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1 | /* A pass for lowering trees to RTL. |
2 | Copyright (C) 2004 Free Software Foundation, Inc. | |
3 | ||
4 | This file is part of GCC. | |
5 | ||
6 | GCC 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 | GCC 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 GCC; see the file COPYING. If not, write to | |
18 | the Free Software Foundation, 59 Temple Place - Suite 330, | |
19 | Boston, MA 02111-1307, USA. */ | |
20 | ||
21 | #include "config.h" | |
22 | #include "system.h" | |
23 | #include "coretypes.h" | |
24 | #include "tm.h" | |
25 | #include "tree.h" | |
26 | #include "rtl.h" | |
27 | #include "tm_p.h" | |
28 | #include "basic-block.h" | |
29 | #include "function.h" | |
30 | #include "expr.h" | |
31 | #include "langhooks.h" | |
32 | #include "tree-flow.h" | |
33 | #include "timevar.h" | |
34 | #include "tree-dump.h" | |
35 | #include "tree-pass.h" | |
36 | #include "except.h" | |
37 | #include "flags.h" | |
1f6d3a08 RH |
38 | #include "diagnostic.h" |
39 | #include "toplev.h" | |
80c7a9eb RH |
40 | |
41 | ||
1f6d3a08 RH |
42 | #ifndef LOCAL_ALIGNMENT |
43 | #define LOCAL_ALIGNMENT(TYPE, ALIGNMENT) ALIGNMENT | |
44 | #endif | |
45 | ||
46 | #ifndef STACK_ALIGNMENT_NEEDED | |
47 | #define STACK_ALIGNMENT_NEEDED 1 | |
48 | #endif | |
49 | ||
50 | #ifdef FRAME_GROWS_DOWNWARD | |
51 | # undef FRAME_GROWS_DOWNWARD | |
52 | # define FRAME_GROWS_DOWNWARD 1 | |
53 | #else | |
54 | # define FRAME_GROWS_DOWNWARD 0 | |
55 | #endif | |
56 | ||
57 | ||
58 | /* This structure holds data relevant to one variable that will be | |
59 | placed in a stack slot. */ | |
60 | struct stack_var | |
61 | { | |
62 | /* The Variable. */ | |
63 | tree decl; | |
64 | ||
65 | /* The offset of the variable. During partitioning, this is the | |
66 | offset relative to the partition. After partitioning, this | |
67 | is relative to the stack frame. */ | |
68 | HOST_WIDE_INT offset; | |
69 | ||
70 | /* Initially, the size of the variable. Later, the size of the partition, | |
71 | if this variable becomes it's partition's representative. */ | |
72 | HOST_WIDE_INT size; | |
73 | ||
74 | /* The *byte* alignment required for this variable. Or as, with the | |
75 | size, the alignment for this partition. */ | |
76 | unsigned int alignb; | |
77 | ||
78 | /* The partition representative. */ | |
79 | size_t representative; | |
80 | ||
81 | /* The next stack variable in the partition, or EOC. */ | |
82 | size_t next; | |
83 | }; | |
84 | ||
85 | #define EOC ((size_t)-1) | |
86 | ||
87 | /* We have an array of such objects while deciding allocation. */ | |
88 | static struct stack_var *stack_vars; | |
89 | static size_t stack_vars_alloc; | |
90 | static size_t stack_vars_num; | |
91 | ||
92 | /* An array of indicies such that stack_vars[stack_vars_sorted[i]].size | |
93 | is non-decreasing. */ | |
94 | static size_t *stack_vars_sorted; | |
95 | ||
96 | /* We have an interference graph between such objects. This graph | |
97 | is lower triangular. */ | |
98 | static bool *stack_vars_conflict; | |
99 | static size_t stack_vars_conflict_alloc; | |
100 | ||
101 | /* The phase of the stack frame. This is the known misalignment of | |
102 | virtual_stack_vars_rtx from PREFERRED_STACK_BOUNDARY. That is, | |
103 | (frame_offset+frame_phase) % PREFERRED_STACK_BOUNDARY == 0. */ | |
104 | static int frame_phase; | |
105 | ||
106 | ||
107 | /* Discover the byte alignment to use for DECL. Ignore alignment | |
108 | we can't do with expected alignment of the stack boundary. */ | |
109 | ||
110 | static unsigned int | |
111 | get_decl_align_unit (tree decl) | |
112 | { | |
113 | unsigned int align; | |
114 | ||
115 | align = DECL_ALIGN (decl); | |
116 | align = LOCAL_ALIGNMENT (TREE_TYPE (decl), align); | |
117 | if (align > PREFERRED_STACK_BOUNDARY) | |
118 | align = PREFERRED_STACK_BOUNDARY; | |
119 | if (cfun->stack_alignment_needed < align) | |
120 | cfun->stack_alignment_needed = align; | |
121 | ||
122 | return align / BITS_PER_UNIT; | |
123 | } | |
124 | ||
125 | /* Allocate SIZE bytes at byte alignment ALIGN from the stack frame. | |
126 | Return the frame offset. */ | |
127 | ||
128 | static HOST_WIDE_INT | |
129 | alloc_stack_frame_space (HOST_WIDE_INT size, HOST_WIDE_INT align) | |
130 | { | |
131 | HOST_WIDE_INT offset, new_frame_offset; | |
132 | ||
133 | new_frame_offset = frame_offset; | |
134 | if (FRAME_GROWS_DOWNWARD) | |
135 | { | |
136 | new_frame_offset -= size + frame_phase; | |
137 | new_frame_offset &= -align; | |
138 | new_frame_offset += frame_phase; | |
139 | offset = new_frame_offset; | |
140 | } | |
141 | else | |
142 | { | |
143 | new_frame_offset -= frame_phase; | |
144 | new_frame_offset += align - 1; | |
145 | new_frame_offset &= -align; | |
