asynchronous_exceptions) |
e881bb1b | 974 | { |
336a6399 RH |
975 | /* If there's an EH region active at the end of a block, |
976 | add the appropriate edges. */ | |
977 | if (bb->eh_end >= 0) | |
978 | make_eh_edge (eh_nest_info, bb, insn, bb->eh_end); | |
979 | ||
980 | /* If we have asynchronous exceptions, do the same for *all* | |
981 | exception regions active in the block. */ | |
982 | if (asynchronous_exceptions | |
983 | && bb->eh_beg != bb->eh_end) | |
e881bb1b | 984 | { |
336a6399 RH |
985 | if (bb->eh_beg >= 0) |
986 | make_eh_edge (eh_nest_info, bb, NULL_RTX, bb->eh_beg); | |
987 | ||
988 | for (x = bb->head; x != bb->end; x = PREV_INSN (x)) | |
989 | if (GET_CODE (x) == NOTE | |
990 | && (NOTE_LINE_NUMBER (x) == NOTE_INSN_EH_REGION_BEG | |
991 | || NOTE_LINE_NUMBER (x) == NOTE_INSN_EH_REGION_END)) | |
992 | { | |
993 | int region = NOTE_EH_HANDLER (x); | |
994 | make_eh_edge (eh_nest_info, bb, NULL_RTX, region); | |
995 | } | |
e881bb1b RH |
996 | } |
997 | ||
998 | if (code == CALL_INSN && nonlocal_goto_handler_labels) | |
999 | { | |
dc2ede84 BS |
1000 | /* ??? This could be made smarter: in some cases it's possible |
1001 | to tell that certain calls will not do a nonlocal goto. | |
1002 | ||
1003 | For example, if the nested functions that do the nonlocal | |
1004 | gotos do not have their addresses taken, then only calls to | |
1005 | those functions or to other nested functions that use them | |
1006 | could possibly do nonlocal gotos. */ | |
1ef1bf06 AM |
1007 | /* We do know that a REG_EH_REGION note with a value less |
1008 | than 0 is guaranteed not to perform a non-local goto. */ | |
1009 | rtx note = find_reg_note (insn, REG_EH_REGION, NULL_RTX); | |
1010 | if (!note || XINT (XEXP (note, 0), 0) >= 0) | |
1011 | for (x = nonlocal_goto_handler_labels; x ; x = XEXP (x, 1)) | |
1012 | make_label_edge (bb, XEXP (x, 0), | |
1013 | EDGE_ABNORMAL | EDGE_ABNORMAL_CALL); | |
dc2ede84 BS |
1014 | } |
1015 | } | |
e881bb1b RH |
1016 | |
1017 | /* We know something about the structure of the function __throw in | |
1018 | libgcc2.c. It is the only function that ever contains eh_stub | |
1019 | labels. It modifies its return address so that the last block | |
1020 | returns to one of the eh_stub labels within it. So we have to | |
1021 | make additional edges in the flow graph. */ | |
1022 | if (i + 1 == n_basic_blocks && eh_return_stub_label != 0) | |
1023 | make_label_edge (bb, eh_return_stub_label, EDGE_EH); | |
1024 | ||
1025 | /* Find out if we can drop through to the next block. */ | |
1026 | insn = next_nonnote_insn (insn); | |
4b523fc4 | 1027 | if (!insn || (i + 1 == n_basic_blocks && force_fallthru)) |
e881bb1b RH |
1028 | make_edge (bb, EXIT_BLOCK_PTR, EDGE_FALLTHRU); |
1029 | else if (i + 1 < n_basic_blocks) | |
1030 | { | |
1031 | rtx tmp = BLOCK_HEAD (i + 1); | |
1032 | if (GET_CODE (tmp) == NOTE) | |
1033 | tmp = next_nonnote_insn (tmp); | |
4b523fc4 | 1034 | if (force_fallthru || insn == tmp) |
e881bb1b RH |
1035 | make_edge (bb, BASIC_BLOCK (i + 1), EDGE_FALLTHRU); |
1036 | } | |
dc2ede84 | 1037 | } |
1ef1bf06 | 1038 | free_eh_nesting_info (eh_nest_info); |
e881bb1b RH |
1039 | } |
1040 | ||
1041 | /* Create an edge between two basic blocks. FLAGS are auxiliary information | |
1042 | about the edge that is accumulated between calls. */ | |
1043 | ||
1044 | static void | |
1045 | make_edge (src, dst, flags) | |
1046 | basic_block src, dst; | |
1047 | int flags; | |
1048 | { | |
1049 | edge e; | |
1050 | ||
1051 | /* Make sure we don't add duplicate edges. */ | |
1052 | ||
1053 | for (e = src->succ; e ; e = e->succ_next) | |
1054 | if (e->dest == dst) | |
1055 | { | |
1056 | e->flags |= flags; | |
1057 | return; | |
1058 | } | |
1059 | ||
1060 | e = (edge) xcalloc (1, sizeof (*e)); | |
1061 | ||
1062 | e->succ_next = src->succ; | |
1063 | e->pred_next = dst->pred; | |
1064 | e->src = src; | |
1065 | e->dest = dst; | |
1066 | e->flags = flags; | |
1067 | ||
1068 | src->succ = e; | |
1069 | dst->pred = e; | |
1070 | } | |
1071 | ||
1072 | /* Create an edge from a basic block to a label. */ | |
1073 | ||
1074 | static void | |
1075 | make_label_edge (src, label, flags) | |
1076 | basic_block src; | |
1077 | rtx label; | |
1078 | int flags; | |
1079 | { | |
1080 | if (GET_CODE (label) != CODE_LABEL) | |
1081 | abort (); | |
1082 | ||
1083 | /* If the label was never emitted, this insn is junk, but avoid a | |
1084 | crash trying to refer to BLOCK_FOR_INSN (label). This can happen | |
1085 | as a result of a syntax error and a diagnostic has already been | |
1086 | printed. */ | |
1087 | ||
1088 | if (INSN_UID (label) == 0) | |
1089 | return; | |
1090 | ||
1091 | make_edge (src, BLOCK_FOR_INSN (label), flags); | |
1092 | } | |
e6cfb550 | 1093 | |
336a6399 RH |
1094 | /* Create the edges generated by INSN in REGION. */ |
1095 | ||
1096 | static void | |
1097 | make_eh_edge (eh_nest_info, src, insn, region) | |
1098 | eh_nesting_info *eh_nest_info; | |
1099 | basic_block src; | |
1100 | rtx insn; | |
1101 | int region; | |
1102 | { | |
1103 | handler_info **handler_list; | |
1104 | int num, is_call; | |
1105 | ||
1106 | is_call = (insn && GET_CODE (insn) == CALL_INSN ? EDGE_ABNORMAL_CALL : 0); | |
1107 | num = reachable_handlers (region, eh_nest_info, insn, &handler_list); | |
1108 | while (--num >= 0) | |
1109 | { | |
1110 | make_label_edge (src, handler_list[num]->handler_label, | |
1111 | EDGE_ABNORMAL | EDGE_EH | is_call); | |
1112 | } | |
1113 | } | |
1114 | ||
1115 | /* EH_REGION notes appearing between basic blocks is ambiguous, and even | |
1116 | dangerous if we intend to move basic blocks around. Move such notes | |
1117 | into the following block. */ | |
1118 | ||
1119 | static void | |
1120 | move_stray_eh_region_notes () | |
1121 | { | |
1122 | int i; | |
1123 | basic_block b1, b2; | |
1124 | ||
1125 | if (n_basic_blocks < 2) | |
1126 | return; | |
1127 | ||
1128 | b2 = BASIC_BLOCK (n_basic_blocks - 1); | |
1129 | for (i = n_basic_blocks - 2; i >= 0; --i, b2 = b1) | |
1130 | { | |
1131 | rtx insn, next, list = NULL_RTX; | |
1132 | ||
1133 | b1 = BASIC_BLOCK (i); | |
1134 | for (insn = NEXT_INSN (b1->end); insn != b2->head; insn = next) | |
1135 | { | |
1136 | next = NEXT_INSN (insn); | |
1137 | if (GET_CODE (insn) == NOTE | |
1138 | && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_BEG | |
1139 | || NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_END)) | |
1140 | { | |
1141 | /* Unlink from the insn chain. */ | |
1142 | NEXT_INSN (PREV_INSN (insn)) = next; | |
1143 | PREV_INSN (next) = PREV_INSN (insn); | |
1144 | ||
1145 | /* Queue it. */ | |
1146 | NEXT_INSN (insn) = list; | |
1147 | list = insn; | |
1148 | } | |
1149 | } | |
1150 | ||
1151 | if (list == NULL_RTX) | |
1152 | continue; | |
1153 | ||
1154 | /* Find where to insert these things. */ | |
1155 | insn = b2->head; | |
1156 | if (GET_CODE (insn) == CODE_LABEL) | |
1157 | insn = NEXT_INSN (insn); | |
1158 | ||
1159 | while (list) | |
1160 | { | |
1161 | next = NEXT_INSN (list); | |
1162 | add_insn_after (list, insn); | |
1163 | list = next; | |
1164 | } | |
1165 | } | |
1166 | } | |
1167 | ||
1168 | /* Recompute eh_beg/eh_end for each basic block. */ | |
1169 | ||
1170 | static void | |
1171 | record_active_eh_regions (f) | |
1172 | rtx f; | |
1173 | { | |
1174 | rtx insn, eh_list = NULL_RTX; | |
1175 | int i = 0; | |
1176 | basic_block bb = BASIC_BLOCK (0); | |
1177 | ||
1178 | for (insn = f; insn ; insn = NEXT_INSN (insn)) | |
1179 | { | |
1180 | if (bb->head == insn) | |
1181 | bb->eh_beg = (eh_list ? NOTE_EH_HANDLER (XEXP (eh_list, 0)) : -1); | |
1182 | ||
1183 | if (GET_CODE (insn) == NOTE) | |
1184 | { | |
1185 | int kind = NOTE_LINE_NUMBER (insn); | |
1186 | if (kind == NOTE_INSN_EH_REGION_BEG) | |
1187 | eh_list = alloc_INSN_LIST (insn, eh_list); | |
1188 | else if (kind == NOTE_INSN_EH_REGION_END) | |
1189 | { | |
1190 | rtx t = XEXP (eh_list, 1); | |
1191 | free_INSN_LIST_node (eh_list); | |
1192 | eh_list = t; | |
1193 | } | |
1194 | } | |
1195 | ||
1196 | if (bb->end == insn) | |
1197 | { | |
1198 | bb->eh_end = (eh_list ? NOTE_EH_HANDLER (XEXP (eh_list, 0)) : -1); | |
1199 | i += 1; | |
1200 | bb = BASIC_BLOCK (i); | |
1201 | } | |
1202 | } | |
1203 | } | |
1204 | ||
e881bb1b | 1205 | /* Identify critical edges and set the bits appropriately. */ |
336a6399 | 1206 | |
e881bb1b RH |
1207 | static void |
1208 | mark_critical_edges () | |
1209 | { | |
1210 | int i, n = n_basic_blocks; | |
1211 | basic_block bb; | |
1212 | ||
1213 | /* We begin with the entry block. This is not terribly important now, | |
1214 | but could be if a front end (Fortran) implemented alternate entry | |
1215 | points. */ | |
1216 | bb = ENTRY_BLOCK_PTR; | |
1217 | i = -1; | |
1218 | ||
1219 | while (1) | |
e6cfb550 | 1220 | { |
e881bb1b RH |
1221 | edge e; |
1222 | ||
1223 | /* (1) Critical edges must have a source with multiple successors. */ | |
1224 | if (bb->succ && bb->succ->succ_next) | |
1225 | { | |
1226 | for (e = bb->succ; e ; e = e->succ_next) | |
1227 | { | |
1228 | /* (2) Critical edges must have a destination with multiple | |
1229 | predecessors. Note that we know there is at least one | |
1230 | predecessor -- the edge we followed to get here. */ | |
1231 | if (e->dest->pred->pred_next) | |
1232 | e->flags |= EDGE_CRITICAL; | |
1233 | else | |
1234 | e->flags &= ~EDGE_CRITICAL; | |
1235 | } | |
1236 | } | |
1237 | else | |
1238 | { | |
1239 | for (e = bb->succ; e ; e = e->succ_next) | |
1240 | e->flags &= ~EDGE_CRITICAL; | |
1241 | } | |
1242 | ||
1243 | if (++i >= n) | |
1244 | break; | |
1245 | bb = BASIC_BLOCK (i); | |
e6cfb550 | 1246 | } |
e881bb1b RH |
1247 | } |
1248 | \f | |
1249 | /* Split a (typically critical) edge. Return the new block. | |
1250 | Abort on abnormal edges. | |
1251 | ||
1252 | ??? The code generally expects to be called on critical edges. | |
1253 | The case of a block ending in an unconditional jump to a | |
1254 | block with multiple predecessors is not handled optimally. */ | |
1255 | ||
1256 | basic_block | |
1257 | split_edge (edge_in) | |
1258 | edge edge_in; | |
1259 | { | |
1260 | basic_block old_pred, bb, old_succ; | |
1261 | edge edge_out; | |
1262 | rtx bb_note; | |
abb14ef5 | 1263 | int i, j; |
e881bb1b RH |
1264 | |
1265 | /* Abnormal edges cannot be split. */ | |
1266 | if ((edge_in->flags & EDGE_ABNORMAL) != 0) | |
1267 | abort (); | |
1268 | ||
1269 | old_pred = edge_in->src; | |
1270 | old_succ = edge_in->dest; | |
1271 | ||
1272 | /* Remove the existing edge from the destination's pred list. */ | |
1273 | { | |
1274 | edge *pp; | |
1275 | for (pp = &old_succ->pred; *pp != edge_in; pp = &(*pp)->pred_next) | |
1276 | continue; | |
1277 | *pp = edge_in->pred_next; | |
1e7d57a3 | 1278 | edge_in->pred_next = NULL; |
e881bb1b RH |
1279 | } |
1280 | ||
1281 | /* Create the new structures. */ | |
1282 | bb = (basic_block) obstack_alloc (function_obstack, sizeof (*bb)); | |
1283 | edge_out = (edge) xcalloc (1, sizeof (*edge_out)); | |
1284 | ||
1285 | memset (bb, 0, sizeof (*bb)); | |
1286 | bb->local_set = OBSTACK_ALLOC_REG_SET (function_obstack); | |
1287 | bb->global_live_at_start = OBSTACK_ALLOC_REG_SET (function_obstack); | |
1288 | bb->global_live_at_end = OBSTACK_ALLOC_REG_SET (function_obstack); | |
1289 | ||
1290 | /* ??? This info is likely going to be out of date very soon. */ | |
1291 | CLEAR_REG_SET (bb->local_set); | |
1292 | if (old_succ->global_live_at_start) | |
1293 | { | |
1294 | COPY_REG_SET (bb->global_live_at_start, old_succ->global_live_at_start); | |
1295 | COPY_REG_SET (bb->global_live_at_end, old_succ->global_live_at_start); | |
1296 | } | |
1297 | else | |
1298 | { | |
1299 | CLEAR_REG_SET (bb->global_live_at_start); | |
1300 | CLEAR_REG_SET (bb->global_live_at_end); | |
1301 | } | |
1302 | ||
1303 | /* Wire them up. */ | |
1304 | bb->pred = edge_in; | |
1305 | bb->succ = edge_out; | |
1e7d57a3 | 1306 | |
e881bb1b | 1307 | edge_in->dest = bb; |
1e7d57a3 JH |
1308 | edge_in->flags &= ~EDGE_CRITICAL; |
1309 | ||
1310 | edge_out->pred_next = old_succ->pred; | |
1311 | edge_out->succ_next = NULL; | |
e881bb1b RH |
1312 | edge_out->src = bb; |
1313 | edge_out->dest = old_succ; | |
1e7d57a3 JH |
1314 | edge_out->flags = EDGE_FALLTHRU; |
1315 | edge_out->probability = REG_BR_PROB_BASE; | |
1316 | ||
1317 | old_succ->pred = edge_out; | |
e881bb1b RH |
1318 | |
1319 | /* Tricky case -- if there existed a fallthru into the successor | |
1320 | (and we're not it) we must add a new unconditional jump around | |
1321 | the new block we're actually interested in. | |
1322 | ||
1323 | Further, if that edge is critical, this means a second new basic | |
1324 | block must be created to hold it. In order to simplify correct | |
1325 | insn placement, do this before we touch the existing basic block | |
1326 | ordering for the block we were really wanting. */ | |
1327 | if ((edge_in->flags & EDGE_FALLTHRU) == 0) | |
1328 | { | |
1329 | edge e; | |
1e7d57a3 | 1330 | for (e = edge_out->pred_next; e ; e = e->pred_next) |
e881bb1b RH |
1331 | if (e->flags & EDGE_FALLTHRU) |
1332 | break; | |
1333 | ||
1334 | if (e) | |
1335 | { | |
1336 | basic_block jump_block; | |
1337 | rtx pos; | |
1338 | ||
1339 | if ((e->flags & EDGE_CRITICAL) == 0) | |
1340 | { | |
1341 | /* Non critical -- we can simply add a jump to the end | |
1342 | of the existing predecessor. */ | |
1343 | jump_block = e->src; | |
e881bb1b RH |
1344 | } |
1345 | else | |
1346 | { | |
1347 | /* We need a new block to hold the jump. The simplest | |
1348 | way to do the bulk of the work here is to recursively | |
1349 | call ourselves. */ | |
1350 | jump_block = split_edge (e); | |
1351 | e = jump_block->succ; | |
e881bb1b RH |
1352 | } |
1353 | ||
1e7d57a3 JH |
1354 | /* Now add the jump insn ... */ |
1355 | pos = emit_jump_insn_after (gen_jump (old_succ->head), | |
1356 | jump_block->end); | |
e881bb1b RH |
1357 | jump_block->end = pos; |
1358 | emit_barrier_after (pos); | |
1e7d57a3 JH |
1359 | |
1360 | /* ... let jump know that label is in use, ... */ | |
a8688bd6 | 1361 | JUMP_LABEL (pos) = old_succ->head; |
1e7d57a3 | 1362 | ++LABEL_NUSES (old_succ->head); |
088e7160 | 1363 | |
e881bb1b RH |
1364 | /* ... and clear fallthru on the outgoing edge. */ |
1365 | e->flags &= ~EDGE_FALLTHRU; | |
1366 | ||
1367 | /* Continue splitting the interesting edge. */ | |
1368 | } | |
1369 | } | |
1370 | ||
1371 | /* Place the new block just in front of the successor. */ | |
1372 | VARRAY_GROW (basic_block_info, ++n_basic_blocks); | |
abb14ef5 AM |
1373 | if (old_succ == EXIT_BLOCK_PTR) |
1374 | j = n_basic_blocks - 1; | |
1375 | else | |
1376 | j = old_succ->index; | |
1377 | for (i = n_basic_blocks - 1; i > j; --i) | |
e881bb1b RH |
1378 | { |
1379 | basic_block tmp = BASIC_BLOCK (i - 1); | |
1380 | BASIC_BLOCK (i) = tmp; | |
1381 | tmp->index = i; | |
1382 | } | |
1383 | BASIC_BLOCK (i) = bb; | |
1384 | bb->index = i; | |
1385 | ||
1386 | /* Create the basic block note. */ | |
abb14ef5 AM |
1387 | if (old_succ != EXIT_BLOCK_PTR) |
1388 | bb_note = emit_note_before (NOTE_INSN_BASIC_BLOCK, old_succ->head); | |
1389 | else | |
1390 | bb_note = emit_note_after (NOTE_INSN_BASIC_BLOCK, get_last_insn ()); | |
e881bb1b RH |
1391 | NOTE_BASIC_BLOCK (bb_note) = bb; |
1392 | bb->head = bb->end = bb_note; | |
1393 | ||
1394 | /* Not quite simple -- for non-fallthru edges, we must adjust the | |
1395 | predecessor's jump instruction to target our new block. */ | |
1396 | if ((edge_in->flags & EDGE_FALLTHRU) == 0) | |
1397 | { | |
1398 | rtx tmp, insn = old_pred->end; | |
1399 | rtx old_label = old_succ->head; | |
1400 | rtx new_label = gen_label_rtx (); | |
1401 | ||
1402 | if (GET_CODE (insn) != JUMP_INSN) | |
1403 | abort (); | |
1404 | ||
1405 | /* ??? Recognize a tablejump and adjust all matching cases. */ | |
1406 | if ((tmp = JUMP_LABEL (insn)) != NULL_RTX | |
1407 | && (tmp = NEXT_INSN (tmp)) != NULL_RTX | |
1408 | && GET_CODE (tmp) == JUMP_INSN | |
1409 | && (GET_CODE (PATTERN (tmp)) == ADDR_VEC | |
1410 | || GET_CODE (PATTERN (tmp)) == ADDR_DIFF_VEC)) | |
1411 | { | |
1412 | rtvec vec; | |
1413 | int j; | |
1414 | ||
1415 | if (GET_CODE (PATTERN (tmp)) == ADDR_VEC) | |
1416 | vec = XVEC (PATTERN (tmp), 0); | |
1417 | else | |
1418 | vec = XVEC (PATTERN (tmp), 1); | |
1419 | ||
1420 | for (j = GET_NUM_ELEM (vec) - 1; j >= 0; --j) | |
1421 | if (XEXP (RTVEC_ELT (vec, j), 0) == old_label) | |
1422 | { | |
1423 | RTVEC_ELT (vec, j) = gen_rtx_LABEL_REF (VOIDmode, new_label); | |
1424 | --LABEL_NUSES (old_label); | |
1425 | ++LABEL_NUSES (new_label); | |
1426 | } | |
1427 | } | |
1428 | else | |
1429 | { | |
1430 | /* This would have indicated an abnormal edge. */ | |
1431 | if (computed_jump_p (insn)) | |
1432 | abort (); | |
1433 | ||
1434 | /* A return instruction can't be redirected. */ | |
1435 | if (returnjump_p (insn)) | |
1436 | abort (); | |
1437 | ||
1438 | /* If the insn doesn't go where we think, we're confused. */ | |
1439 | if (JUMP_LABEL (insn) != old_label) | |
1440 | abort (); | |
1441 | ||
1442 | redirect_jump (insn, new_label); | |
1443 | } | |
1444 | ||
1445 | emit_label_before (new_label, bb_note); | |
1446 | bb->head = new_label; | |
1447 | } | |
1448 | ||
e881bb1b RH |
1449 | return bb; |
1450 | } | |
1451 | ||
1452 | /* Queue instructions for insertion on an edge between two basic blocks. | |
1453 | The new instructions and basic blocks (if any) will not appear in the | |
1454 | CFG until commit_edge_insertions is called. */ | |
1455 | ||
1456 | void | |
1457 | insert_insn_on_edge (pattern, e) | |
1458 | rtx pattern; | |
1459 | edge e; | |
1460 | { | |
1461 | /* We cannot insert instructions on an abnormal critical edge. | |
1462 | It will be easier to find the culprit if we die now. */ | |
1463 | if ((e->flags & (EDGE_ABNORMAL|EDGE_CRITICAL)) | |
1464 | == (EDGE_ABNORMAL|EDGE_CRITICAL)) | |
1465 | abort (); | |
1466 | ||
1467 | if (e->insns == NULL_RTX) | |
1468 | start_sequence (); | |
1469 | else | |
1470 | push_to_sequence (e->insns); | |
1471 | ||
1472 | emit_insn (pattern); | |
1473 | ||
1474 | e->insns = get_insns (); | |
1475 | end_sequence(); | |
1476 | } | |
1477 | ||
1478 | /* Update the CFG for the instructions queued on edge E. */ | |
1479 | ||
1480 | static void | |
1481 | commit_one_edge_insertion (e) | |
1482 | edge e; | |
1483 | { | |
1484 | rtx before = NULL_RTX, after = NULL_RTX, tmp; | |
1485 | basic_block bb; | |
1486 | ||
1487 | /* Figure out where to put these things. If the destination has | |
1488 | one predecessor, insert there. Except for the exit block. */ | |
1489 | if (e->dest->pred->pred_next == NULL | |
1490 | && e->dest != EXIT_BLOCK_PTR) | |
1491 | { | |
1492 | bb = e->dest; | |
1493 | ||
1494 | /* Get the location correct wrt a code label, and "nice" wrt | |
1495 | a basic block note, and before everything else. */ | |
1496 | tmp = bb->head; | |
1497 | if (GET_CODE (tmp) == CODE_LABEL) | |
1498 | tmp = NEXT_INSN (tmp); | |
1499 | if (GET_CODE (tmp) == NOTE | |
1500 | && NOTE_LINE_NUMBER (tmp) == NOTE_INSN_BASIC_BLOCK) | |
1501 | tmp = NEXT_INSN (tmp); | |
1502 | if (tmp == bb->head) | |
1503 | before = tmp; | |
1504 | else | |
1505 | after = PREV_INSN (tmp); | |
1506 | } | |
1507 | ||
1508 | /* If the source has one successor and the edge is not abnormal, | |
1509 | insert there. Except for the entry block. */ | |
1510 | else if ((e->flags & EDGE_ABNORMAL) == 0 | |
1511 | && e->src->succ->succ_next == NULL | |
1512 | && e->src != ENTRY_BLOCK_PTR) | |
1513 | { | |
1514 | bb = e->src; | |
1515 | if (GET_CODE (bb->end) == JUMP_INSN) | |
1516 | { | |
1517 | /* ??? Is it possible to wind up with non-simple jumps? Perhaps | |
1518 | a jump with delay slots already filled? */ | |
1519 | if (! simplejump_p (bb->end)) | |
1520 | abort (); | |
1521 | ||
1522 | before = bb->end; | |
1523 | } | |
1524 | else | |
1525 | { | |
1526 | /* We'd better be fallthru, or we've lost track of what's what. */ | |
1527 | if ((e->flags & EDGE_FALLTHRU) == 0) | |
1528 | abort (); | |
1529 | ||
1530 | after = bb->end; | |
1531 | } | |
1532 | } | |
1533 | ||
1534 | /* Otherwise we must split the edge. */ | |
1535 | else | |
1536 | { | |
1537 | bb = split_edge (e); | |
1538 | after = bb->end; | |
1539 | } | |
1540 | ||
1541 | /* Now that we've found the spot, do the insertion. */ | |
1542 | tmp = e->insns; | |
1543 | e->insns = NULL_RTX; | |
a8688bd6 AM |
1544 | |
1545 | /* Set the new block number for these insns, if structure is allocated. */ | |
1546 | if (basic_block_for_insn) | |
1547 | { | |
1548 | rtx i; | |
1549 | for (i = tmp; i != NULL_RTX; i = NEXT_INSN (i)) | |
1550 | set_block_for_insn (i, bb); | |
1551 | } | |
1552 | ||
e881bb1b RH |
1553 | if (before) |
1554 | { | |
1555 | emit_insns_before (tmp, before); | |
1556 | if (before == bb->head) | |
a8688bd6 | 1557 | bb->head = tmp; |
e881bb1b RH |
1558 | } |
1559 | else | |
1560 | { | |
1561 | tmp = emit_insns_after (tmp, after); | |
1562 | if (after == bb->end) | |
1563 | bb->end = tmp; | |
1564 | } | |
1565 | } | |
1566 | ||
1567 | /* Update the CFG for all queued instructions. */ | |
1568 | ||
1569 | void | |
1570 | commit_edge_insertions () | |
1571 | { | |
1572 | int i; | |
1573 | basic_block bb; | |
1574 | ||
1575 | i = -1; | |
1576 | bb = ENTRY_BLOCK_PTR; | |
1577 | while (1) | |
1578 | { | |
1579 | edge e, next; | |
1580 | ||
1581 | for (e = bb->succ; e ; e = next) | |
1582 | { | |
1583 | next = e->succ_next; | |
1584 | if (e->insns) | |
1585 | commit_one_edge_insertion (e); | |
1586 | } | |
1587 | ||
1588 | if (++i >= n_basic_blocks) | |
1589 | break; | |
1590 | bb = BASIC_BLOCK (i); | |
1591 | } | |
1592 | } | |
1593 | \f | |
1594 | /* Delete all unreachable basic blocks. */ | |
1595 | ||
1596 | static void | |
1597 | delete_unreachable_blocks () | |
1598 | { | |
1599 | basic_block *worklist, *tos; | |
1600 | int deleted_handler; | |
1601 | edge e; | |
1602 | int i, n; | |
1603 | ||
1604 | n = n_basic_blocks; | |
1605 | tos = worklist = (basic_block *) alloca (sizeof (basic_block) * n); | |
1606 | ||
1607 | /* Use basic_block->aux as a marker. Clear them all. */ | |
1608 | ||
1609 | for (i = 0; i < n; ++i) | |
1610 | BASIC_BLOCK (i)->aux = NULL; | |
1611 | ||
1612 | /* Add our starting points to the worklist. Almost always there will | |
1613 | be only one. It isn't inconcievable that we might one day directly | |
1614 | support Fortran alternate entry points. */ | |
1615 | ||
1616 | for (e = ENTRY_BLOCK_PTR->succ; e ; e = e->succ_next) | |
aa3d4bf9 RH |
1617 | { |
1618 | *tos++ = e->dest; | |
1619 | ||
1620 | /* Mark the block with a handy non-null value. */ | |
1621 | e->dest->aux = e; | |
1622 | } | |
e881bb1b RH |
1623 | |
1624 | /* Iterate: find everything reachable from what we've already seen. */ | |
1625 | ||
1626 | while (tos != worklist) | |
1627 | { | |
1628 | basic_block b = *--tos; | |
1629 | ||
e881bb1b RH |
1630 | for (e = b->succ; e ; e = e->succ_next) |
1631 | if (!e->dest->aux) | |
aa3d4bf9 RH |
1632 | { |
1633 | *tos++ = e->dest; | |
1634 | e->dest->aux = e; | |
1635 | } | |
e881bb1b RH |
1636 | } |
1637 | ||
1638 | /* Delete all unreachable basic blocks. Count down so that we don't | |
1639 | interfere with the block renumbering that happens in delete_block. */ | |
1640 | ||
1641 | deleted_handler = 0; | |
1642 | ||
1643 | for (i = n - 1; i >= 0; --i) | |
1644 | { | |
1645 | basic_block b = BASIC_BLOCK (i); | |
1646 | ||
1647 | if (b->aux != NULL) | |
1648 | /* This block was found. Tidy up the mark. */ | |
1649 | b->aux = NULL; | |
1650 | else | |
1651 | deleted_handler |= delete_block (b); | |
1652 | } | |
1653 | ||
1654 | /* Fix up edges that now fall through, or rather should now fall through | |
1655 | but previously required a jump around now deleted blocks. Simplify | |
1656 | the search by only examining blocks numerically adjacent, since this | |
1657 | is how find_basic_blocks created them. */ | |
1658 | ||
1659 | for (i = 1; i < n_basic_blocks; ++i) | |
1660 | { | |
1661 | basic_block b = BASIC_BLOCK (i - 1); | |
1662 | basic_block c = BASIC_BLOCK (i); | |
1663 | edge s; | |
1664 | ||
abb3f0a9 JL |
1665 | /* We care about simple conditional or unconditional jumps with |
1666 | a single successor. | |
1667 | ||
1668 | If we had a conditional branch to the next instruction when | |
1669 | find_basic_blocks was called, then there will only be one | |
1670 | out edge for the block which ended with the conditional | |
1671 | branch (since we do not create duplicate edges). | |
1672 | ||
4f282ba1 JL |
1673 | Furthermore, the edge will be marked as a fallthru because we |
1674 | merge the flags for the duplicate edges. So we do not want to | |
1675 | check that the edge is not a FALLTHRU edge. */ | |
e881bb1b RH |
1676 | if ((s = b->succ) != NULL |
1677 | && s->succ_next == NULL | |
e8fe3cc3 | 1678 | && s->dest == c |
d0e80719 RH |
1679 | /* If the jump insn has side effects, we can't tidy the edge. */ |
1680 | && (GET_CODE (b->end) != JUMP_INSN | |
1681 | || onlyjump_p (b->end))) | |
e881bb1b RH |
1682 | tidy_fallthru_edge (s, b, c); |
1683 | } | |
1684 | ||
e881bb1b RH |
1685 | /* If we deleted an exception handler, we may have EH region begin/end |
1686 | blocks to remove as well. */ | |
1687 | if (deleted_handler) | |
1688 | delete_eh_regions (); | |
1689 | } | |
1690 | ||
1691 | /* Find EH regions for which there is no longer a handler, and delete them. */ | |
1692 | ||
1693 | static void | |
1694 | delete_eh_regions () | |
1695 | { | |
1696 | rtx insn; | |
1697 | ||
1ef1bf06 AM |
1698 | update_rethrow_references (); |
1699 | ||
e881bb1b RH |
1700 | for (insn = get_insns (); insn; insn = NEXT_INSN (insn)) |
1701 | if (GET_CODE (insn) == NOTE) | |
1702 | { | |
1703 | if ((NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_BEG) || | |
1704 | (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_END)) | |
1705 | { | |
ef178af3 | 1706 | int num = NOTE_EH_HANDLER (insn); |
1ef1bf06 AM |
1707 | /* A NULL handler indicates a region is no longer needed, |
1708 | as long as it isn't the target of a rethrow. */ | |
1709 | if (get_first_handler (num) == NULL && ! rethrow_used (num)) | |
e881bb1b RH |
1710 | { |
1711 | NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED; | |
1712 | NOTE_SOURCE_FILE (insn) = 0; | |
1713 | } | |
1714 | } | |
1715 | } | |
1716 | } | |
1717 | ||
1718 | /* Return true if NOTE is not one of the ones that must be kept paired, | |
1719 | so that we may simply delete them. */ | |
1720 | ||
1721 | static int | |
eeea333e | 1722 | can_delete_note_p (note) |
e881bb1b RH |
1723 | rtx note; |
1724 | { | |
1725 | return (NOTE_LINE_NUMBER (note) == NOTE_INSN_DELETED | |
1726 | || NOTE_LINE_NUMBER (note) == NOTE_INSN_BASIC_BLOCK); | |
1727 | } | |
1728 | ||
1729 | /* Unlink a chain of insns between START and FINISH, leaving notes | |
1730 | that must be paired. */ | |
1731 | ||
1732 | static void | |
5aabad00 | 1733 | flow_delete_insn_chain (start, finish) |
e881bb1b RH |
1734 | rtx start, finish; |
1735 | { | |
1736 | /* Unchain the insns one by one. It would be quicker to delete all | |
1737 | of these with a single unchaining, rather than one at a time, but | |
1738 | we need to keep the NOTE's. */ | |
1739 | ||
1740 | rtx next; | |
1741 | ||
1742 | while (1) | |
1743 | { | |
1744 | next = NEXT_INSN (start); | |
eeea333e RH |
1745 | if (GET_CODE (start) == NOTE && !can_delete_note_p (start)) |
1746 | ; | |
1747 | else if (GET_CODE (start) == CODE_LABEL && !can_delete_label_p (start)) | |
1748 | ; | |
1749 | else | |
e881bb1b RH |
1750 | next = flow_delete_insn (start); |
1751 | ||
1752 | if (start == finish) | |
1753 | break; | |
1754 | start = next; | |
1755 | } | |
1756 | } | |
1757 | ||
1758 | /* Delete the insns in a (non-live) block. We physically delete every | |
1759 | non-deleted-note insn, and update the flow graph appropriately. | |
1760 | ||
1761 | Return nonzero if we deleted an exception handler. */ | |
1762 | ||
1763 | /* ??? Preserving all such notes strikes me as wrong. It would be nice | |
