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d7429b6a | 1 | /* Data flow analysis for GNU compiler. |
6a45254e | 2 | Copyright (C) 1987, 88, 92-96, 1997 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 | ||
22 | /* This file contains the data flow analysis pass of the compiler. | |
23 | It computes data flow information | |
24 | which tells combine_instructions which insns to consider combining | |
25 | and controls register allocation. | |
26 | ||
27 | Additional data flow information that is too bulky to record | |
28 | is generated during the analysis, and is used at that time to | |
29 | create autoincrement and autodecrement addressing. | |
30 | ||
31 | The first step is dividing the function into basic blocks. | |
32 | find_basic_blocks does this. Then life_analysis determines | |
33 | where each register is live and where it is dead. | |
34 | ||
35 | ** find_basic_blocks ** | |
36 | ||
37 | find_basic_blocks divides the current function's rtl | |
38 | into basic blocks. It records the beginnings and ends of the | |
39 | basic blocks in the vectors basic_block_head and basic_block_end, | |
40 | and the number of blocks in n_basic_blocks. | |
41 | ||
42 | find_basic_blocks also finds any unreachable loops | |
43 | and deletes them. | |
44 | ||
45 | ** life_analysis ** | |
46 | ||
47 | life_analysis is called immediately after find_basic_blocks. | |
48 | It uses the basic block information to determine where each | |
49 | hard or pseudo register is live. | |
50 | ||
51 | ** live-register info ** | |
52 | ||
53 | The information about where each register is live is in two parts: | |
54 | the REG_NOTES of insns, and the vector basic_block_live_at_start. | |
55 | ||
56 | basic_block_live_at_start has an element for each basic block, | |
57 | and the element is a bit-vector with a bit for each hard or pseudo | |
58 | register. The bit is 1 if the register is live at the beginning | |
59 | of the basic block. | |
60 | ||
61 | Two types of elements can be added to an insn's REG_NOTES. | |
62 | A REG_DEAD note is added to an insn's REG_NOTES for any register | |
63 | that meets both of two conditions: The value in the register is not | |
64 | needed in subsequent insns and the insn does not replace the value in | |
65 | the register (in the case of multi-word hard registers, the value in | |
66 | each register must be replaced by the insn to avoid a REG_DEAD note). | |
67 | ||
68 | In the vast majority of cases, an object in a REG_DEAD note will be | |
69 | used somewhere in the insn. The (rare) exception to this is if an | |
70 | insn uses a multi-word hard register and only some of the registers are | |
71 | needed in subsequent insns. In that case, REG_DEAD notes will be | |
72 | provided for those hard registers that are not subsequently needed. | |
73 | Partial REG_DEAD notes of this type do not occur when an insn sets | |
74 | only some of the hard registers used in such a multi-word operand; | |
75 | omitting REG_DEAD notes for objects stored in an insn is optional and | |
76 | the desire to do so does not justify the complexity of the partial | |
77 | REG_DEAD notes. | |
78 | ||
79 | REG_UNUSED notes are added for each register that is set by the insn | |
80 | but is unused subsequently (if every register set by the insn is unused | |
81 | and the insn does not reference memory or have some other side-effect, | |
82 | the insn is deleted instead). If only part of a multi-word hard | |
83 | register is used in a subsequent insn, REG_UNUSED notes are made for | |
84 | the parts that will not be used. | |
85 | ||
86 | To determine which registers are live after any insn, one can | |
87 | start from the beginning of the basic block and scan insns, noting | |
88 | which registers are set by each insn and which die there. | |
89 | ||
90 | ** Other actions of life_analysis ** | |
91 | ||
92 | life_analysis sets up the LOG_LINKS fields of insns because the | |
93 | information needed to do so is readily available. | |
94 | ||
95 | life_analysis deletes insns whose only effect is to store a value | |
96 | that is never used. | |
97 | ||
98 | life_analysis notices cases where a reference to a register as | |
99 | a memory address can be combined with a preceding or following | |
100 | incrementation or decrementation of the register. The separate | |
101 | instruction to increment or decrement is deleted and the address | |
102 | is changed to a POST_INC or similar rtx. | |
103 | ||
104 | Each time an incrementing or decrementing address is created, | |
105 | a REG_INC element is added to the insn's REG_NOTES list. | |
106 | ||
107 | life_analysis fills in certain vectors containing information about | |
108 | register usage: reg_n_refs, reg_n_deaths, reg_n_sets, reg_live_length, | |
109 | reg_n_calls_crosses and reg_basic_block. */ | |
110 | \f | |
d7429b6a | 111 | #include "config.h" |
e9a25f70 | 112 | #include <stdio.h> |
d7429b6a RK |
113 | #include "rtl.h" |
114 | #include "basic-block.h" | |
115 | #include "insn-config.h" | |
116 | #include "regs.h" | |
117 | #include "hard-reg-set.h" | |
118 | #include "flags.h" | |
119 | #include "output.h" | |
3d195391 | 120 | #include "except.h" |
d7429b6a RK |
121 | |
122 | #include "obstack.h" | |
123 | #define obstack_chunk_alloc xmalloc | |
124 | #define obstack_chunk_free free | |
125 | ||
7eb136d6 MM |
126 | /* The contents of the current function definition are allocated |
127 | in this obstack, and all are freed at the end of the function. | |
128 | For top-level functions, this is temporary_obstack. | |
129 | Separate obstacks are made for nested functions. */ | |
130 | ||
131 | extern struct obstack *function_obstack; | |
132 | ||
d7429b6a RK |
133 | /* List of labels that must never be deleted. */ |
134 | extern rtx forced_labels; | |
135 | ||
136 | /* Get the basic block number of an insn. | |
137 | This info should not be expected to remain available | |
138 | after the end of life_analysis. */ | |
139 | ||
140 | /* This is the limit of the allocated space in the following two arrays. */ | |
141 | ||
142 | static int max_uid_for_flow; | |
143 | ||
144 | #define BLOCK_NUM(INSN) uid_block_number[INSN_UID (INSN)] | |
145 | ||
146 | /* This is where the BLOCK_NUM values are really stored. | |
147 | This is set up by find_basic_blocks and used there and in life_analysis, | |
148 | and then freed. */ | |
149 | ||
6ac271be | 150 | static int *uid_block_number; |
d7429b6a RK |
151 | |
152 | /* INSN_VOLATILE (insn) is 1 if the insn refers to anything volatile. */ | |
153 | ||
154 | #define INSN_VOLATILE(INSN) uid_volatile[INSN_UID (INSN)] | |
155 | static char *uid_volatile; | |
156 | ||
157 | /* Number of basic blocks in the current function. */ | |
158 | ||
159 | int n_basic_blocks; | |
160 | ||
161 | /* Maximum register number used in this function, plus one. */ | |
162 | ||
163 | int max_regno; | |
164 | ||
0f41302f MS |
165 | /* Maximum number of SCRATCH rtx's used in any basic block of this |
166 | function. */ | |
d7429b6a RK |
167 | |
168 | int max_scratch; | |
169 | ||
170 | /* Number of SCRATCH rtx's in the current block. */ | |
171 | ||
172 | static int num_scratch; | |
173 | ||
b1f21e0a | 174 | /* Indexed by n, giving various register information */ |
d7429b6a | 175 | |
b1f21e0a | 176 | reg_info *reg_n_info; |
d7429b6a RK |
177 | |
178 | /* Element N is the next insn that uses (hard or pseudo) register number N | |
179 | within the current basic block; or zero, if there is no such insn. | |
180 | This is valid only during the final backward scan in propagate_block. */ | |
181 | ||
182 | static rtx *reg_next_use; | |
183 | ||
184 | /* Size of a regset for the current function, | |
185 | in (1) bytes and (2) elements. */ | |
186 | ||
187 | int regset_bytes; | |
188 | int regset_size; | |
189 | ||
190 | /* Element N is first insn in basic block N. | |
191 | This info lasts until we finish compiling the function. */ | |
192 | ||
193 | rtx *basic_block_head; | |
194 | ||
195 | /* Element N is last insn in basic block N. | |
196 | This info lasts until we finish compiling the function. */ | |
197 | ||
198 | rtx *basic_block_end; | |
199 | ||
200 | /* Element N is a regset describing the registers live | |
201 | at the start of basic block N. | |
202 | This info lasts until we finish compiling the function. */ | |
203 | ||
204 | regset *basic_block_live_at_start; | |
205 | ||
206 | /* Regset of regs live when calls to `setjmp'-like functions happen. */ | |
207 | ||
208 | regset regs_live_at_setjmp; | |
209 | ||
210 | /* List made of EXPR_LIST rtx's which gives pairs of pseudo registers | |
211 | that have to go in the same hard reg. | |
212 | The first two regs in the list are a pair, and the next two | |
213 | are another pair, etc. */ | |
214 | rtx regs_may_share; | |
215 | ||
216 | /* Element N is nonzero if control can drop into basic block N | |
217 | from the preceding basic block. Freed after life_analysis. */ | |
218 | ||
219 | static char *basic_block_drops_in; | |
220 | ||
221 | /* Element N is depth within loops of the last insn in basic block number N. | |
222 | Freed after life_analysis. */ | |
223 | ||
224 | static short *basic_block_loop_depth; | |
225 | ||
226 | /* Element N nonzero if basic block N can actually be reached. | |
227 | Vector exists only during find_basic_blocks. */ | |
228 | ||
229 | static char *block_live_static; | |
230 | ||
231 | /* Depth within loops of basic block being scanned for lifetime analysis, | |
232 | plus one. This is the weight attached to references to registers. */ | |
233 | ||
234 | static int loop_depth; | |
235 | ||
236 | /* During propagate_block, this is non-zero if the value of CC0 is live. */ | |
237 | ||
238 | static int cc0_live; | |
239 | ||
240 | /* During propagate_block, this contains the last MEM stored into. It | |
241 | is used to eliminate consecutive stores to the same location. */ | |
242 | ||
243 | static rtx last_mem_set; | |
244 | ||
245 | /* Set of registers that may be eliminable. These are handled specially | |
246 | in updating regs_ever_live. */ | |
247 | ||
248 | static HARD_REG_SET elim_reg_set; | |
249 | ||
250 | /* Forward declarations */ | |
e658434c | 251 | static void find_basic_blocks PROTO((rtx, rtx)); |
e658434c RK |
252 | static void mark_label_ref PROTO((rtx, rtx, int)); |
253 | static void life_analysis PROTO((rtx, int)); | |
254 | void allocate_for_life_analysis PROTO((void)); | |
67f0e213 RK |
255 | void init_regset_vector PROTO((regset *, int, struct obstack *)); |
256 | void free_regset_vector PROTO((regset *, int)); | |
e658434c RK |
257 | static void propagate_block PROTO((regset, rtx, rtx, int, |
258 | regset, int)); | |
8329b5ec | 259 | static rtx flow_delete_insn PROTO((rtx)); |
e658434c RK |
260 | static int insn_dead_p PROTO((rtx, regset, int)); |
261 | static int libcall_dead_p PROTO((rtx, regset, rtx, rtx)); | |
262 | static void mark_set_regs PROTO((regset, regset, rtx, | |
263 | rtx, regset)); | |
264 | static void mark_set_1 PROTO((regset, regset, rtx, | |
265 | rtx, regset)); | |
1d300e19 | 266 | #ifdef AUTO_INC_DEC |
e658434c | 267 | static void find_auto_inc PROTO((regset, rtx, rtx)); |
e658434c RK |
268 | static int try_pre_increment_1 PROTO((rtx)); |
269 | static int try_pre_increment PROTO((rtx, rtx, HOST_WIDE_INT)); | |
1d300e19 KG |
270 | #endif |
271 | static void mark_used_regs PROTO((regset, regset, rtx, int, rtx)); | |
e658434c | 272 | void dump_flow_info PROTO((FILE *)); |
d7429b6a RK |
273 | \f |
274 | /* Find basic blocks of the current function and perform data flow analysis. | |
275 | F is the first insn of the function and NREGS the number of register numbers | |
276 | in use. */ | |
277 | ||
278 | void | |
279 | flow_analysis (f, nregs, file) | |
280 | rtx f; | |
281 | int nregs; | |
282 | FILE *file; | |
283 | { | |
284 | register rtx insn; | |
285 | register int i; | |
d7e4fe8b | 286 | rtx nonlocal_label_list = nonlocal_label_rtx_list (); |
d7429b6a RK |
287 | |
288 | #ifdef ELIMINABLE_REGS | |
289 | static struct {int from, to; } eliminables[] = ELIMINABLE_REGS; | |
290 | #endif | |
291 | ||
292 | /* Record which registers will be eliminated. We use this in | |
0f41302f | 293 | mark_used_regs. */ |
d7429b6a RK |
294 | |
295 | CLEAR_HARD_REG_SET (elim_reg_set); | |
296 | ||
297 | #ifdef ELIMINABLE_REGS | |
298 | for (i = 0; i < sizeof eliminables / sizeof eliminables[0]; i++) | |
299 | SET_HARD_REG_BIT (elim_reg_set, eliminables[i].from); | |
300 | #else | |
301 | SET_HARD_REG_BIT (elim_reg_set, FRAME_POINTER_REGNUM); | |
302 | #endif | |
303 | ||
304 | /* Count the basic blocks. Also find maximum insn uid value used. */ | |
305 | ||
306 | { | |
307 | register RTX_CODE prev_code = JUMP_INSN; | |
308 | register RTX_CODE code; | |
74d7ab55 | 309 | int eh_region = 0; |
d7429b6a RK |
310 | |
311 | max_uid_for_flow = 0; | |
312 | ||
313 | for (insn = f, i = 0; insn; insn = NEXT_INSN (insn)) | |
314 | { | |
315 | code = GET_CODE (insn); | |
316 | if (INSN_UID (insn) > max_uid_for_flow) | |
317 | max_uid_for_flow = INSN_UID (insn); | |
318 | if (code == CODE_LABEL | |
d7e4fe8b RS |
319 | || (GET_RTX_CLASS (code) == 'i' |
320 | && (prev_code == JUMP_INSN | |
321 | || (prev_code == CALL_INSN | |
9b8d9d6b JM |
322 | && (nonlocal_label_list != 0 || eh_region) |
323 | && ! find_reg_note (insn, REG_RETVAL, NULL_RTX)) | |
d7e4fe8b | 324 | || prev_code == BARRIER))) |
d7429b6a | 325 | i++; |
8cfe18d6 | 326 | |
2dd4cace | 327 | if (code == CALL_INSN && find_reg_note (insn, REG_RETVAL, NULL_RTX)) |
8cfe18d6 RK |
328 | code = INSN; |
329 | ||
6b67ec08 | 330 | if (code != NOTE) |
d7429b6a | 331 | prev_code = code; |
74d7ab55 JM |
332 | else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_BEG) |
333 | ++eh_region; | |
334 | else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_END) | |
335 | --eh_region; | |
d7429b6a RK |
336 | } |
337 | } | |
338 | ||
339 | #ifdef AUTO_INC_DEC | |
340 | /* Leave space for insns we make in some cases for auto-inc. These cases | |
341 | are rare, so we don't need too much space. */ | |
342 | max_uid_for_flow += max_uid_for_flow / 10; | |
343 | #endif | |
344 | ||
345 | /* Allocate some tables that last till end of compiling this function | |
346 | and some needed only in find_basic_blocks and life_analysis. */ | |
347 | ||
348 | n_basic_blocks = i; | |
349 | basic_block_head = (rtx *) oballoc (n_basic_blocks * sizeof (rtx)); | |
350 | basic_block_end = (rtx *) oballoc (n_basic_blocks * sizeof (rtx)); | |
351 | basic_block_drops_in = (char *) alloca (n_basic_blocks); | |
352 | basic_block_loop_depth = (short *) alloca (n_basic_blocks * sizeof (short)); | |
353 | uid_block_number | |
6ac271be | 354 | = (int *) alloca ((max_uid_for_flow + 1) * sizeof (int)); |
d7429b6a RK |
355 | uid_volatile = (char *) alloca (max_uid_for_flow + 1); |
356 | bzero (uid_volatile, max_uid_for_flow + 1); | |
357 | ||
d7e4fe8b | 358 | find_basic_blocks (f, nonlocal_label_list); |
d7429b6a RK |
359 | life_analysis (f, nregs); |
360 | if (file) | |
361 | dump_flow_info (file); | |
362 | ||
363 | basic_block_drops_in = 0; | |
364 | uid_block_number = 0; | |
365 | basic_block_loop_depth = 0; | |
366 | } | |
367 | \f | |
368 | /* Find all basic blocks of the function whose first insn is F. | |