146 | new_frame_offset += frame_phase; | |
147 | offset = new_frame_offset; | |
148 | new_frame_offset += size; | |
149 | } | |
150 | frame_offset = new_frame_offset; | |
151 | ||
152 | return offset; | |
153 | } | |
154 | ||
155 | /* Accumulate DECL into STACK_VARS. */ | |
156 | ||
157 | static void | |
158 | add_stack_var (tree decl) | |
159 | { | |
160 | if (stack_vars_num >= stack_vars_alloc) | |
161 | { | |
162 | if (stack_vars_alloc) | |
163 | stack_vars_alloc = stack_vars_alloc * 3 / 2; | |
164 | else | |
165 | stack_vars_alloc = 32; | |
166 | stack_vars | |
167 | = XRESIZEVEC (struct stack_var, stack_vars, stack_vars_alloc); | |
168 | } | |
169 | stack_vars[stack_vars_num].decl = decl; | |
170 | stack_vars[stack_vars_num].offset = 0; | |
171 | stack_vars[stack_vars_num].size = tree_low_cst (DECL_SIZE_UNIT (decl), 1); | |
172 | stack_vars[stack_vars_num].alignb = get_decl_align_unit (decl); | |
173 | ||
174 | /* All variables are initially in their own partition. */ | |
175 | stack_vars[stack_vars_num].representative = stack_vars_num; | |
176 | stack_vars[stack_vars_num].next = EOC; | |
177 | ||
178 | /* Ensure that this decl doesn't get put onto the list twice. */ | |
179 | SET_DECL_RTL (decl, pc_rtx); | |
180 | ||
181 | stack_vars_num++; | |
182 | } | |
183 | ||
184 | /* Compute the linear index of a lower-triangular coordinate (I, J). */ | |
185 | ||
186 | static size_t | |
187 | triangular_index (size_t i, size_t j) | |
188 | { | |
189 | if (i < j) | |
190 | { | |
191 | size_t t; | |
192 | t = i, i = j, j = t; | |
193 | } | |
194 | return (i * (i + 1)) / 2 + j; | |
195 | } | |
196 | ||
197 | /* Ensure that STACK_VARS_CONFLICT is large enough for N objects. */ | |
198 | ||
199 | static void | |
200 | resize_stack_vars_conflict (size_t n) | |
201 | { | |
202 | size_t size = triangular_index (n-1, n-1) + 1; | |
203 | ||
204 | if (size <= stack_vars_conflict_alloc) | |
205 | return; | |
206 | ||
207 | stack_vars_conflict = XRESIZEVEC (bool, stack_vars_conflict, size); | |
208 | memset (stack_vars_conflict + stack_vars_conflict_alloc, 0, | |
209 | (size - stack_vars_conflict_alloc) * sizeof (bool)); | |
210 | stack_vars_conflict_alloc = size; | |
211 | } | |
212 | ||
213 | /* Make the decls associated with luid's X and Y conflict. */ | |
214 | ||
215 | static void | |
216 | add_stack_var_conflict (size_t x, size_t y) | |
217 | { | |
218 | size_t index = triangular_index (x, y); | |
219 | gcc_assert (index < stack_vars_conflict_alloc); | |
220 | stack_vars_conflict[index] = true; | |
221 | } | |
222 | ||
223 | /* Check whether the decls associated with luid's X and Y conflict. */ | |
224 | ||
225 | static bool | |
226 | stack_var_conflict_p (size_t x, size_t y) | |
227 | { | |
228 | size_t index = triangular_index (x, y); | |
229 | gcc_assert (index < stack_vars_conflict_alloc); | |
230 | return stack_vars_conflict[index]; | |
231 | } | |
232 | ||
233 | /* A subroutine of expand_used_vars. If two variables X and Y have alias | |
234 | sets that do not conflict, then do add a conflict for these variables | |
235 | in the interference graph. We also have to mind MEM_IN_STRUCT_P and | |
236 | MEM_SCALAR_P. */ | |
237 | ||
238 | static void | |
239 | add_alias_set_conflicts (void) | |
240 | { | |
241 | size_t i, j, n = stack_vars_num; | |
242 | ||
243 | for (i = 0; i < n; ++i) | |
244 | { | |
245 | bool aggr_i = AGGREGATE_TYPE_P (TREE_TYPE (stack_vars[i].decl)); | |
246 | HOST_WIDE_INT set_i = get_alias_set (stack_vars[i].decl); | |
247 | ||
248 | for (j = 0; j < i; ++j) | |
249 | { | |
250 | bool aggr_j = AGGREGATE_TYPE_P (TREE_TYPE (stack_vars[j].decl)); | |
251 | HOST_WIDE_INT set_j = get_alias_set (stack_vars[j].decl); | |
252 | if (aggr_i != aggr_j || !alias_sets_conflict_p (set_i, set_j)) | |
253 | add_stack_var_conflict (i, j); | |
254 | } | |
255 | } | |
256 | } | |
257 | ||
258 | /* A subroutine of partition_stack_vars. A comparison function for qsort, | |
259 | sorting an array of indicies by the size of the object. */ | |
260 | ||
261 | static int | |
262 | stack_var_size_cmp (const void *a, const void *b) | |
263 | { | |
264 | HOST_WIDE_INT sa = stack_vars[*(const size_t *)a].size; | |
265 | HOST_WIDE_INT sb = stack_vars[*(const size_t *)b].size; | |
266 | ||
267 | if (sa < sb) | |
268 | return -1; | |
269 | if (sa > sb) | |
270 | return 1; | |
271 | return 0; | |
272 | } | |
273 | ||
274 | /* A subroutine of partition_stack_vars. The UNION portion of a UNION/FIND | |
275 | partitioning algorithm. Partitions A and B are known to be non-conflicting. | |
276 | Merge them into a single partition A. | |
277 | ||
278 | At the same time, add OFFSET to all variables in partition B. At the end | |
279 | of the partitioning process we've have a nice block easy to lay out within | |