1764 | to post-process the stream to remove empty blocks, loops, ranges, etc. */ | |
1765 | ||
1766 | static int | |
1767 | delete_block (b) | |
1768 | basic_block b; | |
1769 | { | |
1770 | int deleted_handler = 0; | |
1771 | rtx insn, end; | |
1772 | ||
1773 | /* If the head of this block is a CODE_LABEL, then it might be the | |
1774 | label for an exception handler which can't be reached. | |
1775 | ||
1776 | We need to remove the label from the exception_handler_label list | |
3ad47811 MM |
1777 | and remove the associated NOTE_INSN_EH_REGION_BEG and |
1778 | NOTE_INSN_EH_REGION_END notes. */ | |
e881bb1b RH |
1779 | |
1780 | insn = b->head; | |
088e7160 | 1781 | |
312f6255 GK |
1782 | never_reached_warning (insn); |
1783 | ||
e881bb1b RH |
1784 | if (GET_CODE (insn) == CODE_LABEL) |
1785 | { | |
1786 | rtx x, *prev = &exception_handler_labels; | |
1787 | ||
1788 | for (x = exception_handler_labels; x; x = XEXP (x, 1)) | |
1789 | { | |
1790 | if (XEXP (x, 0) == insn) | |
1791 | { | |
1792 | /* Found a match, splice this label out of the EH label list. */ | |
1793 | *prev = XEXP (x, 1); | |
1794 | XEXP (x, 1) = NULL_RTX; | |
1795 | XEXP (x, 0) = NULL_RTX; | |
1796 | ||
1797 | /* Remove the handler from all regions */ | |
1798 | remove_handler (insn); | |
1799 | deleted_handler = 1; | |
1800 | break; | |
1801 | } | |
1802 | prev = &XEXP (x, 1); | |
1803 | } | |
1804 | ||
1805 | /* This label may be referenced by code solely for its value, or | |
1806 | referenced by static data, or something. We have determined | |
1807 | that it is not reachable, but cannot delete the label itself. | |
1808 | Save code space and continue to delete the balance of the block, | |
1809 | along with properly updating the cfg. */ | |
1810 | if (!can_delete_label_p (insn)) | |
1811 | { | |
1812 | /* If we've only got one of these, skip the whole deleting | |
1813 | insns thing. */ | |
1814 | if (insn == b->end) | |
1815 | goto no_delete_insns; | |
1816 | insn = NEXT_INSN (insn); | |
1817 | } | |
1818 | } | |
1819 | ||
1820 | /* Selectively unlink the insn chain. Include any BARRIER that may | |
1821 | follow the basic block. */ | |
1822 | end = next_nonnote_insn (b->end); | |
1823 | if (!end || GET_CODE (end) != BARRIER) | |
1824 | end = b->end; | |
5aabad00 | 1825 | flow_delete_insn_chain (insn, end); |
e881bb1b RH |
1826 | |
1827 | no_delete_insns: | |
1828 | ||
1829 | /* Remove the edges into and out of this block. Note that there may | |
1830 | indeed be edges in, if we are removing an unreachable loop. */ | |
1831 | { | |
1832 | edge e, next, *q; | |
1833 | ||
1834 | for (e = b->pred; e ; e = next) | |
1835 | { | |
1836 | for (q = &e->src->succ; *q != e; q = &(*q)->succ_next) | |
1837 | continue; | |
1838 | *q = e->succ_next; | |
1839 | next = e->pred_next; | |
1840 | free (e); | |
1841 | } | |
1842 | for (e = b->succ; e ; e = next) | |
1843 | { | |
1844 | for (q = &e->dest->pred; *q != e; q = &(*q)->pred_next) | |
1845 | continue; | |
1846 | *q = e->pred_next; | |
1847 | next = e->succ_next; | |
1848 | free (e); | |
1849 | } | |
1850 | ||
1851 | b->pred = NULL; | |
1852 | b->succ = NULL; | |
1853 | } | |
1854 | ||
1855 | /* Remove the basic block from the array, and compact behind it. */ | |
1856 | expunge_block (b); | |
1857 | ||
1858 | return deleted_handler; | |
1859 | } | |
1860 | ||
1861 | /* Remove block B from the basic block array and compact behind it. */ | |
1862 | ||
1863 | static void | |
1864 | expunge_block (b) | |
1865 | basic_block b; | |
1866 | { | |
1867 | int i, n = n_basic_blocks; | |
1868 | ||
1869 | for (i = b->index; i + 1 < n; ++i) | |
1870 | { | |
1871 | basic_block x = BASIC_BLOCK (i + 1); | |
1872 | BASIC_BLOCK (i) = x; | |
1873 | x->index = i; | |
1874 | } | |
1875 | ||
1876 | basic_block_info->num_elements--; | |
1877 | n_basic_blocks--; | |
1878 | } | |
1879 | ||
1880 | /* Delete INSN by patching it out. Return the next insn. */ | |
1881 | ||
1882 | static rtx | |
1883 | flow_delete_insn (insn) | |
1884 | rtx insn; | |
1885 | { | |
1886 | rtx prev = PREV_INSN (insn); | |
1887 | rtx next = NEXT_INSN (insn); | |
1888 | ||
1889 | PREV_INSN (insn) = NULL_RTX; | |
1890 | NEXT_INSN (insn) = NULL_RTX; | |
1891 | ||
1892 | if (prev) | |
1893 | NEXT_INSN (prev) = next; | |
1894 | if (next) | |
1895 | PREV_INSN (next) = prev; | |
1896 | else | |
1897 | set_last_insn (prev); | |
e6cfb550 | 1898 | |
55a98783 JL |
1899 | if (GET_CODE (insn) == CODE_LABEL) |
1900 | remove_node_from_expr_list (insn, &nonlocal_goto_handler_labels); | |
1901 | ||
e881bb1b RH |
1902 | /* If deleting a jump, decrement the use count of the label. Deleting |
1903 | the label itself should happen in the normal course of block merging. */ | |
1904 | if (GET_CODE (insn) == JUMP_INSN && JUMP_LABEL (insn)) | |
1905 | LABEL_NUSES (JUMP_LABEL (insn))--; | |
1906 | ||
1907 | return next; | |
d7429b6a | 1908 | } |
8329b5ec | 1909 | |
e881bb1b RH |
1910 | /* True if a given label can be deleted. */ |
1911 | ||
1912 | static int | |
1913 | can_delete_label_p (label) | |
1914 | rtx label; | |
dc2ede84 | 1915 | { |
e881bb1b | 1916 | rtx x; |
dc2ede84 | 1917 | |
e881bb1b RH |
1918 | if (LABEL_PRESERVE_P (label)) |
1919 | return 0; | |
421382ac | 1920 | |
e881bb1b RH |
1921 | for (x = forced_labels; x ; x = XEXP (x, 1)) |
1922 | if (label == XEXP (x, 0)) | |
1923 | return 0; | |
1924 | for (x = label_value_list; x ; x = XEXP (x, 1)) | |
1925 | if (label == XEXP (x, 0)) | |
1926 | return 0; | |
1927 | for (x = exception_handler_labels; x ; x = XEXP (x, 1)) | |
1928 | if (label == XEXP (x, 0)) | |
1929 | return 0; | |
dc2ede84 | 1930 | |
abb3f0a9 | 1931 | /* User declared labels must be preserved. */ |
088e7160 | 1932 | if (LABEL_NAME (label) != 0) |
abb3f0a9 | 1933 | return 0; |
088e7160 | 1934 | |
e881bb1b RH |
1935 | return 1; |
1936 | } | |
421382ac | 1937 | |
558389e3 JL |
1938 | /* Blocks A and B are to be merged into a single block. A has no incoming |
1939 | fallthru edge, so it can be moved before B without adding or modifying | |
1940 | any jumps (aside from the jump from A to B). */ | |
1941 | ||
1942 | static int | |
336a6399 | 1943 | merge_blocks_move_predecessor_nojumps (a, b) |
558389e3 JL |
1944 | basic_block a, b; |
1945 | { | |
1946 | rtx start, end, insertpoint, barrier; | |
1947 | ||
1948 | start = a->head; | |
1949 | end = a->end; | |
1950 | insertpoint = PREV_INSN (b->head); | |
1951 | ||
1952 | /* We want to delete the BARRIER after the end of the insns we are | |
1953 | going to move. If we don't find a BARRIER, then do nothing. This | |
1954 | can happen in some cases if we have labels we can not delete. | |
1955 | ||
1956 | Similarly, do nothing if we can not delete the label at the start | |
1957 | of the target block. */ | |
1958 | barrier = next_nonnote_insn (end); | |
1959 | if (GET_CODE (barrier) != BARRIER | |
1960 | || (GET_CODE (b->head) == CODE_LABEL | |
1961 | && ! can_delete_label_p (b->head))) | |
1962 | return 0; | |
1963 | else | |
1964 | flow_delete_insn (barrier); | |
1965 | ||
1966 | /* Move block and loop notes out of the chain so that we do not | |
1967 | disturb their order. | |
1968 | ||
1969 | ??? A better solution would be to squeeze out all the non-nested notes | |
1970 | and adjust the block trees appropriately. Even better would be to have | |
1971 | a tighter connection between block trees and rtl so that this is not | |
1972 | necessary. */ | |
1973 | start = squeeze_notes (start, end); | |
1974 | ||
1975 | /* Scramble the insn chain. */ | |
1976 | reorder_insns (start, end, insertpoint); | |
1977 | ||
1978 | /* Now blocks A and B are contiguous. Merge them. */ | |
1979 | merge_blocks_nomove (a, b); | |
336a6399 RH |
1980 | |
1981 | if (rtl_dump_file) | |
1982 | { | |
1983 | fprintf (rtl_dump_file, "Moved block %d before %d and merged.\n", | |
1984 | a->index, b->index); | |
1985 | } | |
1986 | ||
558389e3 JL |
1987 | return 1; |
1988 | } | |
1989 | ||
1990 | /* Blocks A and B are to be merged into a single block. B has no outgoing | |
1991 | fallthru edge, so it can be moved after A without adding or modifying | |
1992 | any jumps (aside from the jump from A to B). */ | |
1993 | ||
1994 | static int | |
336a6399 | 1995 | merge_blocks_move_successor_nojumps (a, b) |
558389e3 JL |
1996 | basic_block a, b; |
1997 | { | |
1998 | rtx start, end, insertpoint, barrier; | |
1999 | ||
2000 | start = b->head; | |
2001 | end = b->end; | |
2002 | insertpoint = a->end; | |
2003 | ||
8288909f | 2004 | /* We want to delete the BARRIER after the end of the insns we are |
558389e3 | 2005 | going to move. If we don't find a BARRIER, then do nothing. This |
8288909f JL |
2006 | can happen in some cases if we have labels we can not delete. |
2007 | ||
2008 | Similarly, do nothing if we can not delete the label at the start | |
2009 | of the target block. */ | |
2010 | barrier = next_nonnote_insn (end); | |
558389e3 JL |
2011 | if (GET_CODE (barrier) != BARRIER |
2012 | || (GET_CODE (b->head) == CODE_LABEL | |
2013 | && ! can_delete_label_p (b->head))) | |
2014 | return 0; | |
2015 | else | |
2016 | flow_delete_insn (barrier); | |
2017 | ||
2018 | /* Move block and loop notes out of the chain so that we do not | |
2019 | disturb their order. | |
2020 | ||
2021 | ??? A better solution would be to squeeze out all the non-nested notes | |
2022 | and adjust the block trees appropriately. Even better would be to have | |
2023 | a tighter connection between block trees and rtl so that this is not | |
2024 | necessary. */ | |
2025 | start = squeeze_notes (start, end); | |
2026 | ||
2027 | /* Scramble the insn chain. */ | |
2028 | reorder_insns (start, end, insertpoint); | |
2029 | ||
2030 | /* Now blocks A and B are contiguous. Merge them. */ | |
2031 | merge_blocks_nomove (a, b); | |
336a6399 RH |
2032 | |
2033 | if (rtl_dump_file) | |
2034 | { | |
2035 | fprintf (rtl_dump_file, "Moved block %d after %d and merged.\n", | |
2036 | b->index, a->index); | |
2037 | } | |
2038 | ||
558389e3 JL |
2039 | return 1; |
2040 | } | |
2041 | ||
e881bb1b RH |
2042 | /* Blocks A and B are to be merged into a single block. The insns |
2043 | are already contiguous, hence `nomove'. */ | |
421382ac | 2044 | |
e881bb1b RH |
2045 | static void |
2046 | merge_blocks_nomove (a, b) | |
2047 | basic_block a, b; | |
2048 | { | |
2049 | edge e; | |
f5c14c21 RH |
2050 | rtx b_head, b_end, a_end; |
2051 | int b_empty = 0; | |
2052 | ||
2053 | /* If there was a CODE_LABEL beginning B, delete it. */ | |
2054 | b_head = b->head; | |
2055 | b_end = b->end; | |
2056 | if (GET_CODE (b_head) == CODE_LABEL) | |
2057 | { | |
2058 | /* Detect basic blocks with nothing but a label. This can happen | |
2059 | in particular at the end of a function. */ | |
2060 | if (b_head == b_end) | |
2061 | b_empty = 1; | |
2062 | b_head = flow_delete_insn (b_head); | |
2063 | } | |
2064 | ||
2065 | /* Delete the basic block note. */ | |
2066 | if (GET_CODE (b_head) == NOTE | |
2067 | && NOTE_LINE_NUMBER (b_head) == NOTE_INSN_BASIC_BLOCK) | |
2068 | { | |
2069 | if (b_head == b_end) | |
2070 | b_empty = 1; | |
2071 | b_head = flow_delete_insn (b_head); | |
2072 | } | |
421382ac | 2073 | |
e881bb1b | 2074 | /* If there was a jump out of A, delete it. */ |
f5c14c21 RH |
2075 | a_end = a->end; |
2076 | if (GET_CODE (a_end) == JUMP_INSN) | |
e881bb1b | 2077 | { |
f5c14c21 | 2078 | rtx prev; |
86879c21 | 2079 | |
f5c14c21 RH |
2080 | prev = prev_nonnote_insn (a_end); |
2081 | if (!prev) | |
2082 | prev = a->head; | |
86879c21 JL |
2083 | |
2084 | #ifdef HAVE_cc0 | |
f5c14c21 RH |
2085 | /* If this was a conditional jump, we need to also delete |
2086 | the insn that set cc0. */ | |
86879c21 | 2087 | |
f5c14c21 RH |
2088 | if (prev && sets_cc0_p (prev)) |
2089 | { | |
2090 | rtx tmp = prev; | |
2091 | prev = prev_nonnote_insn (prev); | |
2092 | if (!prev) | |
2093 | prev = a->head; | |
e881bb1b | 2094 | flow_delete_insn (tmp); |
421382ac | 2095 | } |
f5c14c21 RH |
2096 | #endif |
2097 | ||
2098 | /* Note that a->head != a->end, since we should have at least a | |
2099 | bb note plus the jump, so prev != insn. */ | |
2100 | flow_delete_insn (a_end); | |
2101 | a_end = prev; | |
421382ac | 2102 | } |
421382ac | 2103 | |
e881bb1b RH |
2104 | /* By definition, there should only be one successor of A, and that is |
2105 | B. Free that edge struct. */ | |
2106 | free (a->succ); | |
2107 | ||
2108 | /* Adjust the edges out of B for the new owner. */ | |
2109 | for (e = b->succ; e ; e = e->succ_next) | |
2110 | e->src = a; | |
2111 | a->succ = b->succ; | |
2112 | ||
e881bb1b | 2113 | /* Reassociate the insns of B with A. */ |
f5c14c21 | 2114 | if (!b_empty) |
e881bb1b | 2115 | { |
f5c14c21 RH |
2116 | BLOCK_FOR_INSN (b_head) = a; |
2117 | while (b_head != b_end) | |
dc2ede84 | 2118 | { |
f5c14c21 RH |
2119 | b_head = NEXT_INSN (b_head); |
2120 | BLOCK_FOR_INSN (b_head) = a; | |
dc2ede84 | 2121 | } |
f5c14c21 | 2122 | a_end = b_head; |
e881bb1b | 2123 | } |
f5c14c21 | 2124 | a->end = a_end; |
e881bb1b RH |
2125 | |
2126 | /* Compact the basic block array. */ | |
2127 | expunge_block (b); | |
dc2ede84 BS |
2128 | } |
2129 | ||
e881bb1b RH |
2130 | /* Attempt to merge basic blocks that are potentially non-adjacent. |
2131 | Return true iff the attempt succeeded. */ | |
dc2ede84 | 2132 | |
dc2ede84 | 2133 | static int |
e881bb1b RH |
2134 | merge_blocks (e, b, c) |
2135 | edge e; | |
2136 | basic_block b, c; | |
dc2ede84 | 2137 | { |
e881bb1b | 2138 | /* If B has a fallthru edge to C, no need to move anything. */ |
336a6399 | 2139 | if (e->flags & EDGE_FALLTHRU) |
e881bb1b | 2140 | { |
336a6399 RH |
2141 | /* If a label still appears somewhere and we cannot delete the label, |
2142 | then we cannot merge the blocks. The edge was tidied already. */ | |
558389e3 | 2143 | |
336a6399 RH |
2144 | rtx insn, stop = NEXT_INSN (c->head); |
2145 | for (insn = NEXT_INSN (b->end); insn != stop; insn = NEXT_INSN (insn)) | |
2146 | if (GET_CODE (insn) == CODE_LABEL && !can_delete_label_p (insn)) | |
2147 | return 0; | |
558389e3 | 2148 | |
336a6399 | 2149 | merge_blocks_nomove (b, c); |
558389e3 | 2150 | |
336a6399 RH |
2151 | if (rtl_dump_file) |
2152 | { | |
2153 | fprintf (rtl_dump_file, "Merged %d and %d without moving.\n", | |
2154 | b->index, c->index); | |
2155 | } | |
e881bb1b | 2156 | |
336a6399 RH |
2157 | return 1; |
2158 | } | |
2159 | else | |
2160 | { | |
2161 | edge tmp_edge; | |
2162 | basic_block d; | |
2163 | int c_has_outgoing_fallthru; | |
2164 | int b_has_incoming_fallthru; | |
e881bb1b | 2165 | |
336a6399 RH |
2166 | /* We must make sure to not munge nesting of exception regions, |
2167 | lexical blocks, and loop notes. | |
2168 | ||
2169 | The first is taken care of by requiring that the active eh | |
2170 | region at the end of one block always matches the active eh | |
2171 | region at the beginning of the next block. | |
2172 | ||
2173 | The later two are taken care of by squeezing out all the notes. */ | |
2174 | ||
2175 | /* ??? A throw/catch edge (or any abnormal edge) should be rarely | |
2176 | executed and we may want to treat blocks which have two out | |
2177 | edges, one normal, one abnormal as only having one edge for | |
2178 | block merging purposes. */ | |
558389e3 JL |
2179 | |
2180 | for (tmp_edge = c->succ; tmp_edge ; tmp_edge = tmp_edge->succ_next) | |
2181 | if (tmp_edge->flags & EDGE_FALLTHRU) | |
2182 | break; | |
2183 | c_has_outgoing_fallthru = (tmp_edge != NULL); | |
2184 | ||
2185 | for (tmp_edge = b->pred; tmp_edge ; tmp_edge = tmp_edge->pred_next) | |
2186 | if (tmp_edge->flags & EDGE_FALLTHRU) | |
2187 | break; | |
2188 | b_has_incoming_fallthru = (tmp_edge != NULL); | |
2189 | ||
336a6399 RH |
2190 | /* If B does not have an incoming fallthru, and the exception regions |
2191 | match, then it can be moved immediately before C without introducing | |
2192 | or modifying jumps. */ | |
2193 | d = BASIC_BLOCK (c->index - 1); | |
2194 | if (! b_has_incoming_fallthru | |
2195 | && d->eh_end == b->eh_beg | |
2196 | && b->eh_end == c->eh_beg) | |
2197 | return merge_blocks_move_predecessor_nojumps (b, c); | |
2198 | ||
2199 | /* Otherwise, we're going to try to move C after B. Make sure the | |
2200 | exception regions match. */ | |
2201 | d = BASIC_BLOCK (b->index + 1); | |
2202 | if (b->eh_end == c->eh_beg | |
2203 | && c->eh_end == d->eh_beg) | |
2204 | { | |
2205 | /* If C does not have an outgoing fallthru, then it can be moved | |
2206 | immediately after B without introducing or modifying jumps. */ | |
2207 | if (! c_has_outgoing_fallthru) | |
2208 | return merge_blocks_move_successor_nojumps (b, c); | |
2209 | ||
2210 | /* Otherwise, we'll need to insert an extra jump, and possibly | |
2211 | a new block to contain it. */ | |
2212 | /* ??? Not implemented yet. */ | |
2213 | } | |
558389e3 | 2214 | |
336a6399 | 2215 | return 0; |
e881bb1b | 2216 | } |
336a6399 | 2217 | } |
dc2ede84 | 2218 | |
336a6399 | 2219 | /* Top level driver for merge_blocks. */ |
421382ac | 2220 | |
336a6399 RH |
2221 | static void |
2222 | try_merge_blocks () | |
2223 | { | |
2224 | int i; | |
2225 | ||
2226 | /* Attempt to merge blocks as made possible by edge removal. If a block | |
2227 | has only one successor, and the successor has only one predecessor, | |
2228 | they may be combined. */ | |
2229 | ||
2230 | for (i = 0; i < n_basic_blocks; ) | |
2231 | { | |
2232 | basic_block c, b = BASIC_BLOCK (i); | |
2233 | edge s; | |
2234 | ||
2235 | /* A loop because chains of blocks might be combineable. */ | |
2236 | while ((s = b->succ) != NULL | |
2237 | && s->succ_next == NULL | |
2238 | && (s->flags & EDGE_EH) == 0 | |
2239 | && (c = s->dest) != EXIT_BLOCK_PTR | |
2240 | && c->pred->pred_next == NULL | |
2241 | /* If the jump insn has side effects, we can't kill the edge. */ | |
2242 | && (GET_CODE (b->end) != JUMP_INSN | |
2243 | || onlyjump_p (b->end)) | |
2244 | && merge_blocks (s, b, c)) | |
2245 | continue; | |
2246 | ||
2247 | /* Don't get confused by the index shift caused by deleting blocks. */ | |
2248 | i = b->index + 1; | |
2249 | } | |
e881bb1b | 2250 | } |
421382ac | 2251 | |
e881bb1b RH |
2252 | /* The given edge should potentially a fallthru edge. If that is in |
2253 | fact true, delete the unconditional jump and barriers that are in | |
2254 | the way. */ | |
2255 | ||
2256 | static void | |
2257 | tidy_fallthru_edge (e, b, c) | |
2258 | edge e; | |
2259 | basic_block b, c; | |
2260 | { | |
eeea333e | 2261 | rtx q; |
e881bb1b RH |
2262 | |
2263 | /* ??? In a late-running flow pass, other folks may have deleted basic | |
2264 | blocks by nopping out blocks, leaving multiple BARRIERs between here | |
2265 | and the target label. They ought to be chastized and fixed. | |
2266 | ||
eeea333e RH |
2267 | We can also wind up with a sequence of undeletable labels between |
2268 | one block and the next. | |
dc2ede84 | 2269 | |
eeea333e RH |
2270 | So search through a sequence of barriers, labels, and notes for |
2271 | the head of block C and assert that we really do fall through. */ | |
421382ac | 2272 | |
eeea333e | 2273 | if (next_real_insn (b->end) != next_real_insn (PREV_INSN (c->head))) |
e881bb1b | 2274 | return; |
421382ac | 2275 | |
e881bb1b RH |
2276 | /* Remove what will soon cease being the jump insn from the source block. |
2277 | If block B consisted only of this single jump, turn it into a deleted | |
2278 | note. */ | |
2279 | q = b->end; | |
2280 | if (GET_CODE (q) == JUMP_INSN) | |
421382ac | 2281 | { |
86a1db60 RH |
2282 | #ifdef HAVE_cc0 |
2283 | /* If this was a conditional jump, we need to also delete | |
2284 | the insn that set cc0. */ | |
b30f05db | 2285 | if (! simplejump_p (q) && condjump_p (q) && sets_cc0_p (PREV_INSN (q))) |
86a1db60 RH |
2286 | q = PREV_INSN (q); |
2287 | #endif | |
2288 | ||
e881bb1b RH |
2289 | if (b->head == q) |
2290 | { | |
2291 | PUT_CODE (q, NOTE); | |
2292 | NOTE_LINE_NUMBER (q) = NOTE_INSN_DELETED; | |
2293 | NOTE_SOURCE_FILE (q) = 0; | |
2294 | } | |
e3f6ee23 | 2295 | else |
e881bb1b | 2296 | b->end = q = PREV_INSN (q); |
421382ac | 2297 | } |
421382ac | 2298 | |
e881bb1b | 2299 | /* Selectively unlink the sequence. */ |
86a1db60 | 2300 | if (q != PREV_INSN (c->head)) |
5aabad00 | 2301 | flow_delete_insn_chain (NEXT_INSN (q), PREV_INSN (c->head)); |
b7f7462b | 2302 | |
e881bb1b RH |
2303 | e->flags |= EDGE_FALLTHRU; |
2304 | } | |
dc2ede84 | 2305 | |
e881bb1b RH |
2306 | /* Discover and record the loop depth at the head of each basic block. */ |
2307 | ||
2308 | static void | |
2309 | calculate_loop_depth (insns) | |
2310 | rtx insns; | |
2311 | { | |
2312 | basic_block bb; | |
2313 | rtx insn; | |
2314 | int i = 0, depth = 1; | |
dc2ede84 | 2315 | |
e881bb1b RH |
2316 | bb = BASIC_BLOCK (i); |
2317 | for (insn = insns; insn ; insn = NEXT_INSN (insn)) | |
dc2ede84 | 2318 | { |
e881bb1b RH |
2319 | if (insn == bb->head) |
2320 | { | |
2321 | bb->loop_depth = depth; | |
2322 | if (++i >= n_basic_blocks) | |
dc2ede84 | 2323 | break; |
e881bb1b RH |
2324 | bb = BASIC_BLOCK (i); |
2325 | } | |
dc2ede84 | 2326 | |
e881bb1b RH |
2327 | if (GET_CODE (insn) == NOTE) |
2328 | { | |
2329 | if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG) | |
2330 | depth++; | |
2331 | else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_END) | |
2332 | depth--; | |
2333 | ||
2334 | /* If we have LOOP_DEPTH == 0, there has been a bookkeeping error. */ | |
2335 | if (depth == 0) | |
2336 | abort (); | |
2337 | } | |
2338 | } | |
dc2ede84 | 2339 | } |
d7429b6a | 2340 | \f |
5ece9746 JL |
2341 | /* Perform data flow analysis. |
2342 | F is the first insn of the function and NREGS the number of register numbers | |
2343 | in use. */ | |
2344 | ||
2345 | void | |
11f246f6 | 2346 | life_analysis (f, nregs, file, remove_dead_code) |
5ece9746 JL |
2347 | rtx f; |
2348 | int nregs; | |
2349 | FILE *file; | |
11f246f6 | 2350 | int remove_dead_code; |
5ece9746 | 2351 | { |
5ece9746 | 2352 | #ifdef ELIMINABLE_REGS |
ecb06768 | 2353 | register size_t i; |
5ece9746 JL |
2354 | static struct {int from, to; } eliminables[] = ELIMINABLE_REGS; |
2355 | #endif | |
2356 | ||
2357 | /* Record which registers will be eliminated. We use this in | |
2358 | mark_used_regs. */ | |
2359 | ||
2360 | CLEAR_HARD_REG_SET (elim_reg_set); | |
2361 | ||
2362 | #ifdef ELIMINABLE_REGS | |
2363 | for (i = 0; i < sizeof eliminables / sizeof eliminables[0]; i++) | |
2364 | SET_HARD_REG_BIT (elim_reg_set, eliminables[i].from); | |
2365 | #else | |
2366 | SET_HARD_REG_BIT (elim_reg_set, FRAME_POINTER_REGNUM); | |
2367 | #endif | |
2368 | ||
e881bb1b RH |
2369 | /* Allocate a bitmap to be filled in by record_volatile_insns. */ |
2370 | uid_volatile = BITMAP_ALLOCA (); | |
2371 | ||
db3a887b CB |
2372 | /* We want alias analysis information for local dead store elimination. */ |
2373 | init_alias_analysis (); | |
7790df19 | 2374 | |
11f246f6 | 2375 | life_analysis_1 (f, nregs, remove_dead_code); |
7790df19 JW |
2376 | |
2377 | if (! reload_completed) | |
2378 | mark_constant_function (); | |
2379 | ||
db3a887b CB |
2380 | end_alias_analysis (); |
2381 | ||
5ece9746 JL |
2382 | if (file) |
2383 | dump_flow_info (file); | |
2384 | ||
e881bb1b | 2385 | BITMAP_FREE (uid_volatile); |
5ece9746 JL |
2386 | free_basic_block_vars (1); |
2387 | } | |
2388 | ||
2389 | /* Free the variables allocated by find_basic_blocks. | |
2390 | ||
e881bb1b | 2391 | KEEP_HEAD_END_P is non-zero if basic_block_info is not to be freed. */ |
5ece9746 JL |
2392 | |
2393 | void | |
2394 | free_basic_block_vars (keep_head_end_p) | |
2395 | int keep_head_end_p; | |
2396 | { | |
e881bb1b | 2397 | if (basic_block_for_insn) |
5ece9746 | 2398 | { |
e881bb1b RH |
2399 | VARRAY_FREE (basic_block_for_insn); |
2400 | basic_block_for_insn = NULL; | |
5ece9746 JL |
2401 | } |
2402 | ||
e881bb1b | 2403 | if (! keep_head_end_p) |
5ece9746 | 2404 | { |
e881bb1b RH |
2405 | clear_edges (); |
2406 | VARRAY_FREE (basic_block_info); | |
2407 | n_basic_blocks = 0; | |
359da67d RH |
2408 | |
2409 | ENTRY_BLOCK_PTR->aux = NULL; | |
2410 | ENTRY_BLOCK_PTR->global_live_at_end = NULL; | |
2411 | EXIT_BLOCK_PTR->aux = NULL; | |
2412 | EXIT_BLOCK_PTR->global_live_at_start = NULL; | |
5ece9746 JL |
2413 | } |
2414 | } | |
2415 | ||
dc2ede84 BS |
2416 | /* Return nonzero if the destination of SET equals the source. */ |
2417 | static int | |
2418 | set_noop_p (set) | |
2419 | rtx set; | |
2420 | { | |
2421 | rtx src = SET_SRC (set); | |
2422 | rtx dst = SET_DEST (set); | |
2423 | if (GET_CODE (src) == REG && GET_CODE (dst) == REG | |
2424 | && REGNO (src) == REGNO (dst)) | |
2425 | return 1; | |
2426 | if (GET_CODE (src) != SUBREG || GET_CODE (dst) != SUBREG | |
2427 | || SUBREG_WORD (src) != SUBREG_WORD (dst)) | |
2428 | return 0; | |
2429 | src = SUBREG_REG (src); | |
2430 | dst = SUBREG_REG (dst); | |
2431 | if (GET_CODE (src) == REG && GET_CODE (dst) == REG | |
2432 | && REGNO (src) == REGNO (dst)) | |
2433 | return 1; | |
2434 | return 0; | |
2435 | } | |
2436 | ||
2437 | /* Return nonzero if an insn consists only of SETs, each of which only sets a | |
2438 | value to itself. */ | |
2439 | static int | |
2440 | noop_move_p (insn) | |
2441 | rtx insn; | |
2442 | { | |
2443 | rtx pat = PATTERN (insn); | |
2444 | ||
2445 | /* Insns carrying these notes are useful later on. */ | |
2446 | if (find_reg_note (insn, REG_EQUAL, NULL_RTX)) | |
2447 | return 0; | |
2448 | ||
2449 | if (GET_CODE (pat) == SET && set_noop_p (pat)) | |
2450 | return 1; | |
2451 | ||
2452 | if (GET_CODE (pat) == PARALLEL) | |
2453 | { | |
2454 | int i; | |
2455 | /* If nothing but SETs of registers to themselves, | |
2456 | this insn can also be deleted. */ | |
2457 | for (i = 0; i < XVECLEN (pat, 0); i++) | |
2458 | { | |
2459 | rtx tem = XVECEXP (pat, 0, i); | |
2460 | ||
2461 | if (GET_CODE (tem) == USE | |
2462 | || GET_CODE (tem) == CLOBBER) | |
2463 | continue; | |
2464 | ||
2465 | if (GET_CODE (tem) != SET || ! set_noop_p (tem)) | |
2466 | return 0; | |
2467 | } | |
2468 | ||
2469 | return 1; | |
2470 | } | |
2471 | return 0; | |
2472 | } | |
2473 | ||
fdb8a883 JW |
2474 | static void |
2475 | notice_stack_pointer_modification (x, pat) | |
2476 | rtx x; | |
2477 | rtx pat ATTRIBUTE_UNUSED; | |
2478 | { | |
2479 | if (x == stack_pointer_rtx | |
2480 | /* The stack pointer is only modified indirectly as the result | |
2481 | of a push until later in flow. See the comments in rtl.texi | |
2482 | regarding Embedded Side-Effects on Addresses. */ | |
2483 | || (GET_CODE (x) == MEM | |
2484 | && (GET_CODE (XEXP (x, 0)) == PRE_DEC | |
2485 | || GET_CODE (XEXP (x, 0)) == PRE_INC | |
2486 | || GET_CODE (XEXP (x, 0)) == POST_DEC | |
2487 | || GET_CODE (XEXP (x, 0)) == POST_INC) | |
2488 | && XEXP (XEXP (x, 0), 0) == stack_pointer_rtx)) | |
2489 | current_function_sp_is_unchanging = 0; | |
2490 | } | |
2491 | ||
dc2ede84 BS |
2492 | /* Record which insns refer to any volatile memory |
2493 | or for any reason can't be deleted just because they are dead stores. | |
fdb8a883 JW |
2494 | Also, delete any insns that copy a register to itself. |
2495 | And see if the stack pointer is modified. */ | |
dc2ede84 BS |
2496 | static void |
2497 | record_volatile_insns (f) | |
2498 | rtx f; | |
2499 | { | |
2500 | rtx insn; | |
2501 | for (insn = f; insn; insn = NEXT_INSN (insn)) | |
2502 | { | |
2503 | enum rtx_code code1 = GET_CODE (insn); | |
2504 | if (code1 == CALL_INSN) | |
e881bb1b | 2505 | SET_INSN_VOLATILE (insn); |
dc2ede84 BS |
2506 | else if (code1 == INSN || code1 == JUMP_INSN) |
2507 | { | |
2508 | if (GET_CODE (PATTERN (insn)) != USE | |
2509 | && volatile_refs_p (PATTERN (insn))) | |
e881bb1b | 2510 | SET_INSN_VOLATILE (insn); |
dc2ede84 BS |
2511 | |
2512 | /* A SET that makes space on the stack cannot be dead. | |
2513 | (Such SETs occur only for allocating variable-size data, | |
2514 | so they will always have a PLUS or MINUS according to the | |
2515 | direction of stack growth.) | |
2516 | Even if this function never uses this stack pointer value, | |