369 | Store the correct data in the tables that describe the basic blocks, | |
370 | set up the chains of references for each CODE_LABEL, and | |
d7e4fe8b RS |
371 | delete any entire basic blocks that cannot be reached. |
372 | ||
373 | NONLOCAL_LABEL_LIST is the same local variable from flow_analysis. */ | |
d7429b6a RK |
374 | |
375 | static void | |
d7e4fe8b RS |
376 | find_basic_blocks (f, nonlocal_label_list) |
377 | rtx f, nonlocal_label_list; | |
d7429b6a RK |
378 | { |
379 | register rtx insn; | |
380 | register int i; | |
381 | register char *block_live = (char *) alloca (n_basic_blocks); | |
382 | register char *block_marked = (char *) alloca (n_basic_blocks); | |
2ec1535d JL |
383 | /* An array of CODE_LABELs, indexed by UID for the start of the active |
384 | EH handler for each insn in F. */ | |
385 | rtx *active_eh_handler; | |
d7429b6a RK |
386 | /* List of label_refs to all labels whose addresses are taken |
387 | and used as data. */ | |
8329b5ec | 388 | rtx label_value_list; |
2ec1535d | 389 | rtx x, note, eh_note; |
e658434c | 390 | enum rtx_code prev_code, code; |
8329b5ec | 391 | int depth, pass; |
d7429b6a | 392 | |
8329b5ec | 393 | pass = 1; |
2ec1535d | 394 | active_eh_handler = (rtx *) alloca ((max_uid_for_flow + 1) * sizeof (rtx)); |
8329b5ec DE |
395 | restart: |
396 | ||
397 | label_value_list = 0; | |
d7429b6a RK |
398 | block_live_static = block_live; |
399 | bzero (block_live, n_basic_blocks); | |
400 | bzero (block_marked, n_basic_blocks); | |
2ec1535d | 401 | bzero (active_eh_handler, (max_uid_for_flow + 1) * sizeof (rtx)); |
d7429b6a RK |
402 | |
403 | /* Initialize with just block 0 reachable and no blocks marked. */ | |
404 | if (n_basic_blocks > 0) | |
405 | block_live[0] = 1; | |
406 | ||
e658434c RK |
407 | /* Initialize the ref chain of each label to 0. Record where all the |
408 | blocks start and end and their depth in loops. For each insn, record | |
409 | the block it is in. Also mark as reachable any blocks headed by labels | |
410 | that must not be deleted. */ | |
d7429b6a | 411 | |
2ec1535d | 412 | for (eh_note = NULL_RTX, insn = f, i = -1, prev_code = JUMP_INSN, depth = 1; |
e658434c RK |
413 | insn; insn = NEXT_INSN (insn)) |
414 | { | |
415 | code = GET_CODE (insn); | |
416 | if (code == NOTE) | |
417 | { | |
418 | if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG) | |
419 | depth++; | |
420 | else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_END) | |
421 | depth--; | |
422 | } | |
d7429b6a | 423 | |
e658434c RK |
424 | /* A basic block starts at label, or after something that can jump. */ |
425 | else if (code == CODE_LABEL | |
426 | || (GET_RTX_CLASS (code) == 'i' | |
427 | && (prev_code == JUMP_INSN | |
428 | || (prev_code == CALL_INSN | |
74d7ab55 | 429 | && (nonlocal_label_list != 0 || eh_note) |
8cfe18d6 | 430 | && ! find_reg_note (insn, REG_RETVAL, NULL_RTX)) |
e658434c RK |
431 | || prev_code == BARRIER))) |
432 | { | |
433 | basic_block_head[++i] = insn; | |
434 | basic_block_end[i] = insn; | |
435 | basic_block_loop_depth[i] = depth; | |
436 | ||
437 | if (code == CODE_LABEL) | |
438 | { | |
d7429b6a RK |
439 | LABEL_REFS (insn) = insn; |
440 | /* Any label that cannot be deleted | |
441 | is considered to start a reachable block. */ | |
442 | if (LABEL_PRESERVE_P (insn)) | |
443 | block_live[i] = 1; | |
444 | } | |
e658434c | 445 | } |
d7429b6a | 446 | |
e658434c RK |
447 | else if (GET_RTX_CLASS (code) == 'i') |
448 | { | |
449 | basic_block_end[i] = insn; | |
450 | basic_block_loop_depth[i] = depth; | |
42fa3cfb | 451 | } |
e658434c | 452 | |
42fa3cfb JW |
453 | if (GET_RTX_CLASS (code) == 'i') |
454 | { | |
e658434c RK |
455 | /* Make a list of all labels referred to other than by jumps. */ |
456 | for (note = REG_NOTES (insn); note; note = XEXP (note, 1)) | |
457 | if (REG_NOTE_KIND (note) == REG_LABEL) | |
d7429b6a RK |
458 | label_value_list = gen_rtx (EXPR_LIST, VOIDmode, XEXP (note, 0), |
459 | label_value_list); | |
42fa3cfb | 460 | } |
d7429b6a | 461 | |
2ec1535d JL |
462 | /* Keep a lifo list of the currently active exception handlers. */ |
463 | if (GET_CODE (insn) == NOTE) | |
464 | { | |
465 | if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_BEG) | |
466 | { | |
467 | for (x = exception_handler_labels; x; x = XEXP (x, 1)) | |
468 | if (CODE_LABEL_NUMBER (XEXP (x, 0)) == NOTE_BLOCK_NUMBER (insn)) | |
469 | { | |
470 | eh_note = gen_rtx (EXPR_LIST, VOIDmode, | |
471 | XEXP (x, 0), eh_note); | |
472 | break; | |
473 | } | |
474 | if (x == NULL_RTX) | |
475 | abort (); | |
476 | } | |
477 | else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_END) | |
478 | eh_note = XEXP (eh_note, 1); | |
479 | } | |
480 | /* If we encounter a CALL_INSN, note which exception handler it | |
481 | might pass control to. | |
482 | ||
483 | If doing asynchronous exceptions, record the active EH handler | |
484 | for every insn, since most insns can throw. */ | |
485 | else if (eh_note | |
486 | && (asynchronous_exceptions | |
487 | || (GET_CODE (insn) == CALL_INSN | |
488 | && ! find_reg_note (insn, REG_RETVAL, NULL_RTX)))) | |
489 | active_eh_handler[INSN_UID (insn)] = XEXP (eh_note, 0); | |
490 | ||
e658434c | 491 | BLOCK_NUM (insn) = i; |
d7e4fe8b | 492 | |
6b67ec08 | 493 | if (code != NOTE) |
e658434c RK |
494 | prev_code = code; |
495 | } | |
496 | ||
2aec79e2 DE |
497 | /* During the second pass, `n_basic_blocks' is only an upper bound. |
498 | Only perform the sanity check for the first pass, and on the second | |
499 | pass ensure `n_basic_blocks' is set to the correct value. */ | |
500 | if (pass == 1 && i + 1 != n_basic_blocks) | |
e658434c | 501 | abort (); |
2aec79e2 | 502 | n_basic_blocks = i + 1; |
d7429b6a RK |
503 | |
504 | /* Record which basic blocks control can drop in to. */ | |
505 | ||
e658434c RK |
506 | for (i = 0; i < n_basic_blocks; i++) |
507 | { | |
508 | for (insn = PREV_INSN (basic_block_head[i]); | |
509 | insn && GET_CODE (insn) == NOTE; insn = PREV_INSN (insn)) | |
510 | ; | |
511 | ||
512 | basic_block_drops_in[i] = insn && GET_CODE (insn) != BARRIER; | |
513 | } | |
d7429b6a RK |
514 | |
515 | /* Now find which basic blocks can actually be reached | |
516 | and put all jump insns' LABEL_REFS onto the ref-chains | |
517 | of their target labels. */ | |
518 | ||
519 | if (n_basic_blocks > 0) | |
520 | { | |
521 | int something_marked = 1; | |
8329b5ec | 522 | int deleted; |
d7429b6a | 523 | |
d7429b6a RK |
524 | /* Pass over all blocks, marking each block that is reachable |
525 | and has not yet been marked. | |
526 | Keep doing this until, in one pass, no blocks have been marked. | |
527 | Then blocks_live and blocks_marked are identical and correct. | |
528 | In addition, all jumps actually reachable have been marked. */ | |
529 | ||
530 | while (something_marked) | |
531 | { | |
532 | something_marked = 0; | |
533 | for (i = 0; i < n_basic_blocks; i++) | |
534 | if (block_live[i] && !block_marked[i]) | |
535 | { | |
536 | block_marked[i] = 1; | |
537 | something_marked = 1; | |
538 | if (i + 1 < n_basic_blocks && basic_block_drops_in[i + 1]) | |
539 | block_live[i + 1] = 1; | |
540 | insn = basic_block_end[i]; | |
541 | if (GET_CODE (insn) == JUMP_INSN) | |
542 | mark_label_ref (PATTERN (insn), insn, 0); | |
812059fe | 543 | |
2ec1535d JL |
544 | /* If we have any forced labels, mark them as potentially |
545 | reachable from this block. */ | |
546 | for (x = forced_labels; x; x = XEXP (x, 1)) | |
547 | if (! LABEL_REF_NONLOCAL_P (x)) | |
548 | mark_label_ref (gen_rtx (LABEL_REF, VOIDmode, XEXP (x, 0)), | |
549 | insn, 0); | |
550 | ||
551 | /* Now scan the insns for this block, we may need to make | |
552 | edges for some of them to various non-obvious locations | |
553 | (exception handlers, nonlocal labels, etc). */ | |
554 | for (insn = basic_block_head[i]; | |
555 | insn != NEXT_INSN (basic_block_end[i]); | |
556 | insn = NEXT_INSN (insn)) | |
557 | { | |
558 | if (GET_RTX_CLASS (GET_CODE (insn)) == 'i') | |
559 | { | |
560 | ||
8930b063 JL |
561 | /* References to labels in non-jumping insns have |
562 | REG_LABEL notes attached to them. | |
563 | ||
564 | This can happen for computed gotos; we don't care | |
565 | about them here since the values are also on the | |
566 | label_value_list and will be marked live if we find | |
567 | a live computed goto. | |
568 | ||
569 | This can also happen when we take the address of | |
570 | a label to pass as an argument to __throw. Note | |
571 | throw only uses the value to determine what handler | |
572 | should be called -- ie the label is not used as | |
573 | a jump target, it just marks regions in the code. | |
574 | ||
575 | In theory we should be able to ignore the REG_LABEL | |
576 | notes, but we have to make sure that the label and | |
577 | associated insns aren't marked dead, so we make | |
578 | the block in question live and create an edge from | |
579 | this insn to the label. This is not strictly | |
e701eb4d | 580 | correct, but it is close enough for now. */ |
2ec1535d JL |
581 | for (note = REG_NOTES (insn); |
582 | note; | |
583 | note = XEXP (note, 1)) | |
584 | { | |
812059fe MS |
585 | if (REG_NOTE_KIND (note) == REG_LABEL) |
586 | { | |
587 | x = XEXP (note, 0); | |
588 | block_live[BLOCK_NUM (x)] = 1; | |
8930b063 JL |
589 | mark_label_ref (gen_rtx (LABEL_REF, |
590 | VOIDmode, x), | |
591 | insn, 0); | |
2ec1535d JL |
592 | } |
593 | } | |
594 | ||
595 | /* If this is a computed jump, then mark it as | |
596 | reaching everything on the label_value_list | |
597 | and forced_labels list. */ | |
598 | if (computed_jump_p (insn)) | |
599 | { | |
600 | for (x = label_value_list; x; x = XEXP (x, 1)) | |
601 | mark_label_ref (gen_rtx (LABEL_REF, VOIDmode, | |
602 | XEXP (x, 0)), | |
603 | insn, 0); | |
604 | ||
605 | for (x = forced_labels; x; x = XEXP (x, 1)) | |
606 | mark_label_ref (gen_rtx (LABEL_REF, VOIDmode, | |
607 | XEXP (x, 0)), | |
608 | insn, 0); | |
609 | } | |
610 | ||
611 | /* If this is a CALL_INSN, then mark it as reaching | |
612 | the active EH handler for this CALL_INSN. If | |
613 | we're handling asynchronous exceptions mark every | |
614 | insn as reaching the active EH handler. | |
615 | ||
616 | Also mark the CALL_INSN as reaching any nonlocal | |
617 | goto sites. */ | |
618 | else if (asynchronous_exceptions | |
619 | || (GET_CODE (insn) == CALL_INSN | |
620 | && ! find_reg_note (insn, REG_RETVAL, | |
621 | NULL_RTX))) | |
622 | { | |
623 | if (active_eh_handler[INSN_UID (insn)]) | |
624 | mark_label_ref (gen_rtx (LABEL_REF, VOIDmode, | |
625 | active_eh_handler[INSN_UID (insn)]), | |
626 | insn, 0); | |
627 | ||
628 | if (!asynchronous_exceptions) | |
629 | { | |
630 | for (x = nonlocal_label_list; | |
631 | x; | |
632 | x = XEXP (x, 1)) | |
633 | mark_label_ref (gen_rtx (LABEL_REF, VOIDmode, | |
634 | XEXP (x, 0)), | |
635 | insn, 0); | |
812059fe | 636 | } |
2ec1535d JL |
637 | /* ??? This could be made smarter: |
638 | in some cases it's possible to tell that | |
639 | certain calls will not do a nonlocal goto. | |
640 | ||
641 | For example, if the nested functions that | |
642 | do the nonlocal gotos do not have their | |
643 | addresses taken, then only calls to those | |
644 | functions or to other nested functions that | |
645 | use them could possibly do nonlocal gotos. */ | |
646 | } | |
647 | } | |
648 | } | |
d7429b6a RK |
649 | } |
650 | } | |
651 | ||
2ec1535d JL |
652 | /* This should never happen. If it does that means we've computed an |
653 | incorrect flow graph, which can lead to aborts/crashes later in the | |
654 | compiler or incorrect code generation. | |
af14ce9c | 655 | |
2ec1535d JL |
656 | We used to try and continue here, but that's just asking for trouble |
657 | later during the compile or at runtime. It's easier to debug the | |
658 | problem here than later! */ | |
af14ce9c RK |
659 | for (i = 1; i < n_basic_blocks; i++) |
660 | if (block_live[i] && ! basic_block_drops_in[i] | |
661 | && GET_CODE (basic_block_head[i]) == CODE_LABEL | |
662 | && LABEL_REFS (basic_block_head[i]) == basic_block_head[i]) | |
2ec1535d | 663 | abort (); |
af14ce9c | 664 | |
d7429b6a RK |
665 | /* Now delete the code for any basic blocks that can't be reached. |
666 | They can occur because jump_optimize does not recognize | |
667 | unreachable loops as unreachable. */ | |
668 | ||
8329b5ec | 669 | deleted = 0; |
d7429b6a RK |
670 | for (i = 0; i < n_basic_blocks; i++) |
671 | if (!block_live[i]) | |
672 | { | |
8329b5ec DE |
673 | deleted++; |
674 | ||
675 | /* Delete the insns in a (non-live) block. We physically delete | |
676 | every non-note insn except the start and end (so | |
677 | basic_block_head/end needn't be updated), we turn the latter | |
678 | into NOTE_INSN_DELETED notes. | |
679 | We use to "delete" the insns by turning them into notes, but | |
680 | we may be deleting lots of insns that subsequent passes would | |
681 | otherwise have to process. Secondly, lots of deleted blocks in | |
682 | a row can really slow down propagate_block since it will | |
683 | otherwise process insn-turned-notes multiple times when it | |
684 | looks for loop begin/end notes. */ | |
685 | if (basic_block_head[i] != basic_block_end[i]) | |
686 | { | |
49b6c81e DE |
687 | /* It would be quicker to delete all of these with a single |
688 | unchaining, rather than one at a time, but we need to keep | |
689 | the NOTE's. */ | |
8329b5ec DE |
690 | insn = NEXT_INSN (basic_block_head[i]); |
691 | while (insn != basic_block_end[i]) | |
692 | { | |
693 | if (GET_CODE (insn) == BARRIER) | |
694 | abort (); | |
695 | else if (GET_CODE (insn) != NOTE) | |
696 | insn = flow_delete_insn (insn); | |
697 | else | |
698 | insn = NEXT_INSN (insn); | |
699 | } | |
700 | } | |
d7429b6a | 701 | insn = basic_block_head[i]; |
8329b5ec | 702 | if (GET_CODE (insn) != NOTE) |
d7429b6a | 703 | { |
8329b5ec | 704 | /* Turn the head into a deleted insn note. */ |
d7429b6a RK |
705 | if (GET_CODE (insn) == BARRIER) |
706 | abort (); | |
f8671389 JL |
707 | |
708 | /* If the head of this block is a CODE_LABEL, then it might | |
709 | be the label for an exception handler which can't be | |
710 | reached. | |
711 | ||
712 | We need to remove the label from the exception_handler_label | |
713 | list and remove the associated NOTE_EH_REGION_BEG and | |
714 | NOTE_EH_REGION_END notes. */ | |
715 | if (GET_CODE (insn) == CODE_LABEL) | |
716 | { | |
717 | rtx x, *prev = &exception_handler_labels; | |
718 | ||
719 | for (x = exception_handler_labels; x; x = XEXP (x, 1)) | |
720 | { | |
721 | if (XEXP (x, 0) == insn) | |
722 | { | |
723 | /* Found a match, splice this label out of the | |
724 | EH label list. */ | |
725 | *prev = XEXP (x, 1); | |
726 | XEXP (x, 1) = NULL_RTX; | |
727 | XEXP (x, 0) = NULL_RTX; | |
728 | ||
729 | /* Now we have to find the EH_BEG and EH_END notes | |
730 | associated with this label and remove them. */ | |
731 | ||
732 | for (x = get_insns (); x; x = NEXT_INSN (x)) | |
733 | { | |
734 | if (GET_CODE (x) == NOTE | |
735 | && ((NOTE_LINE_NUMBER (x) | |
736 | == NOTE_INSN_EH_REGION_BEG) | |
737 | || (NOTE_LINE_NUMBER (x) | |
738 | == NOTE_INSN_EH_REGION_END)) | |
739 | && (NOTE_BLOCK_NUMBER (x) | |
740 | == CODE_LABEL_NUMBER (insn))) | |
741 | { | |
742 | NOTE_LINE_NUMBER (x) = NOTE_INSN_DELETED; | |
743 | NOTE_SOURCE_FILE (x) = 0; | |