280 | the stack frame. */ | |
281 | ||
282 | static void | |
283 | union_stack_vars (size_t a, size_t b, HOST_WIDE_INT offset) | |
284 | { | |
285 | size_t i, last; | |
286 | ||
287 | /* Update each element of partition B with the given offset, | |
288 | and merge them into partition A. */ | |
289 | for (last = i = b; i != EOC; last = i, i = stack_vars[i].next) | |
290 | { | |
291 | stack_vars[i].offset += offset; | |
292 | stack_vars[i].representative = a; | |
293 | } | |
294 | stack_vars[last].next = stack_vars[a].next; | |
295 | stack_vars[a].next = b; | |
296 | ||
297 | /* Update the required alignment of partition A to account for B. */ | |
298 | if (stack_vars[a].alignb < stack_vars[b].alignb) | |
299 | stack_vars[a].alignb = stack_vars[b].alignb; | |
300 | ||
301 | /* Update the interference graph and merge the conflicts. */ | |
302 | for (last = stack_vars_num, i = 0; i < last; ++i) | |
303 | if (stack_var_conflict_p (b, i)) | |
304 | add_stack_var_conflict (a, i); | |
305 | } | |
306 | ||
307 | /* A subroutine of expand_used_vars. Binpack the variables into | |
308 | partitions constrained by the interference graph. The overall | |
309 | algorithm used is as follows: | |
310 | ||
311 | Sort the objects by size. | |
312 | For each object A { | |
313 | S = size(A) | |
314 | O = 0 | |
315 | loop { | |
316 | Look for the largest non-conflicting object B with size <= S. | |
317 | UNION (A, B) | |
318 | offset(B) = O | |
319 | O += size(B) | |
320 | S -= size(B) | |
321 | } | |
322 | } | |
323 | */ | |
324 | ||
325 | static void | |
326 | partition_stack_vars (void) | |
327 | { | |
328 | size_t si, sj, n = stack_vars_num; | |
329 | ||
330 | stack_vars_sorted = XNEWVEC (size_t, stack_vars_num); | |
331 | for (si = 0; si < n; ++si) | |
332 | stack_vars_sorted[si] = si; | |
333 | ||
334 | if (n == 1) | |
335 | return; | |
336 | ||
337 | qsort (stack_vars_sorted, n, sizeof (size_t), stack_var_size_cmp); | |
338 | ||
339 | /* Special case: detect when all variables conflict, and thus we can't | |
340 | do anything during the partitioning loop. It isn't uncommon (with | |
341 | C code at least) to declare all variables at the top of the function, | |
342 | and if we're not inlining, then all variables will be in the same scope. | |
343 | Take advantage of very fast libc routines for this scan. */ | |
344 | gcc_assert (sizeof(bool) == sizeof(char)); | |
345 | if (memchr (stack_vars_conflict, false, stack_vars_conflict_alloc) == NULL) | |
346 | return; | |
347 | ||
348 | for (si = 0; si < n; ++si) | |
349 | { | |
350 | size_t i = stack_vars_sorted[si]; | |
351 | HOST_WIDE_INT isize = stack_vars[i].size; | |
352 | HOST_WIDE_INT offset = 0; | |
353 | ||
354 | for (sj = si; sj-- > 0; ) | |
355 | { | |
356 | size_t j = stack_vars_sorted[sj]; | |
357 | HOST_WIDE_INT jsize = stack_vars[j].size; | |
358 | unsigned int jalign = stack_vars[j].alignb; | |
359 | ||
360 | /* Ignore objects that aren't partition representatives. */ | |
361 | if (stack_vars[j].representative != j) | |
362 | continue; | |
363 | ||
364 | /* Ignore objects too large for the remaining space. */ | |
365 | if (isize < jsize) | |
366 | continue; | |
367 | ||
368 | /* Ignore conflicting objects. */ | |
369 | if (stack_var_conflict_p (i, j)) | |
370 | continue; | |
371 | ||
372 | /* Refine the remaining space check to include alignment. */ | |
373 | if (offset & (jalign - 1)) | |
374 | { | |
375 | HOST_WIDE_INT toff = offset; | |
376 | toff += jalign - 1; | |
377 | toff &= -(HOST_WIDE_INT)jalign; | |
378 | if (isize - (toff - offset) < jsize) | |
379 | continue; | |
380 | ||
381 | isize -= toff - offset; | |
382 | offset = toff; | |
383 | } | |
384 | ||
385 | /* UNION the objects, placing J at OFFSET. */ | |
386 | union_stack_vars (i, j, offset); | |
387 | ||
388 | isize -= jsize; | |
389 | if (isize == 0) | |
390 | break; | |
391 | } | |
392 | } | |
393 | } | |
394 | ||
395 | /* A debugging aid for expand_used_vars. Dump the generated partitions. */ | |
396 | ||
397 | static void | |
398 | dump_stack_var_partition (void) | |
399 | { | |
400 | size_t si, i, j, n = stack_vars_num; | |
401 | ||
402 | for (si = 0; si < n; ++si) | |
403 | { | |
404 | i = stack_vars_sorted[si]; | |
405 | ||
406 | /* Skip variables that aren't partition representatives, for now. */ | |
407 | if (stack_vars[i].representative != i) | |
408 | continue; | |
409 | ||
410 | fprintf (dump_file, "Partition %lu: size " HOST_WIDE_INT_PRINT_DEC | |
411 | " align %u\n", (unsigned long) i, stack_vars[i].size, | |
412 | stack_vars[i].alignb); | |
413 | ||
414 | for (j = i; j != EOC; j = stack_vars[j].next) | |
415 | { | |
416 | fputc ('\t', dump_file); | |
417 | print_generic_expr (dump_file, stack_vars[j].decl, dump_flags); | |