2517 | signal handlers do! */ | |
2518 | else if (code1 == INSN && GET_CODE (PATTERN (insn)) == SET | |
2519 | && SET_DEST (PATTERN (insn)) == stack_pointer_rtx | |
2520 | #ifdef STACK_GROWS_DOWNWARD | |
2521 | && GET_CODE (SET_SRC (PATTERN (insn))) == MINUS | |
2522 | #else | |
2523 | && GET_CODE (SET_SRC (PATTERN (insn))) == PLUS | |
2524 | #endif | |
2525 | && XEXP (SET_SRC (PATTERN (insn)), 0) == stack_pointer_rtx) | |
e881bb1b | 2526 | SET_INSN_VOLATILE (insn); |
dc2ede84 BS |
2527 | |
2528 | /* Delete (in effect) any obvious no-op moves. */ | |
2529 | else if (noop_move_p (insn)) | |
2530 | { | |
2531 | PUT_CODE (insn, NOTE); | |
2532 | NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED; | |
2533 | NOTE_SOURCE_FILE (insn) = 0; | |
2534 | } | |
2535 | } | |
fdb8a883 JW |
2536 | |
2537 | /* Check if insn modifies the stack pointer. */ | |
2538 | if ( current_function_sp_is_unchanging | |
2539 | && GET_RTX_CLASS (GET_CODE (insn)) == 'i') | |
2540 | note_stores (PATTERN (insn), notice_stack_pointer_modification); | |
dc2ede84 BS |
2541 | } |
2542 | } | |
2543 | ||
2544 | /* Mark those regs which are needed at the end of the function as live | |
2545 | at the end of the last basic block. */ | |
2546 | static void | |
2547 | mark_regs_live_at_end (set) | |
2548 | regset set; | |
2549 | { | |
2550 | int i; | |
2551 | ||
e881bb1b RH |
2552 | /* If exiting needs the right stack value, consider the stack pointer |
2553 | live at the end of the function. */ | |
dc2ede84 BS |
2554 | if (! EXIT_IGNORE_STACK |
2555 | || (! FRAME_POINTER_REQUIRED | |
2556 | && ! current_function_calls_alloca | |
fdb8a883 JW |
2557 | && flag_omit_frame_pointer) |
2558 | || current_function_sp_is_unchanging) | |
e881bb1b RH |
2559 | { |
2560 | SET_REGNO_REG_SET (set, STACK_POINTER_REGNUM); | |
2561 | } | |
dc2ede84 | 2562 | |
e881bb1b | 2563 | /* Mark the frame pointer if needed at the end of the function. If |
dc2ede84 BS |
2564 | we end up eliminating it, it will be removed from the live list |
2565 | of each basic block by reload. */ | |
2566 | ||
e4b8a413 JW |
2567 | if (! reload_completed || frame_pointer_needed) |
2568 | { | |
2569 | SET_REGNO_REG_SET (set, FRAME_POINTER_REGNUM); | |
dc2ede84 | 2570 | #if FRAME_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM |
e4b8a413 JW |
2571 | /* If they are different, also mark the hard frame pointer as live */ |
2572 | SET_REGNO_REG_SET (set, HARD_FRAME_POINTER_REGNUM); | |
dc2ede84 | 2573 | #endif |
e4b8a413 | 2574 | } |
dc2ede84 | 2575 | |
e881bb1b | 2576 | /* Mark all global registers, and all registers used by the epilogue |
dc2ede84 BS |
2577 | as being live at the end of the function since they may be |
2578 | referenced by our caller. */ | |
2579 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
2580 | if (global_regs[i] | |
2581 | #ifdef EPILOGUE_USES | |
2582 | || EPILOGUE_USES (i) | |
2583 | #endif | |
2584 | ) | |
2585 | SET_REGNO_REG_SET (set, i); | |
e881bb1b RH |
2586 | |
2587 | /* ??? Mark function return value here rather than as uses. */ | |
dc2ede84 BS |
2588 | } |
2589 | ||
d7429b6a RK |
2590 | /* Determine which registers are live at the start of each |
2591 | basic block of the function whose first insn is F. | |
2592 | NREGS is the number of registers used in F. | |
2593 | We allocate the vector basic_block_live_at_start | |
2594 | and the regsets that it points to, and fill them with the data. | |
2595 | regset_size and regset_bytes are also set here. */ | |
2596 | ||
2597 | static void | |
11f246f6 | 2598 | life_analysis_1 (f, nregs, remove_dead_code) |
d7429b6a RK |
2599 | rtx f; |
2600 | int nregs; | |
11f246f6 | 2601 | int remove_dead_code; |
d7429b6a | 2602 | { |
d7429b6a RK |
2603 | int first_pass; |
2604 | int changed; | |
d7429b6a | 2605 | register int i; |
6764d250 | 2606 | char save_regs_ever_live[FIRST_PSEUDO_REGISTER]; |
e881bb1b | 2607 | regset *new_live_at_end; |
d7429b6a RK |
2608 | |
2609 | struct obstack flow_obstack; | |
2610 | ||
2611 | gcc_obstack_init (&flow_obstack); | |
2612 | ||
2613 | max_regno = nregs; | |
2614 | ||
d7429b6a RK |
2615 | /* Allocate and zero out many data structures |
2616 | that will record the data from lifetime analysis. */ | |
2617 | ||
359da67d RH |
2618 | allocate_reg_life_data (); |
2619 | allocate_bb_life_data (); | |
d7429b6a RK |
2620 | |
2621 | reg_next_use = (rtx *) alloca (nregs * sizeof (rtx)); | |
e881bb1b | 2622 | memset (reg_next_use, 0, nregs * sizeof (rtx)); |
d7429b6a | 2623 | |
e881bb1b | 2624 | /* Set up regset-vectors used internally within this function. |
d7429b6a RK |
2625 | Their meanings are documented above, with their declarations. */ |
2626 | ||
e881bb1b RH |
2627 | new_live_at_end = (regset *) alloca ((n_basic_blocks + 1) * sizeof (regset)); |
2628 | init_regset_vector (new_live_at_end, n_basic_blocks + 1, &flow_obstack); | |
4c9a05bc | 2629 | |
e881bb1b RH |
2630 | /* Stick these vectors into the AUX field of the basic block, so that |
2631 | we don't have to keep going through the index. */ | |
d7429b6a | 2632 | |
e881bb1b RH |
2633 | for (i = 0; i < n_basic_blocks; ++i) |
2634 | BASIC_BLOCK (i)->aux = new_live_at_end[i]; | |
2635 | ENTRY_BLOCK_PTR->aux = new_live_at_end[i]; | |
d7429b6a | 2636 | |
fdb8a883 JW |
2637 | /* Assume that the stack pointer is unchanging if alloca hasn't been used. |
2638 | This will be cleared by record_volatile_insns if it encounters an insn | |
2639 | which modifies the stack pointer. */ | |
2640 | current_function_sp_is_unchanging = !current_function_calls_alloca; | |
2641 | ||
dc2ede84 | 2642 | record_volatile_insns (f); |
fe0f9c4b RK |
2643 | |
2644 | if (n_basic_blocks > 0) | |
2645 | { | |
e881bb1b RH |
2646 | regset theend; |
2647 | register edge e; | |
2648 | ||
2649 | theend = EXIT_BLOCK_PTR->global_live_at_start; | |
2650 | mark_regs_live_at_end (theend); | |
2651 | ||
2652 | /* Propogate this exit data to each of EXIT's predecessors. */ | |
2653 | for (e = EXIT_BLOCK_PTR->pred; e ; e = e->pred_next) | |
2654 | { | |
2655 | COPY_REG_SET (e->src->global_live_at_end, theend); | |
2656 | COPY_REG_SET ((regset) e->src->aux, theend); | |
2657 | } | |
dc2ede84 | 2658 | } |
d7429b6a | 2659 | |
e881bb1b RH |
2660 | /* The post-reload life analysis have (on a global basis) the same registers |
2661 | live as was computed by reload itself. | |
2662 | ||
2663 | Otherwise elimination offsets and such may be incorrect. | |
2664 | ||
2665 | Reload will make some registers as live even though they do not appear | |
2666 | in the rtl. */ | |
2667 | if (reload_completed) | |
2668 | memcpy (save_regs_ever_live, regs_ever_live, sizeof (regs_ever_live)); | |
2669 | memset (regs_ever_live, 0, sizeof regs_ever_live); | |
2670 | ||
d7429b6a RK |
2671 | /* Propagate life info through the basic blocks |
2672 | around the graph of basic blocks. | |
2673 | ||
2674 | This is a relaxation process: each time a new register | |
2675 | is live at the end of the basic block, we must scan the block | |
2676 | to determine which registers are, as a consequence, live at the beginning | |
2677 | of that block. These registers must then be marked live at the ends | |
2678 | of all the blocks that can transfer control to that block. | |
2679 | The process continues until it reaches a fixed point. */ | |
2680 | ||
2681 | first_pass = 1; | |
2682 | changed = 1; | |
2683 | while (changed) | |
2684 | { | |
2685 | changed = 0; | |
2686 | for (i = n_basic_blocks - 1; i >= 0; i--) | |
2687 | { | |
e881bb1b | 2688 | basic_block bb = BASIC_BLOCK (i); |
d7429b6a RK |
2689 | int consider = first_pass; |
2690 | int must_rescan = first_pass; | |
2691 | register int j; | |
2692 | ||
2693 | if (!first_pass) | |
2694 | { | |
2695 | /* Set CONSIDER if this block needs thinking about at all | |
2696 | (that is, if the regs live now at the end of it | |
2697 | are not the same as were live at the end of it when | |
2698 | we last thought about it). | |
2699 | Set must_rescan if it needs to be thought about | |
2700 | instruction by instruction (that is, if any additional | |
2701 | reg that is live at the end now but was not live there before | |
2702 | is one of the significant regs of this basic block). */ | |
2703 | ||
b5835272 | 2704 | EXECUTE_IF_AND_COMPL_IN_REG_SET |
e881bb1b | 2705 | ((regset) bb->aux, bb->global_live_at_end, 0, j, |
b5835272 RK |
2706 | { |
2707 | consider = 1; | |
e881bb1b | 2708 | if (REGNO_REG_SET_P (bb->local_set, j)) |
b5835272 RK |
2709 | { |
2710 | must_rescan = 1; | |
2711 | goto done; | |
2712 | } | |
2713 | }); | |
916b1701 | 2714 | done: |
d7429b6a RK |
2715 | if (! consider) |
2716 | continue; | |
2717 | } | |
2718 | ||
2719 | /* The live_at_start of this block may be changing, | |
2720 | so another pass will be required after this one. */ | |
2721 | changed = 1; | |
2722 | ||
2723 | if (! must_rescan) | |
2724 | { | |
2725 | /* No complete rescan needed; | |
2726 | just record those variables newly known live at end | |
2727 | as live at start as well. */ | |
e881bb1b RH |
2728 | IOR_AND_COMPL_REG_SET (bb->global_live_at_start, |
2729 | (regset) bb->aux, | |
2730 | bb->global_live_at_end); | |
916b1701 | 2731 | |
e881bb1b RH |
2732 | IOR_AND_COMPL_REG_SET (bb->global_live_at_end, |
2733 | (regset) bb->aux, | |
2734 | bb->global_live_at_end); | |
d7429b6a RK |
2735 | } |
2736 | else | |
2737 | { | |
2738 | /* Update the basic_block_live_at_start | |
2739 | by propagation backwards through the block. */ | |
e881bb1b RH |
2740 | COPY_REG_SET (bb->global_live_at_end, (regset) bb->aux); |
2741 | COPY_REG_SET (bb->global_live_at_start, | |
2742 | bb->global_live_at_end); | |
2743 | propagate_block (bb->global_live_at_start, | |
2744 | bb->head, bb->end, 0, | |
2745 | first_pass ? bb->local_set : (regset) 0, | |
11f246f6 | 2746 | i, remove_dead_code); |
d7429b6a RK |
2747 | } |
2748 | ||
e881bb1b | 2749 | /* Update the new_live_at_end's of the block's predecessors. */ |
d7429b6a | 2750 | { |
e881bb1b | 2751 | register edge e; |
af14ce9c | 2752 | |
e881bb1b RH |
2753 | for (e = bb->pred; e ; e = e->pred_next) |
2754 | IOR_REG_SET ((regset) e->src->aux, bb->global_live_at_start); | |
d7429b6a | 2755 | } |
e881bb1b | 2756 | |
d7429b6a RK |
2757 | #ifdef USE_C_ALLOCA |
2758 | alloca (0); | |
2759 | #endif | |
2760 | } | |
2761 | first_pass = 0; | |
2762 | } | |
2763 | ||
2764 | /* The only pseudos that are live at the beginning of the function are | |
2765 | those that were not set anywhere in the function. local-alloc doesn't | |
2766 | know how to handle these correctly, so mark them as not local to any | |
2767 | one basic block. */ | |
2768 | ||
2769 | if (n_basic_blocks > 0) | |
e881bb1b | 2770 | EXECUTE_IF_SET_IN_REG_SET (BASIC_BLOCK (0)->global_live_at_start, |
916b1701 MM |
2771 | FIRST_PSEUDO_REGISTER, i, |
2772 | { | |
2773 | REG_BASIC_BLOCK (i) = REG_BLOCK_GLOBAL; | |
2774 | }); | |
d7429b6a | 2775 | |
e881bb1b RH |
2776 | /* Now the life information is accurate. Make one more pass over each |
2777 | basic block to delete dead stores, create autoincrement addressing | |
2778 | and record how many times each register is used, is set, or dies. */ | |
d7429b6a | 2779 | |
d7429b6a RK |
2780 | for (i = 0; i < n_basic_blocks; i++) |
2781 | { | |
e881bb1b RH |
2782 | basic_block bb = BASIC_BLOCK (i); |
2783 | ||
2784 | /* We start with global_live_at_end to determine which stores are | |
2785 | dead. This process is destructive, and we wish to preserve the | |
2786 | contents of global_live_at_end for posterity. Fortunately, | |
2787 | new_live_at_end, due to the way we converged on a solution, | |
2788 | contains a duplicate of global_live_at_end that we can kill. */ | |
11f246f6 | 2789 | propagate_block ((regset) bb->aux, bb->head, bb->end, 1, (regset) 0, i, remove_dead_code); |
e881bb1b | 2790 | |
d7429b6a RK |
2791 | #ifdef USE_C_ALLOCA |
2792 | alloca (0); | |
2793 | #endif | |
2794 | } | |
2795 | ||
e881bb1b RH |
2796 | /* We have a problem with any pseudoreg that lives across the setjmp. |
2797 | ANSI says that if a user variable does not change in value between | |
2798 | the setjmp and the longjmp, then the longjmp preserves it. This | |
2799 | includes longjmp from a place where the pseudo appears dead. | |
d7429b6a RK |
2800 | (In principle, the value still exists if it is in scope.) |
2801 | If the pseudo goes in a hard reg, some other value may occupy | |
2802 | that hard reg where this pseudo is dead, thus clobbering the pseudo. | |
2803 | Conclusion: such a pseudo must not go in a hard reg. */ | |
916b1701 MM |
2804 | EXECUTE_IF_SET_IN_REG_SET (regs_live_at_setjmp, |
2805 | FIRST_PSEUDO_REGISTER, i, | |
2806 | { | |
2807 | if (regno_reg_rtx[i] != 0) | |
2808 | { | |
2809 | REG_LIVE_LENGTH (i) = -1; | |
2810 | REG_BASIC_BLOCK (i) = -1; | |
2811 | } | |
2812 | }); | |
d7429b6a | 2813 | |
6764d250 BS |
2814 | /* Restore regs_ever_live that was provided by reload. */ |
2815 | if (reload_completed) | |
e881bb1b | 2816 | memcpy (regs_ever_live, save_regs_ever_live, sizeof (regs_ever_live)); |
67f0e213 | 2817 | |
e881bb1b | 2818 | free_regset_vector (new_live_at_end, n_basic_blocks); |
5f4f0e22 | 2819 | obstack_free (&flow_obstack, NULL_PTR); |
e881bb1b RH |
2820 | |
2821 | for (i = 0; i < n_basic_blocks; ++i) | |
2822 | BASIC_BLOCK (i)->aux = NULL; | |
2823 | ENTRY_BLOCK_PTR->aux = NULL; | |
d7429b6a RK |
2824 | } |
2825 | \f | |
2826 | /* Subroutines of life analysis. */ | |
2827 | ||
2828 | /* Allocate the permanent data structures that represent the results | |
2829 | of life analysis. Not static since used also for stupid life analysis. */ | |
2830 | ||
2831 | void | |
359da67d | 2832 | allocate_bb_life_data () |
d7429b6a RK |
2833 | { |
2834 | register int i; | |
d7429b6a | 2835 | |
e881bb1b RH |
2836 | for (i = 0; i < n_basic_blocks; i++) |
2837 | { | |
2838 | basic_block bb = BASIC_BLOCK (i); | |
2839 | ||
2840 | bb->local_set = OBSTACK_ALLOC_REG_SET (function_obstack); | |
2841 | bb->global_live_at_start = OBSTACK_ALLOC_REG_SET (function_obstack); | |
2842 | bb->global_live_at_end = OBSTACK_ALLOC_REG_SET (function_obstack); | |
2843 | } | |
2844 | ||
2845 | ENTRY_BLOCK_PTR->global_live_at_end | |
2846 | = OBSTACK_ALLOC_REG_SET (function_obstack); | |
2847 | EXIT_BLOCK_PTR->global_live_at_start | |
2848 | = OBSTACK_ALLOC_REG_SET (function_obstack); | |
d7429b6a | 2849 | |
7eb136d6 | 2850 | regs_live_at_setjmp = OBSTACK_ALLOC_REG_SET (function_obstack); |
359da67d RH |
2851 | } |
2852 | ||
2853 | void | |
2854 | allocate_reg_life_data () | |
2855 | { | |
2856 | int i; | |
2857 | ||
2858 | /* Recalculate the register space, in case it has grown. Old style | |
2859 | vector oriented regsets would set regset_{size,bytes} here also. */ | |
2860 | allocate_reg_info (max_regno, FALSE, FALSE); | |
2861 | ||
2862 | /* Because both reg_scan and flow_analysis want to set up the REG_N_SETS | |
2863 | information, explicitly reset it here. The allocation should have | |
2864 | already happened on the previous reg_scan pass. Make sure in case | |
2865 | some more registers were allocated. */ | |
2866 | for (i = 0; i < max_regno; i++) | |
2867 | REG_N_SETS (i) = 0; | |
d7429b6a RK |
2868 | } |
2869 | ||
67f0e213 RK |
2870 | /* Make each element of VECTOR point at a regset. The vector has |
2871 | NELTS elements, and space is allocated from the ALLOC_OBSTACK | |
2872 | obstack. */ | |
d7429b6a | 2873 | |
04821e98 | 2874 | static void |
67f0e213 | 2875 | init_regset_vector (vector, nelts, alloc_obstack) |
d7429b6a | 2876 | regset *vector; |
d7429b6a | 2877 | int nelts; |
7eb136d6 | 2878 | struct obstack *alloc_obstack; |
d7429b6a RK |
2879 | { |
2880 | register int i; | |
d7429b6a RK |
2881 | |
2882 | for (i = 0; i < nelts; i++) | |
2883 | { | |
7eb136d6 MM |
2884 | vector[i] = OBSTACK_ALLOC_REG_SET (alloc_obstack); |
2885 | CLEAR_REG_SET (vector[i]); | |
d7429b6a RK |
2886 | } |
2887 | } | |
e658434c | 2888 | |
67f0e213 RK |
2889 | /* Release any additional space allocated for each element of VECTOR point |
2890 | other than the regset header itself. The vector has NELTS elements. */ | |
2891 | ||
2892 | void | |
2893 | free_regset_vector (vector, nelts) | |
2894 | regset *vector; | |
2895 | int nelts; | |
2896 | { | |
2897 | register int i; | |
2898 | ||
2899 | for (i = 0; i < nelts; i++) | |
2900 | FREE_REG_SET (vector[i]); | |
2901 | } | |
2902 | ||
d7429b6a RK |
2903 | /* Compute the registers live at the beginning of a basic block |
2904 | from those live at the end. | |
2905 | ||
2906 | When called, OLD contains those live at the end. | |
2907 | On return, it contains those live at the beginning. | |
2908 | FIRST and LAST are the first and last insns of the basic block. | |
2909 | ||
2910 | FINAL is nonzero if we are doing the final pass which is not | |
2911 | for computing the life info (since that has already been done) | |
2912 | but for acting on it. On this pass, we delete dead stores, | |
2913 | set up the logical links and dead-variables lists of instructions, | |
2914 | and merge instructions for autoincrement and autodecrement addresses. | |
2915 | ||
2916 | SIGNIFICANT is nonzero only the first time for each basic block. | |
2917 | If it is nonzero, it points to a regset in which we store | |
2918 | a 1 for each register that is set within the block. | |
2919 | ||
2920 | BNUM is the number of the basic block. */ | |
2921 | ||
2922 | static void | |
11f246f6 | 2923 | propagate_block (old, first, last, final, significant, bnum, remove_dead_code) |
d7429b6a RK |
2924 | register regset old; |
2925 | rtx first; | |
2926 | rtx last; | |
2927 | int final; | |
2928 | regset significant; | |
2929 | int bnum; | |
11f246f6 | 2930 | int remove_dead_code; |
d7429b6a RK |
2931 | { |
2932 | register rtx insn; | |
2933 | rtx prev; | |
2934 | regset live; | |
2935 | regset dead; | |
2936 | ||
e881bb1b RH |
2937 | /* Find the loop depth for this block. Ignore loop level changes in the |
2938 | middle of the basic block -- for register allocation purposes, the | |
2939 | important uses will be in the blocks wholely contained within the loop | |
2940 | not in the loop pre-header or post-trailer. */ | |
2941 | loop_depth = BASIC_BLOCK (bnum)->loop_depth; | |
d7429b6a | 2942 | |
7eb136d6 MM |
2943 | dead = ALLOCA_REG_SET (); |
2944 | live = ALLOCA_REG_SET (); | |
d7429b6a RK |
2945 | |
2946 | cc0_live = 0; | |
db3a887b | 2947 | mem_set_list = NULL_RTX; |
d7429b6a | 2948 | |
d7429b6a RK |
2949 | if (final) |
2950 | { | |
916b1701 | 2951 | register int i; |
d7429b6a | 2952 | |
d7429b6a | 2953 | /* Process the regs live at the end of the block. |
f8dd7f98 | 2954 | Mark them as not local to any one basic block. */ |
916b1701 MM |
2955 | EXECUTE_IF_SET_IN_REG_SET (old, 0, i, |
2956 | { | |
2957 | REG_BASIC_BLOCK (i) = REG_BLOCK_GLOBAL; | |
916b1701 | 2958 | }); |
d7429b6a RK |
2959 | } |
2960 | ||
2961 | /* Scan the block an insn at a time from end to beginning. */ | |
2962 | ||
2963 | for (insn = last; ; insn = prev) | |
2964 | { | |
2965 | prev = PREV_INSN (insn); | |
2966 | ||
8329b5ec | 2967 | if (GET_CODE (insn) == NOTE) |
d7429b6a | 2968 | { |
8329b5ec DE |
2969 | /* If this is a call to `setjmp' et al, |
2970 | warn if any non-volatile datum is live. */ | |
2971 | ||
2972 | if (final && NOTE_LINE_NUMBER (insn) == NOTE_INSN_SETJMP) | |
916b1701 | 2973 | IOR_REG_SET (regs_live_at_setjmp, old); |
d7429b6a RK |
2974 | } |
2975 | ||
2976 | /* Update the life-status of regs for this insn. | |
2977 | First DEAD gets which regs are set in this insn | |
2978 | then LIVE gets which regs are used in this insn. | |
2979 | Then the regs live before the insn | |
2980 | are those live after, with DEAD regs turned off, | |
2981 | and then LIVE regs turned on. */ | |
2982 | ||
8329b5ec | 2983 | else if (GET_RTX_CLASS (GET_CODE (insn)) == 'i') |
d7429b6a RK |
2984 | { |
2985 | register int i; | |
5f4f0e22 | 2986 | rtx note = find_reg_note (insn, REG_RETVAL, NULL_RTX); |
11f246f6 JH |
2987 | int insn_is_dead = 0; |
2988 | int libcall_is_dead = 0; | |
2989 | ||
2990 | if (remove_dead_code) | |
2991 | { | |
2992 | insn_is_dead = (insn_dead_p (PATTERN (insn), old, 0, REG_NOTES (insn)) | |
2993 | /* Don't delete something that refers to volatile storage! */ | |
2994 | && ! INSN_VOLATILE (insn)); | |
2995 | libcall_is_dead = (insn_is_dead && note != 0 | |
2996 | && libcall_dead_p (PATTERN (insn), old, note, insn)); | |
2997 | } | |
d7429b6a RK |
2998 | |
2999 | /* If an instruction consists of just dead store(s) on final pass, | |
3000 | "delete" it by turning it into a NOTE of type NOTE_INSN_DELETED. | |
3001 | We could really delete it with delete_insn, but that | |
3002 | can cause trouble for first or last insn in a basic block. */ | |
b590bbfd | 3003 | if (final && insn_is_dead) |
d7429b6a RK |
3004 | { |
3005 | PUT_CODE (insn, NOTE); | |
3006 | NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED; | |
3007 | NOTE_SOURCE_FILE (insn) = 0; | |
3008 | ||
e5df1ea3 RK |
3009 | /* CC0 is now known to be dead. Either this insn used it, |
3010 | in which case it doesn't anymore, or clobbered it, | |
3011 | so the next insn can't use it. */ | |
3012 | cc0_live = 0; | |
3013 | ||
d7429b6a RK |
3014 | /* If this insn is copying the return value from a library call, |
3015 | delete the entire library call. */ | |
3016 | if (libcall_is_dead) | |
3017 | { | |
3018 | rtx first = XEXP (note, 0); | |
3019 | rtx p = insn; | |
3020 | while (INSN_DELETED_P (first)) | |
3021 | first = NEXT_INSN (first); | |
3022 | while (p != first) | |
3023 | { | |
3024 | p = PREV_INSN (p); | |
3025 | PUT_CODE (p, NOTE); | |
3026 | NOTE_LINE_NUMBER (p) = NOTE_INSN_DELETED; | |
3027 | NOTE_SOURCE_FILE (p) = 0; | |
3028 | } | |
3029 | } | |
3030 | goto flushed; | |
3031 | } | |
3032 | ||
916b1701 MM |
3033 | CLEAR_REG_SET (dead); |
3034 | CLEAR_REG_SET (live); | |
d7429b6a RK |
3035 | |
3036 | /* See if this is an increment or decrement that can be | |
3037 | merged into a following memory address. */ | |
3038 | #ifdef AUTO_INC_DEC | |
3039 | { | |
956d6950 JL |
3040 | register rtx x = single_set (insn); |
3041 | ||
d7429b6a | 3042 | /* Does this instruction increment or decrement a register? */ |
6764d250 BS |
3043 | if (!reload_completed |
3044 | && final && x != 0 | |
d7429b6a RK |
3045 | && GET_CODE (SET_DEST (x)) == REG |
3046 | && (GET_CODE (SET_SRC (x)) == PLUS | |
3047 | || GET_CODE (SET_SRC (x)) == MINUS) | |
3048 | && XEXP (SET_SRC (x), 0) == SET_DEST (x) | |
3049 | && GET_CODE (XEXP (SET_SRC (x), 1)) == CONST_INT | |
3050 | /* Ok, look for a following memory ref we can combine with. | |
3051 | If one is found, change the memory ref to a PRE_INC | |
3052 | or PRE_DEC, cancel this insn, and return 1. | |
3053 | Return 0 if nothing has been done. */ | |
3054 | && try_pre_increment_1 (insn)) | |
3055 | goto flushed; | |
3056 | } | |
3057 | #endif /* AUTO_INC_DEC */ | |
3058 | ||
3059 | /* If this is not the final pass, and this insn is copying the | |
3060 | value of a library call and it's dead, don't scan the | |
3061 | insns that perform the library call, so that the call's | |
3062 | arguments are not marked live. */ | |
3063 | if (libcall_is_dead) | |
3064 | { | |
3065 | /* Mark the dest reg as `significant'. */ | |
5f4f0e22 | 3066 | mark_set_regs (old, dead, PATTERN (insn), NULL_RTX, significant); |
d7429b6a RK |
3067 | |
3068 | insn = XEXP (note, 0); | |
3069 | prev = PREV_INSN (insn); | |
3070 | } | |
3071 | else if (GET_CODE (PATTERN (insn)) == SET | |
3072 | && SET_DEST (PATTERN (insn)) == stack_pointer_rtx | |
3073 | && GET_CODE (SET_SRC (PATTERN (insn))) == PLUS | |
3074 | && XEXP (SET_SRC (PATTERN (insn)), 0) == stack_pointer_rtx | |
3075 | && GET_CODE (XEXP (SET_SRC (PATTERN (insn)), 1)) == CONST_INT) | |
3076 | /* We have an insn to pop a constant amount off the stack. | |
3077 | (Such insns use PLUS regardless of the direction of the stack, | |
3078 | and any insn to adjust the stack by a constant is always a pop.) | |
3079 | These insns, if not dead stores, have no effect on life. */ | |
3080 | ; | |
3081 | else | |
3082 | { | |
f8dd7f98 BS |
3083 | /* Any regs live at the time of a call instruction |
3084 | must not go in a register clobbered by calls. | |
3085 | Find all regs now live and record this for them. */ | |
3086 | ||
3087 | if (GET_CODE (insn) == CALL_INSN && final) | |
3088 | EXECUTE_IF_SET_IN_REG_SET (old, 0, i, | |
3089 | { | |
3090 | REG_N_CALLS_CROSSED (i)++; | |
3091 | }); | |
3092 | ||
d7429b6a RK |
3093 | /* LIVE gets the regs used in INSN; |
3094 | DEAD gets those set by it. Dead insns don't make anything | |
3095 | live. */ | |
3096 | ||
5f4f0e22 CH |
3097 | mark_set_regs (old, dead, PATTERN (insn), |
3098 | final ? insn : NULL_RTX, significant); | |
d7429b6a RK |
3099 | |
3100 | /* If an insn doesn't use CC0, it becomes dead since we | |
3101 | assume that every insn clobbers it. So show it dead here; | |
3102 | mark_used_regs will set it live if it is referenced. */ | |
3103 | cc0_live = 0; | |
3104 | ||
3105 | if (! insn_is_dead) | |
3106 | mark_used_regs (old, live, PATTERN (insn), final, insn); | |
3107 | ||
3108 | /* Sometimes we may have inserted something before INSN (such as | |
3109 | a move) when we make an auto-inc. So ensure we will scan | |
3110 | those insns. */ | |
3111 | #ifdef AUTO_INC_DEC | |
3112 | prev = PREV_INSN (insn); | |
3113 | #endif | |
3114 | ||
3115 | if (! insn_is_dead && GET_CODE (insn) == CALL_INSN) | |
3116 | { | |
3117 | register int i; | |
3118 | ||
6b67ec08 RK |
3119 | rtx note; |
3120 | ||
3121 | for (note = CALL_INSN_FUNCTION_USAGE (insn); | |
3122 | note; | |
3123 | note = XEXP (note, 1)) | |
3124 | if (GET_CODE (XEXP (note, 0)) == USE) | |
83ab3839 | 3125 | mark_used_regs (old, live, XEXP (XEXP (note, 0), 0), |
6b67ec08 RK |
3126 | final, insn); |
3127 | ||
d7429b6a | 3128 | /* Each call clobbers all call-clobbered regs that are not |
e4329280 | 3129 | global or fixed. Note that the function-value reg is a |
d7429b6a RK |
3130 | call-clobbered reg, and mark_set_regs has already had |
3131 | a chance to handle it. */ | |
3132 | ||
3133 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
e4329280 RK |
3134 | if (call_used_regs[i] && ! global_regs[i] |
3135 | && ! fixed_regs[i]) | |
916b1701 | 3136 | SET_REGNO_REG_SET (dead, i); |
d7429b6a RK |
3137 | |
3138 | /* The stack ptr is used (honorarily) by a CALL insn. */ | |
916b1701 | 3139 | SET_REGNO_REG_SET (live, STACK_POINTER_REGNUM); |
d7429b6a RK |
3140 | |
3141 | /* Calls may also reference any of the global registers, | |
3142 | so they are made live. */ | |
d7429b6a RK |
3143 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) |
3144 | if (global_regs[i]) | |
9b316aa2 | 3145 | mark_used_regs (old, live, |
38a448ca | 3146 | gen_rtx_REG (reg_raw_mode[i], i), |
9b316aa2 | 3147 | final, insn); |
d7429b6a RK |
3148 | |
3149 | /* Calls also clobber memory. */ | |
db3a887b | 3150 | mem_set_list = NULL_RTX; |
d7429b6a RK |
3151 | } |
3152 | ||
3153 | /* Update OLD for the registers used or set. */ | |
916b1701 MM |
3154 | AND_COMPL_REG_SET (old, dead); |
3155 | IOR_REG_SET (old, live); | |
d7429b6a | 3156 | |
d7429b6a RK |
3157 | } |
3158 | ||
f8dd7f98 BS |
3159 | /* On final pass, update counts of how many insns each reg is live |
3160 | at. */ | |
d7429b6a | 3161 | if (final) |
f8dd7f98 BS |
3162 | EXECUTE_IF_SET_IN_REG_SET (old, 0, i, |
3163 | { REG_LIVE_LENGTH (i)++; }); | |
d7429b6a RK |
3164 | } |
3165 | flushed: ; | |
3166 | if (insn == first) | |
3167 | break; | |
3168 | } | |
3169 | ||
67f0e213 RK |
3170 | FREE_REG_SET (dead); |
3171 | FREE_REG_SET (live); | |
d7429b6a RK |
3172 | } |
3173 | \f | |
3174 | /* Return 1 if X (the body of an insn, or part of it) is just dead stores | |
3175 | (SET expressions whose destinations are registers dead after the insn). | |
3176 | NEEDED is the regset that says which regs are alive after the insn. | |
3177 | ||
e398aa80 R |
3178 | Unless CALL_OK is non-zero, an insn is needed if it contains a CALL. |
3179 | ||