744 | } | |
745 | } | |
746 | break; | |
747 | } | |
748 | prev = &XEXP (x, 1); | |
749 | } | |
750 | } | |
751 | ||
8329b5ec DE |
752 | PUT_CODE (insn, NOTE); |
753 | NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED; | |
754 | NOTE_SOURCE_FILE (insn) = 0; | |
755 | } | |
756 | insn = basic_block_end[i]; | |
757 | if (GET_CODE (insn) != NOTE) | |
758 | { | |
759 | /* Turn the tail into a deleted insn note. */ | |
760 | if (GET_CODE (insn) == BARRIER) | |
761 | abort (); | |
762 | PUT_CODE (insn, NOTE); | |
763 | NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED; | |
764 | NOTE_SOURCE_FILE (insn) = 0; | |
d7429b6a | 765 | } |
8329b5ec DE |
766 | /* BARRIERs are between basic blocks, not part of one. |
767 | Delete a BARRIER if the preceding jump is deleted. | |
768 | We cannot alter a BARRIER into a NOTE | |
769 | because it is too short; but we can really delete | |
770 | it because it is not part of a basic block. */ | |
771 | if (NEXT_INSN (insn) != 0 | |
772 | && GET_CODE (NEXT_INSN (insn)) == BARRIER) | |
773 | delete_insn (NEXT_INSN (insn)); | |
774 | ||
d7429b6a RK |
775 | /* Each time we delete some basic blocks, |
776 | see if there is a jump around them that is | |
777 | being turned into a no-op. If so, delete it. */ | |
778 | ||
779 | if (block_live[i - 1]) | |
780 | { | |
781 | register int j; | |
8329b5ec | 782 | for (j = i + 1; j < n_basic_blocks; j++) |
d7429b6a RK |
783 | if (block_live[j]) |
784 | { | |
785 | rtx label; | |
786 | insn = basic_block_end[i - 1]; | |
787 | if (GET_CODE (insn) == JUMP_INSN | |
788 | /* An unconditional jump is the only possibility | |
789 | we must check for, since a conditional one | |
790 | would make these blocks live. */ | |
791 | && simplejump_p (insn) | |
792 | && (label = XEXP (SET_SRC (PATTERN (insn)), 0), 1) | |
793 | && INSN_UID (label) != 0 | |
794 | && BLOCK_NUM (label) == j) | |
795 | { | |
796 | PUT_CODE (insn, NOTE); | |
797 | NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED; | |
798 | NOTE_SOURCE_FILE (insn) = 0; | |
799 | if (GET_CODE (NEXT_INSN (insn)) != BARRIER) | |
800 | abort (); | |
801 | delete_insn (NEXT_INSN (insn)); | |
802 | } | |
803 | break; | |
804 | } | |
805 | } | |
806 | } | |
8329b5ec | 807 | |
9faa82d8 | 808 | /* There are pathological cases where one function calling hundreds of |
8329b5ec DE |
809 | nested inline functions can generate lots and lots of unreachable |
810 | blocks that jump can't delete. Since we don't use sparse matrices | |
811 | a lot of memory will be needed to compile such functions. | |
812 | Implementing sparse matrices is a fair bit of work and it is not | |
813 | clear that they win more than they lose (we don't want to | |
814 | unnecessarily slow down compilation of normal code). By making | |
9faa82d8 | 815 | another pass for the pathological case, we can greatly speed up |
8329b5ec DE |
816 | their compilation without hurting normal code. This works because |
817 | all the insns in the unreachable blocks have either been deleted or | |
49b6c81e DE |
818 | turned into notes. |
819 | Note that we're talking about reducing memory usage by 10's of | |
820 | megabytes and reducing compilation time by several minutes. */ | |
8329b5ec DE |
821 | /* ??? The choice of when to make another pass is a bit arbitrary, |
822 | and was derived from empirical data. */ | |
823 | if (pass == 1 | |
49b6c81e | 824 | && deleted > 200) |
8329b5ec DE |
825 | { |
826 | pass++; | |
827 | n_basic_blocks -= deleted; | |
2aec79e2 DE |
828 | /* `n_basic_blocks' may not be correct at this point: two previously |
829 | separate blocks may now be merged. That's ok though as we | |
830 | recalculate it during the second pass. It certainly can't be | |
831 | any larger than the current value. */ | |
8329b5ec DE |
832 | goto restart; |
833 | } | |
d7429b6a RK |
834 | } |
835 | } | |
836 | \f | |
8329b5ec DE |
837 | /* Subroutines of find_basic_blocks. */ |
838 | ||
d7429b6a RK |
839 | /* Check expression X for label references; |
840 | if one is found, add INSN to the label's chain of references. | |
841 | ||
842 | CHECKDUP means check for and avoid creating duplicate references | |
843 | from the same insn. Such duplicates do no serious harm but | |
844 | can slow life analysis. CHECKDUP is set only when duplicates | |
845 | are likely. */ | |
846 | ||
847 | static void | |
848 | mark_label_ref (x, insn, checkdup) | |
849 | rtx x, insn; | |
850 | int checkdup; | |
851 | { | |
852 | register RTX_CODE code; | |
853 | register int i; | |
854 | register char *fmt; | |
855 | ||
856 | /* We can be called with NULL when scanning label_value_list. */ | |
857 | if (x == 0) | |
858 | return; | |
859 | ||
860 | code = GET_CODE (x); | |
861 | if (code == LABEL_REF) | |
862 | { | |
863 | register rtx label = XEXP (x, 0); | |
864 | register rtx y; | |
865 | if (GET_CODE (label) != CODE_LABEL) | |
866 | abort (); | |
867 | /* If the label was never emitted, this insn is junk, | |
868 | but avoid a crash trying to refer to BLOCK_NUM (label). | |
869 | This can happen as a result of a syntax error | |
870 | and a diagnostic has already been printed. */ | |
871 | if (INSN_UID (label) == 0) | |
872 | return; | |
873 | CONTAINING_INSN (x) = insn; | |
874 | /* if CHECKDUP is set, check for duplicate ref from same insn | |
875 | and don't insert. */ | |
876 | if (checkdup) | |
877 | for (y = LABEL_REFS (label); y != label; y = LABEL_NEXTREF (y)) | |
878 | if (CONTAINING_INSN (y) == insn) | |
879 | return; | |
880 | LABEL_NEXTREF (x) = LABEL_REFS (label); | |
881 | LABEL_REFS (label) = x; | |
882 | block_live_static[BLOCK_NUM (label)] = 1; | |
883 | return; | |
884 | } | |
885 | ||
886 | fmt = GET_RTX_FORMAT (code); | |
887 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
888 | { | |
889 | if (fmt[i] == 'e') | |
890 | mark_label_ref (XEXP (x, i), insn, 0); | |
891 | if (fmt[i] == 'E') | |
892 | { | |
893 | register int j; | |
894 | for (j = 0; j < XVECLEN (x, i); j++) | |
895 | mark_label_ref (XVECEXP (x, i, j), insn, 1); | |
896 | } | |
897 | } | |
898 | } | |
8329b5ec DE |
899 | |
900 | /* Delete INSN by patching it out. | |
901 | Return the next insn. */ | |
902 | ||
903 | static rtx | |
904 | flow_delete_insn (insn) | |
905 | rtx insn; | |
906 | { | |
907 | /* ??? For the moment we assume we don't have to watch for NULLs here | |
908 | since the start/end of basic blocks aren't deleted like this. */ | |
909 | NEXT_INSN (PREV_INSN (insn)) = NEXT_INSN (insn); | |
910 | PREV_INSN (NEXT_INSN (insn)) = PREV_INSN (insn); | |
911 | return NEXT_INSN (insn); | |
912 | } | |
d7429b6a RK |
913 | \f |
914 | /* Determine which registers are live at the start of each | |
915 | basic block of the function whose first insn is F. | |
916 | NREGS is the number of registers used in F. | |
917 | We allocate the vector basic_block_live_at_start | |
918 | and the regsets that it points to, and fill them with the data. | |
919 | regset_size and regset_bytes are also set here. */ | |
920 | ||
921 | static void | |
922 | life_analysis (f, nregs) | |
923 | rtx f; | |
924 | int nregs; | |
925 | { | |
d7429b6a RK |
926 | int first_pass; |
927 | int changed; | |
928 | /* For each basic block, a bitmask of regs | |
929 | live on exit from the block. */ | |
930 | regset *basic_block_live_at_end; | |
931 | /* For each basic block, a bitmask of regs | |
932 | live on entry to a successor-block of this block. | |
933 | If this does not match basic_block_live_at_end, | |
934 | that must be updated, and the block must be rescanned. */ | |
935 | regset *basic_block_new_live_at_end; | |
936 | /* For each basic block, a bitmask of regs | |
937 | whose liveness at the end of the basic block | |
938 | can make a difference in which regs are live on entry to the block. | |
939 | These are the regs that are set within the basic block, | |
940 | possibly excluding those that are used after they are set. */ | |
941 | regset *basic_block_significant; | |
942 | register int i; | |
943 | rtx insn; | |
944 | ||
945 | struct obstack flow_obstack; | |
946 | ||
947 | gcc_obstack_init (&flow_obstack); | |
948 | ||
949 | max_regno = nregs; | |
950 | ||
951 | bzero (regs_ever_live, sizeof regs_ever_live); | |
952 | ||
953 | /* Allocate and zero out many data structures | |
954 | that will record the data from lifetime analysis. */ | |
955 | ||
956 | allocate_for_life_analysis (); | |
957 | ||
958 | reg_next_use = (rtx *) alloca (nregs * sizeof (rtx)); | |
4c9a05bc | 959 | bzero ((char *) reg_next_use, nregs * sizeof (rtx)); |
d7429b6a RK |
960 | |
961 | /* Set up several regset-vectors used internally within this function. | |
962 | Their meanings are documented above, with their declarations. */ | |
963 | ||
4c9a05bc RK |
964 | basic_block_live_at_end |
965 | = (regset *) alloca (n_basic_blocks * sizeof (regset)); | |
966 | ||
d7429b6a RK |
967 | /* Don't use alloca since that leads to a crash rather than an error message |
968 | if there isn't enough space. | |
969 | Don't use oballoc since we may need to allocate other things during | |
970 | this function on the temporary obstack. */ | |
67f0e213 | 971 | init_regset_vector (basic_block_live_at_end, n_basic_blocks, &flow_obstack); |
d7429b6a | 972 | |
4c9a05bc RK |
973 | basic_block_new_live_at_end |
974 | = (regset *) alloca (n_basic_blocks * sizeof (regset)); | |
67f0e213 | 975 | init_regset_vector (basic_block_new_live_at_end, n_basic_blocks, |
7eb136d6 | 976 | &flow_obstack); |
d7429b6a | 977 | |
4c9a05bc RK |
978 | basic_block_significant |
979 | = (regset *) alloca (n_basic_blocks * sizeof (regset)); | |
67f0e213 | 980 | init_regset_vector (basic_block_significant, n_basic_blocks, &flow_obstack); |
d7429b6a RK |
981 | |
982 | /* Record which insns refer to any volatile memory | |
983 | or for any reason can't be deleted just because they are dead stores. | |
0f41302f | 984 | Also, delete any insns that copy a register to itself. */ |
d7429b6a RK |
985 | |
986 | for (insn = f; insn; insn = NEXT_INSN (insn)) | |
987 | { | |
988 | enum rtx_code code1 = GET_CODE (insn); | |
989 | if (code1 == CALL_INSN) | |
990 | INSN_VOLATILE (insn) = 1; | |
991 | else if (code1 == INSN || code1 == JUMP_INSN) | |
992 | { | |
993 | /* Delete (in effect) any obvious no-op moves. */ | |
994 | if (GET_CODE (PATTERN (insn)) == SET | |
995 | && GET_CODE (SET_DEST (PATTERN (insn))) == REG | |
996 | && GET_CODE (SET_SRC (PATTERN (insn))) == REG | |
db3cf6fb MS |
997 | && (REGNO (SET_DEST (PATTERN (insn))) |
998 | == REGNO (SET_SRC (PATTERN (insn)))) | |
d7429b6a | 999 | /* Insns carrying these notes are useful later on. */ |
5f4f0e22 | 1000 | && ! find_reg_note (insn, REG_EQUAL, NULL_RTX)) |
d7429b6a RK |
1001 | { |
1002 | PUT_CODE (insn, NOTE); | |
1003 | NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED; | |
1004 | NOTE_SOURCE_FILE (insn) = 0; | |
1005 | } | |
ac684a20 JL |
1006 | /* Delete (in effect) any obvious no-op moves. */ |
1007 | else if (GET_CODE (PATTERN (insn)) == SET | |
1008 | && GET_CODE (SET_DEST (PATTERN (insn))) == SUBREG | |
1009 | && GET_CODE (SUBREG_REG (SET_DEST (PATTERN (insn)))) == REG | |
1010 | && GET_CODE (SET_SRC (PATTERN (insn))) == SUBREG | |
1011 | && GET_CODE (SUBREG_REG (SET_SRC (PATTERN (insn)))) == REG | |
db3cf6fb MS |
1012 | && (REGNO (SUBREG_REG (SET_DEST (PATTERN (insn)))) |
1013 | == REGNO (SUBREG_REG (SET_SRC (PATTERN (insn))))) | |
ac684a20 JL |
1014 | && SUBREG_WORD (SET_DEST (PATTERN (insn))) == |
1015 | SUBREG_WORD (SET_SRC (PATTERN (insn))) | |
1016 | /* Insns carrying these notes are useful later on. */ | |
1017 | && ! find_reg_note (insn, REG_EQUAL, NULL_RTX)) | |
1018 | { | |
1019 | PUT_CODE (insn, NOTE); | |
1020 | NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED; | |
1021 | NOTE_SOURCE_FILE (insn) = 0; | |
1022 | } | |
d7429b6a RK |
1023 | else if (GET_CODE (PATTERN (insn)) == PARALLEL) |
1024 | { | |
1025 | /* If nothing but SETs of registers to themselves, | |
1026 | this insn can also be deleted. */ | |
1027 | for (i = 0; i < XVECLEN (PATTERN (insn), 0); i++) | |
1028 | { | |
1029 | rtx tem = XVECEXP (PATTERN (insn), 0, i); | |
1030 | ||
1031 | if (GET_CODE (tem) == USE | |
1032 | || GET_CODE (tem) == CLOBBER) | |
1033 | continue; | |
1034 | ||
1035 | if (GET_CODE (tem) != SET | |
1036 | || GET_CODE (SET_DEST (tem)) != REG | |
1037 | || GET_CODE (SET_SRC (tem)) != REG | |
1038 | || REGNO (SET_DEST (tem)) != REGNO (SET_SRC (tem))) | |
1039 | break; | |
1040 | } | |
1041 | ||
1042 | if (i == XVECLEN (PATTERN (insn), 0) | |
1043 | /* Insns carrying these notes are useful later on. */ | |
5f4f0e22 | 1044 | && ! find_reg_note (insn, REG_EQUAL, NULL_RTX)) |
d7429b6a RK |
1045 | { |
1046 | PUT_CODE (insn, NOTE); | |
1047 | NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED; | |
1048 | NOTE_SOURCE_FILE (insn) = 0; | |
1049 | } | |
1050 | else | |
1051 | INSN_VOLATILE (insn) = volatile_refs_p (PATTERN (insn)); | |
1052 | } | |
1053 | else if (GET_CODE (PATTERN (insn)) != USE) | |
1054 | INSN_VOLATILE (insn) = volatile_refs_p (PATTERN (insn)); | |
1055 | /* A SET that makes space on the stack cannot be dead. | |
1056 | (Such SETs occur only for allocating variable-size data, | |
1057 | so they will always have a PLUS or MINUS according to the | |
1058 | direction of stack growth.) | |
1059 | Even if this function never uses this stack pointer value, | |
1060 | signal handlers do! */ | |
1061 | else if (code1 == INSN && GET_CODE (PATTERN (insn)) == SET | |
1062 | && SET_DEST (PATTERN (insn)) == stack_pointer_rtx | |
1063 | #ifdef STACK_GROWS_DOWNWARD | |
1064 | && GET_CODE (SET_SRC (PATTERN (insn))) == MINUS | |
1065 | #else | |
1066 | && GET_CODE (SET_SRC (PATTERN (insn))) == PLUS | |
1067 | #endif | |
1068 | && XEXP (SET_SRC (PATTERN (insn)), 0) == stack_pointer_rtx) | |
1069 | INSN_VOLATILE (insn) = 1; | |
1070 | } | |
1071 | } | |
1072 | ||
1073 | if (n_basic_blocks > 0) | |
1074 | #ifdef EXIT_IGNORE_STACK | |
1075 | if (! EXIT_IGNORE_STACK | |
1076 | || (! FRAME_POINTER_REQUIRED && flag_omit_frame_pointer)) | |
1077 | #endif | |
1078 | { | |
1079 | /* If exiting needs the right stack value, | |
1080 | consider the stack pointer live at the end of the function. */ | |
916b1701 MM |
1081 | SET_REGNO_REG_SET (basic_block_live_at_end[n_basic_blocks - 1], |
1082 | STACK_POINTER_REGNUM); | |
1083 | SET_REGNO_REG_SET (basic_block_new_live_at_end[n_basic_blocks - 1], | |
1084 | STACK_POINTER_REGNUM); | |
d7429b6a RK |
1085 | } |
1086 | ||
fe0f9c4b RK |
1087 | /* Mark the frame pointer is needed at the end of the function. If |
1088 | we end up eliminating it, it will be removed from the live list | |
1089 | of each basic block by reload. */ | |
1090 | ||
1091 | if (n_basic_blocks > 0) | |
1092 | { | |
916b1701 MM |
1093 | SET_REGNO_REG_SET (basic_block_live_at_end[n_basic_blocks - 1], |
1094 | FRAME_POINTER_REGNUM); | |
1095 | SET_REGNO_REG_SET (basic_block_new_live_at_end[n_basic_blocks - 1], | |
1096 | FRAME_POINTER_REGNUM); | |
73a187c1 DE |
1097 | #if FRAME_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM |
1098 | /* If they are different, also mark the hard frame pointer as live */ | |
916b1701 MM |
1099 | SET_REGNO_REG_SET (basic_block_live_at_end[n_basic_blocks - 1], |
1100 | HARD_FRAME_POINTER_REGNUM); | |
1101 | SET_REGNO_REG_SET (basic_block_new_live_at_end[n_basic_blocks - 1], | |