418 | fprintf (dump_file, ", offset " HOST_WIDE_INT_PRINT_DEC "\n", | |
419 | stack_vars[i].offset); | |
420 | } | |
421 | } | |
422 | } | |
423 | ||
424 | /* Assign rtl to DECL at frame offset OFFSET. */ | |
425 | ||
426 | static void | |
427 | expand_one_stack_var_at (tree decl, HOST_WIDE_INT offset) | |
428 | { | |
429 | HOST_WIDE_INT align; | |
430 | rtx x; | |
431 | ||
432 | /* If this fails, we've overflowed the stack frame. Error nicely? */ | |
433 | gcc_assert (offset == trunc_int_for_mode (offset, Pmode)); | |
434 | ||
435 | x = plus_constant (virtual_stack_vars_rtx, offset); | |
436 | x = gen_rtx_MEM (DECL_MODE (decl), x); | |
437 | ||
438 | /* Set alignment we actually gave this decl. */ | |
439 | offset -= frame_phase; | |
440 | align = offset & -offset; | |
441 | align *= BITS_PER_UNIT; | |
442 | if (align > STACK_BOUNDARY || align == 0) | |
443 | align = STACK_BOUNDARY; | |
444 | DECL_ALIGN (decl) = align; | |
445 | DECL_USER_ALIGN (decl) = 0; | |
446 | ||
447 | set_mem_attributes (x, decl, true); | |
448 | SET_DECL_RTL (decl, x); | |
449 | } | |
450 | ||
451 | /* A subroutine of expand_used_vars. Give each partition representative | |
452 | a unique location within the stack frame. Update each partition member | |
453 | with that location. */ | |
454 | ||
455 | static void | |
456 | expand_stack_vars (void) | |
457 | { | |
458 | size_t si, i, j, n = stack_vars_num; | |
459 | ||
460 | for (si = 0; si < n; ++si) | |
461 | { | |
462 | HOST_WIDE_INT offset; | |
463 | ||
464 | i = stack_vars_sorted[si]; | |
465 | ||
466 | /* Skip variables that aren't partition representatives, for now. */ | |
467 | if (stack_vars[i].representative != i) | |
468 | continue; | |
469 | ||
470 | offset = alloc_stack_frame_space (stack_vars[i].size, | |
471 | stack_vars[i].alignb); | |
472 | ||
473 | /* Create rtl for each variable based on their location within the | |
474 | partition. */ | |
475 | for (j = i; j != EOC; j = stack_vars[j].next) | |
476 | expand_one_stack_var_at (stack_vars[j].decl, | |
477 | stack_vars[j].offset + offset); | |
478 | } | |
479 | } | |
480 | ||
481 | /* A subroutine of expand_one_var. Called to immediately assign rtl | |
482 | to a variable to be allocated in the stack frame. */ | |
483 | ||
484 | static void | |
485 | expand_one_stack_var (tree var) | |
486 | { | |
487 | HOST_WIDE_INT size, offset, align; | |
488 | ||
489 | size = tree_low_cst (DECL_SIZE_UNIT (var), 1); | |
490 | align = get_decl_align_unit (var); | |
491 | offset = alloc_stack_frame_space (size, align); | |
492 | ||
493 | expand_one_stack_var_at (var, offset); | |
494 | } | |
495 | ||
496 | /* A subroutine of expand_one_var. Called to assign rtl | |
497 | to a TREE_STATIC VAR_DECL. */ | |
498 | ||
499 | static void | |
500 | expand_one_static_var (tree var) | |
501 | { | |
502 | /* If this is an inlined copy of a static local variable, | |
503 | look up the original. */ | |
504 | var = DECL_ORIGIN (var); | |
505 | ||
506 | /* If we've already processed this variable because of that, do nothing. */ | |
507 | if (TREE_ASM_WRITTEN (var)) | |
508 | return; | |
509 | ||
510 | /* Give the front end a chance to do whatever. In practice, this is | |
511 | resolving duplicate names for IMA in C. */ | |
512 | if (lang_hooks.expand_decl (var)) | |
513 | return; | |
514 | ||
515 | /* Otherwise, just emit the variable. */ | |
516 | rest_of_decl_compilation (var, 0, 0); | |
517 | } | |
518 | ||
519 | /* A subroutine of expand_one_var. Called to assign rtl to a VAR_DECL | |
520 | that will reside in a hard register. */ | |
521 | ||
522 | static void | |
523 | expand_one_hard_reg_var (tree var) | |
524 | { | |
525 | rest_of_decl_compilation (var, 0, 0); | |
526 | } | |
527 | ||
528 | /* A subroutine of expand_one_var. Called to assign rtl to a VAR_DECL | |
529 | that will reside in a pseudo register. */ | |
530 | ||
531 | static void | |
532 | expand_one_register_var (tree var) | |
533 | { | |
534 | tree type = TREE_TYPE (var); | |
535 | int unsignedp = TYPE_UNSIGNED (type); | |
536 | enum machine_mode reg_mode | |
537 | = promote_mode (type, DECL_MODE (var), &unsignedp, 0); | |
538 | rtx x = gen_reg_rtx (reg_mode); | |
539 | ||
540 | SET_DECL_RTL (var, x); | |
541 | ||
542 | /* Note if the object is a user variable. */ | |
543 | if (!DECL_ARTIFICIAL (var)) | |
544 | { | |
545 | mark_user_reg (x); | |
546 | ||
547 | /* Trust user variables which have a pointer type to really | |
548 | be pointers. Do not trust compiler generated temporaries | |
549 | as our type system is totally busted as it relates to | |
550 | pointer arithmetic which translates into lots of compiler | |
551 | generated objects with pointer types, but which are not really | |
552 | pointers. */ | |
553 | if (POINTER_TYPE_P (type)) | |