3180 | If X is the entire body of an insn, NOTES contains the reg notes | |
3181 | pertaining to the insn. */ | |
d7429b6a RK |
3182 | |
3183 | static int | |
e398aa80 | 3184 | insn_dead_p (x, needed, call_ok, notes) |
d7429b6a RK |
3185 | rtx x; |
3186 | regset needed; | |
3187 | int call_ok; | |
e398aa80 | 3188 | rtx notes ATTRIBUTE_UNUSED; |
d7429b6a | 3189 | { |
e5e809f4 JL |
3190 | enum rtx_code code = GET_CODE (x); |
3191 | ||
e398aa80 R |
3192 | #ifdef AUTO_INC_DEC |
3193 | /* If flow is invoked after reload, we must take existing AUTO_INC | |
3194 | expresions into account. */ | |
3195 | if (reload_completed) | |
3196 | { | |
3197 | for ( ; notes; notes = XEXP (notes, 1)) | |
3198 | { | |
3199 | if (REG_NOTE_KIND (notes) == REG_INC) | |
3200 | { | |
3201 | int regno = REGNO (XEXP (notes, 0)); | |
3202 | ||
3203 | /* Don't delete insns to set global regs. */ | |
3204 | if ((regno < FIRST_PSEUDO_REGISTER && global_regs[regno]) | |
3205 | || REGNO_REG_SET_P (needed, regno)) | |
3206 | return 0; | |
3207 | } | |
3208 | } | |
3209 | } | |
3210 | #endif | |
3211 | ||
d7429b6a RK |
3212 | /* If setting something that's a reg or part of one, |
3213 | see if that register's altered value will be live. */ | |
3214 | ||
3215 | if (code == SET) | |
3216 | { | |
e5e809f4 JL |
3217 | rtx r = SET_DEST (x); |
3218 | ||
d7429b6a RK |
3219 | /* A SET that is a subroutine call cannot be dead. */ |
3220 | if (! call_ok && GET_CODE (SET_SRC (x)) == CALL) | |
3221 | return 0; | |
3222 | ||
3223 | #ifdef HAVE_cc0 | |
3224 | if (GET_CODE (r) == CC0) | |
3225 | return ! cc0_live; | |
3226 | #endif | |
3227 | ||
db3a887b CB |
3228 | if (GET_CODE (r) == MEM && ! MEM_VOLATILE_P (r)) |
3229 | { | |
3230 | rtx temp; | |
3231 | /* Walk the set of memory locations we are currently tracking | |
3232 | and see if one is an identical match to this memory location. | |
3233 | If so, this memory write is dead (remember, we're walking | |
3234 | backwards from the end of the block to the start. */ | |
3235 | temp = mem_set_list; | |
3236 | while (temp) | |
3237 | { | |
3238 | if (rtx_equal_p (XEXP (temp, 0), r)) | |
3239 | return 1; | |
3240 | temp = XEXP (temp, 1); | |
3241 | } | |
3242 | } | |
d7429b6a | 3243 | |
e5e809f4 JL |
3244 | while (GET_CODE (r) == SUBREG || GET_CODE (r) == STRICT_LOW_PART |
3245 | || GET_CODE (r) == ZERO_EXTRACT) | |
355fca3e | 3246 | r = XEXP (r, 0); |
d7429b6a RK |
3247 | |
3248 | if (GET_CODE (r) == REG) | |
3249 | { | |
e5e809f4 | 3250 | int regno = REGNO (r); |
d7429b6a | 3251 | |
d8c8b8e3 | 3252 | /* Don't delete insns to set global regs. */ |
d7429b6a RK |
3253 | if ((regno < FIRST_PSEUDO_REGISTER && global_regs[regno]) |
3254 | /* Make sure insns to set frame pointer aren't deleted. */ | |
e4b8a413 JW |
3255 | || (regno == FRAME_POINTER_REGNUM |
3256 | && (! reload_completed || frame_pointer_needed)) | |
73a187c1 | 3257 | #if FRAME_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM |
e4b8a413 JW |
3258 | || (regno == HARD_FRAME_POINTER_REGNUM |
3259 | && (! reload_completed || frame_pointer_needed)) | |
73a187c1 | 3260 | #endif |
d7e4fe8b RS |
3261 | #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM |
3262 | /* Make sure insns to set arg pointer are never deleted | |
3263 | (if the arg pointer isn't fixed, there will be a USE for | |
0f41302f | 3264 | it, so we can treat it normally). */ |
d7e4fe8b RS |
3265 | || (regno == ARG_POINTER_REGNUM && fixed_regs[regno]) |
3266 | #endif | |
916b1701 | 3267 | || REGNO_REG_SET_P (needed, regno)) |
d7429b6a RK |
3268 | return 0; |
3269 | ||
3270 | /* If this is a hard register, verify that subsequent words are | |
3271 | not needed. */ | |
3272 | if (regno < FIRST_PSEUDO_REGISTER) | |
3273 | { | |
3274 | int n = HARD_REGNO_NREGS (regno, GET_MODE (r)); | |
3275 | ||
3276 | while (--n > 0) | |
916b1701 | 3277 | if (REGNO_REG_SET_P (needed, regno+n)) |
d7429b6a RK |
3278 | return 0; |
3279 | } | |
3280 | ||
3281 | return 1; | |
3282 | } | |
3283 | } | |
e5e809f4 | 3284 | |
d7429b6a RK |
3285 | /* If performing several activities, |
3286 | insn is dead if each activity is individually dead. | |
3287 | Also, CLOBBERs and USEs can be ignored; a CLOBBER or USE | |
3288 | that's inside a PARALLEL doesn't make the insn worth keeping. */ | |
3289 | else if (code == PARALLEL) | |
3290 | { | |
e5e809f4 JL |
3291 | int i = XVECLEN (x, 0); |
3292 | ||
d7429b6a | 3293 | for (i--; i >= 0; i--) |
e5e809f4 JL |
3294 | if (GET_CODE (XVECEXP (x, 0, i)) != CLOBBER |
3295 | && GET_CODE (XVECEXP (x, 0, i)) != USE | |
e398aa80 | 3296 | && ! insn_dead_p (XVECEXP (x, 0, i), needed, call_ok, NULL_RTX)) |
e5e809f4 JL |
3297 | return 0; |
3298 | ||
d7429b6a RK |
3299 | return 1; |
3300 | } | |
e5e809f4 JL |
3301 | |
3302 | /* A CLOBBER of a pseudo-register that is dead serves no purpose. That | |
3303 | is not necessarily true for hard registers. */ | |
3304 | else if (code == CLOBBER && GET_CODE (XEXP (x, 0)) == REG | |
3305 | && REGNO (XEXP (x, 0)) >= FIRST_PSEUDO_REGISTER | |
3306 | && ! REGNO_REG_SET_P (needed, REGNO (XEXP (x, 0)))) | |
3307 | return 1; | |
3308 | ||
3309 | /* We do not check other CLOBBER or USE here. An insn consisting of just | |
3310 | a CLOBBER or just a USE should not be deleted. */ | |
d7429b6a RK |
3311 | return 0; |
3312 | } | |
3313 | ||
3314 | /* If X is the pattern of the last insn in a libcall, and assuming X is dead, | |
3315 | return 1 if the entire library call is dead. | |
3316 | This is true if X copies a register (hard or pseudo) | |
3317 | and if the hard return reg of the call insn is dead. | |
3318 | (The caller should have tested the destination of X already for death.) | |
3319 | ||
3320 | If this insn doesn't just copy a register, then we don't | |
3321 | have an ordinary libcall. In that case, cse could not have | |
3322 | managed to substitute the source for the dest later on, | |
3323 | so we can assume the libcall is dead. | |
3324 | ||
3325 | NEEDED is the bit vector of pseudoregs live before this insn. | |
3326 | NOTE is the REG_RETVAL note of the insn. INSN is the insn itself. */ | |
3327 | ||
3328 | static int | |
3329 | libcall_dead_p (x, needed, note, insn) | |
3330 | rtx x; | |
3331 | regset needed; | |
3332 | rtx note; | |
3333 | rtx insn; | |
3334 | { | |
3335 | register RTX_CODE code = GET_CODE (x); | |
3336 | ||
3337 | if (code == SET) | |
3338 | { | |
3339 | register rtx r = SET_SRC (x); | |
3340 | if (GET_CODE (r) == REG) | |
3341 | { | |
3342 | rtx call = XEXP (note, 0); | |
e398aa80 | 3343 | rtx call_pat; |
d7429b6a RK |
3344 | register int i; |
3345 | ||
3346 | /* Find the call insn. */ | |
3347 | while (call != insn && GET_CODE (call) != CALL_INSN) | |
3348 | call = NEXT_INSN (call); | |
3349 | ||
3350 | /* If there is none, do nothing special, | |
3351 | since ordinary death handling can understand these insns. */ | |
3352 | if (call == insn) | |
3353 | return 0; | |
3354 | ||
3355 | /* See if the hard reg holding the value is dead. | |
3356 | If this is a PARALLEL, find the call within it. */ | |
e398aa80 R |
3357 | call_pat = PATTERN (call); |
3358 | if (GET_CODE (call_pat) == PARALLEL) | |
d7429b6a | 3359 | { |
e398aa80 R |
3360 | for (i = XVECLEN (call_pat, 0) - 1; i >= 0; i--) |
3361 | if (GET_CODE (XVECEXP (call_pat, 0, i)) == SET | |
3362 | && GET_CODE (SET_SRC (XVECEXP (call_pat, 0, i))) == CALL) | |
d7429b6a RK |
3363 | break; |
3364 | ||
761a5bcd JW |
3365 | /* This may be a library call that is returning a value |
3366 | via invisible pointer. Do nothing special, since | |
3367 | ordinary death handling can understand these insns. */ | |
d7429b6a | 3368 | if (i < 0) |
761a5bcd | 3369 | return 0; |
d7429b6a | 3370 | |
e398aa80 | 3371 | call_pat = XVECEXP (call_pat, 0, i); |
d7429b6a RK |
3372 | } |
3373 | ||
e398aa80 | 3374 | return insn_dead_p (call_pat, needed, 1, REG_NOTES (call)); |
d7429b6a RK |
3375 | } |
3376 | } | |
3377 | return 1; | |
3378 | } | |
3379 | ||
bd80fbde RH |
3380 | /* Return 1 if register REGNO was used before it was set, i.e. if it is |
3381 | live at function entry. Don't count global register variables, variables | |
3382 | in registers that can be used for function arg passing, or variables in | |
3383 | fixed hard registers. */ | |
d7429b6a RK |
3384 | |
3385 | int | |
3386 | regno_uninitialized (regno) | |
3387 | int regno; | |
3388 | { | |
b0b7b46a | 3389 | if (n_basic_blocks == 0 |
6a45254e | 3390 | || (regno < FIRST_PSEUDO_REGISTER |
bd80fbde RH |
3391 | && (global_regs[regno] |
3392 | || fixed_regs[regno] | |
3393 | || FUNCTION_ARG_REGNO_P (regno)))) | |
d7429b6a RK |
3394 | return 0; |
3395 | ||
e881bb1b | 3396 | return REGNO_REG_SET_P (BASIC_BLOCK (0)->global_live_at_start, regno); |
d7429b6a RK |
3397 | } |
3398 | ||
3399 | /* 1 if register REGNO was alive at a place where `setjmp' was called | |
3400 | and was set more than once or is an argument. | |
3401 | Such regs may be clobbered by `longjmp'. */ | |
3402 | ||
3403 | int | |
3404 | regno_clobbered_at_setjmp (regno) | |
3405 | int regno; | |
3406 | { | |
3407 | if (n_basic_blocks == 0) | |
3408 | return 0; | |
3409 | ||
b1f21e0a | 3410 | return ((REG_N_SETS (regno) > 1 |
e881bb1b | 3411 | || REGNO_REG_SET_P (BASIC_BLOCK (0)->global_live_at_start, regno)) |
916b1701 | 3412 | && REGNO_REG_SET_P (regs_live_at_setjmp, regno)); |
d7429b6a RK |
3413 | } |
3414 | \f | |
15e088b2 JL |
3415 | /* INSN references memory, possibly using autoincrement addressing modes. |
3416 | Find any entries on the mem_set_list that need to be invalidated due | |
3417 | to an address change. */ | |
3418 | static void | |
3419 | invalidate_mems_from_autoinc (insn) | |
3420 | rtx insn; | |
3421 | { | |
3422 | rtx note = REG_NOTES (insn); | |
3423 | for (note = REG_NOTES (insn); note; note = XEXP (note, 1)) | |
3424 | { | |
3425 | if (REG_NOTE_KIND (note) == REG_INC) | |
3426 | { | |
3427 | rtx temp = mem_set_list; | |
3428 | rtx prev = NULL_RTX; | |
3429 | ||
3430 | while (temp) | |
3431 | { | |
3432 | if (reg_overlap_mentioned_p (XEXP (note, 0), XEXP (temp, 0))) | |
3433 | { | |
3434 | /* Splice temp out of list. */ | |
3435 | if (prev) | |
3436 | XEXP (prev, 1) = XEXP (temp, 1); | |
3437 | else | |
3438 | mem_set_list = XEXP (temp, 1); | |
3439 | } | |
3440 | else | |
3441 | prev = temp; | |
3442 | temp = XEXP (temp, 1); | |
3443 | } | |
3444 | } | |
3445 | } | |
3446 | } | |
3447 | ||
d7429b6a RK |
3448 | /* Process the registers that are set within X. |
3449 | Their bits are set to 1 in the regset DEAD, | |
3450 | because they are dead prior to this insn. | |
3451 | ||
3452 | If INSN is nonzero, it is the insn being processed | |
3453 | and the fact that it is nonzero implies this is the FINAL pass | |
3454 | in propagate_block. In this case, various info about register | |
3455 | usage is stored, LOG_LINKS fields of insns are set up. */ | |
3456 | ||
d7429b6a RK |
3457 | static void |
3458 | mark_set_regs (needed, dead, x, insn, significant) | |
3459 | regset needed; | |
3460 | regset dead; | |
3461 | rtx x; | |
3462 | rtx insn; | |
3463 | regset significant; | |
3464 | { | |
3465 | register RTX_CODE code = GET_CODE (x); | |
3466 | ||
3467 | if (code == SET || code == CLOBBER) | |
3468 | mark_set_1 (needed, dead, x, insn, significant); | |
3469 | else if (code == PARALLEL) | |
3470 | { | |
3471 | register int i; | |
3472 | for (i = XVECLEN (x, 0) - 1; i >= 0; i--) | |
3473 | { | |
3474 | code = GET_CODE (XVECEXP (x, 0, i)); | |
3475 | if (code == SET || code == CLOBBER) | |
3476 | mark_set_1 (needed, dead, XVECEXP (x, 0, i), insn, significant); | |
3477 | } | |
3478 | } | |
3479 | } | |
3480 | ||
3481 | /* Process a single SET rtx, X. */ | |
3482 | ||
3483 | static void | |
3484 | mark_set_1 (needed, dead, x, insn, significant) | |
3485 | regset needed; | |
3486 | regset dead; | |
3487 | rtx x; | |
3488 | rtx insn; | |
3489 | regset significant; | |
3490 | { | |
3491 | register int regno; | |
3492 | register rtx reg = SET_DEST (x); | |
3493 | ||
86465af7 DM |
3494 | /* Some targets place small structures in registers for |
3495 | return values of functions. We have to detect this | |
3496 | case specially here to get correct flow information. */ | |
3497 | if (GET_CODE (reg) == PARALLEL | |
3498 | && GET_MODE (reg) == BLKmode) | |
3499 | { | |
3500 | register int i; | |
3501 | ||
3502 | for (i = XVECLEN (reg, 0) - 1; i >= 0; i--) | |
3503 | mark_set_1 (needed, dead, XVECEXP (reg, 0, i), insn, significant); | |
3504 | return; | |
3505 | } | |
3506 | ||
d7429b6a RK |
3507 | /* Modifying just one hardware register of a multi-reg value |
3508 | or just a byte field of a register | |
3509 | does not mean the value from before this insn is now dead. | |
3510 | But it does mean liveness of that register at the end of the block | |
3511 | is significant. | |
3512 | ||
3513 | Within mark_set_1, however, we treat it as if the register is | |
3514 | indeed modified. mark_used_regs will, however, also treat this | |
3515 | register as being used. Thus, we treat these insns as setting a | |
3516 | new value for the register as a function of its old value. This | |
3517 | cases LOG_LINKS to be made appropriately and this will help combine. */ | |
3518 | ||
3519 | while (GET_CODE (reg) == SUBREG || GET_CODE (reg) == ZERO_EXTRACT | |
3520 | || GET_CODE (reg) == SIGN_EXTRACT | |
3521 | || GET_CODE (reg) == STRICT_LOW_PART) | |
3522 | reg = XEXP (reg, 0); | |
3523 | ||
db3a887b CB |
3524 | /* If this set is a MEM, then it kills any aliased writes. |
3525 | If this set is a REG, then it kills any MEMs which use the reg. */ | |
d7429b6a | 3526 | if (GET_CODE (reg) == MEM |
db3a887b CB |
3527 | || GET_CODE (reg) == REG) |
3528 | { | |
3529 | rtx temp = mem_set_list; | |
3530 | rtx prev = NULL_RTX; | |
3531 | ||
3532 | while (temp) | |
3533 | { | |
3534 | if ((GET_CODE (reg) == MEM | |
3535 | && output_dependence (XEXP (temp, 0), reg)) | |
3536 | || (GET_CODE (reg) == REG | |
3537 | && reg_overlap_mentioned_p (reg, XEXP (temp, 0)))) | |
3538 | { | |
3539 | /* Splice this entry out of the list. */ | |
3540 | if (prev) | |
3541 | XEXP (prev, 1) = XEXP (temp, 1); | |
3542 | else | |
3543 | mem_set_list = XEXP (temp, 1); | |
3544 | } | |
3545 | else | |
3546 | prev = temp; | |
3547 | temp = XEXP (temp, 1); | |
3548 | } | |
3549 | } | |
15e088b2 JL |
3550 | |
3551 | /* If the memory reference had embedded side effects (autoincrement | |
3552 | address modes. Then we may need to kill some entries on the | |
3553 | memory set list. */ | |
3554 | if (insn && GET_CODE (reg) == MEM) | |
3555 | invalidate_mems_from_autoinc (insn); | |
3556 | ||
d7429b6a | 3557 | if (GET_CODE (reg) == MEM && ! side_effects_p (reg) |
3ce7c5a2 JL |
3558 | /* We do not know the size of a BLKmode store, so we do not track |
3559 | them for redundant store elimination. */ | |
3560 | && GET_MODE (reg) != BLKmode | |
d7429b6a RK |
3561 | /* There are no REG_INC notes for SP, so we can't assume we'll see |
3562 | everything that invalidates it. To be safe, don't eliminate any | |
3563 | stores though SP; none of them should be redundant anyway. */ | |
3564 | && ! reg_mentioned_p (stack_pointer_rtx, reg)) | |
db3a887b | 3565 | mem_set_list = gen_rtx_EXPR_LIST (VOIDmode, reg, mem_set_list); |
d7429b6a RK |
3566 | |
3567 | if (GET_CODE (reg) == REG | |
e4b8a413 JW |
3568 | && (regno = REGNO (reg), ! (regno == FRAME_POINTER_REGNUM |
3569 | && (! reload_completed || frame_pointer_needed))) | |
73a187c1 | 3570 | #if FRAME_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM |
e4b8a413 JW |
3571 | && ! (regno == HARD_FRAME_POINTER_REGNUM |
3572 | && (! reload_completed || frame_pointer_needed)) | |
73a187c1 | 3573 | #endif |
d7e4fe8b RS |
3574 | #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM |
3575 | && ! (regno == ARG_POINTER_REGNUM && fixed_regs[regno]) | |
3576 | #endif | |
d7429b6a RK |
3577 | && ! (regno < FIRST_PSEUDO_REGISTER && global_regs[regno])) |
3578 | /* && regno != STACK_POINTER_REGNUM) -- let's try without this. */ | |
3579 | { | |
916b1701 MM |
3580 | int some_needed = REGNO_REG_SET_P (needed, regno); |
3581 | int some_not_needed = ! some_needed; | |
d7429b6a RK |
3582 | |
3583 | /* Mark it as a significant register for this basic block. */ | |
3584 | if (significant) | |
916b1701 | 3585 | SET_REGNO_REG_SET (significant, regno); |
d7429b6a | 3586 | |
38e01259 | 3587 | /* Mark it as dead before this insn. */ |
916b1701 | 3588 | SET_REGNO_REG_SET (dead, regno); |
d7429b6a RK |
3589 | |
3590 | /* A hard reg in a wide mode may really be multiple registers. | |
3591 | If so, mark all of them just like the first. */ | |
3592 | if (regno < FIRST_PSEUDO_REGISTER) | |
3593 | { | |
3594 | int n; | |
3595 | ||
3596 | /* Nothing below is needed for the stack pointer; get out asap. | |
3597 | Eg, log links aren't needed, since combine won't use them. */ | |
3598 | if (regno == STACK_POINTER_REGNUM) | |
3599 | return; | |
3600 | ||
3601 | n = HARD_REGNO_NREGS (regno, GET_MODE (reg)); | |
3602 | while (--n > 0) | |
3603 | { | |
916b1701 MM |
3604 | int regno_n = regno + n; |
3605 | int needed_regno = REGNO_REG_SET_P (needed, regno_n); | |
d7429b6a | 3606 | if (significant) |
916b1701 | 3607 | SET_REGNO_REG_SET (significant, regno_n); |
cb9e8ad1 | 3608 | |
916b1701 MM |
3609 | SET_REGNO_REG_SET (dead, regno_n); |
3610 | some_needed |= needed_regno; | |
3611 | some_not_needed |= ! needed_regno; | |
d7429b6a RK |
3612 | } |
3613 | } | |
3614 | /* Additional data to record if this is the final pass. */ | |
3615 | if (insn) | |
3616 | { | |
3617 | register rtx y = reg_next_use[regno]; | |
3618 | register int blocknum = BLOCK_NUM (insn); | |
3619 | ||
3620 | /* If this is a hard reg, record this function uses the reg. */ | |
3621 | ||
3622 | if (regno < FIRST_PSEUDO_REGISTER) | |
3623 | { | |
3624 | register int i; | |
3625 | int endregno = regno + HARD_REGNO_NREGS (regno, GET_MODE (reg)); | |
3626 | ||
3627 | for (i = regno; i < endregno; i++) | |
3628 | { | |
93514916 JW |
3629 | /* The next use is no longer "next", since a store |
3630 | intervenes. */ | |
3631 | reg_next_use[i] = 0; | |
3632 | ||
d7429b6a | 3633 | regs_ever_live[i] = 1; |
b1f21e0a | 3634 | REG_N_SETS (i)++; |
d7429b6a RK |
3635 | } |
3636 | } | |
3637 | else | |
3638 | { | |
93514916 JW |
3639 | /* The next use is no longer "next", since a store |
3640 | intervenes. */ | |
3641 | reg_next_use[regno] = 0; | |
3642 | ||
d7429b6a RK |
3643 | /* Keep track of which basic blocks each reg appears in. */ |
3644 | ||
b1f21e0a MM |
3645 | if (REG_BASIC_BLOCK (regno) == REG_BLOCK_UNKNOWN) |
3646 | REG_BASIC_BLOCK (regno) = blocknum; | |
3647 | else if (REG_BASIC_BLOCK (regno) != blocknum) | |
3648 | REG_BASIC_BLOCK (regno) = REG_BLOCK_GLOBAL; | |
d7429b6a RK |
3649 | |
3650 | /* Count (weighted) references, stores, etc. This counts a | |
3651 | register twice if it is modified, but that is correct. */ | |
b1f21e0a | 3652 | REG_N_SETS (regno)++; |
d7429b6a | 3653 | |
b1f21e0a | 3654 | REG_N_REFS (regno) += loop_depth; |
d7429b6a RK |
3655 | |
3656 | /* The insns where a reg is live are normally counted | |
3657 | elsewhere, but we want the count to include the insn | |
3658 | where the reg is set, and the normal counting mechanism | |
3659 | would not count it. */ | |
b1f21e0a | 3660 | REG_LIVE_LENGTH (regno)++; |
d7429b6a RK |
3661 | } |
3662 | ||
cb9e8ad1 | 3663 | if (! some_not_needed) |
d7429b6a RK |
3664 | { |
3665 | /* Make a logical link from the next following insn | |
3666 | that uses this register, back to this insn. | |
3667 | The following insns have already been processed. | |
3668 | ||
3669 | We don't build a LOG_LINK for hard registers containing | |
3670 | in ASM_OPERANDs. If these registers get replaced, | |
3671 | we might wind up changing the semantics of the insn, | |
3672 | even if reload can make what appear to be valid assignments | |
3673 | later. */ | |
3674 | if (y && (BLOCK_NUM (y) == blocknum) | |
3675 | && (regno >= FIRST_PSEUDO_REGISTER | |
3676 | || asm_noperands (PATTERN (y)) < 0)) | |
3677 | LOG_LINKS (y) | |
38a448ca | 3678 | = gen_rtx_INSN_LIST (VOIDmode, insn, LOG_LINKS (y)); |
d7429b6a RK |
3679 | } |
3680 | else if (! some_needed) | |
3681 | { | |
3682 | /* Note that dead stores have already been deleted when possible | |
3683 | If we get here, we have found a dead store that cannot | |
3684 | be eliminated (because the same insn does something useful). | |
3685 | Indicate this by marking the reg being set as dying here. */ | |
3686 | REG_NOTES (insn) | |
38a448ca | 3687 | = gen_rtx_EXPR_LIST (REG_UNUSED, reg, REG_NOTES (insn)); |
b1f21e0a | 3688 | REG_N_DEATHS (REGNO (reg))++; |
d7429b6a RK |
3689 | } |
3690 | else | |
3691 | { | |
3692 | /* This is a case where we have a multi-word hard register | |
3693 | and some, but not all, of the words of the register are | |
3694 | needed in subsequent insns. Write REG_UNUSED notes | |
3695 | for those parts that were not needed. This case should | |
3696 | be rare. */ | |
3697 | ||
3698 | int i; | |
3699 | ||
3700 | for (i = HARD_REGNO_NREGS (regno, GET_MODE (reg)) - 1; | |
3701 | i >= 0; i--) | |
916b1701 | 3702 | if (!REGNO_REG_SET_P (needed, regno + i)) |
d7429b6a | 3703 | REG_NOTES (insn) |
38a448ca RH |
3704 | = gen_rtx_EXPR_LIST (REG_UNUSED, |
3705 | gen_rtx_REG (reg_raw_mode[regno + i], | |
3706 | regno + i), | |
3707 | REG_NOTES (insn)); | |
d7429b6a RK |
3708 | } |
3709 | } | |
3710 | } | |
8244fc4f RS |
3711 | else if (GET_CODE (reg) == REG) |
3712 | reg_next_use[regno] = 0; | |
d7429b6a RK |
3713 | |
3714 | /* If this is the last pass and this is a SCRATCH, show it will be dying | |
3715 | here and count it. */ | |
3716 | else if (GET_CODE (reg) == SCRATCH && insn != 0) | |
3717 | { | |
3718 | REG_NOTES (insn) | |
38a448ca | 3719 | = gen_rtx_EXPR_LIST (REG_UNUSED, reg, REG_NOTES (insn)); |
d7429b6a RK |
3720 | } |
3721 | } | |
3722 | \f | |
3723 | #ifdef AUTO_INC_DEC | |
3724 | ||
3725 | /* X is a MEM found in INSN. See if we can convert it into an auto-increment | |
3726 | reference. */ | |
3727 | ||
3728 | static void | |
3729 | find_auto_inc (needed, x, insn) | |
3730 | regset needed; | |
3731 | rtx x; | |
3732 | rtx insn; | |
3733 | { | |
3734 | rtx addr = XEXP (x, 0); | |
e658434c | 3735 | HOST_WIDE_INT offset = 0; |
05ed5d57 | 3736 | rtx set; |
d7429b6a RK |
3737 | |
3738 | /* Here we detect use of an index register which might be good for | |
3739 | postincrement, postdecrement, preincrement, or predecrement. */ | |
3740 | ||
3741 | if (GET_CODE (addr) == PLUS && GET_CODE (XEXP (addr, 1)) == CONST_INT) | |
3742 | offset = INTVAL (XEXP (addr, 1)), addr = XEXP (addr, 0); | |
3743 | ||
3744 | if (GET_CODE (addr) == REG) | |
3745 | { | |
3746 | register rtx y; | |
3747 | register int size = GET_MODE_SIZE (GET_MODE (x)); | |
3748 | rtx use; | |
3749 | rtx incr; | |
3750 | int regno = REGNO (addr); | |
3751 | ||
3752 | /* Is the next use an increment that might make auto-increment? */ | |
05ed5d57 RK |
3753 | if ((incr = reg_next_use[regno]) != 0 |
3754 | && (set = single_set (incr)) != 0 | |
3755 | && GET_CODE (set) == SET | |
d7429b6a RK |
3756 | && BLOCK_NUM (incr) == BLOCK_NUM (insn) |
3757 | /* Can't add side effects to jumps; if reg is spilled and | |
3758 | reloaded, there's no way to store back the altered value. */ | |
3759 | && GET_CODE (insn) != JUMP_INSN | |
05ed5d57 | 3760 | && (y = SET_SRC (set), GET_CODE (y) == PLUS) |
d7429b6a RK |
3761 | && XEXP (y, 0) == addr |
3762 | && GET_CODE (XEXP (y, 1)) == CONST_INT | |
940da324 JL |
3763 | && ((HAVE_POST_INCREMENT |
3764 | && (INTVAL (XEXP (y, 1)) == size && offset == 0)) | |
3765 | || (HAVE_POST_DECREMENT | |
3766 | && (INTVAL (XEXP (y, 1)) == - size && offset == 0)) | |
3767 | || (HAVE_PRE_INCREMENT | |
3768 | && (INTVAL (XEXP (y, 1)) == size && offset == size)) | |
3769 | || (HAVE_PRE_DECREMENT | |
3770 | && (INTVAL (XEXP (y, 1)) == - size && offset == - size))) | |
d7429b6a RK |
3771 | /* Make sure this reg appears only once in this insn. */ |
3772 | && (use = find_use_as_address (PATTERN (insn), addr, offset), | |
3773 | use != 0 && use != (rtx) 1)) | |
3774 | { | |
05ed5d57 | 3775 | rtx q = SET_DEST (set); |
7280c2a4 RK |
3776 | enum rtx_code inc_code = (INTVAL (XEXP (y, 1)) == size |
3777 | ? (offset ? PRE_INC : POST_INC) | |
3778 | : (offset ? PRE_DEC : POST_DEC)); | |
d7429b6a RK |
3779 | |
3780 | if (dead_or_set_p (incr, addr)) | |
7280c2a4 RK |
3781 | { |
3782 | /* This is the simple case. Try to make the auto-inc. If | |
3783 | we can't, we are done. Otherwise, we will do any | |
3784 | needed updates below. */ | |
3785 | if (! validate_change (insn, &XEXP (x, 0), | |
38a448ca | 3786 | gen_rtx_fmt_e (inc_code, Pmode, addr), |
7280c2a4 RK |
3787 | 0)) |
3788 | return; | |
3789 | } | |
5175ad37 DE |
3790 | else if (GET_CODE (q) == REG |
3791 | /* PREV_INSN used here to check the semi-open interval | |
3792 | [insn,incr). */ | |
b24884cd JL |
3793 | && ! reg_used_between_p (q, PREV_INSN (insn), incr) |
3794 | /* We must also check for sets of q as q may be | |
3795 | a call clobbered hard register and there may | |
3796 | be a call between PREV_INSN (insn) and incr. */ | |
3797 | && ! reg_set_between_p (q, PREV_INSN (insn), incr)) | |
d7429b6a | 3798 | { |
5175ad37 | 3799 | /* We have *p followed sometime later by q = p+size. |
d7429b6a | 3800 | Both p and q must be live afterward, |
9ec36da5 | 3801 | and q is not used between INSN and its assignment. |
d7429b6a RK |
3802 | Change it to q = p, ...*q..., q = q+size. |
3803 | Then fall into the usual case. */ | |
3804 | rtx insns, temp; | |
e881bb1b | 3805 | basic_block bb; |
d7429b6a RK |
3806 | |
3807 | start_sequence (); | |
3808 | emit_move_insn (q, addr); | |
3809 | insns = get_insns (); | |
3810 | end_sequence (); | |
3811 | ||
e881bb1b | 3812 | bb = BLOCK_FOR_INSN (insn); |
d7429b6a | 3813 | for (temp = insns; temp; temp = NEXT_INSN (temp)) |
e881bb1b | 3814 | set_block_for_insn (temp, bb); |
d7429b6a | 3815 | |
7280c2a4 RK |
3816 | /* If we can't make the auto-inc, or can't make the |
3817 | replacement into Y, exit. There's no point in making | |
3818 | the change below if we can't do the auto-inc and doing | |
3819 | so is not correct in the pre-inc case. */ | |
3820 | ||
3821 | validate_change (insn, &XEXP (x, 0), | |
38a448ca | 3822 | gen_rtx_fmt_e (inc_code, Pmode, q), |
7280c2a4 RK |
3823 | 1); |
3824 | validate_change (incr, &XEXP (y, 0), q, 1); | |
3825 | if (! apply_change_group ()) | |
3826 | return; | |
3827 | ||
3828 | /* We now know we'll be doing this change, so emit the | |
3829 | new insn(s) and do the updates. */ | |
d7429b6a | 3830 | emit_insns_before (insns, insn); |
e8b641a1 | 3831 | |
e881bb1b RH |
3832 | if (BLOCK_FOR_INSN (insn)->head == insn) |
3833 | BLOCK_FOR_INSN (insn)->head = insns; | |
e8b641a1 | 3834 | |
d7429b6a RK |
3835 | /* INCR will become a NOTE and INSN won't contain a |
3836 | use of ADDR. If a use of ADDR was just placed in | |
3837 | the insn before INSN, make that the next use. | |
3838 | Otherwise, invalidate it. */ | |
3839 | if (GET_CODE (PREV_INSN (insn)) == INSN | |
3840 | && GET_CODE (PATTERN (PREV_INSN (insn))) == SET | |
3841 | && SET_SRC (PATTERN (PREV_INSN (insn))) == addr) | |
3842 | reg_next_use[regno] = PREV_INSN (insn); | |
3843 | else | |
3844 | reg_next_use[regno] = 0; | |
3845 | ||
3846 | addr = q; | |
3847 | regno = REGNO (q); | |
d7429b6a RK |
3848 | |
3849 | /* REGNO is now used in INCR which is below INSN, but | |
3850 | it previously wasn't live here. If we don't mark | |
3851 | it as needed, we'll put a REG_DEAD note for it | |
3852 | on this insn, which is incorrect. */ | |
916b1701 | 3853 | SET_REGNO_REG_SET (needed, regno); |
d7429b6a RK |
3854 | |
3855 | /* If there are any calls between INSN and INCR, show | |
3856 | that REGNO now crosses them. */ | |
3857 | for (temp = insn; temp != incr; temp = NEXT_INSN (temp)) | |
3858 | if (GET_CODE (temp) == CALL_INSN) | |
b1f21e0a | 3859 | REG_N_CALLS_CROSSED (regno)++; |
d7429b6a | 3860 | } |
02df8aba RK |
3861 | else |
3862 | return; | |