1102 | HARD_FRAME_POINTER_REGNUM); | |
73a187c1 | 1103 | #endif |
fe0f9c4b RK |
1104 | } |
1105 | ||
632c9d9e MS |
1106 | /* Mark all global registers and all registers used by the epilogue |
1107 | as being live at the end of the function since they may be | |
1108 | referenced by our caller. */ | |
d7429b6a RK |
1109 | |
1110 | if (n_basic_blocks > 0) | |
1111 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
632c9d9e MS |
1112 | if (global_regs[i] |
1113 | #ifdef EPILOGUE_USES | |
1114 | || EPILOGUE_USES (i) | |
1115 | #endif | |
1116 | ) | |
d7429b6a | 1117 | { |
916b1701 MM |
1118 | SET_REGNO_REG_SET (basic_block_live_at_end[n_basic_blocks - 1], i); |
1119 | SET_REGNO_REG_SET (basic_block_new_live_at_end[n_basic_blocks - 1], i); | |
d7429b6a RK |
1120 | } |
1121 | ||
1122 | /* Propagate life info through the basic blocks | |
1123 | around the graph of basic blocks. | |
1124 | ||
1125 | This is a relaxation process: each time a new register | |
1126 | is live at the end of the basic block, we must scan the block | |
1127 | to determine which registers are, as a consequence, live at the beginning | |
1128 | of that block. These registers must then be marked live at the ends | |
1129 | of all the blocks that can transfer control to that block. | |
1130 | The process continues until it reaches a fixed point. */ | |
1131 | ||
1132 | first_pass = 1; | |
1133 | changed = 1; | |
1134 | while (changed) | |
1135 | { | |
1136 | changed = 0; | |
1137 | for (i = n_basic_blocks - 1; i >= 0; i--) | |
1138 | { | |
1139 | int consider = first_pass; | |
1140 | int must_rescan = first_pass; | |
1141 | register int j; | |
1142 | ||
1143 | if (!first_pass) | |
1144 | { | |
1145 | /* Set CONSIDER if this block needs thinking about at all | |
1146 | (that is, if the regs live now at the end of it | |
1147 | are not the same as were live at the end of it when | |
1148 | we last thought about it). | |
1149 | Set must_rescan if it needs to be thought about | |
1150 | instruction by instruction (that is, if any additional | |
1151 | reg that is live at the end now but was not live there before | |
1152 | is one of the significant regs of this basic block). */ | |
1153 | ||
b5835272 RK |
1154 | EXECUTE_IF_AND_COMPL_IN_REG_SET |
1155 | (basic_block_new_live_at_end[i], | |
1156 | basic_block_live_at_end[i], 0, j, | |
1157 | { | |
1158 | consider = 1; | |
1159 | if (REGNO_REG_SET_P (basic_block_significant[i], j)) | |
1160 | { | |
1161 | must_rescan = 1; | |
1162 | goto done; | |
1163 | } | |
1164 | }); | |
916b1701 | 1165 | done: |
d7429b6a RK |
1166 | if (! consider) |
1167 | continue; | |
1168 | } | |
1169 | ||
1170 | /* The live_at_start of this block may be changing, | |
1171 | so another pass will be required after this one. */ | |
1172 | changed = 1; | |
1173 | ||
1174 | if (! must_rescan) | |
1175 | { | |
1176 | /* No complete rescan needed; | |
1177 | just record those variables newly known live at end | |
1178 | as live at start as well. */ | |
916b1701 MM |
1179 | IOR_AND_COMPL_REG_SET (basic_block_live_at_start[i], |
1180 | basic_block_new_live_at_end[i], | |
1181 | basic_block_live_at_end[i]); | |
1182 | ||
1183 | IOR_AND_COMPL_REG_SET (basic_block_live_at_end[i], | |
1184 | basic_block_new_live_at_end[i], | |
1185 | basic_block_live_at_end[i]); | |
d7429b6a RK |
1186 | } |
1187 | else | |
1188 | { | |
1189 | /* Update the basic_block_live_at_start | |
1190 | by propagation backwards through the block. */ | |
916b1701 MM |
1191 | COPY_REG_SET (basic_block_live_at_end[i], |
1192 | basic_block_new_live_at_end[i]); | |
1193 | COPY_REG_SET (basic_block_live_at_start[i], | |
1194 | basic_block_live_at_end[i]); | |
d7429b6a RK |
1195 | propagate_block (basic_block_live_at_start[i], |
1196 | basic_block_head[i], basic_block_end[i], 0, | |
5f4f0e22 CH |
1197 | first_pass ? basic_block_significant[i] |
1198 | : (regset) 0, | |
d7429b6a RK |
1199 | i); |
1200 | } | |
1201 | ||
1202 | { | |
1203 | register rtx jump, head; | |
af14ce9c | 1204 | |
d7429b6a RK |
1205 | /* Update the basic_block_new_live_at_end's of the block |
1206 | that falls through into this one (if any). */ | |
1207 | head = basic_block_head[i]; | |
d7429b6a | 1208 | if (basic_block_drops_in[i]) |
916b1701 MM |
1209 | IOR_REG_SET (basic_block_new_live_at_end[i-1], |
1210 | basic_block_live_at_start[i]); | |
af14ce9c | 1211 | |
d7429b6a RK |
1212 | /* Update the basic_block_new_live_at_end's of |
1213 | all the blocks that jump to this one. */ | |
1214 | if (GET_CODE (head) == CODE_LABEL) | |
1215 | for (jump = LABEL_REFS (head); | |
1216 | jump != head; | |
1217 | jump = LABEL_NEXTREF (jump)) | |
1218 | { | |
1219 | register int from_block = BLOCK_NUM (CONTAINING_INSN (jump)); | |
916b1701 MM |
1220 | IOR_REG_SET (basic_block_new_live_at_end[from_block], |
1221 | basic_block_live_at_start[i]); | |
d7429b6a RK |
1222 | } |
1223 | } | |
1224 | #ifdef USE_C_ALLOCA | |
1225 | alloca (0); | |
1226 | #endif | |
1227 | } | |
1228 | first_pass = 0; | |
1229 | } | |
1230 | ||
1231 | /* The only pseudos that are live at the beginning of the function are | |
1232 | those that were not set anywhere in the function. local-alloc doesn't | |
1233 | know how to handle these correctly, so mark them as not local to any | |
1234 | one basic block. */ | |
1235 | ||
1236 | if (n_basic_blocks > 0) | |
916b1701 MM |
1237 | EXECUTE_IF_SET_IN_REG_SET (basic_block_live_at_start[0], |
1238 | FIRST_PSEUDO_REGISTER, i, | |
1239 | { | |
1240 | REG_BASIC_BLOCK (i) = REG_BLOCK_GLOBAL; | |
1241 | }); | |
d7429b6a RK |
1242 | |
1243 | /* Now the life information is accurate. | |
1244 | Make one more pass over each basic block | |
1245 | to delete dead stores, create autoincrement addressing | |
1246 | and record how many times each register is used, is set, or dies. | |
1247 | ||
1248 | To save time, we operate directly in basic_block_live_at_end[i], | |
1249 | thus destroying it (in fact, converting it into a copy of | |
1250 | basic_block_live_at_start[i]). This is ok now because | |
1251 | basic_block_live_at_end[i] is no longer used past this point. */ | |
1252 | ||
1253 | max_scratch = 0; | |
1254 | ||
1255 | for (i = 0; i < n_basic_blocks; i++) | |
1256 | { | |
1257 | propagate_block (basic_block_live_at_end[i], | |
5f4f0e22 CH |
1258 | basic_block_head[i], basic_block_end[i], 1, |
1259 | (regset) 0, i); | |
d7429b6a RK |
1260 | #ifdef USE_C_ALLOCA |
1261 | alloca (0); | |
1262 | #endif | |
1263 | } | |
1264 | ||
1265 | #if 0 | |
1266 | /* Something live during a setjmp should not be put in a register | |
1267 | on certain machines which restore regs from stack frames | |
1268 | rather than from the jmpbuf. | |
1269 | But we don't need to do this for the user's variables, since | |
1270 | ANSI says only volatile variables need this. */ | |
1271 | #ifdef LONGJMP_RESTORE_FROM_STACK | |
916b1701 MM |
1272 | EXECUTE_IF_SET_IN_REG_SET (regs_live_at_setjmp, |
1273 | FIRST_PSEUDO_REGISTER, i, | |
1274 | { | |
1275 | if (regno_reg_rtx[i] != 0 | |
1276 | && ! REG_USERVAR_P (regno_reg_rtx[i])) | |
1277 | { | |
1278 | REG_LIVE_LENGTH (i) = -1; | |
1279 | REG_BASIC_BLOCK (i) = -1; | |
1280 | } | |
1281 | }); | |
d7429b6a RK |
1282 | #endif |
1283 | #endif | |
1284 | ||
1285 | /* We have a problem with any pseudoreg that | |
1286 | lives across the setjmp. ANSI says that if a | |
1287 | user variable does not change in value | |
1288 | between the setjmp and the longjmp, then the longjmp preserves it. | |
1289 | This includes longjmp from a place where the pseudo appears dead. | |
1290 | (In principle, the value still exists if it is in scope.) | |
1291 | If the pseudo goes in a hard reg, some other value may occupy | |
1292 | that hard reg where this pseudo is dead, thus clobbering the pseudo. | |
1293 | Conclusion: such a pseudo must not go in a hard reg. */ | |
916b1701 MM |
1294 | EXECUTE_IF_SET_IN_REG_SET (regs_live_at_setjmp, |
1295 | FIRST_PSEUDO_REGISTER, i, | |
1296 | { | |
1297 | if (regno_reg_rtx[i] != 0) | |
1298 | { | |
1299 | REG_LIVE_LENGTH (i) = -1; | |
1300 | REG_BASIC_BLOCK (i) = -1; | |
1301 | } | |
1302 | }); | |
d7429b6a | 1303 | |
67f0e213 RK |
1304 | |
1305 | free_regset_vector (basic_block_live_at_end, n_basic_blocks); | |
1306 | free_regset_vector (basic_block_new_live_at_end, n_basic_blocks); | |
1307 | free_regset_vector (basic_block_significant, n_basic_blocks); | |
1308 | basic_block_live_at_end = (regset *)0; | |
1309 | basic_block_new_live_at_end = (regset *)0; | |
1310 | basic_block_significant = (regset *)0; | |
1311 | ||
5f4f0e22 | 1312 | obstack_free (&flow_obstack, NULL_PTR); |
d7429b6a RK |
1313 | } |
1314 | \f | |
1315 | /* Subroutines of life analysis. */ | |
1316 | ||
1317 | /* Allocate the permanent data structures that represent the results | |
1318 | of life analysis. Not static since used also for stupid life analysis. */ | |
1319 | ||
1320 | void | |
1321 | allocate_for_life_analysis () | |
1322 | { | |
1323 | register int i; | |
d7429b6a | 1324 | |
67f0e213 RK |
1325 | /* Recalculate the register space, in case it has grown. Old style |
1326 | vector oriented regsets would set regset_{size,bytes} here also. */ | |
1327 | allocate_reg_info (max_regno, FALSE, FALSE); | |
d7429b6a | 1328 | |
b1f21e0a MM |
1329 | /* Because both reg_scan and flow_analysis want to set up the REG_N_SETS |
1330 | information, explicitly reset it here. The allocation should have | |
1331 | already happened on the previous reg_scan pass. Make sure in case | |
1332 | some more registers were allocated. */ | |
d7429b6a | 1333 | for (i = 0; i < max_regno; i++) |
b1f21e0a | 1334 | REG_N_SETS (i) = 0; |
d7429b6a | 1335 | |
4c9a05bc RK |
1336 | basic_block_live_at_start |
1337 | = (regset *) oballoc (n_basic_blocks * sizeof (regset)); | |
67f0e213 | 1338 | init_regset_vector (basic_block_live_at_start, n_basic_blocks, |
7eb136d6 | 1339 | function_obstack); |
d7429b6a | 1340 | |
7eb136d6 MM |
1341 | regs_live_at_setjmp = OBSTACK_ALLOC_REG_SET (function_obstack); |
1342 | CLEAR_REG_SET (regs_live_at_setjmp); | |
d7429b6a RK |
1343 | } |
1344 | ||
67f0e213 RK |
1345 | /* Make each element of VECTOR point at a regset. The vector has |
1346 | NELTS elements, and space is allocated from the ALLOC_OBSTACK | |
1347 | obstack. */ | |
d7429b6a | 1348 | |
67f0e213 RK |
1349 | void |
1350 | init_regset_vector (vector, nelts, alloc_obstack) | |
d7429b6a | 1351 | regset *vector; |
d7429b6a | 1352 | int nelts; |
7eb136d6 | 1353 | struct obstack *alloc_obstack; |
d7429b6a RK |
1354 | { |
1355 | register int i; | |
d7429b6a RK |
1356 | |
1357 | for (i = 0; i < nelts; i++) | |
1358 | { | |
7eb136d6 MM |
1359 | vector[i] = OBSTACK_ALLOC_REG_SET (alloc_obstack); |
1360 | CLEAR_REG_SET (vector[i]); | |
d7429b6a RK |
1361 | } |
1362 | } | |
e658434c | 1363 | |
67f0e213 RK |
1364 | /* Release any additional space allocated for each element of VECTOR point |
1365 | other than the regset header itself. The vector has NELTS elements. */ | |
1366 | ||
1367 | void | |
1368 | free_regset_vector (vector, nelts) | |
1369 | regset *vector; | |
1370 | int nelts; | |
1371 | { | |
1372 | register int i; | |
1373 | ||
1374 | for (i = 0; i < nelts; i++) | |
1375 | FREE_REG_SET (vector[i]); | |
1376 | } | |
1377 | ||
d7429b6a RK |
1378 | /* Compute the registers live at the beginning of a basic block |
1379 | from those live at the end. | |
1380 | ||
1381 | When called, OLD contains those live at the end. | |
1382 | On return, it contains those live at the beginning. | |
1383 | FIRST and LAST are the first and last insns of the basic block. | |
1384 | ||
1385 | FINAL is nonzero if we are doing the final pass which is not | |
1386 | for computing the life info (since that has already been done) | |
1387 | but for acting on it. On this pass, we delete dead stores, | |
1388 | set up the logical links and dead-variables lists of instructions, | |
1389 | and merge instructions for autoincrement and autodecrement addresses. | |
1390 | ||
1391 | SIGNIFICANT is nonzero only the first time for each basic block. | |
1392 | If it is nonzero, it points to a regset in which we store | |
1393 | a 1 for each register that is set within the block. | |
1394 | ||
1395 | BNUM is the number of the basic block. */ | |
1396 | ||
1397 | static void | |
1398 | propagate_block (old, first, last, final, significant, bnum) | |
1399 | register regset old; | |
1400 | rtx first; | |
1401 | rtx last; | |
1402 | int final; | |
1403 | regset significant; | |
1404 | int bnum; | |
1405 | { | |
1406 | register rtx insn; | |
1407 | rtx prev; | |
1408 | regset live; | |
1409 | regset dead; | |
1410 | ||
1411 | /* The following variables are used only if FINAL is nonzero. */ | |
1412 | /* This vector gets one element for each reg that has been live | |
1413 | at any point in the basic block that has been scanned so far. | |
916b1701 MM |
1414 | SOMETIMES_MAX says how many elements are in use so far. */ |
1415 | register int *regs_sometimes_live; | |
d7429b6a RK |
1416 | int sometimes_max = 0; |
1417 | /* This regset has 1 for each reg that we have seen live so far. | |
1418 | It and REGS_SOMETIMES_LIVE are updated together. */ | |
1419 | regset maxlive; | |
1420 | ||
1421 | /* The loop depth may change in the middle of a basic block. Since we | |
1422 | scan from end to beginning, we start with the depth at the end of the | |
1423 | current basic block, and adjust as we pass ends and starts of loops. */ | |
1424 | loop_depth = basic_block_loop_depth[bnum]; | |
1425 | ||
7eb136d6 MM |
1426 | dead = ALLOCA_REG_SET (); |
1427 | live = ALLOCA_REG_SET (); | |
d7429b6a RK |
1428 | |
1429 | cc0_live = 0; | |
1430 | last_mem_set = 0; | |
1431 | ||
1432 | /* Include any notes at the end of the block in the scan. | |
1433 | This is in case the block ends with a call to setjmp. */ | |
1434 | ||
1435 | while (NEXT_INSN (last) != 0 && GET_CODE (NEXT_INSN (last)) == NOTE) | |
1436 | { | |
1437 | /* Look for loop boundaries, we are going forward here. */ | |
1438 | last = NEXT_INSN (last); | |
1439 | if (NOTE_LINE_NUMBER (last) == NOTE_INSN_LOOP_BEG) | |
1440 | loop_depth++; | |
1441 | else if (NOTE_LINE_NUMBER (last) == NOTE_INSN_LOOP_END) | |
1442 | loop_depth--; | |
1443 | } | |
1444 | ||
1445 | if (final) | |
1446 | { | |
916b1701 | 1447 | register int i; |
d7429b6a RK |
1448 | |
1449 | num_scratch = 0; | |
7eb136d6 | 1450 | maxlive = ALLOCA_REG_SET (); |
916b1701 MM |
1451 | COPY_REG_SET (maxlive, old); |
1452 | regs_sometimes_live = (int *) alloca (max_regno * sizeof (int)); | |
d7429b6a RK |
1453 | |
1454 | /* Process the regs live at the end of the block. | |
1455 | Enter them in MAXLIVE and REGS_SOMETIMES_LIVE. | |
916b1701 MM |
1456 | Also mark them as not local to any one basic block. */ |
1457 | EXECUTE_IF_SET_IN_REG_SET (old, 0, i, | |
1458 | { | |
1459 | REG_BASIC_BLOCK (i) = REG_BLOCK_GLOBAL; | |
1460 | regs_sometimes_live[sometimes_max] = i; | |
1461 | sometimes_max++; | |
1462 | }); | |
d7429b6a RK |
1463 | } |
1464 | ||
1465 | /* Scan the block an insn at a time from end to beginning. */ | |
1466 | ||
1467 | for (insn = last; ; insn = prev) | |
1468 | { | |
1469 | prev = PREV_INSN (insn); | |
1470 | ||
8329b5ec | 1471 | if (GET_CODE (insn) == NOTE) |
d7429b6a | 1472 | { |
8329b5ec DE |
1473 | /* Look for loop boundaries, remembering that we are going |