554 | mark_reg_pointer (x, TYPE_ALIGN (TREE_TYPE (TREE_TYPE (var)))); | |
555 | } | |
556 | } | |
557 | ||
558 | /* A subroutine of expand_one_var. Called to assign rtl to a VAR_DECL that | |
559 | has some associated error, e.g. it's type is error-mark. We just need | |
560 | to pick something that won't crash the rest of the compiler. */ | |
561 | ||
562 | static void | |
563 | expand_one_error_var (tree var) | |
564 | { | |
565 | enum machine_mode mode = DECL_MODE (var); | |
566 | rtx x; | |
567 | ||
568 | if (mode == BLKmode) | |
569 | x = gen_rtx_MEM (BLKmode, const0_rtx); | |
570 | else if (mode == VOIDmode) | |
571 | x = const0_rtx; | |
572 | else | |
573 | x = gen_reg_rtx (mode); | |
574 | ||
575 | SET_DECL_RTL (var, x); | |
576 | } | |
577 | ||
578 | /* A subroutine of expand_one_var. VAR is a variable that will be | |
579 | allocated to the local stack frame. Return true if we wish to | |
580 | add VAR to STACK_VARS so that it will be coalesced with other | |
581 | variables. Return false to allocate VAR immediately. | |
582 | ||
583 | This function is used to reduce the number of variables considered | |
584 | for coalescing, which reduces the size of the quadratic problem. */ | |
585 | ||
586 | static bool | |
587 | defer_stack_allocation (tree var, bool toplevel) | |
588 | { | |
589 | /* Variables in the outermost scope automatically conflict with | |
590 | every other variable. The only reason to want to defer them | |
591 | at all is that, after sorting, we can more efficiently pack | |
592 | small variables in the stack frame. Continue to defer at -O2. */ | |
593 | if (toplevel && optimize < 2) | |
594 | return false; | |
595 | ||
596 | /* Without optimization, *most* variables are allocated from the | |
597 | stack, which makes the quadratic problem large exactly when we | |
598 | want compilation to proceed as quickly as possible. On the | |
599 | other hand, we don't want the function's stack frame size to | |
600 | get completely out of hand. So we avoid adding scalars and | |
601 | "small" aggregates to the list at all. */ | |
602 | if (optimize == 0 && tree_low_cst (DECL_SIZE_UNIT (var), 1) < 32) | |
603 | return false; | |
604 | ||
605 | return true; | |
606 | } | |
607 | ||
608 | /* A subroutine of expand_used_vars. Expand one variable according to | |
2a7e31df | 609 | its flavor. Variables to be placed on the stack are not actually |
1f6d3a08 RH |
610 | expanded yet, merely recorded. */ |
611 | ||
612 | static void | |
613 | expand_one_var (tree var, bool toplevel) | |
614 | { | |
615 | if (TREE_CODE (var) != VAR_DECL) | |
616 | lang_hooks.expand_decl (var); | |
617 | else if (DECL_EXTERNAL (var)) | |
618 | ; | |
619 | else if (DECL_VALUE_EXPR (var)) | |
620 | ; | |
621 | else if (TREE_STATIC (var)) | |
622 | expand_one_static_var (var); | |
623 | else if (DECL_RTL_SET_P (var)) | |
624 | ; | |
625 | else if (TREE_TYPE (var) == error_mark_node) | |
626 | expand_one_error_var (var); | |
627 | else if (DECL_HARD_REGISTER (var)) | |
628 | expand_one_hard_reg_var (var); | |
629 | else if (use_register_for_decl (var)) | |
630 | expand_one_register_var (var); | |
631 | else if (defer_stack_allocation (var, toplevel)) | |
632 | add_stack_var (var); | |
633 | else | |
634 | expand_one_stack_var (var); | |
635 | } | |
636 | ||
637 | /* A subroutine of expand_used_vars. Walk down through the BLOCK tree | |
638 | expanding variables. Those variables that can be put into registers | |
639 | are allocated pseudos; those that can't are put on the stack. | |
640 | ||
641 | TOPLEVEL is true if this is the outermost BLOCK. */ | |
642 | ||
643 | static void | |
644 | expand_used_vars_for_block (tree block, bool toplevel) | |
645 | { | |
646 | size_t i, j, old_sv_num, this_sv_num, new_sv_num; | |
647 | tree t; | |
648 | ||
649 | old_sv_num = toplevel ? 0 : stack_vars_num; | |
650 | ||
651 | /* Expand all variables at this level. */ | |
652 | for (t = BLOCK_VARS (block); t ; t = TREE_CHAIN (t)) | |
653 | if (TREE_USED (t)) | |
654 | expand_one_var (t, toplevel); | |
655 | ||
656 | this_sv_num = stack_vars_num; | |
657 | ||
658 | /* Expand all variables at containing levels. */ | |
659 | for (t = BLOCK_SUBBLOCKS (block); t ; t = BLOCK_CHAIN (t)) | |
660 | expand_used_vars_for_block (t, false); | |
661 | ||
662 | /* Since we do not track exact variable lifetimes (which is not even | |
663 | possible for varibles whose address escapes), we mirror the block | |
664 | tree in the interference graph. Here we cause all variables at this | |
665 | level, and all sublevels, to conflict. Do make certain that a | |
666 | variable conflicts with itself. */ | |
667 | if (old_sv_num < this_sv_num) | |
668 | { | |
669 | new_sv_num = stack_vars_num; | |
670 | resize_stack_vars_conflict (new_sv_num); | |
671 | ||