d7429b6a | 3863 | |
7280c2a4 RK |
3864 | /* If we haven't returned, it means we were able to make the |
3865 | auto-inc, so update the status. First, record that this insn | |
3866 | has an implicit side effect. */ | |
3867 | ||
3868 | REG_NOTES (insn) | |
38a448ca | 3869 | = gen_rtx_EXPR_LIST (REG_INC, addr, REG_NOTES (insn)); |
7280c2a4 RK |
3870 | |
3871 | /* Modify the old increment-insn to simply copy | |
3872 | the already-incremented value of our register. */ | |
3873 | if (! validate_change (incr, &SET_SRC (set), addr, 0)) | |
3874 | abort (); | |
3875 | ||
3876 | /* If that makes it a no-op (copying the register into itself) delete | |
3877 | it so it won't appear to be a "use" and a "set" of this | |
3878 | register. */ | |
3879 | if (SET_DEST (set) == addr) | |
d7429b6a | 3880 | { |
7280c2a4 RK |
3881 | PUT_CODE (incr, NOTE); |
3882 | NOTE_LINE_NUMBER (incr) = NOTE_INSN_DELETED; | |
3883 | NOTE_SOURCE_FILE (incr) = 0; | |
3884 | } | |
d7429b6a | 3885 | |
7280c2a4 RK |
3886 | if (regno >= FIRST_PSEUDO_REGISTER) |
3887 | { | |
3888 | /* Count an extra reference to the reg. When a reg is | |
3889 | incremented, spilling it is worse, so we want to make | |
3890 | that less likely. */ | |
b1f21e0a | 3891 | REG_N_REFS (regno) += loop_depth; |
7280c2a4 RK |
3892 | |
3893 | /* Count the increment as a setting of the register, | |
3894 | even though it isn't a SET in rtl. */ | |
b1f21e0a | 3895 | REG_N_SETS (regno)++; |
d7429b6a RK |
3896 | } |
3897 | } | |
3898 | } | |
3899 | } | |
3900 | #endif /* AUTO_INC_DEC */ | |
3901 | \f | |
3902 | /* Scan expression X and store a 1-bit in LIVE for each reg it uses. | |
3903 | This is done assuming the registers needed from X | |
3904 | are those that have 1-bits in NEEDED. | |
3905 | ||
3906 | On the final pass, FINAL is 1. This means try for autoincrement | |
3907 | and count the uses and deaths of each pseudo-reg. | |
3908 | ||
3909 | INSN is the containing instruction. If INSN is dead, this function is not | |
3910 | called. */ | |
3911 | ||
3912 | static void | |
3913 | mark_used_regs (needed, live, x, final, insn) | |
3914 | regset needed; | |
3915 | regset live; | |
3916 | rtx x; | |
d7429b6a | 3917 | int final; |
e658434c | 3918 | rtx insn; |
d7429b6a RK |
3919 | { |
3920 | register RTX_CODE code; | |
3921 | register int regno; | |
3922 | int i; | |
3923 | ||
3924 | retry: | |
3925 | code = GET_CODE (x); | |
3926 | switch (code) | |
3927 | { | |
3928 | case LABEL_REF: | |
3929 | case SYMBOL_REF: | |
3930 | case CONST_INT: | |
3931 | case CONST: | |
3932 | case CONST_DOUBLE: | |
3933 | case PC: | |
d7429b6a RK |
3934 | case ADDR_VEC: |
3935 | case ADDR_DIFF_VEC: | |
d7429b6a RK |
3936 | return; |
3937 | ||
3938 | #ifdef HAVE_cc0 | |
3939 | case CC0: | |
3940 | cc0_live = 1; | |
3941 | return; | |
3942 | #endif | |
3943 | ||
2f1553a4 RK |
3944 | case CLOBBER: |
3945 | /* If we are clobbering a MEM, mark any registers inside the address | |
3946 | as being used. */ | |
3947 | if (GET_CODE (XEXP (x, 0)) == MEM) | |
3948 | mark_used_regs (needed, live, XEXP (XEXP (x, 0), 0), final, insn); | |
3949 | return; | |
3950 | ||
d7429b6a | 3951 | case MEM: |
7eb136d6 MM |
3952 | /* Invalidate the data for the last MEM stored, but only if MEM is |
3953 | something that can be stored into. */ | |
3954 | if (GET_CODE (XEXP (x, 0)) == SYMBOL_REF | |
3955 | && CONSTANT_POOL_ADDRESS_P (XEXP (x, 0))) | |
db3a887b | 3956 | ; /* needn't clear the memory set list */ |
7eb136d6 | 3957 | else |
db3a887b CB |
3958 | { |
3959 | rtx temp = mem_set_list; | |
3960 | rtx prev = NULL_RTX; | |
3961 | ||
3962 | while (temp) | |
3963 | { | |
063cd522 | 3964 | if (anti_dependence (XEXP (temp, 0), x)) |
db3a887b CB |
3965 | { |
3966 | /* Splice temp out of the list. */ | |
3967 | if (prev) | |
3968 | XEXP (prev, 1) = XEXP (temp, 1); | |
3969 | else | |
3970 | mem_set_list = XEXP (temp, 1); | |
3971 | } | |
3972 | else | |
3973 | prev = temp; | |
3974 | temp = XEXP (temp, 1); | |
3975 | } | |
3976 | } | |
d7429b6a | 3977 | |
15e088b2 JL |
3978 | /* If the memory reference had embedded side effects (autoincrement |
3979 | address modes. Then we may need to kill some entries on the | |
3980 | memory set list. */ | |
3981 | if (insn) | |
3982 | invalidate_mems_from_autoinc (insn); | |
3983 | ||
d7429b6a RK |
3984 | #ifdef AUTO_INC_DEC |
3985 | if (final) | |
3986 | find_auto_inc (needed, x, insn); | |
3987 | #endif | |
3988 | break; | |
3989 | ||
80f8f04a RK |
3990 | case SUBREG: |
3991 | if (GET_CODE (SUBREG_REG (x)) == REG | |
3992 | && REGNO (SUBREG_REG (x)) >= FIRST_PSEUDO_REGISTER | |
3993 | && (GET_MODE_SIZE (GET_MODE (x)) | |
88285acf | 3994 | != GET_MODE_SIZE (GET_MODE (SUBREG_REG (x))))) |
b1f21e0a | 3995 | REG_CHANGES_SIZE (REGNO (SUBREG_REG (x))) = 1; |
80f8f04a RK |
3996 | |
3997 | /* While we're here, optimize this case. */ | |
3998 | x = SUBREG_REG (x); | |
3999 | ||
e100a3bb | 4000 | /* In case the SUBREG is not of a register, don't optimize */ |
ce79abf3 | 4001 | if (GET_CODE (x) != REG) |
e100a3bb MM |
4002 | { |
4003 | mark_used_regs (needed, live, x, final, insn); | |
4004 | return; | |
4005 | } | |
ce79abf3 | 4006 | |
0f41302f | 4007 | /* ... fall through ... */ |
80f8f04a | 4008 | |
d7429b6a RK |
4009 | case REG: |
4010 | /* See a register other than being set | |
4011 | => mark it as needed. */ | |
4012 | ||
4013 | regno = REGNO (x); | |
4014 | { | |
67f0e213 RK |
4015 | int some_needed = REGNO_REG_SET_P (needed, regno); |
4016 | int some_not_needed = ! some_needed; | |
d7429b6a | 4017 | |
916b1701 | 4018 | SET_REGNO_REG_SET (live, regno); |
cb9e8ad1 | 4019 | |
d7429b6a RK |
4020 | /* A hard reg in a wide mode may really be multiple registers. |
4021 | If so, mark all of them just like the first. */ | |
4022 | if (regno < FIRST_PSEUDO_REGISTER) | |
4023 | { | |
4024 | int n; | |
4025 | ||
d7e4fe8b | 4026 | /* For stack ptr or fixed arg pointer, |
d7429b6a RK |
4027 | nothing below can be necessary, so waste no more time. */ |
4028 | if (regno == STACK_POINTER_REGNUM | |
73a187c1 | 4029 | #if FRAME_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM |
e4b8a413 JW |
4030 | || (regno == HARD_FRAME_POINTER_REGNUM |
4031 | && (! reload_completed || frame_pointer_needed)) | |
73a187c1 | 4032 | #endif |
d7e4fe8b RS |
4033 | #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM |
4034 | || (regno == ARG_POINTER_REGNUM && fixed_regs[regno]) | |
4035 | #endif | |
e4b8a413 JW |
4036 | || (regno == FRAME_POINTER_REGNUM |
4037 | && (! reload_completed || frame_pointer_needed))) | |
d7429b6a RK |
4038 | { |
4039 | /* If this is a register we are going to try to eliminate, | |
4040 | don't mark it live here. If we are successful in | |
4041 | eliminating it, it need not be live unless it is used for | |
4042 | pseudos, in which case it will have been set live when | |
4043 | it was allocated to the pseudos. If the register will not | |
4044 | be eliminated, reload will set it live at that point. */ | |
4045 | ||
4046 | if (! TEST_HARD_REG_BIT (elim_reg_set, regno)) | |
4047 | regs_ever_live[regno] = 1; | |
4048 | return; | |
4049 | } | |
4050 | /* No death notes for global register variables; | |
4051 | their values are live after this function exits. */ | |
4052 | if (global_regs[regno]) | |
d8c8b8e3 RS |
4053 | { |
4054 | if (final) | |
4055 | reg_next_use[regno] = insn; | |
4056 | return; | |
4057 | } | |
d7429b6a RK |
4058 | |
4059 | n = HARD_REGNO_NREGS (regno, GET_MODE (x)); | |
4060 | while (--n > 0) | |
4061 | { | |
916b1701 MM |
4062 | int regno_n = regno + n; |
4063 | int needed_regno = REGNO_REG_SET_P (needed, regno_n); | |
cb9e8ad1 | 4064 | |
916b1701 MM |
4065 | SET_REGNO_REG_SET (live, regno_n); |
4066 | some_needed |= needed_regno; | |
931c6c7a | 4067 | some_not_needed |= ! needed_regno; |
d7429b6a RK |
4068 | } |
4069 | } | |
4070 | if (final) | |
4071 | { | |
4072 | /* Record where each reg is used, so when the reg | |
4073 | is set we know the next insn that uses it. */ | |
4074 | ||
4075 | reg_next_use[regno] = insn; | |
4076 | ||
4077 | if (regno < FIRST_PSEUDO_REGISTER) | |
4078 | { | |
4079 | /* If a hard reg is being used, | |
4080 | record that this function does use it. */ | |
4081 | ||
4082 | i = HARD_REGNO_NREGS (regno, GET_MODE (x)); | |
4083 | if (i == 0) | |
4084 | i = 1; | |
4085 | do | |
4086 | regs_ever_live[regno + --i] = 1; | |
4087 | while (i > 0); | |
4088 | } | |
4089 | else | |
4090 | { | |
4091 | /* Keep track of which basic block each reg appears in. */ | |
4092 | ||
4093 | register int blocknum = BLOCK_NUM (insn); | |
4094 | ||
b1f21e0a MM |
4095 | if (REG_BASIC_BLOCK (regno) == REG_BLOCK_UNKNOWN) |
4096 | REG_BASIC_BLOCK (regno) = blocknum; | |
4097 | else if (REG_BASIC_BLOCK (regno) != blocknum) | |
4098 | REG_BASIC_BLOCK (regno) = REG_BLOCK_GLOBAL; | |
d7429b6a RK |
4099 | |
4100 | /* Count (weighted) number of uses of each reg. */ | |
4101 | ||
b1f21e0a | 4102 | REG_N_REFS (regno) += loop_depth; |
d7429b6a RK |
4103 | } |
4104 | ||
4105 | /* Record and count the insns in which a reg dies. | |
4106 | If it is used in this insn and was dead below the insn | |
4107 | then it dies in this insn. If it was set in this insn, | |
4108 | we do not make a REG_DEAD note; likewise if we already | |
4109 | made such a note. */ | |
4110 | ||
cb9e8ad1 | 4111 | if (some_not_needed |
d7429b6a RK |
4112 | && ! dead_or_set_p (insn, x) |
4113 | #if 0 | |
4114 | && (regno >= FIRST_PSEUDO_REGISTER || ! fixed_regs[regno]) | |
4115 | #endif | |
4116 | ) | |
4117 | { | |
ab28041e JW |
4118 | /* Check for the case where the register dying partially |
4119 | overlaps the register set by this insn. */ | |
4120 | if (regno < FIRST_PSEUDO_REGISTER | |
4121 | && HARD_REGNO_NREGS (regno, GET_MODE (x)) > 1) | |
4122 | { | |
480eac3b | 4123 | int n = HARD_REGNO_NREGS (regno, GET_MODE (x)); |
ab28041e JW |
4124 | while (--n >= 0) |
4125 | some_needed |= dead_or_set_regno_p (insn, regno + n); | |
4126 | } | |
4127 | ||
d7429b6a RK |
4128 | /* If none of the words in X is needed, make a REG_DEAD |
4129 | note. Otherwise, we must make partial REG_DEAD notes. */ | |
4130 | if (! some_needed) | |
4131 | { | |
4132 | REG_NOTES (insn) | |
38a448ca | 4133 | = gen_rtx_EXPR_LIST (REG_DEAD, x, REG_NOTES (insn)); |
b1f21e0a | 4134 | REG_N_DEATHS (regno)++; |
d7429b6a RK |
4135 | } |
4136 | else | |
4137 | { | |
4138 | int i; | |
4139 | ||
4140 | /* Don't make a REG_DEAD note for a part of a register | |
4141 | that is set in the insn. */ | |
4142 | ||
4143 | for (i = HARD_REGNO_NREGS (regno, GET_MODE (x)) - 1; | |
4144 | i >= 0; i--) | |
916b1701 | 4145 | if (!REGNO_REG_SET_P (needed, regno + i) |
d7429b6a RK |
4146 | && ! dead_or_set_regno_p (insn, regno + i)) |
4147 | REG_NOTES (insn) | |
38a448ca RH |
4148 | = gen_rtx_EXPR_LIST (REG_DEAD, |
4149 | gen_rtx_REG (reg_raw_mode[regno + i], | |
4150 | regno + i), | |
4151 | REG_NOTES (insn)); | |
d7429b6a RK |
4152 | } |
4153 | } | |
4154 | } | |
4155 | } | |
4156 | return; | |
4157 | ||
4158 | case SET: | |
4159 | { | |
4160 | register rtx testreg = SET_DEST (x); | |
4161 | int mark_dest = 0; | |
4162 | ||
4163 | /* If storing into MEM, don't show it as being used. But do | |
4164 | show the address as being used. */ | |
4165 | if (GET_CODE (testreg) == MEM) | |
4166 | { | |
4167 | #ifdef AUTO_INC_DEC | |
4168 | if (final) | |
4169 | find_auto_inc (needed, testreg, insn); | |
4170 | #endif | |
4171 | mark_used_regs (needed, live, XEXP (testreg, 0), final, insn); | |
4172 | mark_used_regs (needed, live, SET_SRC (x), final, insn); | |
4173 | return; | |
4174 | } | |
4175 | ||
4176 | /* Storing in STRICT_LOW_PART is like storing in a reg | |
4177 | in that this SET might be dead, so ignore it in TESTREG. | |
4178 | but in some other ways it is like using the reg. | |
4179 | ||
4180 | Storing in a SUBREG or a bit field is like storing the entire | |
4181 | register in that if the register's value is not used | |
4182 | then this SET is not needed. */ | |
4183 | while (GET_CODE (testreg) == STRICT_LOW_PART | |
4184 | || GET_CODE (testreg) == ZERO_EXTRACT | |
4185 | || GET_CODE (testreg) == SIGN_EXTRACT | |
4186 | || GET_CODE (testreg) == SUBREG) | |
4187 | { | |
88285acf RK |
4188 | if (GET_CODE (testreg) == SUBREG |
4189 | && GET_CODE (SUBREG_REG (testreg)) == REG | |
4190 | && REGNO (SUBREG_REG (testreg)) >= FIRST_PSEUDO_REGISTER | |
4191 | && (GET_MODE_SIZE (GET_MODE (testreg)) | |
4192 | != GET_MODE_SIZE (GET_MODE (SUBREG_REG (testreg))))) | |
b1f21e0a | 4193 | REG_CHANGES_SIZE (REGNO (SUBREG_REG (testreg))) = 1; |
88285acf | 4194 | |
d7429b6a RK |
4195 | /* Modifying a single register in an alternate mode |
4196 | does not use any of the old value. But these other | |
4197 | ways of storing in a register do use the old value. */ | |
4198 | if (GET_CODE (testreg) == SUBREG | |
4199 | && !(REG_SIZE (SUBREG_REG (testreg)) > REG_SIZE (testreg))) | |
4200 | ; | |
4201 | else | |
4202 | mark_dest = 1; | |
4203 | ||
4204 | testreg = XEXP (testreg, 0); | |
4205 | } | |
4206 | ||
4207 | /* If this is a store into a register, | |
4208 | recursively scan the value being stored. */ | |
4209 | ||
86465af7 DM |
4210 | if ((GET_CODE (testreg) == PARALLEL |
4211 | && GET_MODE (testreg) == BLKmode) | |
4212 | || (GET_CODE (testreg) == REG | |
e4b8a413 JW |
4213 | && (regno = REGNO (testreg), ! (regno == FRAME_POINTER_REGNUM |
4214 | && (! reload_completed || frame_pointer_needed))) | |
73a187c1 | 4215 | #if FRAME_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM |
e4b8a413 JW |
4216 | && ! (regno == HARD_FRAME_POINTER_REGNUM |
4217 | && (! reload_completed || frame_pointer_needed)) | |
73a187c1 | 4218 | #endif |
d7e4fe8b | 4219 | #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM |
86465af7 | 4220 | && ! (regno == ARG_POINTER_REGNUM && fixed_regs[regno]) |
d7e4fe8b | 4221 | #endif |
86465af7 | 4222 | )) |
d8c8b8e3 RS |
4223 | /* We used to exclude global_regs here, but that seems wrong. |
4224 | Storing in them is like storing in mem. */ | |
d7429b6a RK |
4225 | { |
4226 | mark_used_regs (needed, live, SET_SRC (x), final, insn); | |
4227 | if (mark_dest) | |
4228 | mark_used_regs (needed, live, SET_DEST (x), final, insn); | |
4229 | return; | |
4230 | } | |
4231 | } | |
4232 | break; | |
4233 | ||
4234 | case RETURN: | |
4235 | /* If exiting needs the right stack value, consider this insn as | |
4236 | using the stack pointer. In any event, consider it as using | |
632c9d9e | 4237 | all global registers and all registers used by return. */ |
d7429b6a | 4238 | if (! EXIT_IGNORE_STACK |
0200b5ed JL |
4239 | || (! FRAME_POINTER_REQUIRED |
4240 | && ! current_function_calls_alloca | |
bfc5000a JL |
4241 | && flag_omit_frame_pointer) |
4242 | || current_function_sp_is_unchanging) | |
916b1701 | 4243 | SET_REGNO_REG_SET (live, STACK_POINTER_REGNUM); |
d7429b6a RK |
4244 | |
4245 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
632c9d9e MS |
4246 | if (global_regs[i] |
4247 | #ifdef EPILOGUE_USES | |
4248 | || EPILOGUE_USES (i) | |
4249 | #endif | |
4250 | ) | |
916b1701 | 4251 | SET_REGNO_REG_SET (live, i); |
d7429b6a | 4252 | break; |
e9a25f70 | 4253 | |
40b5a77c JL |
4254 | case ASM_OPERANDS: |
4255 | case UNSPEC_VOLATILE: | |
4256 | case TRAP_IF: | |
4257 | case ASM_INPUT: | |
4258 | { | |
4259 | /* Traditional and volatile asm instructions must be considered to use | |
4260 | and clobber all hard registers, all pseudo-registers and all of | |
4261 | memory. So must TRAP_IF and UNSPEC_VOLATILE operations. | |
4262 | ||
4263 | Consider for instance a volatile asm that changes the fpu rounding | |
4264 | mode. An insn should not be moved across this even if it only uses | |
4265 | pseudo-regs because it might give an incorrectly rounded result. | |
4266 | ||
4267 | ?!? Unfortunately, marking all hard registers as live causes massive | |
4268 | problems for the register allocator and marking all pseudos as live | |
4269 | creates mountains of uninitialized variable warnings. | |
4270 | ||
4271 | So for now, just clear the memory set list and mark any regs | |
4272 | we can find in ASM_OPERANDS as used. */ | |
4273 | if (code != ASM_OPERANDS || MEM_VOLATILE_P (x)) | |
4274 | mem_set_list = NULL_RTX; | |
4275 | ||
4276 | /* For all ASM_OPERANDS, we must traverse the vector of input operands. | |
4277 | We can not just fall through here since then we would be confused | |
4278 | by the ASM_INPUT rtx inside ASM_OPERANDS, which do not indicate | |
4279 | traditional asms unlike their normal usage. */ | |
4280 | if (code == ASM_OPERANDS) | |
4281 | { | |
4282 | int j; | |
4283 | ||
4284 | for (j = 0; j < ASM_OPERANDS_INPUT_LENGTH (x); j++) | |
4285 | mark_used_regs (needed, live, ASM_OPERANDS_INPUT (x, j), | |
4286 | final, insn); | |
4287 | } | |
4288 | break; | |
4289 | } | |
4290 | ||
4291 | ||
e9a25f70 JL |
4292 | default: |
4293 | break; | |
d7429b6a RK |
4294 | } |
4295 | ||
4296 | /* Recursively scan the operands of this expression. */ | |
4297 | ||
4298 | { | |
6f7d635c | 4299 | register const char *fmt = GET_RTX_FORMAT (code); |
d7429b6a RK |
4300 | register int i; |
4301 | ||
4302 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
4303 | { | |
4304 | if (fmt[i] == 'e') | |
4305 | { | |
4306 | /* Tail recursive case: save a function call level. */ | |
4307 | if (i == 0) | |
4308 | { | |
4309 | x = XEXP (x, 0); | |
4310 | goto retry; | |
4311 | } | |
4312 | mark_used_regs (needed, live, XEXP (x, i), final, insn); | |
4313 | } | |
4314 | else if (fmt[i] == 'E') | |
4315 | { | |
4316 | register int j; | |
4317 | for (j = 0; j < XVECLEN (x, i); j++) | |
4318 | mark_used_regs (needed, live, XVECEXP (x, i, j), final, insn); | |
4319 | } | |
4320 | } | |
4321 | } | |
4322 | } | |
4323 | \f | |
4324 | #ifdef AUTO_INC_DEC | |
4325 | ||
4326 | static int | |
4327 | try_pre_increment_1 (insn) | |
4328 | rtx insn; | |
4329 | { | |
4330 | /* Find the next use of this reg. If in same basic block, | |
4331 | make it do pre-increment or pre-decrement if appropriate. */ | |
956d6950 | 4332 | rtx x = single_set (insn); |
5f4f0e22 | 4333 | HOST_WIDE_INT amount = ((GET_CODE (SET_SRC (x)) == PLUS ? 1 : -1) |
d7429b6a RK |
4334 | * INTVAL (XEXP (SET_SRC (x), 1))); |
4335 | int regno = REGNO (SET_DEST (x)); | |
4336 | rtx y = reg_next_use[regno]; | |
4337 | if (y != 0 | |
4338 | && BLOCK_NUM (y) == BLOCK_NUM (insn) | |
89861c38 | 4339 | /* Don't do this if the reg dies, or gets set in y; a standard addressing |
0f41302f | 4340 | mode would be better. */ |
89861c38 | 4341 | && ! dead_or_set_p (y, SET_DEST (x)) |
956d6950 | 4342 | && try_pre_increment (y, SET_DEST (x), amount)) |
d7429b6a RK |
4343 | { |
4344 | /* We have found a suitable auto-increment | |
4345 | and already changed insn Y to do it. | |
4346 | So flush this increment-instruction. */ | |
4347 | PUT_CODE (insn, NOTE); | |
4348 | NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED; | |
4349 | NOTE_SOURCE_FILE (insn) = 0; | |
4350 | /* Count a reference to this reg for the increment | |
4351 | insn we are deleting. When a reg is incremented. | |
4352 | spilling it is worse, so we want to make that | |
4353 | less likely. */ | |
4354 | if (regno >= FIRST_PSEUDO_REGISTER) | |
4355 | { | |
b1f21e0a MM |
4356 | REG_N_REFS (regno) += loop_depth; |
4357 | REG_N_SETS (regno)++; | |
d7429b6a RK |
4358 | } |
4359 | return 1; | |
4360 | } | |
4361 | return 0; | |
4362 | } | |
4363 | ||
4364 | /* Try to change INSN so that it does pre-increment or pre-decrement | |
4365 | addressing on register REG in order to add AMOUNT to REG. | |
4366 | AMOUNT is negative for pre-decrement. | |
4367 | Returns 1 if the change could be made. | |
4368 | This checks all about the validity of the result of modifying INSN. */ | |
4369 | ||
4370 | static int | |
4371 | try_pre_increment (insn, reg, amount) | |
4372 | rtx insn, reg; | |
5f4f0e22 | 4373 | HOST_WIDE_INT amount; |
d7429b6a RK |
4374 | { |
4375 | register rtx use; | |
4376 | ||
4377 | /* Nonzero if we can try to make a pre-increment or pre-decrement. | |
4378 | For example, addl $4,r1; movl (r1),... can become movl +(r1),... */ | |
4379 | int pre_ok = 0; | |
4380 | /* Nonzero if we can try to make a post-increment or post-decrement. | |
4381 | For example, addl $4,r1; movl -4(r1),... can become movl (r1)+,... | |
4382 | It is possible for both PRE_OK and POST_OK to be nonzero if the machine | |
4383 | supports both pre-inc and post-inc, or both pre-dec and post-dec. */ | |
4384 | int post_ok = 0; | |
4385 | ||
4386 | /* Nonzero if the opportunity actually requires post-inc or post-dec. */ | |
4387 | int do_post = 0; | |
4388 | ||
4389 | /* From the sign of increment, see which possibilities are conceivable | |
4390 | on this target machine. */ | |
940da324 | 4391 | if (HAVE_PRE_INCREMENT && amount > 0) |
d7429b6a | 4392 | pre_ok = 1; |
940da324 | 4393 | if (HAVE_POST_INCREMENT && amount > 0) |
d7429b6a | 4394 | post_ok = 1; |
d7429b6a | 4395 | |
940da324 | 4396 | if (HAVE_PRE_DECREMENT && amount < 0) |
d7429b6a | 4397 | pre_ok = 1; |
940da324 | 4398 | if (HAVE_POST_DECREMENT && amount < 0) |
d7429b6a | 4399 | post_ok = 1; |
d7429b6a RK |
4400 | |
4401 | if (! (pre_ok || post_ok)) | |
4402 | return 0; | |
4403 | ||
4404 | /* It is not safe to add a side effect to a jump insn | |
4405 | because if the incremented register is spilled and must be reloaded | |
4406 | there would be no way to store the incremented value back in memory. */ | |
4407 | ||
4408 | if (GET_CODE (insn) == JUMP_INSN) | |
4409 | return 0; | |
4410 | ||
4411 | use = 0; | |
4412 | if (pre_ok) | |
4413 | use = find_use_as_address (PATTERN (insn), reg, 0); | |
4414 | if (post_ok && (use == 0 || use == (rtx) 1)) | |
4415 | { | |
4416 | use = find_use_as_address (PATTERN (insn), reg, -amount); | |
4417 | do_post = 1; | |
4418 | } | |
4419 | ||
4420 | if (use == 0 || use == (rtx) 1) | |
4421 | return 0; | |
4422 | ||
4423 | if (GET_MODE_SIZE (GET_MODE (use)) != (amount > 0 ? amount : - amount)) | |
4424 | return 0; | |
4425 | ||
a0fbc3a9 SC |
4426 | /* See if this combination of instruction and addressing mode exists. */ |
4427 | if (! validate_change (insn, &XEXP (use, 0), | |
38a448ca RH |
4428 | gen_rtx_fmt_e (amount > 0 |
4429 | ? (do_post ? POST_INC : PRE_INC) | |
4430 | : (do_post ? POST_DEC : PRE_DEC), | |
4431 | Pmode, reg), 0)) | |
a0fbc3a9 | 4432 | return 0; |
d7429b6a RK |
4433 | |
4434 | /* Record that this insn now has an implicit side effect on X. */ | |
38a448ca | 4435 | REG_NOTES (insn) = gen_rtx_EXPR_LIST (REG_INC, reg, REG_NOTES (insn)); |
d7429b6a RK |
4436 | return 1; |
4437 | } | |
4438 | ||
4439 | #endif /* AUTO_INC_DEC */ | |
4440 | \f | |
4441 | /* Find the place in the rtx X where REG is used as a memory address. | |
4442 | Return the MEM rtx that so uses it. | |
4443 | If PLUSCONST is nonzero, search instead for a memory address equivalent to | |
4444 | (plus REG (const_int PLUSCONST)). | |
4445 | ||
4446 | If such an address does not appear, return 0. | |
4447 | If REG appears more than once, or is used other than in such an address, | |
4448 | return (rtx)1. */ | |
4449 | ||
8c660648 | 4450 | rtx |
d7429b6a RK |
4451 | find_use_as_address (x, reg, plusconst) |
4452 | register rtx x; | |
4453 | rtx reg; | |
e658434c | 4454 | HOST_WIDE_INT plusconst; |
d7429b6a RK |
4455 | { |
4456 | enum rtx_code code = GET_CODE (x); | |
6f7d635c | 4457 | const char *fmt = GET_RTX_FORMAT (code); |
d7429b6a RK |
4458 | register int i; |
4459 | register rtx value = 0; | |
4460 | register rtx tem; | |
4461 | ||
4462 | if (code == MEM && XEXP (x, 0) == reg && plusconst == 0) | |
4463 | return x; | |
4464 | ||
4465 | if (code == MEM && GET_CODE (XEXP (x, 0)) == PLUS | |
4466 | && XEXP (XEXP (x, 0), 0) == reg | |
4467 | && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT | |
4468 | && INTVAL (XEXP (XEXP (x, 0), 1)) == plusconst) | |
4469 | return x; | |
4470 | ||
4471 | if (code == SIGN_EXTRACT || code == ZERO_EXTRACT) | |
4472 | { | |
4473 | /* If REG occurs inside a MEM used in a bit-field reference, | |
4474 | that is unacceptable. */ | |
4475 | if (find_use_as_address (XEXP (x, 0), reg, 0) != 0) | |
6fa5c106 | 4476 | return (rtx) (HOST_WIDE_INT) 1; |
d7429b6a RK |
4477 | } |
4478 | ||
4479 | if (x == reg) | |
6fa5c106 | 4480 | return (rtx) (HOST_WIDE_INT) 1; |
d7429b6a RK |
4481 | |
4482 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
4483 | { | |
4484 | if (fmt[i] == 'e') | |
4485 | { | |
4486 | tem = find_use_as_address (XEXP (x, i), reg, plusconst); | |
4487 | if (value == 0) | |
4488 | value = tem; | |
4489 | else if (tem != 0) | |
6fa5c106 | 4490 | return (rtx) (HOST_WIDE_INT) 1; |
d7429b6a RK |
4491 | } |
4492 | if (fmt[i] == 'E') | |
4493 | { | |
4494 | register int j; | |
4495 | for (j = XVECLEN (x, i) - 1; j >= 0; j--) | |
4496 | { | |
4497 | tem = find_use_as_address (XVECEXP (x, i, j), reg, plusconst); | |
4498 | if (value == 0) | |
4499 | value = tem; | |
4500 | else if (tem != 0) | |
6fa5c106 | 4501 | return (rtx) (HOST_WIDE_INT) 1; |
d7429b6a RK |
4502 | } |
4503 | } | |
4504 | } | |
4505 | ||
4506 | return value; | |
4507 | } | |
4508 | \f | |
4509 | /* Write information about registers and basic blocks into FILE. | |
4510 | This is part of making a debugging dump. */ | |
4511 | ||
4512 | void | |
4513 | dump_flow_info (file) | |
4514 | FILE *file; | |
4515 | { | |
4516 | register int i; | |
6f7d635c | 4517 | static const char * const reg_class_names[] = REG_CLASS_NAMES; |
d7429b6a RK |
4518 | |
4519 | fprintf (file, "%d registers.\n", max_regno); | |
d7429b6a | 4520 | for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++) |
b1f21e0a | 4521 | if (REG_N_REFS (i)) |
d7429b6a | 4522 | { |
e4600702 | 4523 | enum reg_class class, altclass; |
d7429b6a | 4524 | fprintf (file, "\nRegister %d used %d times across %d insns", |
b1f21e0a MM |
4525 | i, REG_N_REFS (i), REG_LIVE_LENGTH (i)); |
4526 | if (REG_BASIC_BLOCK (i) >= 0) | |
4527 | fprintf (file, " in block %d", REG_BASIC_BLOCK (i)); | |
6fc4610b MM |
4528 | if (REG_N_SETS (i)) |
4529 | fprintf (file, "; set %d time%s", REG_N_SETS (i), | |
4530 | (REG_N_SETS (i) == 1) ? "" : "s"); | |
4531 | if (REG_USERVAR_P (regno_reg_rtx[i])) | |
4532 | fprintf (file, "; user var"); | |
b1f21e0a MM |
4533 | if (REG_N_DEATHS (i) != 1) |
4534 | fprintf (file, "; dies in %d places", REG_N_DEATHS (i)); | |
4535 | if (REG_N_CALLS_CROSSED (i) == 1) | |
d7429b6a | 4536 | fprintf (file, "; crosses 1 call"); |
b1f21e0a MM |
4537 | else if (REG_N_CALLS_CROSSED (i)) |
4538 | fprintf (file, "; crosses %d calls", REG_N_CALLS_CROSSED (i)); | |
d7429b6a RK |
4539 | if (PSEUDO_REGNO_BYTES (i) != UNITS_PER_WORD) |
4540 | fprintf (file, "; %d bytes", PSEUDO_REGNO_BYTES (i)); | |
4541 | class = reg_preferred_class (i); | |
e4600702 RK |
4542 | altclass = reg_alternate_class (i); |
4543 | if (class != GENERAL_REGS || altclass != ALL_REGS) | |
d7429b6a | 4544 | { |
e4600702 RK |
4545 | if (altclass == ALL_REGS || class == ALL_REGS) |
4546 | fprintf (file, "; pref %s", reg_class_names[(int) class]); | |
4547 | else if (altclass == NO_REGS) | |
d7429b6a RK |
4548 | fprintf (file, "; %s or none", reg_class_names[(int) class]); |
4549 | else | |
e4600702 RK |
4550 | fprintf (file, "; pref %s, else %s", |
4551 | reg_class_names[(int) class], | |
4552 | reg_class_names[(int) altclass]); | |
d7429b6a RK |
4553 | } |
4554 | if (REGNO_POINTER_FLAG (i)) | |
4555 | fprintf (file, "; pointer"); | |
4556 | fprintf (file, ".\n"); | |
4557 | } | |
e881bb1b | 4558 | |
d7429b6a | 4559 | fprintf (file, "\n%d basic blocks.\n", n_basic_blocks); |
e881bb1b RH |
4560 | for (i = 0; i < n_basic_blocks; i++) |
4561 | { | |
4562 | register basic_block bb = BASIC_BLOCK (i); | |
4563 | register int regno; | |
4564 | register edge e; | |
4565 | ||
4566 | fprintf (file, "\nBasic block %d: first insn %d, last %d.\n", | |
4567 | i, INSN_UID (bb->head), INSN_UID (bb->end)); | |
4568 | ||
4569 | fprintf (file, "Predecessors: "); | |
4570 | for (e = bb->pred; e ; e = e->pred_next) | |