1474 | backwards. */ | |
1475 | if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_END) | |
1476 | loop_depth++; | |
1477 | else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG) | |
1478 | loop_depth--; | |
1479 | ||
1480 | /* If we have LOOP_DEPTH == 0, there has been a bookkeeping error. | |
1481 | Abort now rather than setting register status incorrectly. */ | |
1482 | if (loop_depth == 0) | |
1483 | abort (); | |
1484 | ||
1485 | /* If this is a call to `setjmp' et al, | |
1486 | warn if any non-volatile datum is live. */ | |
1487 | ||
1488 | if (final && NOTE_LINE_NUMBER (insn) == NOTE_INSN_SETJMP) | |
916b1701 | 1489 | IOR_REG_SET (regs_live_at_setjmp, old); |
d7429b6a RK |
1490 | } |
1491 | ||
1492 | /* Update the life-status of regs for this insn. | |
1493 | First DEAD gets which regs are set in this insn | |
1494 | then LIVE gets which regs are used in this insn. | |
1495 | Then the regs live before the insn | |
1496 | are those live after, with DEAD regs turned off, | |
1497 | and then LIVE regs turned on. */ | |
1498 | ||
8329b5ec | 1499 | else if (GET_RTX_CLASS (GET_CODE (insn)) == 'i') |
d7429b6a RK |
1500 | { |
1501 | register int i; | |
5f4f0e22 | 1502 | rtx note = find_reg_note (insn, REG_RETVAL, NULL_RTX); |
d7429b6a RK |
1503 | int insn_is_dead |
1504 | = (insn_dead_p (PATTERN (insn), old, 0) | |
1505 | /* Don't delete something that refers to volatile storage! */ | |
1506 | && ! INSN_VOLATILE (insn)); | |
1507 | int libcall_is_dead | |
1508 | = (insn_is_dead && note != 0 | |
1509 | && libcall_dead_p (PATTERN (insn), old, note, insn)); | |
1510 | ||
1511 | /* If an instruction consists of just dead store(s) on final pass, | |
1512 | "delete" it by turning it into a NOTE of type NOTE_INSN_DELETED. | |
1513 | We could really delete it with delete_insn, but that | |
1514 | can cause trouble for first or last insn in a basic block. */ | |
1515 | if (final && insn_is_dead) | |
1516 | { | |
1517 | PUT_CODE (insn, NOTE); | |
1518 | NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED; | |
1519 | NOTE_SOURCE_FILE (insn) = 0; | |
1520 | ||
e5df1ea3 RK |
1521 | /* CC0 is now known to be dead. Either this insn used it, |
1522 | in which case it doesn't anymore, or clobbered it, | |
1523 | so the next insn can't use it. */ | |
1524 | cc0_live = 0; | |
1525 | ||
d7429b6a RK |
1526 | /* If this insn is copying the return value from a library call, |
1527 | delete the entire library call. */ | |
1528 | if (libcall_is_dead) | |
1529 | { | |
1530 | rtx first = XEXP (note, 0); | |
1531 | rtx p = insn; | |
1532 | while (INSN_DELETED_P (first)) | |
1533 | first = NEXT_INSN (first); | |
1534 | while (p != first) | |
1535 | { | |
1536 | p = PREV_INSN (p); | |
1537 | PUT_CODE (p, NOTE); | |
1538 | NOTE_LINE_NUMBER (p) = NOTE_INSN_DELETED; | |
1539 | NOTE_SOURCE_FILE (p) = 0; | |
1540 | } | |
1541 | } | |
1542 | goto flushed; | |
1543 | } | |
1544 | ||
916b1701 MM |
1545 | CLEAR_REG_SET (dead); |
1546 | CLEAR_REG_SET (live); | |
d7429b6a RK |
1547 | |
1548 | /* See if this is an increment or decrement that can be | |
1549 | merged into a following memory address. */ | |
1550 | #ifdef AUTO_INC_DEC | |
1551 | { | |
956d6950 JL |
1552 | register rtx x = single_set (insn); |
1553 | ||
d7429b6a | 1554 | /* Does this instruction increment or decrement a register? */ |
956d6950 | 1555 | if (final && x != 0 |
d7429b6a RK |
1556 | && GET_CODE (SET_DEST (x)) == REG |
1557 | && (GET_CODE (SET_SRC (x)) == PLUS | |
1558 | || GET_CODE (SET_SRC (x)) == MINUS) | |
1559 | && XEXP (SET_SRC (x), 0) == SET_DEST (x) | |
1560 | && GET_CODE (XEXP (SET_SRC (x), 1)) == CONST_INT | |
1561 | /* Ok, look for a following memory ref we can combine with. | |
1562 | If one is found, change the memory ref to a PRE_INC | |
1563 | or PRE_DEC, cancel this insn, and return 1. | |
1564 | Return 0 if nothing has been done. */ | |
1565 | && try_pre_increment_1 (insn)) | |
1566 | goto flushed; | |
1567 | } | |
1568 | #endif /* AUTO_INC_DEC */ | |
1569 | ||
1570 | /* If this is not the final pass, and this insn is copying the | |
1571 | value of a library call and it's dead, don't scan the | |
1572 | insns that perform the library call, so that the call's | |
1573 | arguments are not marked live. */ | |
1574 | if (libcall_is_dead) | |
1575 | { | |
1576 | /* Mark the dest reg as `significant'. */ | |
5f4f0e22 | 1577 | mark_set_regs (old, dead, PATTERN (insn), NULL_RTX, significant); |
d7429b6a RK |
1578 | |
1579 | insn = XEXP (note, 0); | |
1580 | prev = PREV_INSN (insn); | |
1581 | } | |
1582 | else if (GET_CODE (PATTERN (insn)) == SET | |
1583 | && SET_DEST (PATTERN (insn)) == stack_pointer_rtx | |
1584 | && GET_CODE (SET_SRC (PATTERN (insn))) == PLUS | |
1585 | && XEXP (SET_SRC (PATTERN (insn)), 0) == stack_pointer_rtx | |
1586 | && GET_CODE (XEXP (SET_SRC (PATTERN (insn)), 1)) == CONST_INT) | |
1587 | /* We have an insn to pop a constant amount off the stack. | |
1588 | (Such insns use PLUS regardless of the direction of the stack, | |
1589 | and any insn to adjust the stack by a constant is always a pop.) | |
1590 | These insns, if not dead stores, have no effect on life. */ | |
1591 | ; | |
1592 | else | |
1593 | { | |
1594 | /* LIVE gets the regs used in INSN; | |
1595 | DEAD gets those set by it. Dead insns don't make anything | |
1596 | live. */ | |
1597 | ||
5f4f0e22 CH |
1598 | mark_set_regs (old, dead, PATTERN (insn), |
1599 | final ? insn : NULL_RTX, significant); | |
d7429b6a RK |
1600 | |
1601 | /* If an insn doesn't use CC0, it becomes dead since we | |
1602 | assume that every insn clobbers it. So show it dead here; | |
1603 | mark_used_regs will set it live if it is referenced. */ | |
1604 | cc0_live = 0; | |
1605 | ||
1606 | if (! insn_is_dead) | |
1607 | mark_used_regs (old, live, PATTERN (insn), final, insn); | |
1608 | ||
1609 | /* Sometimes we may have inserted something before INSN (such as | |
1610 | a move) when we make an auto-inc. So ensure we will scan | |
1611 | those insns. */ | |
1612 | #ifdef AUTO_INC_DEC | |
1613 | prev = PREV_INSN (insn); | |
1614 | #endif | |
1615 | ||
1616 | if (! insn_is_dead && GET_CODE (insn) == CALL_INSN) | |
1617 | { | |
1618 | register int i; | |
1619 | ||
6b67ec08 RK |
1620 | rtx note; |
1621 | ||
1622 | for (note = CALL_INSN_FUNCTION_USAGE (insn); | |
1623 | note; | |
1624 | note = XEXP (note, 1)) | |
1625 | if (GET_CODE (XEXP (note, 0)) == USE) | |
1626 | mark_used_regs (old, live, SET_DEST (XEXP (note, 0)), | |
1627 | final, insn); | |
1628 | ||
d7429b6a | 1629 | /* Each call clobbers all call-clobbered regs that are not |
e4329280 | 1630 | global or fixed. Note that the function-value reg is a |
d7429b6a RK |
1631 | call-clobbered reg, and mark_set_regs has already had |
1632 | a chance to handle it. */ | |
1633 | ||
1634 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
e4329280 RK |
1635 | if (call_used_regs[i] && ! global_regs[i] |
1636 | && ! fixed_regs[i]) | |
916b1701 | 1637 | SET_REGNO_REG_SET (dead, i); |
d7429b6a RK |
1638 | |
1639 | /* The stack ptr is used (honorarily) by a CALL insn. */ | |
916b1701 | 1640 | SET_REGNO_REG_SET (live, STACK_POINTER_REGNUM); |
d7429b6a RK |
1641 | |
1642 | /* Calls may also reference any of the global registers, | |
1643 | so they are made live. */ | |
d7429b6a RK |
1644 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) |
1645 | if (global_regs[i]) | |
9b316aa2 RK |
1646 | mark_used_regs (old, live, |
1647 | gen_rtx (REG, reg_raw_mode[i], i), | |
1648 | final, insn); | |
d7429b6a RK |
1649 | |
1650 | /* Calls also clobber memory. */ | |
1651 | last_mem_set = 0; | |
1652 | } | |
1653 | ||
1654 | /* Update OLD for the registers used or set. */ | |
916b1701 MM |
1655 | AND_COMPL_REG_SET (old, dead); |
1656 | IOR_REG_SET (old, live); | |
d7429b6a RK |
1657 | |
1658 | if (GET_CODE (insn) == CALL_INSN && final) | |
1659 | { | |
1660 | /* Any regs live at the time of a call instruction | |
1661 | must not go in a register clobbered by calls. | |
1662 | Find all regs now live and record this for them. */ | |
1663 | ||
916b1701 | 1664 | register int *p = regs_sometimes_live; |
d7429b6a RK |
1665 | |
1666 | for (i = 0; i < sometimes_max; i++, p++) | |
916b1701 MM |
1667 | if (REGNO_REG_SET_P (old, *p)) |
1668 | REG_N_CALLS_CROSSED (*p)++; | |
d7429b6a RK |
1669 | } |
1670 | } | |
1671 | ||
1672 | /* On final pass, add any additional sometimes-live regs | |
1673 | into MAXLIVE and REGS_SOMETIMES_LIVE. | |
1674 | Also update counts of how many insns each reg is live at. */ | |
1675 | ||
1676 | if (final) | |
1677 | { | |
916b1701 MM |
1678 | register int regno; |
1679 | register int *p; | |
d7429b6a | 1680 | |
b5835272 RK |
1681 | EXECUTE_IF_AND_COMPL_IN_REG_SET |
1682 | (live, maxlive, 0, regno, | |
1683 | { | |
1684 | regs_sometimes_live[sometimes_max++] = regno; | |
1685 | SET_REGNO_REG_SET (maxlive, regno); | |
1686 | }); | |
d7429b6a | 1687 | |
916b1701 MM |
1688 | p = regs_sometimes_live; |
1689 | for (i = 0; i < sometimes_max; i++) | |
1690 | { | |
1691 | regno = *p++; | |
1692 | if (REGNO_REG_SET_P (old, regno)) | |
1693 | REG_LIVE_LENGTH (regno)++; | |
1694 | } | |
d7429b6a RK |
1695 | } |
1696 | } | |
1697 | flushed: ; | |
1698 | if (insn == first) | |
1699 | break; | |
1700 | } | |
1701 | ||
67f0e213 RK |
1702 | FREE_REG_SET (dead); |
1703 | FREE_REG_SET (live); | |
1704 | if (final) | |
1705 | FREE_REG_SET (maxlive); | |
1706 | ||
d7429b6a RK |
1707 | if (num_scratch > max_scratch) |
1708 | max_scratch = num_scratch; | |
1709 | } | |
1710 | \f | |
1711 | /* Return 1 if X (the body of an insn, or part of it) is just dead stores | |
1712 | (SET expressions whose destinations are registers dead after the insn). | |
1713 | NEEDED is the regset that says which regs are alive after the insn. | |
1714 | ||
1715 | Unless CALL_OK is non-zero, an insn is needed if it contains a CALL. */ | |
1716 | ||
1717 | static int | |
1718 | insn_dead_p (x, needed, call_ok) | |
1719 | rtx x; | |
1720 | regset needed; | |
1721 | int call_ok; | |
1722 | { | |
1723 | register RTX_CODE code = GET_CODE (x); | |
1724 | /* If setting something that's a reg or part of one, | |
1725 | see if that register's altered value will be live. */ | |
1726 | ||
1727 | if (code == SET) | |
1728 | { | |
1729 | register rtx r = SET_DEST (x); | |
1730 | /* A SET that is a subroutine call cannot be dead. */ | |
1731 | if (! call_ok && GET_CODE (SET_SRC (x)) == CALL) | |
1732 | return 0; | |
1733 | ||
1734 | #ifdef HAVE_cc0 | |
1735 | if (GET_CODE (r) == CC0) | |
1736 | return ! cc0_live; | |
1737 | #endif | |
1738 | ||
1739 | if (GET_CODE (r) == MEM && last_mem_set && ! MEM_VOLATILE_P (r) | |
1740 | && rtx_equal_p (r, last_mem_set)) | |
1741 | return 1; | |
1742 | ||
1743 | while (GET_CODE (r) == SUBREG | |
1744 | || GET_CODE (r) == STRICT_LOW_PART | |
1745 | || GET_CODE (r) == ZERO_EXTRACT | |
1746 | || GET_CODE (r) == SIGN_EXTRACT) | |
1747 | r = SUBREG_REG (r); | |
1748 | ||
1749 | if (GET_CODE (r) == REG) | |
1750 | { | |
1751 | register int regno = REGNO (r); | |
d7429b6a | 1752 | |
d8c8b8e3 | 1753 | /* Don't delete insns to set global regs. */ |
d7429b6a RK |
1754 | if ((regno < FIRST_PSEUDO_REGISTER && global_regs[regno]) |
1755 | /* Make sure insns to set frame pointer aren't deleted. */ | |
1756 | || regno == FRAME_POINTER_REGNUM | |
73a187c1 DE |
1757 | #if FRAME_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM |
1758 | || regno == HARD_FRAME_POINTER_REGNUM | |
1759 | #endif | |
d7e4fe8b RS |
1760 | #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM |
1761 | /* Make sure insns to set arg pointer are never deleted | |
1762 | (if the arg pointer isn't fixed, there will be a USE for | |
0f41302f | 1763 | it, so we can treat it normally). */ |
d7e4fe8b RS |
1764 | || (regno == ARG_POINTER_REGNUM && fixed_regs[regno]) |
1765 | #endif | |
916b1701 | 1766 | || REGNO_REG_SET_P (needed, regno)) |
d7429b6a RK |
1767 | return 0; |
1768 | ||
1769 | /* If this is a hard register, verify that subsequent words are | |
1770 | not needed. */ | |
1771 | if (regno < FIRST_PSEUDO_REGISTER) | |
1772 | { | |
1773 | int n = HARD_REGNO_NREGS (regno, GET_MODE (r)); | |
1774 | ||
1775 | while (--n > 0) | |
916b1701 | 1776 | if (REGNO_REG_SET_P (needed, regno+n)) |
d7429b6a RK |
1777 | return 0; |
1778 | } | |
1779 | ||
1780 | return 1; | |
1781 | } | |
1782 | } | |
1783 | /* If performing several activities, | |
1784 | insn is dead if each activity is individually dead. | |
1785 | Also, CLOBBERs and USEs can be ignored; a CLOBBER or USE | |
1786 | that's inside a PARALLEL doesn't make the insn worth keeping. */ | |
1787 | else if (code == PARALLEL) | |
1788 | { | |
1789 | register int i = XVECLEN (x, 0); | |
1790 | for (i--; i >= 0; i--) | |
1791 | { | |
1792 | rtx elt = XVECEXP (x, 0, i); | |
1793 | if (!insn_dead_p (elt, needed, call_ok) | |
1794 | && GET_CODE (elt) != CLOBBER | |
1795 | && GET_CODE (elt) != USE) | |
1796 | return 0; | |
1797 | } | |
1798 | return 1; | |
1799 | } | |
1800 | /* We do not check CLOBBER or USE here. | |
1801 | An insn consisting of just a CLOBBER or just a USE | |
1802 | should not be deleted. */ | |
1803 | return 0; | |
1804 | } | |
1805 | ||
1806 | /* If X is the pattern of the last insn in a libcall, and assuming X is dead, | |
1807 | return 1 if the entire library call is dead. | |
1808 | This is true if X copies a register (hard or pseudo) | |
1809 | and if the hard return reg of the call insn is dead. | |
1810 | (The caller should have tested the destination of X already for death.) | |
1811 | ||
1812 | If this insn doesn't just copy a register, then we don't | |
1813 | have an ordinary libcall. In that case, cse could not have | |
1814 | managed to substitute the source for the dest later on, | |
1815 | so we can assume the libcall is dead. | |
1816 | ||
1817 | NEEDED is the bit vector of pseudoregs live before this insn. | |
1818 | NOTE is the REG_RETVAL note of the insn. INSN is the insn itself. */ | |
1819 | ||
1820 | static int | |
1821 | libcall_dead_p (x, needed, note, insn) | |
1822 | rtx x; | |
1823 | regset needed; | |
1824 | rtx note; | |
1825 | rtx insn; | |
1826 | { | |
1827 | register RTX_CODE code = GET_CODE (x); | |
1828 | ||
1829 | if (code == SET) | |
1830 | { | |
1831 | register rtx r = SET_SRC (x); | |
1832 | if (GET_CODE (r) == REG) | |
1833 | { | |
1834 | rtx call = XEXP (note, 0); | |
1835 | register int i; | |
1836 | ||
1837 | /* Find the call insn. */ | |
1838 | while (call != insn && GET_CODE (call) != CALL_INSN) | |
1839 | call = NEXT_INSN (call); | |
1840 | ||
1841 | /* If there is none, do nothing special, | |
1842 | since ordinary death handling can understand these insns. */ | |
1843 | if (call == insn) | |
1844 | return 0; | |
1845 | ||
1846 | /* See if the hard reg holding the value is dead. | |
1847 | If this is a PARALLEL, find the call within it. */ | |
1848 | call = PATTERN (call); | |
1849 | if (GET_CODE (call) == PARALLEL) | |
1850 | { | |
1851 | for (i = XVECLEN (call, 0) - 1; i >= 0; i--) | |
1852 | if (GET_CODE (XVECEXP (call, 0, i)) == SET | |
1853 | && GET_CODE (SET_SRC (XVECEXP (call, 0, i))) == CALL) | |
1854 | break; | |
1855 | ||
761a5bcd JW |
1856 | /* This may be a library call that is returning a value |
1857 | via invisible pointer. Do nothing special, since | |