672 | for (i = old_sv_num; i < new_sv_num; ++i) | |
673 | for (j = i < this_sv_num ? i : this_sv_num; ; --j) | |
674 | { | |
675 | add_stack_var_conflict (i, j); | |
676 | if (j == old_sv_num) | |
677 | break; | |
678 | } | |
679 | } | |
680 | } | |
681 | ||
682 | /* A subroutine of expand_used_vars. Walk down through the BLOCK tree | |
683 | and clear TREE_USED on all local variables. */ | |
684 | ||
685 | static void | |
686 | clear_tree_used (tree block) | |
687 | { | |
688 | tree t; | |
689 | ||
690 | for (t = BLOCK_VARS (block); t ; t = TREE_CHAIN (t)) | |
691 | /* if (!TREE_STATIC (t) && !DECL_EXTERNAL (t)) */ | |
692 | TREE_USED (t) = 0; | |
693 | ||
694 | for (t = BLOCK_SUBBLOCKS (block); t ; t = BLOCK_CHAIN (t)) | |
695 | clear_tree_used (t); | |
696 | } | |
697 | ||
698 | /* Expand all variables used in the function. */ | |
727a31fa RH |
699 | |
700 | static void | |
701 | expand_used_vars (void) | |
702 | { | |
1f6d3a08 | 703 | tree t, outer_block = DECL_INITIAL (current_function_decl); |
727a31fa | 704 | |
1f6d3a08 RH |
705 | /* Compute the phase of the stack frame for this function. */ |
706 | { | |
707 | int align = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT; | |
708 | int off = STARTING_FRAME_OFFSET % align; | |
709 | frame_phase = off ? align - off : 0; | |
710 | } | |
727a31fa | 711 | |
1f6d3a08 RH |
712 | /* Set TREE_USED on all variables in the unexpanded_var_list. */ |
713 | for (t = cfun->unexpanded_var_list; t; t = TREE_CHAIN (t)) | |
714 | TREE_USED (TREE_VALUE (t)) = 1; | |
727a31fa | 715 | |
1f6d3a08 RH |
716 | /* Clear TREE_USED on all variables associated with a block scope. */ |
717 | clear_tree_used (outer_block); | |
718 | ||
719 | /* At this point all variables on the unexpanded_var_list with TREE_USED | |
720 | set are not associated with any block scope. Lay them out. */ | |
721 | for (t = cfun->unexpanded_var_list; t; t = TREE_CHAIN (t)) | |
722 | { | |
723 | tree var = TREE_VALUE (t); | |
724 | bool expand_now = false; | |
725 | ||
726 | /* We didn't set a block for static or extern because it's hard | |
727 | to tell the difference between a global variable (re)declared | |
728 | in a local scope, and one that's really declared there to | |
729 | begin with. And it doesn't really matter much, since we're | |
730 | not giving them stack space. Expand them now. */ | |
731 | if (TREE_STATIC (var) || DECL_EXTERNAL (var)) | |
732 | expand_now = true; | |
733 | ||
734 | /* Any variable that could have been hoisted into an SSA_NAME | |
735 | will have been propagated anywhere the optimizers chose, | |
736 | i.e. not confined to their original block. Allocate them | |
737 | as if they were defined in the outermost scope. */ | |
738 | else if (is_gimple_reg (var)) | |
739 | expand_now = true; | |
740 | ||
741 | /* If the variable is not associated with any block, then it | |
742 | was created by the optimizers, and could be live anywhere | |
743 | in the function. */ | |
744 | else if (TREE_USED (var)) | |
745 | expand_now = true; | |
746 | ||
747 | /* Finally, mark all variables on the list as used. We'll use | |
748 | this in a moment when we expand those associated with scopes. */ | |
749 | TREE_USED (var) = 1; | |
750 | ||
751 | if (expand_now) | |
752 | expand_one_var (var, true); | |
753 | } | |
727a31fa | 754 | cfun->unexpanded_var_list = NULL_TREE; |
1f6d3a08 RH |
755 | |
756 | /* At this point, all variables within the block tree with TREE_USED | |
757 | set are actually used by the optimized function. Lay them out. */ | |
758 | expand_used_vars_for_block (outer_block, true); | |
759 | ||
760 | if (stack_vars_num > 0) | |
761 | { | |
762 | /* Due to the way alias sets work, no variables with non-conflicting | |
763 | alias sets may be assigned the same address. Add conflicts to | |
764 | reflect this. */ | |
765 | add_alias_set_conflicts (); | |
766 | ||
767 | /* Now that we have collected all stack variables, and have computed a | |
768 | minimal interference graph, attempt to save some stack space. */ | |
769 | partition_stack_vars (); | |
770 | if (dump_file) | |
771 | dump_stack_var_partition (); | |
772 | ||
773 | /* Assign rtl to each variable based on these partitions. */ | |
774 | expand_stack_vars (); | |
775 | ||
776 | /* Free up stack variable graph data. */ | |
777 | XDELETEVEC (stack_vars); | |
778 | XDELETEVEC (stack_vars_sorted); | |
779 | XDELETEVEC (stack_vars_conflict); | |
780 | stack_vars = NULL; | |
781 | stack_vars_alloc = stack_vars_num = 0; | |
782 | stack_vars_conflict = NULL; | |
783 | stack_vars_conflict_alloc = 0; | |
784 | } | |
785 | ||
786 | /* If the target requires that FRAME_OFFSET be aligned, do it. */ | |
787 | if (STACK_ALIGNMENT_NEEDED) | |
788 | { | |
789 | HOST_WIDE_INT align = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT; | |