4571 | dump_edge_info (file, e, 0); | |
4572 | ||
4573 | fprintf (file, "\nSuccessors: "); | |
4574 | for (e = bb->succ; e ; e = e->succ_next) | |
4575 | dump_edge_info (file, e, 1); | |
4576 | ||
4577 | fprintf (file, "\nRegisters live at start:"); | |
4578 | if (bb->global_live_at_start) | |
4579 | { | |
4580 | for (regno = 0; regno < max_regno; regno++) | |
4581 | if (REGNO_REG_SET_P (bb->global_live_at_start, regno)) | |
4582 | fprintf (file, " %d", regno); | |
4583 | } | |
4584 | else | |
4585 | fprintf (file, " n/a"); | |
4586 | ||
4587 | fprintf (file, "\nRegisters live at end:"); | |
4588 | if (bb->global_live_at_end) | |
4589 | { | |
4590 | for (regno = 0; regno < max_regno; regno++) | |
4591 | if (REGNO_REG_SET_P (bb->global_live_at_end, regno)) | |
4592 | fprintf (file, " %d", regno); | |
4593 | } | |
4594 | else | |
4595 | fprintf (file, " n/a"); | |
4596 | ||
4597 | putc('\n', file); | |
4598 | } | |
4599 | ||
4600 | putc('\n', file); | |
4601 | } | |
4602 | ||
4603 | static void | |
4604 | dump_edge_info (file, e, do_succ) | |
4605 | FILE *file; | |
4606 | edge e; | |
4607 | int do_succ; | |
4608 | { | |
4609 | basic_block side = (do_succ ? e->dest : e->src); | |
4610 | ||
4611 | if (side == ENTRY_BLOCK_PTR) | |
4612 | fputs (" ENTRY", file); | |
4613 | else if (side == EXIT_BLOCK_PTR) | |
4614 | fputs (" EXIT", file); | |
4615 | else | |
4616 | fprintf (file, " %d", side->index); | |
4617 | ||
4618 | if (e->flags) | |
4619 | { | |
6f7d635c | 4620 | static const char * const bitnames[] = { |
e881bb1b RH |
4621 | "fallthru", "crit", "ab", "abcall", "eh", "fake" |
4622 | }; | |
4623 | int comma = 0; | |
4624 | int i, flags = e->flags; | |
4625 | ||
4626 | fputc (' ', file); | |
4627 | fputc ('(', file); | |
4628 | for (i = 0; flags; i++) | |
4629 | if (flags & (1 << i)) | |
4630 | { | |
4631 | flags &= ~(1 << i); | |
4632 | ||
4633 | if (comma) | |
4634 | fputc (',', file); | |
4635 | if (i < (int)(sizeof (bitnames) / sizeof (*bitnames))) | |
4636 | fputs (bitnames[i], file); | |
4637 | else | |
4638 | fprintf (file, "%d", i); | |
4639 | comma = 1; | |
4640 | } | |
4641 | fputc (')', file); | |
4642 | } | |
d7429b6a | 4643 | } |
3e28fe44 MM |
4644 | |
4645 | \f | |
4646 | /* Like print_rtl, but also print out live information for the start of each | |
4647 | basic block. */ | |
4648 | ||
4649 | void | |
4650 | print_rtl_with_bb (outf, rtx_first) | |
4651 | FILE *outf; | |
4652 | rtx rtx_first; | |
4653 | { | |
4654 | register rtx tmp_rtx; | |
4655 | ||
4656 | if (rtx_first == 0) | |
4657 | fprintf (outf, "(nil)\n"); | |
3e28fe44 MM |
4658 | else |
4659 | { | |
e881bb1b | 4660 | int i; |
3e28fe44 MM |
4661 | enum bb_state { NOT_IN_BB, IN_ONE_BB, IN_MULTIPLE_BB }; |
4662 | int max_uid = get_max_uid (); | |
54ea1de9 KG |
4663 | basic_block *start = (basic_block *) |
4664 | alloca (max_uid * sizeof (basic_block)); | |
4665 | basic_block *end = (basic_block *) | |
4666 | alloca (max_uid * sizeof (basic_block)); | |
2a92c071 GS |
4667 | enum bb_state *in_bb_p = (enum bb_state *) |
4668 | alloca (max_uid * sizeof (enum bb_state)); | |
3e28fe44 | 4669 | |
e881bb1b RH |
4670 | memset (start, 0, max_uid * sizeof (basic_block)); |
4671 | memset (end, 0, max_uid * sizeof (basic_block)); | |
4672 | memset (in_bb_p, 0, max_uid * sizeof (enum bb_state)); | |
3e28fe44 | 4673 | |
e881bb1b | 4674 | for (i = n_basic_blocks - 1; i >= 0; i--) |
3e28fe44 | 4675 | { |
e881bb1b | 4676 | basic_block bb = BASIC_BLOCK (i); |
3e28fe44 | 4677 | rtx x; |
e881bb1b RH |
4678 | |
4679 | start[INSN_UID (bb->head)] = bb; | |
4680 | end[INSN_UID (bb->end)] = bb; | |
4681 | for (x = bb->head; x != NULL_RTX; x = NEXT_INSN (x)) | |
3e28fe44 | 4682 | { |
e881bb1b RH |
4683 | enum bb_state state = IN_MULTIPLE_BB; |
4684 | if (in_bb_p[INSN_UID(x)] == NOT_IN_BB) | |
4685 | state = IN_ONE_BB; | |
4686 | in_bb_p[INSN_UID(x)] = state; | |
4687 | ||
4688 | if (x == bb->end) | |
3e28fe44 MM |
4689 | break; |
4690 | } | |
4691 | } | |
4692 | ||
4693 | for (tmp_rtx = rtx_first; NULL != tmp_rtx; tmp_rtx = NEXT_INSN (tmp_rtx)) | |
4694 | { | |
b707b450 | 4695 | int did_output; |
e881bb1b | 4696 | basic_block bb; |
b707b450 | 4697 | |
e881bb1b | 4698 | if ((bb = start[INSN_UID (tmp_rtx)]) != NULL) |
3e28fe44 MM |
4699 | { |
4700 | fprintf (outf, ";; Start of basic block %d, registers live:", | |
e881bb1b | 4701 | bb->index); |
3e28fe44 | 4702 | |
e881bb1b | 4703 | EXECUTE_IF_SET_IN_REG_SET (bb->global_live_at_start, 0, i, |
3e28fe44 MM |
4704 | { |
4705 | fprintf (outf, " %d", i); | |
4706 | if (i < FIRST_PSEUDO_REGISTER) | |
4707 | fprintf (outf, " [%s]", | |
4708 | reg_names[i]); | |
4709 | }); | |
4710 | putc ('\n', outf); | |
4711 | } | |
4712 | ||
ab87f8c8 | 4713 | if (in_bb_p[INSN_UID(tmp_rtx)] == NOT_IN_BB |
3e28fe44 | 4714 | && GET_CODE (tmp_rtx) != NOTE |
ab87f8c8 JL |
4715 | && GET_CODE (tmp_rtx) != BARRIER |
4716 | && ! obey_regdecls) | |
3e28fe44 | 4717 | fprintf (outf, ";; Insn is not within a basic block\n"); |
e881bb1b | 4718 | else if (in_bb_p[INSN_UID(tmp_rtx)] == IN_MULTIPLE_BB) |
3e28fe44 MM |
4719 | fprintf (outf, ";; Insn is in multiple basic blocks\n"); |
4720 | ||
b707b450 | 4721 | did_output = print_rtl_single (outf, tmp_rtx); |
3e28fe44 | 4722 | |
e881bb1b RH |
4723 | if ((bb = end[INSN_UID (tmp_rtx)]) != NULL) |
4724 | fprintf (outf, ";; End of basic block %d\n", bb->index); | |
3e28fe44 | 4725 | |
b707b450 | 4726 | if (did_output) |
9ec36da5 | 4727 | putc ('\n', outf); |
3e28fe44 MM |
4728 | } |
4729 | } | |
c5c76735 JL |
4730 | |
4731 | if (current_function_epilogue_delay_list != 0) | |
4732 | { | |
4733 | fprintf (outf, "\n;; Insns in epilogue delay list:\n\n"); | |
4734 | for (tmp_rtx = current_function_epilogue_delay_list; tmp_rtx != 0; | |
4735 | tmp_rtx = XEXP (tmp_rtx, 1)) | |
4736 | print_rtl_single (outf, XEXP (tmp_rtx, 0)); | |
4737 | } | |
3e28fe44 | 4738 | } |
5ece9746 JL |
4739 | |
4740 | \f | |
4741 | /* Integer list support. */ | |
4742 | ||
4743 | /* Allocate a node from list *HEAD_PTR. */ | |
4744 | ||
4745 | static int_list_ptr | |
4746 | alloc_int_list_node (head_ptr) | |
4747 | int_list_block **head_ptr; | |
4748 | { | |
4749 | struct int_list_block *first_blk = *head_ptr; | |
4750 | ||
4751 | if (first_blk == NULL || first_blk->nodes_left <= 0) | |
4752 | { | |
4753 | first_blk = (struct int_list_block *) xmalloc (sizeof (struct int_list_block)); | |
4754 | first_blk->nodes_left = INT_LIST_NODES_IN_BLK; | |
4755 | first_blk->next = *head_ptr; | |
4756 | *head_ptr = first_blk; | |
4757 | } | |
4758 | ||
4759 | first_blk->nodes_left--; | |
4760 | return &first_blk->nodes[first_blk->nodes_left]; | |
4761 | } | |
4762 | ||
4763 | /* Pointer to head of predecessor/successor block list. */ | |
4764 | static int_list_block *pred_int_list_blocks; | |
4765 | ||
4766 | /* Add a new node to integer list LIST with value VAL. | |
4767 | LIST is a pointer to a list object to allow for different implementations. | |
4768 | If *LIST is initially NULL, the list is empty. | |
4769 | The caller must not care whether the element is added to the front or | |
4770 | to the end of the list (to allow for different implementations). */ | |
4771 | ||
4772 | static int_list_ptr | |
4773 | add_int_list_node (blk_list, list, val) | |
4774 | int_list_block **blk_list; | |
4775 | int_list **list; | |
4776 | int val; | |
4777 | { | |
4778 | int_list_ptr p = alloc_int_list_node (blk_list); | |
4779 | ||
4780 | p->val = val; | |
4781 | p->next = *list; | |
4782 | *list = p; | |
4783 | return p; | |
4784 | } | |
4785 | ||
4786 | /* Free the blocks of lists at BLK_LIST. */ | |
4787 | ||
4788 | void | |
4789 | free_int_list (blk_list) | |
4790 | int_list_block **blk_list; | |
4791 | { | |
4792 | int_list_block *p, *next; | |
4793 | ||
4794 | for (p = *blk_list; p != NULL; p = next) | |
4795 | { | |
4796 | next = p->next; | |
4797 | free (p); | |
4798 | } | |
4799 | ||
4800 | /* Mark list as empty for the next function we compile. */ | |
4801 | *blk_list = NULL; | |
4802 | } | |
4803 | \f | |
4804 | /* Predecessor/successor computation. */ | |
4805 | ||
4806 | /* Mark PRED_BB a precessor of SUCC_BB, | |
4807 | and conversely SUCC_BB a successor of PRED_BB. */ | |
4808 | ||
4809 | static void | |
4810 | add_pred_succ (pred_bb, succ_bb, s_preds, s_succs, num_preds, num_succs) | |
4811 | int pred_bb; | |
4812 | int succ_bb; | |
4813 | int_list_ptr *s_preds; | |
4814 | int_list_ptr *s_succs; | |
4815 | int *num_preds; | |
4816 | int *num_succs; | |
4817 | { | |
4818 | if (succ_bb != EXIT_BLOCK) | |
4819 | { | |
4820 | add_int_list_node (&pred_int_list_blocks, &s_preds[succ_bb], pred_bb); | |
4821 | num_preds[succ_bb]++; | |
4822 | } | |
4823 | if (pred_bb != ENTRY_BLOCK) | |
4824 | { | |
4825 | add_int_list_node (&pred_int_list_blocks, &s_succs[pred_bb], succ_bb); | |
4826 | num_succs[pred_bb]++; | |
4827 | } | |
4828 | } | |
4829 | ||
e881bb1b RH |
4830 | /* Convert edge lists into pred/succ lists for backward compatibility. */ |
4831 | ||
743bb12d | 4832 | void |
5ece9746 JL |
4833 | compute_preds_succs (s_preds, s_succs, num_preds, num_succs) |
4834 | int_list_ptr *s_preds; | |
4835 | int_list_ptr *s_succs; | |
4836 | int *num_preds; | |
4837 | int *num_succs; | |
4838 | { | |
e881bb1b RH |
4839 | int i, n = n_basic_blocks; |
4840 | edge e; | |
5ece9746 | 4841 | |
e881bb1b RH |
4842 | memset (s_preds, 0, n_basic_blocks * sizeof (int_list_ptr)); |
4843 | memset (s_succs, 0, n_basic_blocks * sizeof (int_list_ptr)); | |
4844 | memset (num_preds, 0, n_basic_blocks * sizeof (int)); | |
4845 | memset (num_succs, 0, n_basic_blocks * sizeof (int)); | |
5ece9746 | 4846 | |
e881bb1b | 4847 | for (i = 0; i < n; ++i) |
5ece9746 | 4848 | { |
e881bb1b RH |
4849 | basic_block bb = BASIC_BLOCK (i); |
4850 | ||
4851 | for (e = bb->succ; e ; e = e->succ_next) | |
4852 | add_pred_succ (i, e->dest->index, s_preds, s_succs, | |
4853 | num_preds, num_succs); | |
5ece9746 JL |
4854 | } |
4855 | ||
e881bb1b RH |
4856 | for (e = ENTRY_BLOCK_PTR->succ; e ; e = e->succ_next) |
4857 | add_pred_succ (ENTRY_BLOCK, e->dest->index, s_preds, s_succs, | |
4858 | num_preds, num_succs); | |
5ece9746 JL |
4859 | } |
4860 | ||
4861 | void | |
421382ac | 4862 | dump_bb_data (file, preds, succs, live_info) |
5ece9746 JL |
4863 | FILE *file; |
4864 | int_list_ptr *preds; | |
4865 | int_list_ptr *succs; | |
421382ac | 4866 | int live_info; |
5ece9746 JL |
4867 | { |
4868 | int bb; | |
4869 | int_list_ptr p; | |
4870 | ||
4871 | fprintf (file, "BB data\n\n"); | |
4872 | for (bb = 0; bb < n_basic_blocks; bb++) | |
4873 | { | |
4874 | fprintf (file, "BB %d, start %d, end %d\n", bb, | |
4875 | INSN_UID (BLOCK_HEAD (bb)), INSN_UID (BLOCK_END (bb))); | |
4876 | fprintf (file, " preds:"); | |
4877 | for (p = preds[bb]; p != NULL; p = p->next) | |
4878 | { | |
4879 | int pred_bb = INT_LIST_VAL (p); | |
4880 | if (pred_bb == ENTRY_BLOCK) | |
4881 | fprintf (file, " entry"); | |
4882 | else | |
4883 | fprintf (file, " %d", pred_bb); | |
4884 | } | |
4885 | fprintf (file, "\n"); | |
4886 | fprintf (file, " succs:"); | |
4887 | for (p = succs[bb]; p != NULL; p = p->next) | |
4888 | { | |
4889 | int succ_bb = INT_LIST_VAL (p); | |
4890 | if (succ_bb == EXIT_BLOCK) | |
4891 | fprintf (file, " exit"); | |
4892 | else | |
4893 | fprintf (file, " %d", succ_bb); | |
4894 | } | |
421382ac BS |
4895 | if (live_info) |
4896 | { | |
4897 | int regno; | |
4898 | fprintf (file, "\nRegisters live at start:"); | |
4899 | for (regno = 0; regno < max_regno; regno++) | |
e881bb1b | 4900 | if (REGNO_REG_SET_P (BASIC_BLOCK (bb)->global_live_at_start, regno)) |
421382ac BS |
4901 | fprintf (file, " %d", regno); |
4902 | fprintf (file, "\n"); | |
4903 | } | |
5ece9746 JL |
4904 | fprintf (file, "\n"); |
4905 | } | |
4906 | fprintf (file, "\n"); | |
4907 | } | |
4908 | ||
4909 | /* Free basic block data storage. */ | |
4910 | ||
4911 | void | |
4912 | free_bb_mem () | |
4913 | { | |
4914 | free_int_list (&pred_int_list_blocks); | |
4915 | } | |
5e89e58b | 4916 | |
5ece9746 JL |
4917 | /* Compute dominator relationships. */ |
4918 | void | |
4919 | compute_dominators (dominators, post_dominators, s_preds, s_succs) | |
4920 | sbitmap *dominators; | |
4921 | sbitmap *post_dominators; | |
4922 | int_list_ptr *s_preds; | |
4923 | int_list_ptr *s_succs; | |
4924 | { | |
4925 | int bb, changed, passes; | |
4926 | sbitmap *temp_bitmap; | |
4927 | ||
4928 | temp_bitmap = sbitmap_vector_alloc (n_basic_blocks, n_basic_blocks); | |
4929 | sbitmap_vector_ones (dominators, n_basic_blocks); | |
4930 | sbitmap_vector_ones (post_dominators, n_basic_blocks); | |
4931 | sbitmap_vector_zero (temp_bitmap, n_basic_blocks); | |
4932 | ||
4933 | sbitmap_zero (dominators[0]); | |
4934 | SET_BIT (dominators[0], 0); | |
4935 | ||
e881bb1b RH |
4936 | sbitmap_zero (post_dominators[n_basic_blocks - 1]); |
4937 | SET_BIT (post_dominators[n_basic_blocks - 1], 0); | |
5ece9746 JL |
4938 | |
4939 | passes = 0; | |
4940 | changed = 1; | |
4941 | while (changed) | |
4942 | { | |
4943 | changed = 0; | |
4944 | for (bb = 1; bb < n_basic_blocks; bb++) | |
4945 | { | |
4946 | sbitmap_intersect_of_predecessors (temp_bitmap[bb], dominators, | |
4947 | bb, s_preds); | |
4948 | SET_BIT (temp_bitmap[bb], bb); | |
4949 | changed |= sbitmap_a_and_b (dominators[bb], | |
4950 | dominators[bb], | |
4951 | temp_bitmap[bb]); | |
4952 | sbitmap_intersect_of_successors (temp_bitmap[bb], post_dominators, | |
4953 | bb, s_succs); | |
4954 | SET_BIT (temp_bitmap[bb], bb); | |
4955 | changed |= sbitmap_a_and_b (post_dominators[bb], | |
4956 | post_dominators[bb], | |
4957 | temp_bitmap[bb]); | |
4958 | } | |
4959 | passes++; | |
4960 | } | |
4961 | ||
4962 | free (temp_bitmap); | |
4963 | } | |
4c649323 | 4964 | |
36349f8b AM |
4965 | /* Compute dominator relationships using new flow graph structures. */ |
4966 | void | |
4967 | compute_flow_dominators (dominators, post_dominators) | |
4968 | sbitmap *dominators; | |
4969 | sbitmap *post_dominators; | |
4970 | { | |
4971 | int bb, changed, passes; | |
4972 | sbitmap *temp_bitmap; | |
4973 | ||
4974 | temp_bitmap = sbitmap_vector_alloc (n_basic_blocks, n_basic_blocks); | |
4975 | sbitmap_vector_ones (dominators, n_basic_blocks); | |
4976 | sbitmap_vector_ones (post_dominators, n_basic_blocks); | |
4977 | sbitmap_vector_zero (temp_bitmap, n_basic_blocks); | |
4978 | ||
4979 | sbitmap_zero (dominators[0]); | |
4980 | SET_BIT (dominators[0], 0); | |
4981 | ||
4982 | sbitmap_zero (post_dominators[n_basic_blocks - 1]); | |
4983 | SET_BIT (post_dominators[n_basic_blocks - 1], 0); | |
4984 | ||
4985 | passes = 0; | |
4986 | changed = 1; | |
4987 | while (changed) | |
4988 | { | |
4989 | changed = 0; | |
4990 | for (bb = 1; bb < n_basic_blocks; bb++) | |
4991 | { | |
4992 | sbitmap_intersection_of_preds (temp_bitmap[bb], dominators, bb); | |
4993 | SET_BIT (temp_bitmap[bb], bb); | |
4994 | changed |= sbitmap_a_and_b (dominators[bb], | |
4995 | dominators[bb], | |
4996 | temp_bitmap[bb]); | |
4997 | sbitmap_intersection_of_succs (temp_bitmap[bb], post_dominators, bb); | |
4998 | SET_BIT (temp_bitmap[bb], bb); | |
4999 | changed |= sbitmap_a_and_b (post_dominators[bb], | |
5000 | post_dominators[bb], | |
5001 | temp_bitmap[bb]); | |
5002 | } | |
5003 | passes++; | |
5004 | } | |
5005 | ||
5006 | free (temp_bitmap); | |
5007 | } | |
5008 | ||
422d0fb0 RH |
5009 | /* Given DOMINATORS, compute the immediate dominators into IDOM. */ |
5010 | ||
5011 | void | |
5012 | compute_immediate_dominators (idom, dominators) | |
5013 | int *idom; | |
5014 | sbitmap *dominators; | |
5015 | { | |
5016 | sbitmap *tmp; | |
5017 | int b; | |
5018 | ||
5019 | tmp = sbitmap_vector_alloc (n_basic_blocks, n_basic_blocks); | |
5020 | ||
5021 | /* Begin with tmp(n) = dom(n) - { n }. */ | |
5022 | for (b = n_basic_blocks; --b >= 0; ) | |
5023 | { | |
5024 | sbitmap_copy (tmp[b], dominators[b]); | |
5025 | RESET_BIT (tmp[b], b); | |
5026 | } | |
5027 | ||
5028 | /* Subtract out all of our dominator's dominators. */ | |
5029 | for (b = n_basic_blocks; --b >= 0; ) | |
5030 | { | |
5031 | sbitmap tmp_b = tmp[b]; | |
5032 | int s; | |
5033 | ||
5034 | for (s = n_basic_blocks; --s >= 0; ) | |
5035 | if (TEST_BIT (tmp_b, s)) | |
5036 | sbitmap_difference (tmp_b, tmp_b, tmp[s]); | |
5037 | } | |
5038 | ||
5039 | /* Find the one bit set in the bitmap and put it in the output array. */ | |
5040 | for (b = n_basic_blocks; --b >= 0; ) | |
5041 | { | |
5042 | int t; | |
5043 | EXECUTE_IF_SET_IN_SBITMAP (tmp[b], 0, t, { idom[b] = t; }); | |
5044 | } | |
5045 | ||
5046 | sbitmap_vector_free (tmp); | |
5047 | } | |
5048 | ||
4c649323 JL |
5049 | /* Count for a single SET rtx, X. */ |
5050 | ||
5051 | static void | |
5052 | count_reg_sets_1 (x) | |
5053 | rtx x; | |
5054 | { | |
5055 | register int regno; | |
5056 | register rtx reg = SET_DEST (x); | |
5057 | ||
5058 | /* Find the register that's set/clobbered. */ | |
5059 | while (GET_CODE (reg) == SUBREG || GET_CODE (reg) == ZERO_EXTRACT | |
5060 | || GET_CODE (reg) == SIGN_EXTRACT | |
5061 | || GET_CODE (reg) == STRICT_LOW_PART) | |
5062 | reg = XEXP (reg, 0); | |
5063 | ||
86465af7 DM |
5064 | if (GET_CODE (reg) == PARALLEL |
5065 | && GET_MODE (reg) == BLKmode) | |
5066 | { | |
5067 | register int i; | |
5068 | for (i = XVECLEN (reg, 0) - 1; i >= 0; i--) | |
5069 | count_reg_sets_1 (XVECEXP (reg, 0, i)); | |
5070 | return; | |
5071 | } | |
5072 | ||
4c649323 JL |
5073 | if (GET_CODE (reg) == REG) |
5074 | { | |
5075 | regno = REGNO (reg); | |
5076 | if (regno >= FIRST_PSEUDO_REGISTER) | |
5077 | { | |
5078 | /* Count (weighted) references, stores, etc. This counts a | |
5079 | register twice if it is modified, but that is correct. */ | |
5080 | REG_N_SETS (regno)++; | |
5081 | ||
5082 | REG_N_REFS (regno) += loop_depth; | |
5083 | } | |
5084 | } | |
5085 | } | |
5086 | ||
5087 | /* Increment REG_N_SETS for each SET or CLOBBER found in X; also increment | |
5088 | REG_N_REFS by the current loop depth for each SET or CLOBBER found. */ | |
5089 | ||
5090 | static void | |
5091 | count_reg_sets (x) | |
5092 | rtx x; | |
5093 | { | |
5094 | register RTX_CODE code = GET_CODE (x); | |
5095 | ||
5096 | if (code == SET || code == CLOBBER) | |
5097 | count_reg_sets_1 (x); | |
5098 | else if (code == PARALLEL) | |
5099 | { | |
5100 | register int i; | |
5101 | for (i = XVECLEN (x, 0) - 1; i >= 0; i--) | |
5102 | { | |
5103 | code = GET_CODE (XVECEXP (x, 0, i)); | |
5104 | if (code == SET || code == CLOBBER) | |
5105 | count_reg_sets_1 (XVECEXP (x, 0, i)); | |
5106 | } | |
5107 | } | |
5108 | } | |
5109 | ||
5110 | /* Increment REG_N_REFS by the current loop depth each register reference | |
5111 | found in X. */ | |
5112 | ||
5113 | static void | |
5114 | count_reg_references (x) | |
5115 | rtx x; | |
5116 | { | |
5117 | register RTX_CODE code; | |
4c649323 JL |
5118 | |
5119 | retry: | |
5120 | code = GET_CODE (x); | |
5121 | switch (code) | |
5122 | { | |
5123 | case LABEL_REF: | |
5124 | case SYMBOL_REF: | |
5125 | case CONST_INT: | |
5126 | case CONST: | |
5127 | case CONST_DOUBLE: | |
5128 | case PC: | |
5129 | case ADDR_VEC: | |
5130 | case ADDR_DIFF_VEC: | |
5131 | case ASM_INPUT: | |
5132 | return; | |
5133 | ||
5134 | #ifdef HAVE_cc0 | |
5135 | case CC0: | |
5136 | return; | |
5137 | #endif | |
5138 | ||
5139 | case CLOBBER: | |
5140 | /* If we are clobbering a MEM, mark any registers inside the address | |
5141 | as being used. */ | |
5142 | if (GET_CODE (XEXP (x, 0)) == MEM) | |
5143 | count_reg_references (XEXP (XEXP (x, 0), 0)); | |
5144 | return; | |
5145 | ||
5146 | case SUBREG: | |
5147 | /* While we're here, optimize this case. */ | |
5148 | x = SUBREG_REG (x); | |
5149 | ||
5150 | /* In case the SUBREG is not of a register, don't optimize */ | |
5151 | if (GET_CODE (x) != REG) | |
5152 | { | |
5153 | count_reg_references (x); | |
5154 | return; | |
5155 | } | |
5156 | ||
5157 | /* ... fall through ... */ | |
5158 | ||
5159 | case REG: | |
5160 | if (REGNO (x) >= FIRST_PSEUDO_REGISTER) | |
5161 | REG_N_REFS (REGNO (x)) += loop_depth; | |
5162 | return; | |
5163 | ||
5164 | case SET: | |
5165 | { | |
5166 | register rtx testreg = SET_DEST (x); | |
5167 | int mark_dest = 0; | |
5168 | ||
5169 | /* If storing into MEM, don't show it as being used. But do | |
5170 | show the address as being used. */ | |
5171 | if (GET_CODE (testreg) == MEM) | |
5172 | { | |
5173 | count_reg_references (XEXP (testreg, 0)); | |
5174 | count_reg_references (SET_SRC (x)); | |
5175 | return; | |
5176 | } | |
5177 | ||
5178 | /* Storing in STRICT_LOW_PART is like storing in a reg | |
5179 | in that this SET might be dead, so ignore it in TESTREG. | |
5180 | but in some other ways it is like using the reg. | |
5181 | ||
5182 | Storing in a SUBREG or a bit field is like storing the entire | |
5183 | register in that if the register's value is not used | |
5184 | then this SET is not needed. */ | |
5185 | while (GET_CODE (testreg) == STRICT_LOW_PART | |
5186 | || GET_CODE (testreg) == ZERO_EXTRACT | |
5187 | || GET_CODE (testreg) == SIGN_EXTRACT | |
5188 | || GET_CODE (testreg) == SUBREG) | |
5189 | { | |
5190 | /* Modifying a single register in an alternate mode | |
5191 | does not use any of the old value. But these other | |
5192 | ways of storing in a register do use the old value. */ | |
5193 | if (GET_CODE (testreg) == SUBREG | |
5194 | && !(REG_SIZE (SUBREG_REG (testreg)) > REG_SIZE (testreg))) | |
5195 | ; | |
5196 | else | |
5197 | mark_dest = 1; | |
5198 | ||
5199 | testreg = XEXP (testreg, 0); | |
5200 | } | |
5201 | ||
5202 | /* If this is a store into a register, | |
5203 | recursively scan the value being stored. */ | |
5204 | ||
86465af7 DM |
5205 | if ((GET_CODE (testreg) == PARALLEL |
5206 | && GET_MODE (testreg) == BLKmode) | |
5207 | || GET_CODE (testreg) == REG) | |
4c649323 JL |
5208 | { |
5209 | count_reg_references (SET_SRC (x)); | |
5210 | if (mark_dest) | |
5211 | count_reg_references (SET_DEST (x)); | |
5212 | return; | |
5213 | } | |
5214 | } | |
5215 | break; | |
5216 | ||
5217 | default: | |
5218 | break; | |
5219 | } | |
5220 | ||
5221 | /* Recursively scan the operands of this expression. */ | |
5222 | ||
5223 | { | |
6f7d635c | 5224 | register const char *fmt = GET_RTX_FORMAT (code); |
4c649323 JL |
5225 | register int i; |
5226 | ||
5227 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
5228 | { | |
5229 | if (fmt[i] == 'e') | |
5230 | { | |
5231 | /* Tail recursive case: save a function call level. */ | |
5232 | if (i == 0) | |
5233 | { | |
5234 | x = XEXP (x, 0); | |
5235 | goto retry; | |
5236 | } | |
5237 | count_reg_references (XEXP (x, i)); | |
5238 | } | |
5239 | else if (fmt[i] == 'E') | |
5240 | { | |
5241 | register int j; | |
5242 | for (j = 0; j < XVECLEN (x, i); j++) | |
5243 | count_reg_references (XVECEXP (x, i, j)); | |
5244 | } | |
5245 | } | |
5246 | } | |
5247 | } | |
5248 | ||
5249 | /* Recompute register set/reference counts immediately prior to register | |
5250 | allocation. | |
5251 | ||
5252 | This avoids problems with set/reference counts changing to/from values | |
5253 | which have special meanings to the register allocators. | |
5254 | ||
5255 | Additionally, the reference counts are the primary component used by the | |
5256 | register allocators to prioritize pseudos for allocation to hard regs. | |
5257 | More accurate reference counts generally lead to better register allocation. | |
5258 | ||
213c4983 R |
5259 | F is the first insn to be scanned. |
5260 | LOOP_STEP denotes how much loop_depth should be incremented per | |
5261 | loop nesting level in order to increase the ref count more for references | |
5262 | in a loop. | |
5263 | ||
4c649323 JL |
5264 | It might be worthwhile to update REG_LIVE_LENGTH, REG_BASIC_BLOCK and |
5265 | possibly other information which is used by the register allocators. */ | |
5266 | ||
762a1d90 | 5267 | void |
213c4983 | 5268 | recompute_reg_usage (f, loop_step) |
4c649323 | 5269 | rtx f; |
213c4983 | 5270 | int loop_step; |
4c649323 JL |
5271 | { |
5272 | rtx insn; | |
5273 | int i, max_reg; | |
5274 | ||
5275 | /* Clear out the old data. */ | |
5276 | max_reg = max_reg_num (); | |
5277 | for (i = FIRST_PSEUDO_REGISTER; i < max_reg; i++) | |
5278 | { | |
5279 | REG_N_SETS (i) = 0; | |
5280 | REG_N_REFS (i) = 0; | |
5281 | } | |
5282 | ||
5283 | /* Scan each insn in the chain and count how many times each register is | |
5284 | set/used. */ | |
5285 | loop_depth = 1; | |
5286 | for (insn = f; insn; insn = NEXT_INSN (insn)) | |
5287 | { | |
5288 | /* Keep track of loop depth. */ | |
5289 | if (GET_CODE (insn) == NOTE) | |
5290 | { | |
5291 | /* Look for loop boundaries. */ | |
5292 | if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_END) | |
213c4983 | 5293 | loop_depth -= loop_step; |
4c649323 | 5294 | else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG) |
213c4983 | 5295 | loop_depth += loop_step; |
4c649323 JL |
5296 | |
5297 | /* If we have LOOP_DEPTH == 0, there has been a bookkeeping error. | |
5298 | Abort now rather than setting register status incorrectly. */ | |
5299 | if (loop_depth == 0) | |
5300 | abort (); | |
5301 | } | |
5302 | else if (GET_RTX_CLASS (GET_CODE (insn)) == 'i') | |
5303 | { | |
5304 | rtx links; | |
5305 | ||
5306 | /* This call will increment REG_N_SETS for each SET or CLOBBER | |
5307 | of a register in INSN. It will also increment REG_N_REFS | |
5308 | by the loop depth for each set of a register in INSN. */ | |
5309 | count_reg_sets (PATTERN (insn)); | |
5310 | ||
5311 | /* count_reg_sets does not detect autoincrement address modes, so | |
5312 | detect them here by looking at the notes attached to INSN. */ | |
5313 | for (links = REG_NOTES (insn); links; links = XEXP (links, 1)) | |
5314 | { | |
5315 | if (REG_NOTE_KIND (links) == REG_INC) | |
5316 | /* Count (weighted) references, stores, etc. This counts a | |
5317 | register twice if it is modified, but that is correct. */ | |
5318 | REG_N_SETS (REGNO (XEXP (links, 0)))++; | |
5319 | } | |
5320 | ||
5321 | /* This call will increment REG_N_REFS by the current loop depth for | |
5322 | each reference to a register in INSN. */ | |
5323 | count_reg_references (PATTERN (insn)); | |
5324 | ||
5325 | /* count_reg_references will not include counts for arguments to | |
5326 | function calls, so detect them here by examining the | |
5327 | CALL_INSN_FUNCTION_USAGE data. */ | |
5328 | if (GET_CODE (insn) == CALL_INSN) | |
5329 | { | |
5330 | rtx note; | |
5331 | ||
5332 | for (note = CALL_INSN_FUNCTION_USAGE (insn); | |
5333 | note; | |
5334 | note = XEXP (note, 1)) | |
5335 | if (GET_CODE (XEXP (note, 0)) == USE) | |
83ab3839 | 5336 | count_reg_references (XEXP (XEXP (note, 0), 0)); |
4c649323 JL |
5337 | } |
5338 | } | |
5339 | } | |
5340 | } | |
e881bb1b RH |
5341 | |
5342 | /* Record INSN's block as BB. */ | |
5343 | ||
5344 | void | |
5345 | set_block_for_insn (insn, bb) | |
5346 | rtx insn; | |
5347 | basic_block bb; | |
5348 | { | |
5349 | size_t uid = INSN_UID (insn); | |
5350 | if (uid >= basic_block_for_insn->num_elements) | |
5351 | { | |
5352 | int new_size; | |
5353 | ||
5354 | /* Add one-eighth the size so we don't keep calling xrealloc. */ | |
5355 | new_size = uid + (uid + 7) / 8; | |
5356 | ||
5357 | VARRAY_GROW (basic_block_for_insn, new_size); | |
5358 | } | |
5359 | VARRAY_BB (basic_block_for_insn, uid) = bb; | |
5360 | } | |
5361 | ||
5362 | /* Record INSN's block number as BB. */ | |
5363 | /* ??? This has got to go. */ | |
5364 | ||
5365 | void | |
5366 | set_block_num (insn, bb) | |
5367 | rtx insn; | |
5368 | int bb; | |
5369 | { | |
5370 | set_block_for_insn (insn, BASIC_BLOCK (bb)); | |
5371 | } | |
34487bf8 | 5372 | \f |
f2a1bc02 BM |
5373 | /* Unlink a chain of insns between START and FINISH inclusive, leaving notes |
5374 | that must be paired, and return the new chain. */ | |
5375 | ||
5376 | rtx | |
5377 | unlink_insn_chain (start, finish) | |
5378 | rtx start, finish; | |
5379 | { | |
5380 | rtx insert_point = PREV_INSN (start); | |