1858 | ordinary death handling can understand these insns. */ | |
d7429b6a | 1859 | if (i < 0) |
761a5bcd | 1860 | return 0; |
d7429b6a RK |
1861 | |
1862 | call = XVECEXP (call, 0, i); | |
1863 | } | |
1864 | ||
1865 | return insn_dead_p (call, needed, 1); | |
1866 | } | |
1867 | } | |
1868 | return 1; | |
1869 | } | |
1870 | ||
1871 | /* Return 1 if register REGNO was used before it was set. | |
944e5f77 | 1872 | In other words, if it is live at function entry. |
6a45254e RK |
1873 | Don't count global register variables or variables in registers |
1874 | that can be used for function arg passing, though. */ | |
d7429b6a RK |
1875 | |
1876 | int | |
1877 | regno_uninitialized (regno) | |
1878 | int regno; | |
1879 | { | |
b0b7b46a | 1880 | if (n_basic_blocks == 0 |
6a45254e RK |
1881 | || (regno < FIRST_PSEUDO_REGISTER |
1882 | && (global_regs[regno] || FUNCTION_ARG_REGNO_P (regno)))) | |
d7429b6a RK |
1883 | return 0; |
1884 | ||
916b1701 | 1885 | return REGNO_REG_SET_P (basic_block_live_at_start[0], regno); |
d7429b6a RK |
1886 | } |
1887 | ||
1888 | /* 1 if register REGNO was alive at a place where `setjmp' was called | |
1889 | and was set more than once or is an argument. | |
1890 | Such regs may be clobbered by `longjmp'. */ | |
1891 | ||
1892 | int | |
1893 | regno_clobbered_at_setjmp (regno) | |
1894 | int regno; | |
1895 | { | |
1896 | if (n_basic_blocks == 0) | |
1897 | return 0; | |
1898 | ||
b1f21e0a | 1899 | return ((REG_N_SETS (regno) > 1 |
916b1701 MM |
1900 | || REGNO_REG_SET_P (basic_block_live_at_start[0], regno)) |
1901 | && REGNO_REG_SET_P (regs_live_at_setjmp, regno)); | |
d7429b6a RK |
1902 | } |
1903 | \f | |
1904 | /* Process the registers that are set within X. | |
1905 | Their bits are set to 1 in the regset DEAD, | |
1906 | because they are dead prior to this insn. | |
1907 | ||
1908 | If INSN is nonzero, it is the insn being processed | |
1909 | and the fact that it is nonzero implies this is the FINAL pass | |
1910 | in propagate_block. In this case, various info about register | |
1911 | usage is stored, LOG_LINKS fields of insns are set up. */ | |
1912 | ||
d7429b6a RK |
1913 | static void |
1914 | mark_set_regs (needed, dead, x, insn, significant) | |
1915 | regset needed; | |
1916 | regset dead; | |
1917 | rtx x; | |
1918 | rtx insn; | |
1919 | regset significant; | |
1920 | { | |
1921 | register RTX_CODE code = GET_CODE (x); | |
1922 | ||
1923 | if (code == SET || code == CLOBBER) | |
1924 | mark_set_1 (needed, dead, x, insn, significant); | |
1925 | else if (code == PARALLEL) | |
1926 | { | |
1927 | register int i; | |
1928 | for (i = XVECLEN (x, 0) - 1; i >= 0; i--) | |
1929 | { | |
1930 | code = GET_CODE (XVECEXP (x, 0, i)); | |
1931 | if (code == SET || code == CLOBBER) | |
1932 | mark_set_1 (needed, dead, XVECEXP (x, 0, i), insn, significant); | |
1933 | } | |
1934 | } | |
1935 | } | |
1936 | ||
1937 | /* Process a single SET rtx, X. */ | |
1938 | ||
1939 | static void | |
1940 | mark_set_1 (needed, dead, x, insn, significant) | |
1941 | regset needed; | |
1942 | regset dead; | |
1943 | rtx x; | |
1944 | rtx insn; | |
1945 | regset significant; | |
1946 | { | |
1947 | register int regno; | |
1948 | register rtx reg = SET_DEST (x); | |
1949 | ||
1950 | /* Modifying just one hardware register of a multi-reg value | |
1951 | or just a byte field of a register | |
1952 | does not mean the value from before this insn is now dead. | |
1953 | But it does mean liveness of that register at the end of the block | |
1954 | is significant. | |
1955 | ||
1956 | Within mark_set_1, however, we treat it as if the register is | |
1957 | indeed modified. mark_used_regs will, however, also treat this | |
1958 | register as being used. Thus, we treat these insns as setting a | |
1959 | new value for the register as a function of its old value. This | |
1960 | cases LOG_LINKS to be made appropriately and this will help combine. */ | |
1961 | ||
1962 | while (GET_CODE (reg) == SUBREG || GET_CODE (reg) == ZERO_EXTRACT | |
1963 | || GET_CODE (reg) == SIGN_EXTRACT | |
1964 | || GET_CODE (reg) == STRICT_LOW_PART) | |
1965 | reg = XEXP (reg, 0); | |
1966 | ||
1967 | /* If we are writing into memory or into a register mentioned in the | |
1968 | address of the last thing stored into memory, show we don't know | |
1969 | what the last store was. If we are writing memory, save the address | |
1970 | unless it is volatile. */ | |
1971 | if (GET_CODE (reg) == MEM | |
1972 | || (GET_CODE (reg) == REG | |
1973 | && last_mem_set != 0 && reg_overlap_mentioned_p (reg, last_mem_set))) | |
1974 | last_mem_set = 0; | |
1975 | ||
1976 | if (GET_CODE (reg) == MEM && ! side_effects_p (reg) | |
1977 | /* There are no REG_INC notes for SP, so we can't assume we'll see | |
1978 | everything that invalidates it. To be safe, don't eliminate any | |
1979 | stores though SP; none of them should be redundant anyway. */ | |
1980 | && ! reg_mentioned_p (stack_pointer_rtx, reg)) | |
1981 | last_mem_set = reg; | |
1982 | ||
1983 | if (GET_CODE (reg) == REG | |
1984 | && (regno = REGNO (reg), regno != FRAME_POINTER_REGNUM) | |
73a187c1 DE |
1985 | #if FRAME_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM |
1986 | && regno != HARD_FRAME_POINTER_REGNUM | |
1987 | #endif | |
d7e4fe8b RS |
1988 | #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM |
1989 | && ! (regno == ARG_POINTER_REGNUM && fixed_regs[regno]) | |
1990 | #endif | |
d7429b6a RK |
1991 | && ! (regno < FIRST_PSEUDO_REGISTER && global_regs[regno])) |
1992 | /* && regno != STACK_POINTER_REGNUM) -- let's try without this. */ | |
1993 | { | |
916b1701 MM |
1994 | int some_needed = REGNO_REG_SET_P (needed, regno); |
1995 | int some_not_needed = ! some_needed; | |
d7429b6a RK |
1996 | |
1997 | /* Mark it as a significant register for this basic block. */ | |
1998 | if (significant) | |
916b1701 | 1999 | SET_REGNO_REG_SET (significant, regno); |
d7429b6a RK |
2000 | |
2001 | /* Mark it as as dead before this insn. */ | |
916b1701 | 2002 | SET_REGNO_REG_SET (dead, regno); |
d7429b6a RK |
2003 | |
2004 | /* A hard reg in a wide mode may really be multiple registers. | |
2005 | If so, mark all of them just like the first. */ | |
2006 | if (regno < FIRST_PSEUDO_REGISTER) | |
2007 | { | |
2008 | int n; | |
2009 | ||
2010 | /* Nothing below is needed for the stack pointer; get out asap. | |
2011 | Eg, log links aren't needed, since combine won't use them. */ | |
2012 | if (regno == STACK_POINTER_REGNUM) | |
2013 | return; | |
2014 | ||
2015 | n = HARD_REGNO_NREGS (regno, GET_MODE (reg)); | |
2016 | while (--n > 0) | |
2017 | { | |
916b1701 MM |
2018 | int regno_n = regno + n; |
2019 | int needed_regno = REGNO_REG_SET_P (needed, regno_n); | |
d7429b6a | 2020 | if (significant) |
916b1701 | 2021 | SET_REGNO_REG_SET (significant, regno_n); |
cb9e8ad1 | 2022 | |
916b1701 MM |
2023 | SET_REGNO_REG_SET (dead, regno_n); |
2024 | some_needed |= needed_regno; | |
2025 | some_not_needed |= ! needed_regno; | |
d7429b6a RK |
2026 | } |
2027 | } | |
2028 | /* Additional data to record if this is the final pass. */ | |
2029 | if (insn) | |
2030 | { | |
2031 | register rtx y = reg_next_use[regno]; | |
2032 | register int blocknum = BLOCK_NUM (insn); | |
2033 | ||
2034 | /* If this is a hard reg, record this function uses the reg. */ | |
2035 | ||
2036 | if (regno < FIRST_PSEUDO_REGISTER) | |
2037 | { | |
2038 | register int i; | |
2039 | int endregno = regno + HARD_REGNO_NREGS (regno, GET_MODE (reg)); | |
2040 | ||
2041 | for (i = regno; i < endregno; i++) | |
2042 | { | |
93514916 JW |
2043 | /* The next use is no longer "next", since a store |
2044 | intervenes. */ | |
2045 | reg_next_use[i] = 0; | |
2046 | ||
d7429b6a | 2047 | regs_ever_live[i] = 1; |
b1f21e0a | 2048 | REG_N_SETS (i)++; |
d7429b6a RK |
2049 | } |
2050 | } | |
2051 | else | |
2052 | { | |
93514916 JW |
2053 | /* The next use is no longer "next", since a store |
2054 | intervenes. */ | |
2055 | reg_next_use[regno] = 0; | |
2056 | ||
d7429b6a RK |
2057 | /* Keep track of which basic blocks each reg appears in. */ |
2058 | ||
b1f21e0a MM |
2059 | if (REG_BASIC_BLOCK (regno) == REG_BLOCK_UNKNOWN) |
2060 | REG_BASIC_BLOCK (regno) = blocknum; | |
2061 | else if (REG_BASIC_BLOCK (regno) != blocknum) | |
2062 | REG_BASIC_BLOCK (regno) = REG_BLOCK_GLOBAL; | |
d7429b6a RK |
2063 | |
2064 | /* Count (weighted) references, stores, etc. This counts a | |
2065 | register twice if it is modified, but that is correct. */ | |
b1f21e0a | 2066 | REG_N_SETS (regno)++; |
d7429b6a | 2067 | |
b1f21e0a | 2068 | REG_N_REFS (regno) += loop_depth; |
d7429b6a RK |
2069 | |
2070 | /* The insns where a reg is live are normally counted | |
2071 | elsewhere, but we want the count to include the insn | |
2072 | where the reg is set, and the normal counting mechanism | |
2073 | would not count it. */ | |
b1f21e0a | 2074 | REG_LIVE_LENGTH (regno)++; |
d7429b6a RK |
2075 | } |
2076 | ||
cb9e8ad1 | 2077 | if (! some_not_needed) |
d7429b6a RK |
2078 | { |
2079 | /* Make a logical link from the next following insn | |
2080 | that uses this register, back to this insn. | |
2081 | The following insns have already been processed. | |
2082 | ||
2083 | We don't build a LOG_LINK for hard registers containing | |
2084 | in ASM_OPERANDs. If these registers get replaced, | |
2085 | we might wind up changing the semantics of the insn, | |
2086 | even if reload can make what appear to be valid assignments | |
2087 | later. */ | |
2088 | if (y && (BLOCK_NUM (y) == blocknum) | |
2089 | && (regno >= FIRST_PSEUDO_REGISTER | |
2090 | || asm_noperands (PATTERN (y)) < 0)) | |
2091 | LOG_LINKS (y) | |
2092 | = gen_rtx (INSN_LIST, VOIDmode, insn, LOG_LINKS (y)); | |
2093 | } | |
2094 | else if (! some_needed) | |
2095 | { | |
2096 | /* Note that dead stores have already been deleted when possible | |
2097 | If we get here, we have found a dead store that cannot | |
2098 | be eliminated (because the same insn does something useful). | |
2099 | Indicate this by marking the reg being set as dying here. */ | |
2100 | REG_NOTES (insn) | |
2101 | = gen_rtx (EXPR_LIST, REG_UNUSED, reg, REG_NOTES (insn)); | |
b1f21e0a | 2102 | REG_N_DEATHS (REGNO (reg))++; |
d7429b6a RK |
2103 | } |
2104 | else | |
2105 | { | |
2106 | /* This is a case where we have a multi-word hard register | |
2107 | and some, but not all, of the words of the register are | |
2108 | needed in subsequent insns. Write REG_UNUSED notes | |
2109 | for those parts that were not needed. This case should | |
2110 | be rare. */ | |
2111 | ||
2112 | int i; | |
2113 | ||
2114 | for (i = HARD_REGNO_NREGS (regno, GET_MODE (reg)) - 1; | |
2115 | i >= 0; i--) | |
916b1701 | 2116 | if (!REGNO_REG_SET_P (needed, regno + i)) |
d7429b6a RK |
2117 | REG_NOTES (insn) |
2118 | = gen_rtx (EXPR_LIST, REG_UNUSED, | |
04227afa DE |
2119 | gen_rtx (REG, reg_raw_mode[regno + i], |
2120 | regno + i), | |
d7429b6a RK |
2121 | REG_NOTES (insn)); |
2122 | } | |
2123 | } | |
2124 | } | |
8244fc4f RS |
2125 | else if (GET_CODE (reg) == REG) |
2126 | reg_next_use[regno] = 0; | |
d7429b6a RK |
2127 | |
2128 | /* If this is the last pass and this is a SCRATCH, show it will be dying | |
2129 | here and count it. */ | |
2130 | else if (GET_CODE (reg) == SCRATCH && insn != 0) | |
2131 | { | |
2132 | REG_NOTES (insn) | |
2133 | = gen_rtx (EXPR_LIST, REG_UNUSED, reg, REG_NOTES (insn)); | |
2134 | num_scratch++; | |
2135 | } | |
2136 | } | |
2137 | \f | |
2138 | #ifdef AUTO_INC_DEC | |
2139 | ||
2140 | /* X is a MEM found in INSN. See if we can convert it into an auto-increment | |
2141 | reference. */ | |
2142 | ||
2143 | static void | |
2144 | find_auto_inc (needed, x, insn) | |
2145 | regset needed; | |
2146 | rtx x; | |
2147 | rtx insn; | |
2148 | { | |
2149 | rtx addr = XEXP (x, 0); | |
e658434c | 2150 | HOST_WIDE_INT offset = 0; |
05ed5d57 | 2151 | rtx set; |
d7429b6a RK |
2152 | |
2153 | /* Here we detect use of an index register which might be good for | |
2154 | postincrement, postdecrement, preincrement, or predecrement. */ | |
2155 | ||
2156 | if (GET_CODE (addr) == PLUS && GET_CODE (XEXP (addr, 1)) == CONST_INT) | |
2157 | offset = INTVAL (XEXP (addr, 1)), addr = XEXP (addr, 0); | |
2158 | ||
2159 | if (GET_CODE (addr) == REG) | |
2160 | { | |
2161 | register rtx y; | |
2162 | register int size = GET_MODE_SIZE (GET_MODE (x)); | |
2163 | rtx use; | |
2164 | rtx incr; | |
2165 | int regno = REGNO (addr); | |
2166 | ||
2167 | /* Is the next use an increment that might make auto-increment? */ | |
05ed5d57 RK |
2168 | if ((incr = reg_next_use[regno]) != 0 |
2169 | && (set = single_set (incr)) != 0 | |
2170 | && GET_CODE (set) == SET | |
d7429b6a RK |
2171 | && BLOCK_NUM (incr) == BLOCK_NUM (insn) |
2172 | /* Can't add side effects to jumps; if reg is spilled and | |
2173 | reloaded, there's no way to store back the altered value. */ | |
2174 | && GET_CODE (insn) != JUMP_INSN | |
05ed5d57 | 2175 | && (y = SET_SRC (set), GET_CODE (y) == PLUS) |
d7429b6a RK |
2176 | && XEXP (y, 0) == addr |
2177 | && GET_CODE (XEXP (y, 1)) == CONST_INT | |
2178 | && (0 | |
2179 | #ifdef HAVE_POST_INCREMENT | |
2180 | || (INTVAL (XEXP (y, 1)) == size && offset == 0) | |
2181 | #endif | |
2182 | #ifdef HAVE_POST_DECREMENT | |
2183 | || (INTVAL (XEXP (y, 1)) == - size && offset == 0) | |
2184 | #endif | |
2185 | #ifdef HAVE_PRE_INCREMENT | |
2186 | || (INTVAL (XEXP (y, 1)) == size && offset == size) | |
2187 | #endif | |
2188 | #ifdef HAVE_PRE_DECREMENT | |
2189 | || (INTVAL (XEXP (y, 1)) == - size && offset == - size) | |
2190 | #endif | |
2191 | ) | |
2192 | /* Make sure this reg appears only once in this insn. */ | |
2193 | && (use = find_use_as_address (PATTERN (insn), addr, offset), | |
2194 | use != 0 && use != (rtx) 1)) | |
2195 | { | |
05ed5d57 | 2196 | rtx q = SET_DEST (set); |
7280c2a4 RK |
2197 | enum rtx_code inc_code = (INTVAL (XEXP (y, 1)) == size |
2198 | ? (offset ? PRE_INC : POST_INC) | |
2199 | : (offset ? PRE_DEC : POST_DEC)); | |
d7429b6a RK |
2200 | |
2201 | if (dead_or_set_p (incr, addr)) | |
7280c2a4 RK |
2202 | { |
2203 | /* This is the simple case. Try to make the auto-inc. If | |
2204 | we can't, we are done. Otherwise, we will do any | |
2205 | needed updates below. */ | |
2206 | if (! validate_change (insn, &XEXP (x, 0), | |
2207 | gen_rtx (inc_code, Pmode, addr), | |
2208 | 0)) | |
2209 | return; | |
2210 | } | |
5175ad37 DE |
2211 | else if (GET_CODE (q) == REG |
2212 | /* PREV_INSN used here to check the semi-open interval | |
2213 | [insn,incr). */ | |
b24884cd JL |
2214 | && ! reg_used_between_p (q, PREV_INSN (insn), incr) |
2215 | /* We must also check for sets of q as q may be | |
2216 | a call clobbered hard register and there may | |
2217 | be a call between PREV_INSN (insn) and incr. */ | |
2218 | && ! reg_set_between_p (q, PREV_INSN (insn), incr)) | |
d7429b6a | 2219 | { |
5175ad37 | 2220 | /* We have *p followed sometime later by q = p+size. |
d7429b6a | 2221 | Both p and q must be live afterward, |
5175ad37 | 2222 | and q is not used between INSN and it's assignment. |
d7429b6a RK |
2223 | Change it to q = p, ...*q..., q = q+size. |
2224 | Then fall into the usual case. */ | |
2225 | rtx insns, temp; | |
2226 | ||
2227 | start_sequence (); | |
2228 | emit_move_insn (q, addr); | |
2229 | insns = get_insns (); | |
2230 | end_sequence (); | |