790 | if (!FRAME_GROWS_DOWNWARD) | |
791 | frame_offset += align - 1; | |
792 | frame_offset &= -align; | |
793 | } | |
727a31fa RH |
794 | } |
795 | ||
796 | ||
80c7a9eb RH |
797 | /* A subroutine of expand_gimple_basic_block. Expand one COND_EXPR. |
798 | Returns a new basic block if we've terminated the current basic | |
799 | block and created a new one. */ | |
800 | ||
801 | static basic_block | |
802 | expand_gimple_cond_expr (basic_block bb, tree stmt) | |
803 | { | |
804 | basic_block new_bb, dest; | |
805 | edge new_edge; | |
806 | edge true_edge; | |
807 | edge false_edge; | |
808 | tree pred = COND_EXPR_COND (stmt); | |
809 | tree then_exp = COND_EXPR_THEN (stmt); | |
810 | tree else_exp = COND_EXPR_ELSE (stmt); | |
811 | rtx last; | |
812 | ||
813 | extract_true_false_edges_from_block (bb, &true_edge, &false_edge); | |
814 | if (EXPR_LOCUS (stmt)) | |
815 | { | |
816 | emit_line_note (*(EXPR_LOCUS (stmt))); | |
817 | record_block_change (TREE_BLOCK (stmt)); | |
818 | } | |
819 | ||
820 | /* These flags have no purpose in RTL land. */ | |
821 | true_edge->flags &= ~EDGE_TRUE_VALUE; | |
822 | false_edge->flags &= ~EDGE_FALSE_VALUE; | |
823 | ||
824 | /* We can either have a pure conditional jump with one fallthru edge or | |
825 | two-way jump that needs to be decomposed into two basic blocks. */ | |
826 | if (TREE_CODE (then_exp) == GOTO_EXPR && IS_EMPTY_STMT (else_exp)) | |
827 | { | |
828 | jumpif (pred, label_rtx (GOTO_DESTINATION (then_exp))); | |
829 | return NULL; | |
830 | } | |
831 | if (TREE_CODE (else_exp) == GOTO_EXPR && IS_EMPTY_STMT (then_exp)) | |
832 | { | |
833 | jumpifnot (pred, label_rtx (GOTO_DESTINATION (else_exp))); | |
834 | return NULL; | |
835 | } | |
836 | if (TREE_CODE (then_exp) != GOTO_EXPR || TREE_CODE (else_exp) != GOTO_EXPR) | |
837 | abort (); | |
838 | ||
839 | jumpif (pred, label_rtx (GOTO_DESTINATION (then_exp))); | |
840 | last = get_last_insn (); | |
841 | expand_expr (else_exp, const0_rtx, VOIDmode, 0); | |
842 | ||
843 | BB_END (bb) = last; | |
844 | if (BARRIER_P (BB_END (bb))) | |
845 | BB_END (bb) = PREV_INSN (BB_END (bb)); | |
846 | update_bb_for_insn (bb); | |
847 | ||
848 | new_bb = create_basic_block (NEXT_INSN (last), get_last_insn (), bb); | |
849 | dest = false_edge->dest; | |
850 | redirect_edge_succ (false_edge, new_bb); | |
851 | false_edge->flags |= EDGE_FALLTHRU; | |
852 | new_bb->count = false_edge->count; | |
853 | new_bb->frequency = EDGE_FREQUENCY (false_edge); | |
854 | new_edge = make_edge (new_bb, dest, 0); | |
855 | new_edge->probability = REG_BR_PROB_BASE; | |
856 | new_edge->count = new_bb->count; | |
857 | if (BARRIER_P (BB_END (new_bb))) | |
858 | BB_END (new_bb) = PREV_INSN (BB_END (new_bb)); | |
859 | update_bb_for_insn (new_bb); | |
860 | ||
861 | if (dump_file) | |
862 | { | |
863 | dump_bb (bb, dump_file, 0); | |
864 | dump_bb (new_bb, dump_file, 0); | |
865 | } | |
866 | ||
867 | return new_bb; | |
868 | } | |
869 | ||
870 | /* A subroutine of expand_gimple_basic_block. Expand one CALL_EXPR | |
224e770b RH |
871 | that has CALL_EXPR_TAILCALL set. Returns non-null if we actually |
872 | generated a tail call (something that might be denied by the ABI | |
cea49550 RH |
873 | rules governing the call; see calls.c). |
874 | ||
875 | Sets CAN_FALLTHRU if we generated a *conditional* tail call, and | |
876 | can still reach the rest of BB. The case here is __builtin_sqrt, | |
877 | where the NaN result goes through the external function (with a | |
878 | tailcall) and the normal result happens via a sqrt instruction. */ | |
80c7a9eb RH |
879 | |
880 | static basic_block | |
cea49550 | 881 | expand_gimple_tailcall (basic_block bb, tree stmt, bool *can_fallthru) |
80c7a9eb RH |
882 | { |
883 | rtx last = get_last_insn (); | |
224e770b RH |
884 | edge e; |
885 | int probability; | |
886 | gcov_type count; | |
80c7a9eb RH |
887 | |
888 | expand_expr_stmt (stmt); | |
889 | ||
890 | for (last = NEXT_INSN (last); last; last = NEXT_INSN (last)) | |
224e770b RH |
891 | if (CALL_P (last) && SIBLING_CALL_P (last)) |
892 | goto found; | |
80c7a9eb | 893 | |
cea49550 | 894 | *can_fallthru = true; |
224e770b | 895 | return NULL; |
80c7a9eb | 896 | |
224e770b RH |
897 | found: |
898 | /* ??? Wouldn't it be better to just reset any pending stack adjust? | |
899 | Any instructions emitted here are about to be deleted. */ | |
900 | do_pending_stack_adjust (); | |
901 | ||
902 | /* Remove any non-eh, non-abnormal edges that don't go to exit. */ | |
903 | /* ??? I.e. the fallthrough edge. HOWEVER! If there were to be | |
904 | EH or abnormal edges, we shouldn't have created a tail call in | |
905 | the first place. So it seems to me we should just be removing | |