5381 | rtx chain = NULL_RTX, curr; | |
5382 | ||
5383 | /* Unchain the insns one by one. It would be quicker to delete all | |
5384 | of these with a single unchaining, rather than one at a time, but | |
5385 | we need to keep the NOTE's. */ | |
5386 | ||
5387 | while (1) | |
5388 | { | |
5389 | rtx next = NEXT_INSN (start); | |
5390 | ||
5391 | remove_insn (start); | |
5392 | ||
5393 | /* ??? Despite the fact that we're patching out the insn, it's | |
5394 | still referenced in LOG_LINKS. Rather than try and track | |
5395 | them all down and remove them, just mark the insn deleted. */ | |
5396 | INSN_DELETED_P (start) = 1; | |
5397 | ||
5398 | if (GET_CODE (start) == NOTE && ! can_delete_note_p (start)) | |
5399 | { | |
5400 | add_insn_after (start, insert_point); | |
5401 | insert_point = start; | |
5402 | } | |
5403 | else | |
5404 | { | |
5405 | if (chain != NULL) | |
5406 | { | |
5407 | NEXT_INSN (curr) = start; | |
5408 | PREV_INSN (start) = curr; | |
5409 | curr = start; | |
5410 | } | |
5411 | else | |
5412 | { | |
5413 | chain = start; | |
5414 | curr = start; | |
5415 | PREV_INSN (chain) = NULL_RTX; | |
5416 | } | |
5417 | } | |
5418 | ||
5419 | if (start == finish) | |
5420 | break; | |
5421 | start = next; | |
5422 | } | |
5423 | ||
5424 | if (chain != NULL_RTX) | |
5425 | NEXT_INSN (curr) = NULL_RTX; | |
5426 | ||
5427 | return chain; | |
5428 | } | |
5429 | ||
5430 | /* Subroutine of update_life_info. Determines whether multiple | |
5431 | REG_NOTEs need to be distributed for the hard register mentioned in | |
5432 | NOTE. This can happen if a reference to a hard register in the | |
5433 | original insns was split into several smaller hard register | |
5434 | references in the new insns. */ | |
5435 | ||
5436 | static void | |
5437 | split_hard_reg_notes (curr_insn, note, first, last) | |
5438 | rtx curr_insn, note, first, last; | |
5439 | { | |
5440 | rtx reg, temp, link; | |
5441 | rtx insn; | |
5442 | int n_regs, i, new_reg; | |
5443 | ||
5444 | reg = XEXP (note, 0); | |
5445 | ||
5446 | if (REG_NOTE_KIND (note) != REG_DEAD | |
5447 | || GET_CODE (reg) != REG | |
5448 | || REGNO (reg) >= FIRST_PSEUDO_REGISTER | |
5449 | || HARD_REGNO_NREGS (REGNO (reg), GET_MODE (reg)) == 1) | |
5450 | { | |
5451 | XEXP (note, 1) = REG_NOTES (curr_insn); | |
5452 | REG_NOTES (curr_insn) = note; | |
5453 | return; | |
5454 | } | |
5455 | ||
5456 | n_regs = HARD_REGNO_NREGS (REGNO (reg), GET_MODE (reg)); | |
5457 | ||
5458 | for (i = 0; i < n_regs; i++) | |
5459 | { | |
5460 | new_reg = REGNO (reg) + i; | |
5461 | ||
5462 | /* Check for references to new_reg in the split insns. */ | |
5463 | for (insn = last; ; insn = PREV_INSN (insn)) | |
5464 | { | |
5465 | if (GET_RTX_CLASS (GET_CODE (insn)) == 'i' | |
5466 | && (temp = regno_use_in (new_reg, PATTERN (insn)))) | |
5467 | { | |
5468 | /* Create a new reg dead note here. */ | |
5469 | link = rtx_alloc (EXPR_LIST); | |
5470 | PUT_REG_NOTE_KIND (link, REG_DEAD); | |
5471 | XEXP (link, 0) = temp; | |
5472 | XEXP (link, 1) = REG_NOTES (insn); | |
5473 | REG_NOTES (insn) = link; | |
5474 | ||
5475 | /* If killed multiple registers here, then add in the excess. */ | |
5476 | i += HARD_REGNO_NREGS (REGNO (temp), GET_MODE (temp)) - 1; | |
5477 | ||
5478 | break; | |
5479 | } | |
5480 | /* It isn't mentioned anywhere, so no new reg note is needed for | |
5481 | this register. */ | |
5482 | if (insn == first) | |
5483 | break; | |
5484 | } | |
5485 | } | |
5486 | } | |
5487 | ||
5488 | /* SET_INSN kills REG; add a REG_DEAD note mentioning REG to the last | |
5489 | use of REG in the insns after SET_INSN and before or including | |
5490 | LAST, if necessary. | |
5491 | ||
5492 | A non-zero value is returned if we added a REG_DEAD note, or if we | |
5493 | determined that a REG_DEAD note because of this particular SET | |
5494 | wasn't necessary. */ | |
5495 | ||
5496 | static int | |
5497 | maybe_add_dead_note (reg, set_insn, last) | |
5498 | rtx reg, set_insn, last; | |
5499 | { | |
5500 | rtx insn; | |
5501 | ||
5502 | for (insn = last; insn != set_insn; insn = PREV_INSN (insn)) | |
5503 | { | |
5504 | rtx set; | |
5505 | ||
5506 | if (GET_RTX_CLASS (GET_CODE (insn)) == 'i' | |
5507 | && reg_overlap_mentioned_p (reg, PATTERN (insn)) | |
5508 | && (set = single_set (insn))) | |
5509 | { | |
5510 | rtx insn_dest = SET_DEST (set); | |
5511 | ||
5512 | while (GET_CODE (insn_dest) == ZERO_EXTRACT | |
5513 | || GET_CODE (insn_dest) == SUBREG | |
5514 | || GET_CODE (insn_dest) == STRICT_LOW_PART | |
5515 | || GET_CODE (insn_dest) == SIGN_EXTRACT) | |
5516 | insn_dest = XEXP (insn_dest, 0); | |
5517 | ||
5518 | if (! rtx_equal_p (insn_dest, reg)) | |
5519 | { | |
5520 | /* Use the same scheme as combine.c, don't put both REG_DEAD | |
5521 | and REG_UNUSED notes on the same insn. */ | |
5522 | if (! find_regno_note (insn, REG_UNUSED, REGNO (reg)) | |
5523 | && ! find_regno_note (insn, REG_DEAD, REGNO (reg))) | |
5524 | { | |
5525 | rtx note = rtx_alloc (EXPR_LIST); | |
5526 | PUT_REG_NOTE_KIND (note, REG_DEAD); | |
5527 | XEXP (note, 0) = reg; | |
5528 | XEXP (note, 1) = REG_NOTES (insn); | |
5529 | REG_NOTES (insn) = note; | |
5530 | } | |
5531 | return 1; | |
5532 | } | |
5533 | else if (reg_overlap_mentioned_p (reg, SET_SRC (set))) | |
5534 | { | |
5535 | /* We found an instruction that both uses the register and | |
5536 | sets it, so no new REG_NOTE is needed for the previous | |
5537 | set. */ | |
5538 | return 0; | |
5539 | } | |
5540 | } | |
5541 | } | |
5542 | return 0; | |
5543 | } | |
5544 | ||
5545 | static int | |
5546 | maybe_add_dead_note_use (insn, dest) | |
5547 | rtx insn, dest; | |
5548 | { | |
5549 | rtx set; | |
5550 | ||
5551 | /* We need to add a REG_DEAD note to the last place DEST is | |
5552 | referenced. */ | |
5553 | ||
5554 | if (GET_RTX_CLASS (GET_CODE (insn)) == 'i' | |
5555 | && reg_mentioned_p (dest, PATTERN (insn)) | |
5556 | && (set = single_set (insn))) | |
5557 | { | |
5558 | rtx insn_dest = SET_DEST (set); | |
5559 | ||
5560 | while (GET_CODE (insn_dest) == ZERO_EXTRACT | |
5561 | || GET_CODE (insn_dest) == SUBREG | |
5562 | || GET_CODE (insn_dest) == STRICT_LOW_PART | |
5563 | || GET_CODE (insn_dest) == SIGN_EXTRACT) | |
5564 | insn_dest = XEXP (insn_dest, 0); | |
5565 | ||
5566 | if (! rtx_equal_p (insn_dest, dest)) | |
5567 | { | |
5568 | /* Use the same scheme as combine.c, don't put both REG_DEAD | |
5569 | and REG_UNUSED notes on the same insn. */ | |
5570 | if (! find_regno_note (insn, REG_UNUSED, REGNO (dest)) | |
5571 | && ! find_regno_note (insn, REG_DEAD, REGNO (dest))) | |
5572 | { | |
5573 | rtx note = rtx_alloc (EXPR_LIST); | |
5574 | PUT_REG_NOTE_KIND (note, REG_DEAD); | |
5575 | XEXP (note, 0) = dest; | |
5576 | XEXP (note, 1) = REG_NOTES (insn); | |
5577 | REG_NOTES (insn) = note; | |
5578 | } | |
5579 | return 1; | |
5580 | } | |
5581 | } | |
5582 | return 0; | |
5583 | } | |
5584 | ||
5585 | /* Find the first insn in the set of insns from FIRST to LAST inclusive | |
5586 | that contains the note NOTE. */ | |
5587 | rtx | |
5588 | find_insn_with_note (note, first, last) | |
5589 | rtx note, first, last; | |
5590 | { | |
5591 | rtx insn; | |
5592 | ||
5593 | for (insn = first; insn != NULL_RTX; insn = NEXT_INSN (insn)) | |
5594 | { | |
5595 | rtx temp = find_reg_note (insn, REG_NOTE_KIND (note), XEXP (note, 0)); | |
5596 | if (temp == note) | |
5597 | { | |
5598 | return insn; | |
5599 | } | |
5600 | if (insn == last) | |
5601 | { | |
5602 | break; | |
5603 | } | |
5604 | } | |
5605 | return NULL_RTX; | |
5606 | } | |
5607 | ||
5608 | /* Subroutine of update_life_info. Determines whether a SET or | |
5609 | CLOBBER in an insn created by splitting needs a REG_DEAD or | |
5610 | REG_UNUSED note added. */ | |
5611 | ||
5612 | static void | |
5613 | new_insn_dead_notes (pat, insn, first, last, orig_first_insn, orig_last_insn) | |
5614 | rtx pat, insn, first, last, orig_first_insn, orig_last_insn; | |
5615 | { | |
5616 | rtx dest, tem; | |
5617 | ||
5618 | if (GET_CODE (pat) != CLOBBER && GET_CODE (pat) != SET) | |
5619 | abort (); | |
5620 | ||
5621 | dest = XEXP (pat, 0); | |
5622 | ||
5623 | while (GET_CODE (dest) == ZERO_EXTRACT || GET_CODE (dest) == SUBREG | |
5624 | || GET_CODE (dest) == STRICT_LOW_PART | |
5625 | || GET_CODE (dest) == SIGN_EXTRACT) | |
5626 | dest = XEXP (dest, 0); | |
5627 | ||
5628 | if (GET_CODE (dest) == REG) | |
5629 | { | |
9831d640 | 5630 | #if 0 |
f2a1bc02 BM |
5631 | /* If the original insns already used this register, we may not |
5632 | add new notes for it. One example for a replacement that | |
5633 | needs this test is when a multi-word memory access with | |
5634 | register-indirect addressing is changed into multiple memory | |
5635 | accesses with auto-increment and one adjusting add | |
5636 | instruction for the address register. | |
5637 | ||
5638 | However, there is a problem with this code. We're assuming | |
5639 | that any registers that are set in the new insns are either | |
5640 | set/referenced in the old insns (and thus "inherit" the | |
5641 | liveness of the old insns), or are registers that are dead | |
5642 | before we enter this part of the stream (and thus should be | |
5643 | dead when we leave). | |
5644 | ||
5645 | To do this absolutely correctly, we must determine the actual | |
5646 | liveness of the registers before we go randomly adding | |
5647 | REG_DEAD notes. This can probably be accurately done by | |
5648 | calling mark_referenced_resources() on the old stream before | |
5649 | replacing the old insns. */ | |
9831d640 RH |
5650 | /* ??? The conclusion reached here -- that we can't add DEAD notes |
5651 | when the register is preexisting -- is false. I can't envision | |
5652 | a sequence postulated above that wouldn't be properly handled | |
5653 | by the code below. In the meantime, consider the 1->2 split | |
5654 | ||
5655 | (set (reg:SI 100) (ne:SI (reg:SI 100) (const_int 0))) | |
5656 | to | |
5657 | (set (reg:CC icc) (compare:CC (reg:SI 100) (const_int 0))) | |
5658 | (set (reg:SI 100) (ne:SI (reg:CC icc) (const_int 0))) | |
5659 | ||
5660 | We do in fact need a new DEAD note on the first insn for reg 100. */ | |
f2a1bc02 BM |
5661 | |
5662 | for (tem = orig_first_insn; tem != NULL_RTX; tem = NEXT_INSN (tem)) | |
5663 | { | |
5664 | if (GET_RTX_CLASS (GET_CODE (tem)) == 'i' | |
5665 | && reg_referenced_p (dest, PATTERN (tem))) | |
5666 | return; | |
5667 | if (tem == orig_last_insn) | |
5668 | break; | |
5669 | } | |
9831d640 | 5670 | #endif |
963d4411 | 5671 | |
f2a1bc02 BM |
5672 | /* So it's a new register, presumably only used within this |
5673 | group of insns. Find the last insn in the set of new insns | |
5674 | that DEST is referenced in, and add a dead note to it. */ | |
5675 | if (! maybe_add_dead_note (dest, insn, last)) | |
5676 | { | |
5677 | /* If this is a set, it must die somewhere, unless it is the | |
5678 | dest of the original insn, and thus is live after the | |
5679 | original insn. Abort if it isn't supposed to be live after | |
5680 | the original insn. | |
5681 | ||
5682 | If this is a clobber, then just add a REG_UNUSED note. */ | |
5683 | if (GET_CODE (pat) == CLOBBER) | |
5684 | { | |
5685 | rtx note = rtx_alloc (EXPR_LIST); | |
5686 | PUT_REG_NOTE_KIND (note, REG_UNUSED); | |
5687 | XEXP (note, 0) = dest; | |
5688 | XEXP (note, 1) = REG_NOTES (insn); | |
5689 | REG_NOTES (insn) = note; | |
5690 | return; | |
5691 | } | |
5692 | else | |
5693 | { | |
f2a1bc02 | 5694 | rtx curr; |
963d4411 | 5695 | int got_set = 0; |
f2a1bc02 | 5696 | |
963d4411 | 5697 | for (curr = orig_first_insn; curr; curr = NEXT_INSN (curr)) |
f2a1bc02 | 5698 | { |
963d4411 RH |
5699 | got_set = sets_reg_or_subreg (curr, dest); |
5700 | if (got_set) | |
f2a1bc02 BM |
5701 | break; |
5702 | if (curr == orig_last_insn) | |
5703 | break; | |
5704 | } | |
5705 | ||
5706 | /* In case reg was not used later, it is dead store. | |
5707 | add REG_UNUSED note. */ | |
963d4411 | 5708 | if (! got_set) |
f2a1bc02 BM |
5709 | { |
5710 | rtx note = rtx_alloc (EXPR_LIST); | |
5711 | PUT_REG_NOTE_KIND (note, REG_UNUSED); | |
5712 | XEXP (note, 0) = dest; | |
5713 | XEXP (note, 1) = REG_NOTES (insn); | |
5714 | REG_NOTES (insn) = note; | |
5715 | return; | |
5716 | } | |
5717 | } | |
5718 | } | |
963d4411 | 5719 | |
f2a1bc02 BM |
5720 | if (insn != first) |
5721 | { | |
5722 | rtx set = single_set (insn); | |
963d4411 | 5723 | |
f2a1bc02 BM |
5724 | /* If this is a set, scan backwards for a previous |
5725 | reference, and attach a REG_DEAD note to it. But we don't | |
5726 | want to do it if the insn is both using and setting the | |
5727 | register. | |
5728 | ||
5729 | Global registers are always live. */ | |
5730 | if (set && ! reg_overlap_mentioned_p (dest, SET_SRC (pat)) | |
5731 | && (REGNO (dest) >= FIRST_PSEUDO_REGISTER | |
5732 | || ! global_regs[REGNO (dest)])) | |
5733 | { | |
5734 | for (tem = PREV_INSN (insn); | |
5735 | tem != NULL_RTX; tem = PREV_INSN (tem)) | |
5736 | { | |
5737 | if (maybe_add_dead_note_use (tem, dest)) | |
5738 | break; | |
5739 | if (tem == first) | |
5740 | break; | |
5741 | } | |
5742 | } | |
5743 | } | |
5744 | } | |
5745 | } | |
5746 | ||
5747 | /* Subroutine of update_life_info. Update the value of reg_n_sets for all | |
5748 | registers modified by X. INC is -1 if the containing insn is being deleted, | |
5749 | and is 1 if the containing insn is a newly generated insn. */ | |
5750 | ||
5751 | static void | |
5752 | update_n_sets (x, inc) | |
5753 | rtx x; | |
5754 | int inc; | |
5755 | { | |
5756 | rtx dest = SET_DEST (x); | |
5757 | ||
5758 | while (GET_CODE (dest) == STRICT_LOW_PART || GET_CODE (dest) == SUBREG | |
5759 | || GET_CODE (dest) == ZERO_EXTRACT || GET_CODE (dest) == SIGN_EXTRACT) | |
5760 | dest = SUBREG_REG (dest); | |
5761 | ||
5762 | if (GET_CODE (dest) == REG) | |
5763 | { | |
5764 | int regno = REGNO (dest); | |
5765 | ||
5766 | if (regno < FIRST_PSEUDO_REGISTER) | |
5767 | { | |
5768 | register int i; | |
5769 | int endregno = regno + HARD_REGNO_NREGS (regno, GET_MODE (dest)); | |
5770 | ||
5771 | for (i = regno; i < endregno; i++) | |
5772 | REG_N_SETS (i) += inc; | |
5773 | } | |
5774 | else | |
5775 | REG_N_SETS (regno) += inc; | |
5776 | } | |
5777 | } | |
5778 | ||
5779 | /* Scan INSN for a SET that sets REG. If it sets REG via a SUBREG, | |
5780 | then return 2. If it sets REG directly, return 1. Otherwise, return | |
5781 | 0. */ | |
5782 | ||
5783 | static int sets_reg_or_subreg_ret; | |
5784 | static rtx sets_reg_or_subreg_rtx; | |
5785 | ||
5786 | static void | |
5787 | sets_reg_or_subreg_1 (x, set) | |
5788 | rtx x, set; | |
5789 | { | |
5790 | if (rtx_equal_p (x, sets_reg_or_subreg_rtx)) | |
5791 | { | |
5792 | if (x == XEXP (set, 0)) | |
5793 | sets_reg_or_subreg_ret = 1; | |
5794 | else if (GET_CODE (XEXP (set, 0)) == SUBREG) | |
5795 | sets_reg_or_subreg_ret = 2; | |
5796 | } | |
5797 | } | |
5798 | ||
5799 | static int | |
5800 | sets_reg_or_subreg (insn, reg) | |
5801 | rtx insn; | |
5802 | rtx reg; | |
5803 | { | |
5804 | if (GET_RTX_CLASS (GET_CODE (insn)) != 'i') | |
5805 | return 0; | |
5806 | ||
5807 | sets_reg_or_subreg_ret = 0; | |
5808 | sets_reg_or_subreg_rtx = reg; | |
5809 | note_stores (PATTERN (insn), sets_reg_or_subreg_1); | |
5810 | return sets_reg_or_subreg_ret; | |
5811 | } | |
5812 | ||
5813 | /* If a replaced SET_INSN (which is part of the insns between | |
5814 | OLD_FIRST_INSN and OLD_LAST_INSN inclusive) is modifying a multiple | |
5815 | register target, and the original dest is now set in the new insns | |
5816 | (between FIRST_INSN and LAST_INSN inclusive) by one or more subreg | |
5817 | sets, then the new insns no longer kill the destination of the | |
5818 | original insn. | |
5819 | ||
5820 | We may also be directly using the register in the new insns before | |
5821 | setting it. | |
5822 | ||
5823 | In either case, if there exists an instruction in the same basic | |
5824 | block before the replaced insns which uses the original dest (and | |
5825 | contains a corresponding REG_DEAD note), then we must remove this | |
5826 | REG_DEAD note. | |
5827 | ||
5828 | SET_INSN is the insn that contains the SET; it may be a PARALLEL | |
5829 | containing the SET insn. | |
5830 | ||
5831 | SET is the actual SET insn proper. */ | |
5832 | ||
5833 | static void | |
5834 | maybe_remove_dead_notes (set_insn, set, first_insn, last_insn, | |
5835 | old_first_insn, old_last_insn) | |
5836 | rtx set_insn, set; | |
5837 | rtx first_insn, last_insn; | |
5838 | rtx old_first_insn, old_last_insn; | |
5839 | { | |
5840 | rtx insn; | |
5841 | rtx stop_insn = NEXT_INSN (last_insn); | |
5842 | int set_type = 0; | |
5843 | rtx set_dest; | |
5844 | rtx set_pattern; | |
5845 | ||
5846 | if (GET_RTX_CLASS (GET_CODE (set)) != 'i') | |
5847 | return; | |
5848 | ||
5849 | set_pattern = PATTERN (set); | |
5850 | ||
5851 | if (GET_CODE (set_pattern) == PARALLEL) | |
5852 | { | |
5853 | int i; | |
5854 | ||
5855 | for (i = 0; i < XVECLEN (set_pattern, 0); i++) | |
5856 | { | |
5857 | maybe_remove_dead_notes (set_insn, XVECEXP (set_pattern, 0, i), | |
5858 | first_insn, last_insn, | |
5859 | old_first_insn, old_last_insn); | |
5860 | } | |
5861 | return; | |
5862 | } | |
5863 | ||
5864 | if (GET_CODE (set_pattern) != SET) | |
5865 | { | |
5866 | return; | |
5867 | } | |
5868 | ||
5869 | set_dest = SET_DEST (set_pattern); | |
5870 | ||
5871 | if (GET_CODE (set_dest) != REG) | |
5872 | { | |
5873 | return; | |
5874 | } | |
5875 | ||
5876 | /* We have a set of a REG. First we need to determine if this set is | |
5877 | both using and setting the register. (FIXME: if this is in a | |
5878 | PARALLEL, we will have to check the other exprs as well.) */ | |
5879 | if (reg_overlap_mentioned_p (set_dest, SET_SRC (set_pattern))) | |
5880 | { | |
5881 | return; | |
5882 | } | |
5883 | ||
5884 | /* Now determine if we used or set the register in the old insns | |
5885 | previous to this one. */ | |
5886 | ||
5887 | for (insn = old_first_insn; insn != set_insn; insn = NEXT_INSN (insn)) | |
5888 | { | |
5889 | if (reg_overlap_mentioned_p (set_dest, insn)) | |
5890 | { | |
5891 | return; | |
5892 | } | |
5893 | } | |
5894 | ||
5895 | /* Now determine if we're setting it in the new insns, or using | |
5896 | it. */ | |
5897 | for (insn = first_insn; insn != stop_insn; insn = NEXT_INSN (insn)) | |
5898 | { | |
5899 | set_type = sets_reg_or_subreg (insn, set_dest); | |
5900 | if (set_type != 0) | |
5901 | { | |
5902 | break; | |
5903 | } | |
5904 | else if (reg_overlap_mentioned_p (set_dest, insn)) | |
5905 | { | |
5906 | /* Is the reg now used in this new insn? -- This is probably an | |
5907 | error. */ | |
5908 | set_type = 2; | |
5909 | break; | |
5910 | } | |
5911 | } | |
5912 | if (set_type == 2) | |
5913 | { | |
5914 | /* The register is being set via a SUBREG or is being used in | |
5915 | some other way, so it's no longer dead. | |
5916 | ||
5917 | Search backwards from first_insn, looking for the first insn | |
5918 | that uses the original dest. Stop if we pass a CODE_LABEL or | |
5919 | a JUMP_INSN. | |
5920 | ||
5921 | If we find such an insn and it has a REG_DEAD note referring | |
5922 | to the original dest, then delete the note. */ | |
5923 | ||
5924 | for (insn = first_insn; insn != NULL_RTX; insn = PREV_INSN (insn)) | |
5925 | { | |
5926 | if (GET_CODE (insn) == CODE_LABEL | |
5927 | || GET_CODE (insn) == JUMP_INSN) | |
5928 | break; | |
5929 | else if (GET_RTX_CLASS (GET_CODE (insn)) == 'i' | |
5930 | && reg_mentioned_p (set_dest, insn)) | |
5931 | { | |
5932 | rtx note = find_regno_note (insn, REG_DEAD, REGNO (set_dest)); | |
5933 | if (note != NULL_RTX) | |
5934 | { | |
5935 | remove_note (insn, note); | |
5936 | } | |
5937 | /* ??? -- Is this right? */ | |
5938 | break; | |
5939 | } | |
5940 | } | |
5941 | } | |
5942 | else if (set_type == 0) | |
5943 | { | |
5944 | /* The reg is not being set or used in the new insns at all. */ | |
5945 | int i, regno; | |
5946 | ||
5947 | /* Should never reach here for a pseudo reg. */ | |
5948 | if (REGNO (set_dest) >= FIRST_PSEUDO_REGISTER) | |
5949 | abort (); | |
5950 | ||
5951 | /* This can happen for a hard register, if the new insns do not | |
5952 | contain instructions which would be no-ops referring to the | |
5953 | old registers. | |
5954 | ||
5955 | We try to verify that this is the case by checking to see if | |
5956 | the original instruction uses all of the registers that it | |
5957 | set. This case is OK, because deleting a no-op can not affect | |
5958 | REG_DEAD notes on other insns. If this is not the case, then | |
5959 | abort. */ | |
5960 | ||
5961 | regno = REGNO (set_dest); | |
5962 | for (i = HARD_REGNO_NREGS (regno, GET_MODE (set_dest)) - 1; | |
5963 | i >= 0; i--) | |
5964 | { | |
5965 | if (! refers_to_regno_p (regno + i, regno + i + 1, set, | |
5966 | NULL_PTR)) | |
5967 | break; | |
5968 | } | |
5969 | if (i >= 0) | |
5970 | abort (); | |
5971 | } | |
5972 | } | |
5973 | ||
5974 | /* Updates all flow-analysis related quantities (including REG_NOTES) for | |
5975 | the insns from FIRST to LAST inclusive that were created by replacing | |
5976 | the insns from ORIG_INSN_FIRST to ORIG_INSN_LAST inclusive. NOTES | |
5977 | are the original REG_NOTES. */ | |
5978 | ||
5979 | void | |
5980 | update_life_info (notes, first, last, orig_first_insn, orig_last_insn) | |
5981 | rtx notes; | |
5982 | rtx first, last; | |
5983 | rtx orig_first_insn, orig_last_insn; | |
5984 | { | |
5985 | rtx insn, note; | |
5986 | rtx next; | |
5987 | rtx orig_dest, temp; | |
5988 | rtx orig_insn; | |
5989 | rtx tem; | |
5990 | ||
5991 | /* Get and save the destination set by the original insn, if there | |
5992 | was only one insn replaced. */ | |
5993 | ||
5994 | if (orig_first_insn == orig_last_insn) | |
5995 | { | |
5996 | orig_insn = orig_first_insn; | |
5997 | orig_dest = single_set (orig_insn); | |
5998 | if (orig_dest) | |
5999 | orig_dest = SET_DEST (orig_dest); | |
6000 | } | |
6001 | else | |
6002 | { | |
6003 | orig_insn = NULL_RTX; | |
6004 | orig_dest = NULL_RTX; | |
6005 | } | |
6006 | ||
6007 | /* Move REG_NOTES from the original insns to where they now belong. */ | |
6008 | ||
6009 | for (note = notes; note; note = next) | |
6010 | { | |
6011 | next = XEXP (note, 1); | |
6012 | switch (REG_NOTE_KIND (note)) | |
6013 | { | |
6014 | case REG_DEAD: | |
6015 | case REG_UNUSED: | |
6016 | /* Move these notes from the original insn to the last new | |
6017 | insn where the register is mentioned. */ | |
6018 | ||
6019 | for (insn = last; ; insn = PREV_INSN (insn)) | |
6020 | { | |
6021 | if (GET_RTX_CLASS (GET_CODE (insn)) == 'i' | |
6022 | && reg_mentioned_p (XEXP (note, 0), PATTERN (insn))) | |
6023 | { | |
6024 | /* Sometimes need to convert REG_UNUSED notes to | |
6025 | REG_DEAD notes. */ | |
6026 | if (REG_NOTE_KIND (note) == REG_UNUSED | |
6027 | && GET_CODE (XEXP (note, 0)) == REG | |
6028 | && ! dead_or_set_p (insn, XEXP (note, 0))) | |
6029 | { | |
6030 | PUT_REG_NOTE_KIND (note, REG_DEAD); | |
6031 | } | |
6032 | split_hard_reg_notes (insn, note, first, last); | |
6033 | /* The reg only dies in one insn, the last one that uses | |
6034 | it. */ | |
6035 | break; | |
6036 | } | |
6037 | /* It must die somewhere, fail if we couldn't find where it died. | |
6038 | ||
6039 | We abort because otherwise the register will be live | |
6040 | longer than it should, and we'll probably take an | |
6041 | abort later. What we should do instead is search back | |
6042 | and find the appropriate places to insert the note. */ | |
6043 | if (insn == first) | |
6044 | { | |
6045 | if (REG_NOTE_KIND (note) == REG_DEAD) | |
6046 | { | |
6047 | abort (); | |
6048 | } | |
6049 | break; | |
6050 | } | |
6051 | } | |
6052 | break; | |
6053 | ||
6054 | case REG_WAS_0: | |
6055 | { | |
6056 | rtx note_dest; | |
6057 | ||
6058 | /* If the insn that set the register to 0 was deleted, this | |
6059 | note cannot be relied on any longer. The destination might | |
6060 | even have been moved to memory. | |
6061 | This was observed for SH4 with execute/920501-6.c compilation, | |
6062 | -O2 -fomit-frame-pointer -finline-functions . */ | |
6063 | ||
6064 | if (GET_CODE (XEXP (note, 0)) == NOTE | |
6065 | || INSN_DELETED_P (XEXP (note, 0))) | |
6066 | break; | |
6067 | if (orig_insn != NULL_RTX) | |
6068 | { | |
6069 | note_dest = orig_dest; | |
6070 | } | |
6071 | else | |
6072 | { | |
5aabad00 RH |
6073 | note_dest = find_insn_with_note (note, orig_first_insn, |
6074 | orig_last_insn); | |
f2a1bc02 BM |
6075 | if (note_dest != NULL_RTX) |
6076 | { | |
5aabad00 | 6077 | note_dest = single_set (note_dest); |
f2a1bc02 | 6078 | if (note_dest != NULL_RTX) |
5aabad00 | 6079 | note_dest = SET_DEST (note_dest); |
f2a1bc02 BM |
6080 | } |
6081 | } | |
6082 | /* This note applies to the dest of the original insn. Find the | |
6083 | first new insn that now has the same dest, and move the note | |
6084 | there. */ | |
6085 | ||
6086 | if (! note_dest) | |
5aabad00 | 6087 | break; |
f2a1bc02 BM |
6088 | |
6089 | for (insn = first; ; insn = NEXT_INSN (insn)) | |
6090 | { | |
6091 | if (GET_RTX_CLASS (GET_CODE (insn)) == 'i' | |
6092 | && (temp = single_set (insn)) | |
6093 | && rtx_equal_p (SET_DEST (temp), note_dest)) | |
6094 | { | |
6095 | XEXP (note, 1) = REG_NOTES (insn); | |
6096 | REG_NOTES (insn) = note; | |
6097 | /* The reg is only zero before one insn, the first that | |
6098 | uses it. */ | |
6099 | break; | |
6100 | } | |
6101 | /* If this note refers to a multiple word hard | |
6102 | register, it may have been split into several smaller | |
6103 | hard register references. We could split the notes, | |
6104 | but simply dropping them is good enough. */ | |
6105 | if (GET_CODE (note_dest) == REG | |
6106 | && REGNO (note_dest) < FIRST_PSEUDO_REGISTER | |
6107 | && HARD_REGNO_NREGS (REGNO (note_dest), | |
6108 | GET_MODE (note_dest)) > 1) | |
6109 | break; | |
5aabad00 RH |
6110 | |
6111 | /* It must be set somewhere; bail if we couldn't find | |
f2a1bc02 | 6112 | where it was set. */ |
f2a1bc02 BM |
6113 | } |
6114 | } | |
6115 | break; | |
6116 | ||
6117 | case REG_EQUAL: | |
6118 | case REG_EQUIV: | |
6119 | /* A REG_EQUIV or REG_EQUAL note on an insn with more than one | |
6120 | set is meaningless. Just drop the note. */ | |
6121 | if (! orig_dest) | |
6122 | break; | |
6123 | ||
6124 | case REG_NO_CONFLICT: | |
5aabad00 | 6125 | case REG_NOALIAS: |
f2a1bc02 BM |
6126 | /* These notes apply to the dest of the original insn. Find the last |
6127 | new insn that now has the same dest, and move the note there. | |
6128 | ||
6129 | If we are replacing multiple insns, just drop the note. */ | |
6130 | ||
6131 | if (! orig_insn) | |
6132 | break; | |
6133 | ||
6134 | if (! orig_dest) | |
6135 | abort (); | |
6136 | ||
6137 | for (insn = last; ; insn = PREV_INSN (insn)) | |
6138 | { | |
6139 | if (GET_RTX_CLASS (GET_CODE (insn)) == 'i' | |
6140 | && (temp = single_set (insn)) | |
6141 | && rtx_equal_p (SET_DEST (temp), orig_dest)) | |
6142 | { | |
6143 | XEXP (note, 1) = REG_NOTES (insn); | |
6144 | REG_NOTES (insn) = note; | |
6145 | /* Only put this note on one of the new insns. */ | |
6146 | break; | |
6147 | } | |
6148 | ||
6149 | /* The original dest must still be set someplace. Abort if we | |
6150 | couldn't find it. */ | |
6151 | if (insn == first) | |
6152 | { | |
6153 | /* However, if this note refers to a multiple word hard | |
6154 | register, it may have been split into several smaller | |
6155 | hard register references. We could split the notes, | |
6156 | but simply dropping them is good enough. */ | |
6157 | if (GET_CODE (orig_dest) == REG | |
6158 | && REGNO (orig_dest) < FIRST_PSEUDO_REGISTER | |
6159 | && HARD_REGNO_NREGS (REGNO (orig_dest), | |
6160 | GET_MODE (orig_dest)) > 1) | |
6161 | break; | |
6162 | /* Likewise for multi-word memory references. */ | |
6163 | if (GET_CODE (orig_dest) == MEM | |
6164 | && GET_MODE_SIZE (GET_MODE (orig_dest)) > MOVE_MAX) | |