2231 | ||
2232 | /* If anything in INSNS have UID's that don't fit within the | |
2233 | extra space we allocate earlier, we can't make this auto-inc. | |
2234 | This should never happen. */ | |
2235 | for (temp = insns; temp; temp = NEXT_INSN (temp)) | |
2236 | { | |
2237 | if (INSN_UID (temp) > max_uid_for_flow) | |
2238 | return; | |
2239 | BLOCK_NUM (temp) = BLOCK_NUM (insn); | |
2240 | } | |
2241 | ||
7280c2a4 RK |
2242 | /* If we can't make the auto-inc, or can't make the |
2243 | replacement into Y, exit. There's no point in making | |
2244 | the change below if we can't do the auto-inc and doing | |
2245 | so is not correct in the pre-inc case. */ | |
2246 | ||
2247 | validate_change (insn, &XEXP (x, 0), | |
2248 | gen_rtx (inc_code, Pmode, q), | |
2249 | 1); | |
2250 | validate_change (incr, &XEXP (y, 0), q, 1); | |
2251 | if (! apply_change_group ()) | |
2252 | return; | |
2253 | ||
2254 | /* We now know we'll be doing this change, so emit the | |
2255 | new insn(s) and do the updates. */ | |
d7429b6a | 2256 | emit_insns_before (insns, insn); |
e8b641a1 RK |
2257 | |
2258 | if (basic_block_head[BLOCK_NUM (insn)] == insn) | |
2259 | basic_block_head[BLOCK_NUM (insn)] = insns; | |
2260 | ||
d7429b6a RK |
2261 | /* INCR will become a NOTE and INSN won't contain a |
2262 | use of ADDR. If a use of ADDR was just placed in | |
2263 | the insn before INSN, make that the next use. | |
2264 | Otherwise, invalidate it. */ | |
2265 | if (GET_CODE (PREV_INSN (insn)) == INSN | |
2266 | && GET_CODE (PATTERN (PREV_INSN (insn))) == SET | |
2267 | && SET_SRC (PATTERN (PREV_INSN (insn))) == addr) | |
2268 | reg_next_use[regno] = PREV_INSN (insn); | |
2269 | else | |
2270 | reg_next_use[regno] = 0; | |
2271 | ||
2272 | addr = q; | |
2273 | regno = REGNO (q); | |
d7429b6a RK |
2274 | |
2275 | /* REGNO is now used in INCR which is below INSN, but | |
2276 | it previously wasn't live here. If we don't mark | |
2277 | it as needed, we'll put a REG_DEAD note for it | |
2278 | on this insn, which is incorrect. */ | |
916b1701 | 2279 | SET_REGNO_REG_SET (needed, regno); |
d7429b6a RK |
2280 | |
2281 | /* If there are any calls between INSN and INCR, show | |
2282 | that REGNO now crosses them. */ | |
2283 | for (temp = insn; temp != incr; temp = NEXT_INSN (temp)) | |
2284 | if (GET_CODE (temp) == CALL_INSN) | |
b1f21e0a | 2285 | REG_N_CALLS_CROSSED (regno)++; |
d7429b6a | 2286 | } |
02df8aba RK |
2287 | else |
2288 | return; | |
d7429b6a | 2289 | |
7280c2a4 RK |
2290 | /* If we haven't returned, it means we were able to make the |
2291 | auto-inc, so update the status. First, record that this insn | |
2292 | has an implicit side effect. */ | |
2293 | ||
2294 | REG_NOTES (insn) | |
2295 | = gen_rtx (EXPR_LIST, REG_INC, addr, REG_NOTES (insn)); | |
2296 | ||
2297 | /* Modify the old increment-insn to simply copy | |
2298 | the already-incremented value of our register. */ | |
2299 | if (! validate_change (incr, &SET_SRC (set), addr, 0)) | |
2300 | abort (); | |
2301 | ||
2302 | /* If that makes it a no-op (copying the register into itself) delete | |
2303 | it so it won't appear to be a "use" and a "set" of this | |
2304 | register. */ | |
2305 | if (SET_DEST (set) == addr) | |
d7429b6a | 2306 | { |
7280c2a4 RK |
2307 | PUT_CODE (incr, NOTE); |
2308 | NOTE_LINE_NUMBER (incr) = NOTE_INSN_DELETED; | |
2309 | NOTE_SOURCE_FILE (incr) = 0; | |
2310 | } | |
d7429b6a | 2311 | |
7280c2a4 RK |
2312 | if (regno >= FIRST_PSEUDO_REGISTER) |
2313 | { | |
2314 | /* Count an extra reference to the reg. When a reg is | |
2315 | incremented, spilling it is worse, so we want to make | |
2316 | that less likely. */ | |
b1f21e0a | 2317 | REG_N_REFS (regno) += loop_depth; |
7280c2a4 RK |
2318 | |
2319 | /* Count the increment as a setting of the register, | |
2320 | even though it isn't a SET in rtl. */ | |
b1f21e0a | 2321 | REG_N_SETS (regno)++; |
d7429b6a RK |
2322 | } |
2323 | } | |
2324 | } | |
2325 | } | |
2326 | #endif /* AUTO_INC_DEC */ | |
2327 | \f | |
2328 | /* Scan expression X and store a 1-bit in LIVE for each reg it uses. | |
2329 | This is done assuming the registers needed from X | |
2330 | are those that have 1-bits in NEEDED. | |
2331 | ||
2332 | On the final pass, FINAL is 1. This means try for autoincrement | |
2333 | and count the uses and deaths of each pseudo-reg. | |
2334 | ||
2335 | INSN is the containing instruction. If INSN is dead, this function is not | |
2336 | called. */ | |
2337 | ||
2338 | static void | |
2339 | mark_used_regs (needed, live, x, final, insn) | |
2340 | regset needed; | |
2341 | regset live; | |
2342 | rtx x; | |
d7429b6a | 2343 | int final; |
e658434c | 2344 | rtx insn; |
d7429b6a RK |
2345 | { |
2346 | register RTX_CODE code; | |
2347 | register int regno; | |
2348 | int i; | |
2349 | ||
2350 | retry: | |
2351 | code = GET_CODE (x); | |
2352 | switch (code) | |
2353 | { | |
2354 | case LABEL_REF: | |
2355 | case SYMBOL_REF: | |
2356 | case CONST_INT: | |
2357 | case CONST: | |
2358 | case CONST_DOUBLE: | |
2359 | case PC: | |
d7429b6a RK |
2360 | case ADDR_VEC: |
2361 | case ADDR_DIFF_VEC: | |
2362 | case ASM_INPUT: | |
2363 | return; | |
2364 | ||
2365 | #ifdef HAVE_cc0 | |
2366 | case CC0: | |
2367 | cc0_live = 1; | |
2368 | return; | |
2369 | #endif | |
2370 | ||
2f1553a4 RK |
2371 | case CLOBBER: |
2372 | /* If we are clobbering a MEM, mark any registers inside the address | |
2373 | as being used. */ | |
2374 | if (GET_CODE (XEXP (x, 0)) == MEM) | |
2375 | mark_used_regs (needed, live, XEXP (XEXP (x, 0), 0), final, insn); | |
2376 | return; | |
2377 | ||
d7429b6a | 2378 | case MEM: |
7eb136d6 MM |
2379 | /* Invalidate the data for the last MEM stored, but only if MEM is |
2380 | something that can be stored into. */ | |
2381 | if (GET_CODE (XEXP (x, 0)) == SYMBOL_REF | |
2382 | && CONSTANT_POOL_ADDRESS_P (XEXP (x, 0))) | |
2383 | ; /* needn't clear last_mem_set */ | |
2384 | else | |
2385 | last_mem_set = 0; | |
d7429b6a RK |
2386 | |
2387 | #ifdef AUTO_INC_DEC | |
2388 | if (final) | |
2389 | find_auto_inc (needed, x, insn); | |
2390 | #endif | |
2391 | break; | |
2392 | ||
80f8f04a RK |
2393 | case SUBREG: |
2394 | if (GET_CODE (SUBREG_REG (x)) == REG | |
2395 | && REGNO (SUBREG_REG (x)) >= FIRST_PSEUDO_REGISTER | |
2396 | && (GET_MODE_SIZE (GET_MODE (x)) | |
88285acf | 2397 | != GET_MODE_SIZE (GET_MODE (SUBREG_REG (x))))) |
b1f21e0a | 2398 | REG_CHANGES_SIZE (REGNO (SUBREG_REG (x))) = 1; |
80f8f04a RK |
2399 | |
2400 | /* While we're here, optimize this case. */ | |
2401 | x = SUBREG_REG (x); | |
2402 | ||
e100a3bb | 2403 | /* In case the SUBREG is not of a register, don't optimize */ |
ce79abf3 | 2404 | if (GET_CODE (x) != REG) |
e100a3bb MM |
2405 | { |
2406 | mark_used_regs (needed, live, x, final, insn); | |
2407 | return; | |
2408 | } | |
ce79abf3 | 2409 | |
0f41302f | 2410 | /* ... fall through ... */ |
80f8f04a | 2411 | |
d7429b6a RK |
2412 | case REG: |
2413 | /* See a register other than being set | |
2414 | => mark it as needed. */ | |
2415 | ||
2416 | regno = REGNO (x); | |
2417 | { | |
67f0e213 RK |
2418 | int some_needed = REGNO_REG_SET_P (needed, regno); |
2419 | int some_not_needed = ! some_needed; | |
d7429b6a | 2420 | |
916b1701 | 2421 | SET_REGNO_REG_SET (live, regno); |
cb9e8ad1 | 2422 | |
d7429b6a RK |
2423 | /* A hard reg in a wide mode may really be multiple registers. |
2424 | If so, mark all of them just like the first. */ | |
2425 | if (regno < FIRST_PSEUDO_REGISTER) | |
2426 | { | |
2427 | int n; | |
2428 | ||
d7e4fe8b | 2429 | /* For stack ptr or fixed arg pointer, |
d7429b6a RK |
2430 | nothing below can be necessary, so waste no more time. */ |
2431 | if (regno == STACK_POINTER_REGNUM | |
73a187c1 DE |
2432 | #if FRAME_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM |
2433 | || regno == HARD_FRAME_POINTER_REGNUM | |
2434 | #endif | |
d7e4fe8b RS |
2435 | #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM |
2436 | || (regno == ARG_POINTER_REGNUM && fixed_regs[regno]) | |
2437 | #endif | |
d7429b6a RK |
2438 | || regno == FRAME_POINTER_REGNUM) |
2439 | { | |
2440 | /* If this is a register we are going to try to eliminate, | |
2441 | don't mark it live here. If we are successful in | |
2442 | eliminating it, it need not be live unless it is used for | |
2443 | pseudos, in which case it will have been set live when | |
2444 | it was allocated to the pseudos. If the register will not | |
2445 | be eliminated, reload will set it live at that point. */ | |
2446 | ||
2447 | if (! TEST_HARD_REG_BIT (elim_reg_set, regno)) | |
2448 | regs_ever_live[regno] = 1; | |
2449 | return; | |
2450 | } | |
2451 | /* No death notes for global register variables; | |
2452 | their values are live after this function exits. */ | |
2453 | if (global_regs[regno]) | |
d8c8b8e3 RS |
2454 | { |
2455 | if (final) | |
2456 | reg_next_use[regno] = insn; | |
2457 | return; | |
2458 | } | |
d7429b6a RK |
2459 | |
2460 | n = HARD_REGNO_NREGS (regno, GET_MODE (x)); | |
2461 | while (--n > 0) | |
2462 | { | |
916b1701 MM |
2463 | int regno_n = regno + n; |
2464 | int needed_regno = REGNO_REG_SET_P (needed, regno_n); | |
cb9e8ad1 | 2465 | |
916b1701 MM |
2466 | SET_REGNO_REG_SET (live, regno_n); |
2467 | some_needed |= needed_regno; | |
931c6c7a | 2468 | some_not_needed |= ! needed_regno; |
d7429b6a RK |
2469 | } |
2470 | } | |
2471 | if (final) | |
2472 | { | |
2473 | /* Record where each reg is used, so when the reg | |
2474 | is set we know the next insn that uses it. */ | |
2475 | ||
2476 | reg_next_use[regno] = insn; | |
2477 | ||
2478 | if (regno < FIRST_PSEUDO_REGISTER) | |
2479 | { | |
2480 | /* If a hard reg is being used, | |
2481 | record that this function does use it. */ | |
2482 | ||
2483 | i = HARD_REGNO_NREGS (regno, GET_MODE (x)); | |
2484 | if (i == 0) | |
2485 | i = 1; | |
2486 | do | |
2487 | regs_ever_live[regno + --i] = 1; | |
2488 | while (i > 0); | |
2489 | } | |
2490 | else | |
2491 | { | |
2492 | /* Keep track of which basic block each reg appears in. */ | |
2493 | ||
2494 | register int blocknum = BLOCK_NUM (insn); | |
2495 | ||
b1f21e0a MM |
2496 | if (REG_BASIC_BLOCK (regno) == REG_BLOCK_UNKNOWN) |
2497 | REG_BASIC_BLOCK (regno) = blocknum; | |
2498 | else if (REG_BASIC_BLOCK (regno) != blocknum) | |
2499 | REG_BASIC_BLOCK (regno) = REG_BLOCK_GLOBAL; | |
d7429b6a RK |
2500 | |
2501 | /* Count (weighted) number of uses of each reg. */ | |
2502 | ||
b1f21e0a | 2503 | REG_N_REFS (regno) += loop_depth; |
d7429b6a RK |
2504 | } |
2505 | ||
2506 | /* Record and count the insns in which a reg dies. | |
2507 | If it is used in this insn and was dead below the insn | |
2508 | then it dies in this insn. If it was set in this insn, | |
2509 | we do not make a REG_DEAD note; likewise if we already | |
2510 | made such a note. */ | |
2511 | ||
cb9e8ad1 | 2512 | if (some_not_needed |
d7429b6a RK |
2513 | && ! dead_or_set_p (insn, x) |
2514 | #if 0 | |
2515 | && (regno >= FIRST_PSEUDO_REGISTER || ! fixed_regs[regno]) | |
2516 | #endif | |
2517 | ) | |
2518 | { | |
ab28041e JW |
2519 | /* Check for the case where the register dying partially |
2520 | overlaps the register set by this insn. */ | |
2521 | if (regno < FIRST_PSEUDO_REGISTER | |
2522 | && HARD_REGNO_NREGS (regno, GET_MODE (x)) > 1) | |
2523 | { | |
480eac3b | 2524 | int n = HARD_REGNO_NREGS (regno, GET_MODE (x)); |
ab28041e JW |
2525 | while (--n >= 0) |
2526 | some_needed |= dead_or_set_regno_p (insn, regno + n); | |
2527 | } | |
2528 | ||
d7429b6a RK |
2529 | /* If none of the words in X is needed, make a REG_DEAD |
2530 | note. Otherwise, we must make partial REG_DEAD notes. */ | |
2531 | if (! some_needed) | |
2532 | { | |
2533 | REG_NOTES (insn) | |
2534 | = gen_rtx (EXPR_LIST, REG_DEAD, x, REG_NOTES (insn)); | |
b1f21e0a | 2535 | REG_N_DEATHS (regno)++; |
d7429b6a RK |
2536 | } |
2537 | else | |
2538 | { | |
2539 | int i; | |
2540 | ||
2541 | /* Don't make a REG_DEAD note for a part of a register | |
2542 | that is set in the insn. */ | |
2543 | ||
2544 | for (i = HARD_REGNO_NREGS (regno, GET_MODE (x)) - 1; | |
2545 | i >= 0; i--) | |
916b1701 | 2546 | if (!REGNO_REG_SET_P (needed, regno + i) |
d7429b6a RK |
2547 | && ! dead_or_set_regno_p (insn, regno + i)) |
2548 | REG_NOTES (insn) | |
2549 | = gen_rtx (EXPR_LIST, REG_DEAD, | |
04227afa DE |
2550 | gen_rtx (REG, reg_raw_mode[regno + i], |
2551 | regno + i), | |
d7429b6a RK |
2552 | REG_NOTES (insn)); |
2553 | } | |
2554 | } | |
2555 | } | |
2556 | } | |
2557 | return; | |
2558 | ||
2559 | case SET: | |
2560 | { | |
2561 | register rtx testreg = SET_DEST (x); | |
2562 | int mark_dest = 0; | |
2563 | ||
2564 | /* If storing into MEM, don't show it as being used. But do | |
2565 | show the address as being used. */ | |
2566 | if (GET_CODE (testreg) == MEM) | |
2567 | { | |
2568 | #ifdef AUTO_INC_DEC | |
2569 | if (final) | |
2570 | find_auto_inc (needed, testreg, insn); | |
2571 | #endif | |
2572 | mark_used_regs (needed, live, XEXP (testreg, 0), final, insn); | |
2573 | mark_used_regs (needed, live, SET_SRC (x), final, insn); | |
2574 | return; | |
2575 | } | |
2576 | ||
2577 | /* Storing in STRICT_LOW_PART is like storing in a reg | |
2578 | in that this SET might be dead, so ignore it in TESTREG. | |
2579 | but in some other ways it is like using the reg. | |
2580 | ||
2581 | Storing in a SUBREG or a bit field is like storing the entire | |
2582 | register in that if the register's value is not used | |
2583 | then this SET is not needed. */ | |
2584 | while (GET_CODE (testreg) == STRICT_LOW_PART | |
2585 | || GET_CODE (testreg) == ZERO_EXTRACT | |
2586 | || GET_CODE (testreg) == SIGN_EXTRACT | |
2587 | || GET_CODE (testreg) == SUBREG) | |
2588 | { | |
88285acf RK |
2589 | if (GET_CODE (testreg) == SUBREG |
2590 | && GET_CODE (SUBREG_REG (testreg)) == REG | |
2591 | && REGNO (SUBREG_REG (testreg)) >= FIRST_PSEUDO_REGISTER | |
2592 | && (GET_MODE_SIZE (GET_MODE (testreg)) | |
2593 | != GET_MODE_SIZE (GET_MODE (SUBREG_REG (testreg))))) | |
b1f21e0a | 2594 | REG_CHANGES_SIZE (REGNO (SUBREG_REG (testreg))) = 1; |
88285acf | 2595 | |
d7429b6a RK |
2596 | /* Modifying a single register in an alternate mode |
2597 | does not use any of the old value. But these other | |
2598 | ways of storing in a register do use the old value. */ | |
2599 | if (GET_CODE (testreg) == SUBREG | |
2600 | && !(REG_SIZE (SUBREG_REG (testreg)) > REG_SIZE (testreg))) | |
2601 | ; | |
2602 | else | |
2603 | mark_dest = 1; | |
2604 | ||
2605 | testreg = XEXP (testreg, 0); | |
2606 | } | |
2607 | ||
2608 | /* If this is a store into a register, | |
2609 | recursively scan the value being stored. */ | |
2610 | ||
2611 | if (GET_CODE (testreg) == REG | |
2612 | && (regno = REGNO (testreg), regno != FRAME_POINTER_REGNUM) | |
73a187c1 DE |
2613 | #if FRAME_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM |
2614 | && regno != HARD_FRAME_POINTER_REGNUM | |
2615 | #endif | |
d7e4fe8b RS |
2616 | #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM |
2617 | && ! (regno == ARG_POINTER_REGNUM && fixed_regs[regno]) | |
2618 | #endif | |
d8c8b8e3 RS |
2619 | ) |
2620 | /* We used to exclude global_regs here, but that seems wrong. | |
2621 | Storing in them is like storing in mem. */ | |
d7429b6a RK |
2622 | { |
2623 | mark_used_regs (needed, live, SET_SRC (x), final, insn); | |
2624 | if (mark_dest) | |
2625 | mark_used_regs (needed, live, SET_DEST (x), final, insn); | |
2626 | return; | |
2627 | } | |
2628 | } | |
2629 | break; | |
2630 | ||
2631 | case RETURN: | |
2632 | /* If exiting needs the right stack value, consider this insn as | |
2633 | using the stack pointer. In any event, consider it as using | |
632c9d9e | 2634 | all global registers and all registers used by return. */ |
d7429b6a RK |
2635 | |
2636 | #ifdef EXIT_IGNORE_STACK | |
2637 | if (! EXIT_IGNORE_STACK | |
2638 | || (! FRAME_POINTER_REQUIRED && flag_omit_frame_pointer)) | |
2639 | #endif | |
916b1701 | 2640 | SET_REGNO_REG_SET (live, STACK_POINTER_REGNUM); |
d7429b6a RK |
2641 | |
2642 | for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
632c9d9e MS |
2643 | if (global_regs[i] |
2644 | #ifdef EPILOGUE_USES | |
2645 | || EPILOGUE_USES (i) | |
2646 | #endif | |
2647 | ) | |
916b1701 | 2648 | SET_REGNO_REG_SET (live, i); |
d7429b6a | 2649 | break; |
e9a25f70 JL |
2650 | |
2651 | default: | |
2652 | break; | |
d7429b6a RK |
2653 | } |
2654 | ||
2655 | /* Recursively scan the operands of this expression. */ | |
2656 | ||
2657 | { | |
2658 | register char *fmt = GET_RTX_FORMAT (code); | |
2659 | register int i; | |
2660 | ||
2661 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
2662 | { | |
2663 | if (fmt[i] == 'e') | |
2664 | { | |
2665 | /* Tail recursive case: save a function call level. */ | |
2666 | if (i == 0) | |
2667 | { | |
2668 | x = XEXP (x, 0); | |
2669 | goto retry; | |
2670 | } | |
2671 | mark_used_regs (needed, live, XEXP (x, i), final, insn); | |
2672 | } | |
2673 | else if (fmt[i] == 'E') | |
2674 | { | |
2675 | register int j; | |
2676 | for (j = 0; j < XVECLEN (x, i); j++) | |
2677 | mark_used_regs (needed, live, XVECEXP (x, i, j), final, insn); | |
2678 | } | |
2679 | } | |
2680 | } | |
2681 | } | |
2682 | \f | |
2683 | #ifdef AUTO_INC_DEC | |
2684 | ||
2685 | static int | |
2686 | try_pre_increment_1 (insn) | |
2687 | rtx insn; | |
2688 | { | |
2689 | /* Find the next use of this reg. If in same basic block, | |
2690 | make it do pre-increment or pre-decrement if appropriate. */ | |
956d6950 | 2691 | rtx x = single_set (insn); |
5f4f0e22 | 2692 | HOST_WIDE_INT amount = ((GET_CODE (SET_SRC (x)) == PLUS ? 1 : -1) |
d7429b6a RK |
2693 | * INTVAL (XEXP (SET_SRC (x), 1))); |
2694 | int regno = REGNO (SET_DEST (x)); | |
2695 | rtx y = reg_next_use[regno]; | |
2696 | if (y != 0 | |
2697 | && BLOCK_NUM (y) == BLOCK_NUM (insn) | |
89861c38 | 2698 | /* Don't do this if the reg dies, or gets set in y; a standard addressing |
0f41302f | 2699 | mode would be better. */ |
89861c38 | 2700 | && ! dead_or_set_p (y, SET_DEST (x)) |
956d6950 | 2701 | && try_pre_increment (y, SET_DEST (x), amount)) |
d7429b6a RK |
2702 | { |
2703 | /* We have found a suitable auto-increment | |
2704 | and already changed insn Y to do it. | |
2705 | So flush this increment-instruction. */ | |
2706 | PUT_CODE (insn, NOTE); | |
2707 | NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED; | |
2708 | NOTE_SOURCE_FILE (insn) = 0; | |
2709 | /* Count a reference to this reg for the increment | |
2710 | insn we are deleting. When a reg is incremented. | |
2711 | spilling it is worse, so we want to make that | |
2712 | less likely. */ | |
2713 | if (regno >= FIRST_PSEUDO_REGISTER) | |
2714 | { | |
b1f21e0a MM |
2715 | REG_N_REFS (regno) += loop_depth; |
2716 | REG_N_SETS (regno)++; | |
d7429b6a RK |
2717 | } |
2718 | return 1; | |
2719 | } | |
2720 | return 0; | |
2721 | } | |
2722 | ||
2723 | /* Try to change INSN so that it does pre-increment or pre-decrement | |
2724 | addressing on register REG in order to add AMOUNT to REG. | |
2725 | AMOUNT is negative for pre-decrement. | |
2726 | Returns 1 if the change could be made. | |
2727 | This checks all about the validity of the result of modifying INSN. */ | |
2728 | ||
2729 | static int | |
2730 | try_pre_increment (insn, reg, amount) | |
2731 | rtx insn, reg; | |
5f4f0e22 | 2732 | HOST_WIDE_INT amount; |
d7429b6a RK |
2733 | { |
2734 | register rtx use; | |
2735 | ||
2736 | /* Nonzero if we can try to make a pre-increment or pre-decrement. | |
2737 | For example, addl $4,r1; movl (r1),... can become movl +(r1),... */ | |
2738 | int pre_ok = 0; | |
2739 | /* Nonzero if we can try to make a post-increment or post-decrement. | |
2740 | For example, addl $4,r1; movl -4(r1),... can become movl (r1)+,... | |
2741 | It is possible for both PRE_OK and POST_OK to be nonzero if the machine | |
2742 | supports both pre-inc and post-inc, or both pre-dec and post-dec. */ | |
2743 | int post_ok = 0; | |
2744 | ||
2745 | /* Nonzero if the opportunity actually requires post-inc or post-dec. */ | |
2746 | int do_post = 0; | |
2747 | ||
2748 | /* From the sign of increment, see which possibilities are conceivable | |
2749 | on this target machine. */ | |
2750 | #ifdef HAVE_PRE_INCREMENT | |
2751 | if (amount > 0) | |
2752 | pre_ok = 1; | |
2753 | #endif | |
2754 | #ifdef HAVE_POST_INCREMENT | |
2755 | if (amount > 0) | |
2756 | post_ok = 1; | |
2757 | #endif | |
2758 | ||
2759 | #ifdef HAVE_PRE_DECREMENT | |
2760 | if (amount < 0) | |
2761 | pre_ok = 1; | |
2762 | #endif | |
2763 | #ifdef HAVE_POST_DECREMENT | |
2764 | if (amount < 0) | |
2765 | post_ok = 1; | |
2766 | #endif | |
2767 | ||
2768 | if (! (pre_ok || post_ok)) | |
2769 | return 0; | |
2770 | ||
2771 | /* It is not safe to add a side effect to a jump insn | |
2772 | because if the incremented register is spilled and must be reloaded | |
2773 | there would be no way to store the incremented value back in memory. */ | |
2774 | ||
2775 | if (GET_CODE (insn) == JUMP_INSN) | |
2776 | return 0; | |
2777 | ||
2778 | use = 0; | |
2779 | if (pre_ok) | |
2780 | use = find_use_as_address (PATTERN (insn), reg, 0); | |
2781 | if (post_ok && (use == 0 || use == (rtx) 1)) | |
2782 | { | |
2783 | use = find_use_as_address (PATTERN (insn), reg, -amount); | |
2784 | do_post = 1; | |
2785 | } | |
2786 | ||
2787 | if (use == 0 || use == (rtx) 1) | |
2788 | return 0; | |
2789 | ||
2790 | if (GET_MODE_SIZE (GET_MODE (use)) != (amount > 0 ? amount : - amount)) | |
2791 | return 0; | |
2792 | ||
a0fbc3a9 SC |
2793 | /* See if this combination of instruction and addressing mode exists. */ |
2794 | if (! validate_change (insn, &XEXP (use, 0), | |
2795 | gen_rtx (amount > 0 | |
2796 | ? (do_post ? POST_INC : PRE_INC) | |
2797 | : (do_post ? POST_DEC : PRE_DEC), | |
2798 | Pmode, reg), 0)) | |
2799 | return 0; | |
d7429b6a RK |
2800 | |
2801 | /* Record that this insn now has an implicit side effect on X. */ | |
2802 | REG_NOTES (insn) = gen_rtx (EXPR_LIST, REG_INC, reg, REG_NOTES (insn)); | |
2803 | return 1; | |
2804 | } | |
2805 | ||
2806 | #endif /* AUTO_INC_DEC */ | |
2807 | \f | |
2808 | /* Find the place in the rtx X where REG is used as a memory address. | |
2809 | Return the MEM rtx that so uses it. | |
2810 | If PLUSCONST is nonzero, search instead for a memory address equivalent to | |
2811 | (plus REG (const_int PLUSCONST)). | |
2812 | ||
2813 | If such an address does not appear, return 0. | |
2814 | If REG appears more than once, or is used other than in such an address, | |
2815 | return (rtx)1. */ | |
2816 | ||
8c660648 | 2817 | rtx |
d7429b6a RK |
2818 | find_use_as_address (x, reg, plusconst) |
2819 | register rtx x; | |
2820 | rtx reg; | |
e658434c | 2821 | HOST_WIDE_INT plusconst; |
d7429b6a RK |
2822 | { |
2823 | enum rtx_code code = GET_CODE (x); | |
2824 | char *fmt = GET_RTX_FORMAT (code); | |
2825 | register int i; | |
2826 | register rtx value = 0; | |
2827 | register rtx tem; | |
2828 | ||
2829 | if (code == MEM && XEXP (x, 0) == reg && plusconst == 0) | |
2830 | return x; | |
2831 | ||
2832 | if (code == MEM && GET_CODE (XEXP (x, 0)) == PLUS | |
2833 | && XEXP (XEXP (x, 0), 0) == reg | |
2834 | && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT | |
2835 | && INTVAL (XEXP (XEXP (x, 0), 1)) == plusconst) | |
2836 | return x; | |
2837 | ||
2838 | if (code == SIGN_EXTRACT || code == ZERO_EXTRACT) | |
2839 | { | |
2840 | /* If REG occurs inside a MEM used in a bit-field reference, | |
2841 | that is unacceptable. */ | |
2842 | if (find_use_as_address (XEXP (x, 0), reg, 0) != 0) | |
6fa5c106 | 2843 | return (rtx) (HOST_WIDE_INT) 1; |
d7429b6a RK |
2844 | } |
2845 | ||
2846 | if (x == reg) | |
6fa5c106 | 2847 | return (rtx) (HOST_WIDE_INT) 1; |
d7429b6a RK |
2848 | |
2849 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
2850 | { | |
2851 | if (fmt[i] == 'e') | |
2852 | { | |
2853 | tem = find_use_as_address (XEXP (x, i), reg, plusconst); | |
2854 | if (value == 0) | |
2855 | value = tem; | |
2856 | else if (tem != 0) | |
6fa5c106 | 2857 | return (rtx) (HOST_WIDE_INT) 1; |
d7429b6a RK |
2858 | } |
2859 | if (fmt[i] == 'E') | |
2860 | { | |
2861 | register int j; | |
2862 | for (j = XVECLEN (x, i) - 1; j >= 0; j--) | |
2863 | { | |
2864 | tem = find_use_as_address (XVECEXP (x, i, j), reg, plusconst); | |
2865 | if (value == 0) | |
2866 | value = tem; | |
2867 | else if (tem != 0) | |
6fa5c106 | 2868 | return (rtx) (HOST_WIDE_INT) 1; |
d7429b6a RK |
2869 | } |
2870 | } | |
2871 | } | |
2872 | ||
2873 | return value; | |
2874 | } | |
2875 | \f | |
2876 | /* Write information about registers and basic blocks into FILE. | |
2877 | This is part of making a debugging dump. */ | |
2878 | ||
2879 | void | |
2880 | dump_flow_info (file) | |
2881 | FILE *file; | |
2882 | { | |
2883 | register int i; | |
2884 | static char *reg_class_names[] = REG_CLASS_NAMES; | |
2885 | ||
2886 | fprintf (file, "%d registers.\n", max_regno); | |
2887 | ||
2888 | for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++) | |
b1f21e0a | 2889 | if (REG_N_REFS (i)) |
d7429b6a | 2890 | { |
e4600702 | 2891 | enum reg_class class, altclass; |
d7429b6a | 2892 | fprintf (file, "\nRegister %d used %d times across %d insns", |
b1f21e0a MM |
2893 | i, REG_N_REFS (i), REG_LIVE_LENGTH (i)); |
2894 | if (REG_BASIC_BLOCK (i) >= 0) | |
2895 | fprintf (file, " in block %d", REG_BASIC_BLOCK (i)); | |
2896 | if (REG_N_DEATHS (i) != 1) | |
2897 | fprintf (file, "; dies in %d places", REG_N_DEATHS (i)); | |
2898 | if (REG_N_CALLS_CROSSED (i) == 1) | |
d7429b6a | 2899 | fprintf (file, "; crosses 1 call"); |
b1f21e0a MM |
2900 | else if (REG_N_CALLS_CROSSED (i)) |
2901 | fprintf (file, "; crosses %d calls", REG_N_CALLS_CROSSED (i)); | |
d7429b6a RK |
2902 | if (PSEUDO_REGNO_BYTES (i) != UNITS_PER_WORD) |
2903 | fprintf (file, "; %d bytes", PSEUDO_REGNO_BYTES (i)); | |
2904 | class = reg_preferred_class (i); | |
e4600702 RK |
2905 | altclass = reg_alternate_class (i); |
2906 | if (class != GENERAL_REGS || altclass != ALL_REGS) | |
d7429b6a | 2907 | { |
e4600702 RK |
2908 | if (altclass == ALL_REGS || class == ALL_REGS) |
2909 | fprintf (file, "; pref %s", reg_class_names[(int) class]); | |
2910 | else if (altclass == NO_REGS) | |
d7429b6a RK |
2911 | fprintf (file, "; %s or none", reg_class_names[(int) class]); |
2912 | else | |
e4600702 RK |
2913 | fprintf (file, "; pref %s, else %s", |
2914 | reg_class_names[(int) class], | |
2915 | reg_class_names[(int) altclass]); | |
d7429b6a RK |
2916 | } |
2917 | if (REGNO_POINTER_FLAG (i)) | |
2918 | fprintf (file, "; pointer"); | |
2919 | fprintf (file, ".\n"); | |
2920 | } | |
2921 | fprintf (file, "\n%d basic blocks.\n", n_basic_blocks); | |
2922 | for (i = 0; i < n_basic_blocks; i++) | |
2923 | { | |
2924 | register rtx head, jump; | |
2925 | register int regno; | |
2926 | fprintf (file, "\nBasic block %d: first insn %d, last %d.\n", | |
2927 | i, | |
2928 | INSN_UID (basic_block_head[i]), | |
2929 | INSN_UID (basic_block_end[i])); | |
2930 | /* The control flow graph's storage is freed | |
2931 | now when flow_analysis returns. | |
2932 | Don't try to print it if it is gone. */ | |
2933 | if (basic_block_drops_in) | |
2934 | { | |
2935 | fprintf (file, "Reached from blocks: "); | |
2936 | head = basic_block_head[i]; | |
2937 | if (GET_CODE (head) == CODE_LABEL) | |
2938 | for (jump = LABEL_REFS (head); | |
2939 | jump != head; | |
2940 | jump = LABEL_NEXTREF (jump)) | |
2941 | { | |
2942 | register int from_block = BLOCK_NUM (CONTAINING_INSN (jump)); | |
2943 | fprintf (file, " %d", from_block); | |
2944 | } | |
2945 | if (basic_block_drops_in[i]) | |
2946 | fprintf (file, " previous"); | |
2947 | } | |
2948 | fprintf (file, "\nRegisters live at start:"); | |
2949 | for (regno = 0; regno < max_regno; regno++) | |
916b1701 MM |
2950 | if (REGNO_REG_SET_P (basic_block_live_at_start[i], regno)) |
2951 | fprintf (file, " %d", regno); | |
d7429b6a RK |
2952 | fprintf (file, "\n"); |
2953 | } | |
2954 | fprintf (file, "\n"); | |
2955 | } | |
3e28fe44 MM |
2956 | |
2957 | \f | |
2958 | /* Like print_rtl, but also print out live information for the start of each | |
2959 | basic block. */ | |
2960 | ||
2961 | void | |
2962 | print_rtl_with_bb (outf, rtx_first) | |
2963 | FILE *outf; | |
2964 | rtx rtx_first; | |
2965 | { | |
2966 | register rtx tmp_rtx; | |
2967 | ||
2968 | if (rtx_first == 0) | |
2969 | fprintf (outf, "(nil)\n"); | |
2970 | ||
2971 | else | |
2972 | { | |
2973 | int i, bb; | |
2974 | enum bb_state { NOT_IN_BB, IN_ONE_BB, IN_MULTIPLE_BB }; | |
2975 | int max_uid = get_max_uid (); | |
adfc539e PDM |
2976 | int *start = (int *) alloca (max_uid * sizeof (int)); |
2977 | int *end = (int *) alloca (max_uid * sizeof (int)); | |
d8d64559 | 2978 | char *in_bb_p = (char *) alloca (max_uid * sizeof (enum bb_state)); |
3e28fe44 MM |
2979 | |
2980 | for (i = 0; i < max_uid; i++) | |
2981 | { | |
2982 | start[i] = end[i] = -1; | |
2983 | in_bb_p[i] = NOT_IN_BB; | |
2984 | } | |
2985 | ||
2986 | for (i = n_basic_blocks-1; i >= 0; i--) | |
2987 | { | |
2988 | rtx x; | |
2989 | start[INSN_UID (basic_block_head[i])] = i; | |
2990 | end[INSN_UID (basic_block_end[i])] = i; | |
2991 | for (x = basic_block_head[i]; x != NULL_RTX; x = NEXT_INSN (x)) | |
2992 | { | |
1791f8e2 MM |
2993 | in_bb_p[ INSN_UID(x)] |
2994 | = (in_bb_p[ INSN_UID(x)] == NOT_IN_BB) | |
3b33f637 | 2995 | ? IN_ONE_BB : IN_MULTIPLE_BB; |
3e28fe44 MM |
2996 | if (x == basic_block_end[i]) |
2997 | break; | |
2998 | } | |
2999 | } | |
3000 | ||
3001 | for (tmp_rtx = rtx_first; NULL != tmp_rtx; tmp_rtx = NEXT_INSN (tmp_rtx)) | |
3002 | { | |
3003 | if ((bb = start[INSN_UID (tmp_rtx)]) >= 0) | |
3004 | { | |
3005 | fprintf (outf, ";; Start of basic block %d, registers live:", | |
3006 | bb); | |
3007 | ||
3008 | EXECUTE_IF_SET_IN_REG_SET (basic_block_live_at_start[bb], 0, i, | |
3009 | { | |
3010 | fprintf (outf, " %d", i); | |
3011 | if (i < FIRST_PSEUDO_REGISTER) | |
3012 | fprintf (outf, " [%s]", | |
3013 | reg_names[i]); | |
3014 | }); | |
3015 | putc ('\n', outf); | |
3016 | } | |
3017 | ||
3018 | if (in_bb_p[ INSN_UID(tmp_rtx)] == NOT_IN_BB | |
3019 | && GET_CODE (tmp_rtx) != NOTE | |
3020 | && GET_CODE (tmp_rtx) != BARRIER) | |
3021 | fprintf (outf, ";; Insn is not within a basic block\n"); | |
3022 | else if (in_bb_p[ INSN_UID(tmp_rtx)] == IN_MULTIPLE_BB) | |
3023 | fprintf (outf, ";; Insn is in multiple basic blocks\n"); | |
3024 | ||
3025 | print_rtl_single (outf, tmp_rtx); | |
3026 | ||
3027 | if ((bb = end[INSN_UID (tmp_rtx)]) >= 0) | |
3028 | fprintf (outf, ";; End of basic block %d\n", bb); | |
3029 | ||
3030 | putc ('\n', outf); | |
3031 | } | |
3032 | } | |
3033 | } |