6165 | break; | |
6166 | abort (); | |
6167 | } | |
6168 | } | |
6169 | break; | |
6170 | ||
6171 | case REG_LIBCALL: | |
6172 | /* Move a REG_LIBCALL note to the first insn created, and update | |
6173 | the corresponding REG_RETVAL note. */ | |
6174 | XEXP (note, 1) = REG_NOTES (first); | |
6175 | REG_NOTES (first) = note; | |
6176 | ||
6177 | insn = XEXP (note, 0); | |
6178 | note = find_reg_note (insn, REG_RETVAL, NULL_RTX); | |
6179 | if (note) | |
6180 | XEXP (note, 0) = first; | |
6181 | break; | |
6182 | ||
6183 | case REG_EXEC_COUNT: | |
6184 | /* Move a REG_EXEC_COUNT note to the first insn created. */ | |
6185 | XEXP (note, 1) = REG_NOTES (first); | |
6186 | REG_NOTES (first) = note; | |
6187 | break; | |
6188 | ||
6189 | case REG_RETVAL: | |
6190 | /* Move a REG_RETVAL note to the last insn created, and update | |
6191 | the corresponding REG_LIBCALL note. */ | |
6192 | XEXP (note, 1) = REG_NOTES (last); | |
6193 | REG_NOTES (last) = note; | |
6194 | ||
6195 | insn = XEXP (note, 0); | |
6196 | note = find_reg_note (insn, REG_LIBCALL, NULL_RTX); | |
6197 | if (note) | |
6198 | XEXP (note, 0) = last; | |
6199 | break; | |
6200 | ||
6201 | case REG_NONNEG: | |
6202 | case REG_BR_PROB: | |
6203 | /* This should be moved to whichever instruction is a JUMP_INSN. */ | |
6204 | ||
6205 | for (insn = last; ; insn = PREV_INSN (insn)) | |
6206 | { | |
6207 | if (GET_CODE (insn) == JUMP_INSN) | |
6208 | { | |
6209 | XEXP (note, 1) = REG_NOTES (insn); | |
6210 | REG_NOTES (insn) = note; | |
6211 | /* Only put this note on one of the new insns. */ | |
6212 | break; | |
6213 | } | |
6214 | /* Fail if we couldn't find a JUMP_INSN. */ | |
6215 | if (insn == first) | |
6216 | abort (); | |
6217 | } | |
6218 | break; | |
6219 | ||
6220 | case REG_INC: | |
6221 | /* reload sometimes leaves obsolete REG_INC notes around. */ | |
6222 | if (reload_completed) | |
6223 | break; | |
6224 | /* This should be moved to whichever instruction now has the | |
6225 | increment operation. */ | |
6226 | abort (); | |
6227 | ||
6228 | case REG_LABEL: | |
6229 | /* Should be moved to the new insn(s) which use the label. */ | |
6230 | for (insn = first; insn != NEXT_INSN (last); insn = NEXT_INSN (insn)) | |
6231 | if (GET_RTX_CLASS (GET_CODE (insn)) == 'i' | |
6232 | && reg_mentioned_p (XEXP (note, 0), PATTERN (insn))) | |
6233 | REG_NOTES (insn) = gen_rtx_EXPR_LIST (REG_LABEL, | |
6234 | XEXP (note, 0), | |
6235 | REG_NOTES (insn)); | |
6236 | break; | |
6237 | ||
6238 | case REG_CC_SETTER: | |
6239 | case REG_CC_USER: | |
6240 | /* These two notes will never appear until after reorg, so we don't | |
6241 | have to handle them here. */ | |
6242 | default: | |
6243 | abort (); | |
6244 | } | |
6245 | } | |
6246 | ||
6247 | /* Each new insn created has a new set. If the destination is a | |
6248 | register, then this reg is now live across several insns, whereas | |
6249 | previously the dest reg was born and died within the same insn. | |
6250 | To reflect this, we now need a REG_DEAD note on the insn where | |
6251 | this dest reg dies. | |
6252 | ||
6253 | Similarly, the new insns may have clobbers that need REG_UNUSED | |
6254 | notes. */ | |
6255 | ||
6256 | for (insn = first; ;insn = NEXT_INSN (insn)) | |
6257 | { | |
6258 | rtx pat; | |
6259 | int i; | |
6260 | ||
6261 | pat = PATTERN (insn); | |
6262 | if (GET_CODE (pat) == SET || GET_CODE (pat) == CLOBBER) | |
6263 | new_insn_dead_notes (pat, insn, first, last, | |
6264 | orig_first_insn, orig_last_insn); | |
6265 | else if (GET_CODE (pat) == PARALLEL) | |
6266 | { | |
6267 | for (i = 0; i < XVECLEN (pat, 0); i++) | |
6268 | { | |
6269 | if (GET_CODE (XVECEXP (pat, 0, i)) == SET | |
6270 | || GET_CODE (XVECEXP (pat, 0, i)) == CLOBBER) | |
6271 | { | |
6272 | rtx parpat = XVECEXP (pat, 0, i); | |
6273 | ||
6274 | new_insn_dead_notes (parpat, insn, first, last, | |
6275 | orig_first_insn, orig_last_insn); | |
6276 | } | |
6277 | } | |
6278 | } | |
6279 | if (insn == last) | |
6280 | { | |
6281 | break; | |
6282 | } | |
6283 | } | |
6284 | ||
6285 | /* Check to see if we have any REG_DEAD notes on insns previous to | |
6286 | the new ones that are now incorrect and need to be removed. */ | |
6287 | ||
6288 | for (insn = orig_first_insn; ; insn = NEXT_INSN (insn)) | |
6289 | { | |
6290 | maybe_remove_dead_notes (insn, insn, first, last, | |
6291 | orig_first_insn, orig_last_insn); | |
6292 | ||
6293 | if (insn == orig_last_insn) | |
6294 | break; | |
6295 | } | |
6296 | ||
6297 | /* Update reg_n_sets. This is necessary to prevent local alloc from | |
6298 | converting REG_EQUAL notes to REG_EQUIV when the new insns are setting | |
6299 | a reg multiple times instead of once. */ | |
6300 | ||
6301 | for (tem = orig_first_insn; tem != NULL_RTX; tem = NEXT_INSN (tem)) | |
6302 | { | |
6303 | rtx x; | |
6304 | RTX_CODE code; | |
6305 | ||
6306 | if (GET_RTX_CLASS (GET_CODE (tem)) != 'i') | |
6307 | continue; | |
6308 | ||
6309 | x = PATTERN (tem); | |
6310 | code = GET_CODE (x); | |
6311 | if (code == SET || code == CLOBBER) | |
6312 | update_n_sets (x, -1); | |
6313 | else if (code == PARALLEL) | |
6314 | { | |
6315 | int i; | |
6316 | for (i = XVECLEN (x, 0) - 1; i >= 0; i--) | |
6317 | { | |
6318 | code = GET_CODE (XVECEXP (x, 0, i)); | |
6319 | if (code == SET || code == CLOBBER) | |
6320 | update_n_sets (XVECEXP (x, 0, i), -1); | |
6321 | } | |
6322 | } | |
6323 | if (tem == orig_last_insn) | |
6324 | break; | |
6325 | } | |
6326 | ||
6327 | for (insn = first; ; insn = NEXT_INSN (insn)) | |
6328 | { | |
6329 | rtx x = PATTERN (insn); | |
6330 | RTX_CODE code = GET_CODE (x); | |
6331 | ||
6332 | if (code == SET || code == CLOBBER) | |
6333 | update_n_sets (x, 1); | |
6334 | else if (code == PARALLEL) | |
6335 | { | |
6336 | int i; | |
6337 | for (i = XVECLEN (x, 0) - 1; i >= 0; i--) | |
6338 | { | |
6339 | code = GET_CODE (XVECEXP (x, 0, i)); | |
6340 | if (code == SET || code == CLOBBER) | |
6341 | update_n_sets (XVECEXP (x, 0, i), 1); | |
6342 | } | |
6343 | } | |
6344 | ||
6345 | if (insn == last) | |
6346 | break; | |
6347 | } | |
6348 | } | |
6349 | \f | |
6350 | /* Prepends the set of REG_NOTES in NEW to NOTES, and returns NEW. */ | |
6351 | static rtx | |
6352 | prepend_reg_notes (notes, new) | |
6353 | rtx notes, new; | |
6354 | { | |
6355 | rtx end; | |
6356 | ||
6357 | if (new == NULL_RTX) | |
6358 | { | |
6359 | return notes; | |
6360 | } | |
6361 | if (notes == NULL_RTX) | |
6362 | { | |
6363 | return new; | |
6364 | } | |
6365 | end = new; | |
6366 | while (XEXP (end, 1) != NULL_RTX) | |
6367 | { | |
6368 | end = XEXP (end, 1); | |
6369 | } | |
6370 | XEXP (end, 1) = notes; | |
6371 | return new; | |
6372 | } | |
6373 | \f | |
6374 | /* Replace the insns from FIRST to LAST inclusive with the set of insns in | |
6375 | NEW, and update the life analysis info accordingly. */ | |
6376 | void | |
6377 | replace_insns (first, last, first_new, notes) | |
6378 | rtx first, last, first_new, notes; | |
6379 | { | |
6380 | rtx stop = NEXT_INSN (last); | |
f2a1bc02 | 6381 | rtx prev = PREV_INSN (first); |
e2bef702 | 6382 | rtx last_new, curr; |
f2a1bc02 BM |
6383 | int i; |
6384 | ||
6385 | if (notes == NULL_RTX) | |
6386 | { | |
6387 | for (curr = first; curr != stop; curr = NEXT_INSN (curr)) | |
5aabad00 | 6388 | if (GET_RTX_CLASS (GET_CODE (curr)) == 'i') |
f2a1bc02 | 6389 | notes = prepend_reg_notes (notes, REG_NOTES (curr)); |
f2a1bc02 | 6390 | } |
5aabad00 | 6391 | |
f2a1bc02 BM |
6392 | last_new = emit_insn_after (first_new, prev); |
6393 | first_new = NEXT_INSN (prev); | |
5aabad00 | 6394 | |
f2a1bc02 BM |
6395 | for (i = 0; i < n_basic_blocks; i++) |
6396 | { | |
6397 | if (BLOCK_HEAD (i) == first) | |
5aabad00 | 6398 | BLOCK_HEAD (i) = first_new; |
f2a1bc02 | 6399 | if (BLOCK_END (i) == last) |
5aabad00 | 6400 | BLOCK_END (i) = last_new; |
f2a1bc02 BM |
6401 | } |
6402 | /* This is probably bogus. */ | |
6403 | if (first_new == last_new) | |
6404 | { | |
6405 | if (GET_CODE (first_new) == SEQUENCE) | |
6406 | { | |
6407 | first_new = XVECEXP (first_new, 0, 0); | |
6408 | last_new = XVECEXP (last_new, 0, XVECLEN (last_new, 0) - 1); | |
6409 | } | |
6410 | } | |
6411 | update_life_info (notes, first_new, last_new, first, last); | |
5aabad00 | 6412 | flow_delete_insn_chain (first, last); |
f2a1bc02 BM |
6413 | } |
6414 | \f | |
34487bf8 RH |
6415 | /* Verify the CFG consistency. This function check some CFG invariants and |
6416 | aborts when something is wrong. Hope that this function will help to | |
6417 | convert many optimization passes to preserve CFG consistent. | |
6418 | ||
6419 | Currently it does following checks: | |
6420 | ||
6421 | - test head/end pointers | |
6422 | - overlapping of basic blocks | |
6423 | - edge list corectness | |
6424 | - headers of basic blocks (the NOTE_INSN_BASIC_BLOCK note) | |
6425 | - tails of basic blocks (ensure that boundary is necesary) | |
6426 | - scans body of the basic block for JUMP_INSN, CODE_LABEL | |
6427 | and NOTE_INSN_BASIC_BLOCK | |
6428 | - check that all insns are in the basic blocks | |
6429 | (except the switch handling code, barriers and notes) | |
6430 | ||
6431 | In future it can be extended check a lot of other stuff as well | |
6432 | (reachability of basic blocks, life information, etc. etc.). */ | |
6433 | ||
6434 | void | |
6435 | verify_flow_info () | |
6436 | { | |
6437 | const int max_uid = get_max_uid (); | |
6438 | const rtx rtx_first = get_insns (); | |
6439 | basic_block *bb_info; | |
6440 | rtx x; | |
6441 | int i; | |
6442 | ||
6443 | bb_info = (basic_block *) alloca (max_uid * sizeof (basic_block)); | |
6444 | memset (bb_info, 0, max_uid * sizeof (basic_block)); | |
6445 | ||
6446 | /* First pass check head/end pointers and set bb_info array used by | |
6447 | later passes. */ | |
6448 | for (i = n_basic_blocks - 1; i >= 0; i--) | |
6449 | { | |
6450 | basic_block bb = BASIC_BLOCK (i); | |
6451 | ||
6452 | /* Check the head pointer and make sure that it is pointing into | |
6453 | insn list. */ | |
6454 | for (x = rtx_first; x != NULL_RTX; x = NEXT_INSN (x)) | |
6455 | if (x == bb->head) | |
6456 | break; | |
6457 | if (!x) | |
6458 | { | |
987009bf | 6459 | error ("Head insn %d for block %d not found in the insn stream.", |
34487bf8 | 6460 | INSN_UID (bb->head), bb->index); |
987009bf | 6461 | abort (); |
34487bf8 RH |
6462 | } |
6463 | ||
6464 | /* Check the end pointer and make sure that it is pointing into | |
6465 | insn list. */ | |
6466 | for (x = bb->head; x != NULL_RTX; x = NEXT_INSN (x)) | |
6467 | { | |
6468 | if (bb_info[INSN_UID (x)] != NULL) | |
6469 | { | |
987009bf | 6470 | error ("Insn %d is in multiple basic blocks (%d and %d)", |
34487bf8 | 6471 | INSN_UID (x), bb->index, bb_info[INSN_UID (x)]->index); |
987009bf | 6472 | abort (); |
34487bf8 RH |
6473 | } |
6474 | bb_info[INSN_UID (x)] = bb; | |
6475 | ||
6476 | if (x == bb->end) | |
6477 | break; | |
6478 | } | |
6479 | if (!x) | |
6480 | { | |
987009bf | 6481 | error ("End insn %d for block %d not found in the insn stream.", |
34487bf8 | 6482 | INSN_UID (bb->end), bb->index); |
987009bf | 6483 | abort (); |
34487bf8 RH |
6484 | } |
6485 | } | |
6486 | ||
6487 | /* Now check the basic blocks (boundaries etc.) */ | |
6488 | for (i = n_basic_blocks - 1; i >= 0; i--) | |
6489 | { | |
6490 | basic_block bb = BASIC_BLOCK (i); | |
6491 | /* Check corectness of edge lists */ | |
6492 | edge e; | |
6493 | ||
6494 | e = bb->succ; | |
6495 | while (e) | |
6496 | { | |
6497 | if (e->src != bb) | |
6498 | { | |
6499 | fprintf (stderr, "verify_flow_info: Basic block %d succ edge is corrupted\n", | |
6500 | bb->index); | |
6501 | fprintf (stderr, "Predecessor: "); | |
6502 | dump_edge_info (stderr, e, 0); | |
6503 | fprintf (stderr, "\nSuccessor: "); | |
6504 | dump_edge_info (stderr, e, 1); | |
6505 | fflush (stderr); | |
6506 | abort (); | |
6507 | } | |
6508 | if (e->dest != EXIT_BLOCK_PTR) | |
6509 | { | |
6510 | edge e2 = e->dest->pred; | |
6511 | while (e2 && e2 != e) | |
6512 | e2 = e2->pred_next; | |
6513 | if (!e2) | |
6514 | { | |
987009bf ZW |
6515 | error ("Basic block %i edge lists are corrupted", bb->index); |
6516 | abort (); | |
34487bf8 RH |
6517 | } |
6518 | } | |
6519 | e = e->succ_next; | |
6520 | } | |
6521 | ||
6522 | e = bb->pred; | |
6523 | while (e) | |
6524 | { | |
6525 | if (e->dest != bb) | |
6526 | { | |
987009bf ZW |
6527 | error ("Basic block %d pred edge is corrupted", bb->index); |
6528 | fputs ("Predecessor: ", stderr); | |
34487bf8 | 6529 | dump_edge_info (stderr, e, 0); |
987009bf | 6530 | fputs ("\nSuccessor: ", stderr); |
34487bf8 | 6531 | dump_edge_info (stderr, e, 1); |
987009bf | 6532 | fputc ('\n', stderr); |
34487bf8 RH |
6533 | abort (); |
6534 | } | |
6535 | if (e->src != ENTRY_BLOCK_PTR) | |
6536 | { | |
6537 | edge e2 = e->src->succ; | |
6538 | while (e2 && e2 != e) | |
6539 | e2 = e2->succ_next; | |
6540 | if (!e2) | |
6541 | { | |
987009bf | 6542 | error ("Basic block %i edge lists are corrupted", bb->index); |
b8024b59 | 6543 | abort (); |
34487bf8 RH |
6544 | } |
6545 | } | |
6546 | e = e->pred_next; | |
6547 | } | |
6548 | ||
6549 | /* OK pointers are correct. Now check the header of basic | |
6550 | block. It ought to contain optional CODE_LABEL followed | |
6551 | by NOTE_BASIC_BLOCK. */ | |
6552 | x = bb->head; | |
6553 | if (GET_CODE (x) == CODE_LABEL) | |
6554 | { | |
6555 | if (bb->end == x) | |
6556 | { | |
987009bf ZW |
6557 | error ("NOTE_INSN_BASIC_BLOCK is missing for block %d", |
6558 | bb->index); | |
6559 | abort (); | |
34487bf8 RH |
6560 | } |
6561 | x = NEXT_INSN (x); | |
6562 | } | |
6563 | if (GET_CODE (x) != NOTE | |
6564 | || NOTE_LINE_NUMBER (x) != NOTE_INSN_BASIC_BLOCK | |
6565 | || NOTE_BASIC_BLOCK (x) != bb) | |
6566 | { | |
987009bf | 6567 | error ("NOTE_INSN_BASIC_BLOCK is missing for block %d\n", |
34487bf8 | 6568 | bb->index); |
987009bf | 6569 | abort (); |
34487bf8 RH |
6570 | } |
6571 | ||
6572 | if (bb->end == x) | |
6573 | { | |
6574 | /* Do checks for empty blocks here */ | |
6575 | } | |
6576 | else | |
6577 | { | |
6578 | x = NEXT_INSN (x); | |
6579 | while (x) | |
6580 | { | |
6581 | if (GET_CODE (x) == NOTE | |
6582 | && NOTE_LINE_NUMBER (x) == NOTE_INSN_BASIC_BLOCK) | |
6583 | { | |
987009bf | 6584 | error ("NOTE_INSN_BASIC_BLOCK %d in the middle of basic block %d", |
34487bf8 | 6585 | INSN_UID (x), bb->index); |
987009bf | 6586 | abort (); |
34487bf8 RH |
6587 | } |
6588 | ||
6589 | if (x == bb->end) | |
6590 | break; | |
6591 | ||
6592 | if (GET_CODE (x) == JUMP_INSN | |
6593 | || GET_CODE (x) == CODE_LABEL | |
6594 | || GET_CODE (x) == BARRIER) | |
6595 | { | |
987009bf ZW |
6596 | error ("In basic block %d:", bb->index); |
6597 | fatal_insn ("Flow control insn inside a basic block", x); | |
34487bf8 RH |
6598 | } |
6599 | ||
6600 | x = NEXT_INSN (x); | |
6601 | } | |
6602 | } | |
6603 | } | |
6604 | ||
6605 | x = rtx_first; | |
6606 | while (x) | |
6607 | { | |
6608 | if (!bb_info[INSN_UID (x)]) | |
6609 | { | |
6610 | switch (GET_CODE (x)) | |
6611 | { | |
6612 | case BARRIER: | |
6613 | case NOTE: | |
6614 | break; | |
6615 | ||
6616 | case CODE_LABEL: | |
6617 | /* An addr_vec is placed outside any block block. */ | |
6618 | if (NEXT_INSN (x) | |
6619 | && GET_CODE (NEXT_INSN (x)) == JUMP_INSN | |
6620 | && (GET_CODE (PATTERN (NEXT_INSN (x))) == ADDR_DIFF_VEC | |
6621 | || GET_CODE (PATTERN (NEXT_INSN (x))) == ADDR_VEC)) | |
6622 | { | |
6623 | x = NEXT_INSN (x); | |
6624 | } | |
6625 | ||
6626 | /* But in any case, non-deletable labels can appear anywhere. */ | |
6627 | break; | |
6628 | ||
6629 | default: | |
987009bf | 6630 | fatal_insn ("Insn outside basic block", x); |
34487bf8 RH |
6631 | } |
6632 | } | |
6633 | ||
6634 | x = NEXT_INSN (x); | |
6635 | } | |
6636 | } | |
410538ea AM |
6637 | \f |
6638 | /* Functions to access an edge list with a vector representation. | |
6639 | Enough data is kept such that given an index number, the | |
6640 | pred and succ that edge reprsents can be determined, or | |
6641 | given a pred and a succ, it's index number can be returned. | |
6642 | This allows algorithms which comsume a lot of memory to | |
6643 | represent the normally full matrix of edge (pred,succ) with a | |
6644 | single indexed vector, edge (EDGE_INDEX (pred, succ)), with no | |
6645 | wasted space in the client code due to sparse flow graphs. */ | |
6646 | ||
6647 | /* This functions initializes the edge list. Basically the entire | |
6648 | flowgraph is processed, and all edges are assigned a number, | |
6649 | and the data structure is filed in. */ | |
6650 | struct edge_list * | |
6651 | create_edge_list () | |
6652 | { | |
6653 | struct edge_list *elist; | |
6654 | edge e; | |
6655 | int num_edges; | |
e2bef702 | 6656 | int x; |
410538ea AM |
6657 | int block_count; |
6658 | ||
6659 | block_count = n_basic_blocks + 2; /* Include the entry and exit blocks. */ | |
6660 | ||
6661 | num_edges = 0; | |
6662 | ||
6663 | /* Determine the number of edges in the flow graph by counting successor | |
6664 | edges on each basic block. */ | |
6665 | for (x = 0; x < n_basic_blocks; x++) | |
6666 | { | |
6667 | basic_block bb = BASIC_BLOCK (x); | |
6668 | ||
6669 | for (e = bb->succ; e; e = e->succ_next) | |
6670 | num_edges++; | |
6671 | } | |
6672 | /* Don't forget successors of the entry block. */ | |
6673 | for (e = ENTRY_BLOCK_PTR->succ; e; e = e->succ_next) | |
6674 | num_edges++; | |
6675 | ||
57ad4479 | 6676 | elist = xmalloc (sizeof (struct edge_list)); |
410538ea AM |
6677 | elist->num_blocks = block_count; |
6678 | elist->num_edges = num_edges; | |
57ad4479 | 6679 | elist->index_to_edge = xmalloc (sizeof (edge) * num_edges); |
410538ea AM |
6680 | |
6681 | num_edges = 0; | |
6682 | ||
6683 | /* Follow successors of the entry block, and register these edges. */ | |
6684 | for (e = ENTRY_BLOCK_PTR->succ; e; e = e->succ_next) | |
6685 | { | |
6686 | elist->index_to_edge[num_edges] = e; | |
6687 | num_edges++; | |
6688 | } | |
6689 | ||
6690 | for (x = 0; x < n_basic_blocks; x++) | |
6691 | { | |
6692 | basic_block bb = BASIC_BLOCK (x); | |
6693 | ||
6694 | /* Follow all successors of blocks, and register these edges. */ | |
6695 | for (e = bb->succ; e; e = e->succ_next) | |
6696 | { | |
6697 | elist->index_to_edge[num_edges] = e; | |
6698 | num_edges++; | |
6699 | } | |
6700 | } | |
6701 | return elist; | |
6702 | } | |
6703 | ||
6704 | /* This function free's memory associated with an edge list. */ | |
6705 | void | |
6706 | free_edge_list (elist) | |
6707 | struct edge_list *elist; | |
6708 | { | |
6709 | if (elist) | |
6710 | { | |
6711 | free (elist->index_to_edge); | |
6712 | free (elist); | |
6713 | } | |
6714 | } | |
6715 | ||
6716 | /* This function provides debug output showing an edge list. */ | |
6717 | void | |
6718 | print_edge_list (f, elist) | |
6719 | FILE *f; | |
6720 | struct edge_list *elist; | |
6721 | { | |
6722 | int x; | |
6723 | fprintf(f, "Compressed edge list, %d BBs + entry & exit, and %d edges\n", | |
6724 | elist->num_blocks - 2, elist->num_edges); | |
6725 | ||
6726 | for (x = 0; x < elist->num_edges; x++) | |
6727 | { | |
6728 | fprintf (f, " %-4d - edge(", x); | |
6729 | if (INDEX_EDGE_PRED_BB (elist, x) == ENTRY_BLOCK_PTR) | |
6730 | fprintf (f,"entry,"); | |
6731 | else | |
6732 | fprintf (f,"%d,", INDEX_EDGE_PRED_BB (elist, x)->index); | |
6733 | ||
6734 | if (INDEX_EDGE_SUCC_BB (elist, x) == EXIT_BLOCK_PTR) | |
6735 | fprintf (f,"exit)\n"); | |
6736 | else | |
6737 | fprintf (f,"%d)\n", INDEX_EDGE_SUCC_BB (elist, x)->index); | |
6738 | } | |
6739 | } | |
6740 | ||
6741 | /* This function provides an internal consistancy check of an edge list, | |
6742 | verifying that all edges are present, and that there are no | |
6743 | extra edges. */ | |
6744 | void | |
6745 | verify_edge_list (f, elist) | |
6746 | FILE *f; | |
6747 | struct edge_list *elist; | |
6748 | { | |
6749 | int x, pred, succ, index; | |
410538ea AM |
6750 | edge e; |
6751 | ||
6752 | for (x = 0; x < n_basic_blocks; x++) | |
6753 | { | |
6754 | basic_block bb = BASIC_BLOCK (x); | |
6755 | ||
6756 | for (e = bb->succ; e; e = e->succ_next) | |
6757 | { | |
6758 | pred = e->src->index; | |
6759 | succ = e->dest->index; | |
6760 | index = EDGE_INDEX (elist, pred, succ); | |
6761 | if (index == EDGE_INDEX_NO_EDGE) | |
6762 | { | |
6763 | fprintf (f, "*p* No index for edge from %d to %d\n",pred, succ); | |
6764 | continue; | |
6765 | } | |
6766 | if (INDEX_EDGE_PRED_BB (elist, index)->index != pred) | |
6767 | fprintf (f, "*p* Pred for index %d should be %d not %d\n", | |
6768 | index, pred, INDEX_EDGE_PRED_BB (elist, index)->index); | |
6769 | if (INDEX_EDGE_SUCC_BB (elist, index)->index != succ) | |
6770 | fprintf (f, "*p* Succ for index %d should be %d not %d\n", | |
6771 | index, succ, INDEX_EDGE_SUCC_BB (elist, index)->index); | |
6772 | } | |
6773 | } | |
6774 | for (e = ENTRY_BLOCK_PTR->succ; e; e = e->succ_next) | |
6775 | { | |
6776 | pred = e->src->index; | |
6777 | succ = e->dest->index; | |
6778 | index = EDGE_INDEX (elist, pred, succ); | |
6779 | if (index == EDGE_INDEX_NO_EDGE) | |
6780 | { | |
6781 | fprintf (f, "*p* No index for edge from %d to %d\n",pred, succ); | |
6782 | continue; | |
6783 | } | |
6784 | if (INDEX_EDGE_PRED_BB (elist, index)->index != pred) | |
6785 | fprintf (f, "*p* Pred for index %d should be %d not %d\n", | |
6786 | index, pred, INDEX_EDGE_PRED_BB (elist, index)->index); | |
6787 | if (INDEX_EDGE_SUCC_BB (elist, index)->index != succ) | |
6788 | fprintf (f, "*p* Succ for index %d should be %d not %d\n", | |
6789 | index, succ, INDEX_EDGE_SUCC_BB (elist, index)->index); | |
6790 | } | |
6791 | /* We've verified that all the edges are in the list, no lets make sure | |
6792 | there are no spurious edges in the list. */ | |
6793 | ||
6794 | for (pred = 0 ; pred < n_basic_blocks; pred++) | |
6795 | for (succ = 0 ; succ < n_basic_blocks; succ++) | |
6796 | { | |
6797 | basic_block p = BASIC_BLOCK (pred); | |
6798 | basic_block s = BASIC_BLOCK (succ); | |
6799 | ||
6800 | int found_edge = 0; | |
6801 | ||
6802 | for (e = p->succ; e; e = e->succ_next) | |
6803 | if (e->dest == s) | |
6804 | { | |
6805 | found_edge = 1; | |
6806 | break; | |
6807 | } | |
6808 | for (e = s->pred; e; e = e->pred_next) | |
6809 | if (e->src == p) | |
6810 | { | |
6811 | found_edge = 1; | |
6812 | break; | |
6813 | } | |
6814 | if (EDGE_INDEX (elist, pred, succ) == EDGE_INDEX_NO_EDGE | |
6815 | && found_edge != 0) | |
6816 | fprintf (f, "*** Edge (%d, %d) appears to not have an index\n", | |
6817 | pred, succ); | |
6818 | if (EDGE_INDEX (elist, pred, succ) != EDGE_INDEX_NO_EDGE | |
6819 | && found_edge == 0) | |
6820 | fprintf (f, "*** Edge (%d, %d) has index %d, but there is no edge\n", | |
6821 | pred, succ, EDGE_INDEX (elist, pred, succ)); | |
6822 | } | |
6823 | for (succ = 0 ; succ < n_basic_blocks; succ++) | |
6824 | { | |
6825 | basic_block p = ENTRY_BLOCK_PTR; | |
6826 | basic_block s = BASIC_BLOCK (succ); | |
6827 | ||
6828 | int found_edge = 0; | |
6829 | ||
6830 | for (e = p->succ; e; e = e->succ_next) | |
6831 | if (e->dest == s) | |
6832 | { | |
6833 | found_edge = 1; | |
6834 | break; | |
6835 | } | |
6836 | for (e = s->pred; e; e = e->pred_next) | |
6837 | if (e->src == p) | |
6838 | { | |
6839 | found_edge = 1; | |
6840 | break; | |
6841 | } | |
6842 | if (EDGE_INDEX (elist, ENTRY_BLOCK, succ) == EDGE_INDEX_NO_EDGE | |
6843 | && found_edge != 0) | |
6844 | fprintf (f, "*** Edge (entry, %d) appears to not have an index\n", | |
6845 | succ); | |
6846 | if (EDGE_INDEX (elist, ENTRY_BLOCK, succ) != EDGE_INDEX_NO_EDGE | |
6847 | && found_edge == 0) | |
6848 | fprintf (f, "*** Edge (entry, %d) has index %d, but no edge exists\n", | |
6849 | succ, EDGE_INDEX (elist, ENTRY_BLOCK, succ)); | |
6850 | } | |
6851 | for (pred = 0 ; pred < n_basic_blocks; pred++) | |
6852 | { | |
6853 | basic_block p = BASIC_BLOCK (pred); | |
6854 | basic_block s = EXIT_BLOCK_PTR; | |
6855 | ||
6856 | int found_edge = 0; | |
6857 | ||
6858 | for (e = p->succ; e; e = e->succ_next) | |
6859 | if (e->dest == s) | |
6860 | { | |
6861 | found_edge = 1; | |
6862 | break; | |
6863 | } | |
6864 | for (e = s->pred; e; e = e->pred_next) | |
6865 | if (e->src == p) | |
6866 | { | |
6867 | found_edge = 1; | |
6868 | break; | |
6869 | } | |
6870 | if (EDGE_INDEX (elist, pred, EXIT_BLOCK) == EDGE_INDEX_NO_EDGE | |
6871 | && found_edge != 0) | |
6872 | fprintf (f, "*** Edge (%d, exit) appears to not have an index\n", | |
6873 | pred); | |
6874 | if (EDGE_INDEX (elist, pred, EXIT_BLOCK) != EDGE_INDEX_NO_EDGE | |
6875 | && found_edge == 0) | |
6876 | fprintf (f, "*** Edge (%d, exit) has index %d, but no edge exists\n", | |
6877 | pred, EDGE_INDEX (elist, pred, EXIT_BLOCK)); | |
6878 | } | |
6879 | } | |
6880 | ||
6881 | /* This routine will determine what, if any, edge there is between | |
6882 | a specified predecessor and successor. */ | |
6883 | ||
6884 | int | |
6885 | find_edge_index (edge_list, pred, succ) | |
6886 | struct edge_list *edge_list; | |
6887 | int pred, succ; | |
6888 | { | |
6889 | int x; | |
6890 | for (x = 0; x < NUM_EDGES (edge_list); x++) | |
6891 | { | |
6892 | if (INDEX_EDGE_PRED_BB (edge_list, x)->index == pred | |
6893 | && INDEX_EDGE_SUCC_BB (edge_list, x)->index == succ) | |
6894 | return x; | |
6895 | } | |
6896 | return (EDGE_INDEX_NO_EDGE); | |
6897 | } | |
6898 | ||
87fdf7ff AM |
6899 | /* This function will remove an edge from the flow graph. */ |
6900 | static void | |
6901 | remove_edge (e) | |
6902 | edge e; | |
6903 | { | |
6904 | edge last_pred = NULL; | |
6905 | edge last_succ = NULL; | |
6906 | edge tmp; | |
6907 | basic_block src, dest; | |
6908 | src = e->src; | |
6909 | dest = e->dest; | |
6910 | for (tmp = src->succ; tmp && tmp != e; tmp = tmp->succ_next) | |
6911 | last_succ = tmp; | |
6912 | ||
6913 | if (!tmp) | |
6914 | abort (); | |
6915 | if (last_succ) | |
6916 | last_succ->succ_next = e->succ_next; | |
6917 | else | |
6918 | src->succ = e->succ_next; | |
6919 | ||
6920 | for (tmp = dest->pred; tmp && tmp != e; tmp = tmp->pred_next) | |
6921 | last_pred = tmp; | |
6922 | ||
6923 | if (!tmp) | |
6924 | abort (); | |
6925 | if (last_pred) | |
6926 | last_pred->pred_next = e->pred_next; | |
6927 | else | |
6928 | dest->pred = e->pred_next; | |
6929 | ||
6930 | free (e); | |
6931 | ||
6932 | } | |
6933 | ||
6934 | /* This routine will remove any fake successor edges for a basic block. | |
6935 | When the edge is removed, it is also removed from whatever predecessor | |
6936 | list it is in. */ | |
6937 | static void | |
6938 | remove_fake_successors (bb) | |
6939 | basic_block bb; | |
6940 | { | |
6941 | edge e; | |
6942 | for (e = bb->succ; e ; ) | |
6943 | { | |
6944 | edge tmp = e; | |
6945 | e = e->succ_next; | |
6946 | if ((tmp->flags & EDGE_FAKE) == EDGE_FAKE) | |
6947 | remove_edge (tmp); | |
6948 | } | |
6949 | } | |
6950 | ||
6951 | /* This routine will remove all fake edges from the flow graph. If | |
6952 | we remove all fake successors, it will automatically remove all | |
6953 | fake predecessors. */ | |
6954 | void | |
6955 | remove_fake_edges () | |
6956 | { | |
6957 | int x; | |
6958 | edge e; | |
6959 | basic_block bb; | |
6960 | ||
6961 | for (x = 0; x < n_basic_blocks; x++) | |
6962 | { | |
6963 | edge tmp, last = NULL; | |
6964 | bb = BASIC_BLOCK (x); | |
6965 | remove_fake_successors (bb); | |
6966 | } | |
6967 | /* we've handled all successors except the entry block's. */ | |
6968 | remove_fake_successors (ENTRY_BLOCK_PTR); | |
6969 | } | |
6970 | ||
6971 | /* This functions will add a fake edge between any block which has no | |
6972 | successors, and the exit block. Some data flow equations require these | |
6973 | edges to exist. */ | |
6974 | void | |
6975 | add_fake_exit_edges () | |
6976 | { | |
6977 | int x; | |
6978 | ||
6979 | for (x = 0; x < n_basic_blocks; x++) | |
6980 | if (BASIC_BLOCK (x)->succ == NULL) | |
6981 | make_edge (BASIC_BLOCK (x), EXIT_BLOCK_PTR, EDGE_FAKE); | |
6982 | } |