906 | all edges here, or redirecting the existing fallthru edge to | |
907 | the exit block. */ | |
908 | ||
909 | e = bb->succ; | |
910 | probability = 0; | |
911 | count = 0; | |
912 | while (e) | |
913 | { | |
914 | edge next = e->succ_next; | |
915 | ||
916 | if (!(e->flags & (EDGE_ABNORMAL | EDGE_EH))) | |
917 | { | |
918 | if (e->dest != EXIT_BLOCK_PTR) | |
80c7a9eb | 919 | { |
224e770b RH |
920 | e->dest->count -= e->count; |
921 | e->dest->frequency -= EDGE_FREQUENCY (e); | |
922 | if (e->dest->count < 0) | |
923 | e->dest->count = 0; | |
924 | if (e->dest->frequency < 0) | |
925 | e->dest->frequency = 0; | |
80c7a9eb | 926 | } |
224e770b RH |
927 | count += e->count; |
928 | probability += e->probability; | |
929 | remove_edge (e); | |
80c7a9eb | 930 | } |
224e770b RH |
931 | |
932 | e = next; | |
80c7a9eb RH |
933 | } |
934 | ||
224e770b RH |
935 | /* This is somewhat ugly: the call_expr expander often emits instructions |
936 | after the sibcall (to perform the function return). These confuse the | |
937 | find_sub_basic_blocks code, so we need to get rid of these. */ | |
938 | last = NEXT_INSN (last); | |
939 | if (!BARRIER_P (last)) | |
940 | abort (); | |
cea49550 RH |
941 | |
942 | *can_fallthru = false; | |
224e770b RH |
943 | while (NEXT_INSN (last)) |
944 | { | |
945 | /* For instance an sqrt builtin expander expands if with | |
946 | sibcall in the then and label for `else`. */ | |
947 | if (LABEL_P (NEXT_INSN (last))) | |
cea49550 RH |
948 | { |
949 | *can_fallthru = true; | |
950 | break; | |
951 | } | |
224e770b RH |
952 | delete_insn (NEXT_INSN (last)); |
953 | } | |
954 | ||
955 | e = make_edge (bb, EXIT_BLOCK_PTR, EDGE_ABNORMAL | EDGE_SIBCALL); | |
956 | e->probability += probability; | |
957 | e->count += count; | |
958 | BB_END (bb) = last; | |
959 | update_bb_for_insn (bb); | |
960 | ||
961 | if (NEXT_INSN (last)) | |
962 | { | |
963 | bb = create_basic_block (NEXT_INSN (last), get_last_insn (), bb); | |
964 | ||
965 | last = BB_END (bb); | |
966 | if (BARRIER_P (last)) | |
967 | BB_END (bb) = PREV_INSN (last); | |
968 | } | |
969 | ||
970 | return bb; | |
80c7a9eb RH |
971 | } |
972 | ||
242229bb JH |
973 | /* Expand basic block BB from GIMPLE trees to RTL. */ |
974 | ||
975 | static basic_block | |
80c7a9eb | 976 | expand_gimple_basic_block (basic_block bb, FILE * dump_file) |
242229bb JH |
977 | { |
978 | block_stmt_iterator bsi = bsi_start (bb); | |
979 | tree stmt = NULL; | |
980 | rtx note, last; | |
981 | edge e; | |
982 | ||
983 | if (dump_file) | |
984 | { | |
985 | tree_register_cfg_hooks (); | |
986 | dump_bb (bb, dump_file, 0); | |
987 | rtl_register_cfg_hooks (); | |
988 | } | |
989 | ||
990 | if (!bsi_end_p (bsi)) | |
991 | stmt = bsi_stmt (bsi); | |
992 | ||
993 | if (stmt && TREE_CODE (stmt) == LABEL_EXPR) | |
994 | { | |
995 | last = get_last_insn (); | |
996 | ||
4dfa0342 | 997 | expand_expr_stmt (stmt); |
242229bb | 998 | |
caf93cb0 | 999 | /* Java emits line number notes in the top of labels. |
242229bb JH |
1000 | ??? Make this go away once line number notes are obsoleted. */ |
1001 | BB_HEAD (bb) = NEXT_INSN (last); | |
4b4bf941 | 1002 | if (NOTE_P (BB_HEAD (bb))) |
242229bb JH |
1003 | BB_HEAD (bb) = NEXT_INSN (BB_HEAD (bb)); |
1004 | bsi_next (&bsi); | |
1005 | note = emit_note_after (NOTE_INSN_BASIC_BLOCK, BB_HEAD (bb)); | |
1006 | } | |
1007 | else | |
1008 | note = BB_HEAD (bb) = emit_note (NOTE_INSN_BASIC_BLOCK); | |
1009 | ||
1010 | NOTE_BASIC_BLOCK (note) = bb; | |
1011 | ||
1012 | e = bb->succ; | |
1013 | while (e) | |
1014 | { | |
1015 | edge next = e->succ_next; | |
1016 | ||
1017 | /* Clear EDGE_EXECUTABLE. This flag is never used in the backend. */ | |
1018 | e->flags &= ~EDGE_EXECUTABLE; | |
1019 | ||
1020 | /* At the moment not all abnormal edges match the RTL representation. | |
1021 | It is safe to remove them here as find_sub_basic_blocks will | |
1022 | rediscover them. In the future we should get this fixed properly. */ | |
1023 | if (e->flags & EDGE_ABNORMAL) | |
1024 | remove_edge (e); | |
1025 | ||
1026 | e = next; | |
1027 | } | |
1028 | ||
1029 | for (; !bsi_end_p (bsi); bsi_next (&bsi)) | |
1030 | { | |
1031 | tree stmt = bsi_stmt (bsi); | |
cea49550 | 1032 | basic_block new_bb; |
242229bb JH |
1033 | |
1034 | if (!stmt) | |
1035 | continue; | |
1036 | ||
1037 | /* Expand this statement, then evaluate the resulting RTL and | |
1038 | fixup the CFG accordingly. */ | |
80c7a9eb | 1039 | if (TREE_CODE (stmt) == COND_EXPR) |
cea49550 RH |
1040 | { |
1041 | new_bb = expand_gimple_cond_expr (bb, stmt); | |
1042 | if (new_bb) | |
1043 | return new_bb; | |
1044 | } | |
80c7a9eb | 1045 | else |
242229bb | 1046 | { |
80c7a9eb RH |
1047 | tree call = get_call_expr_in (stmt); |
1048 | if (call && CALL_EXPR_TAILCALL (call)) | |
cea49550 RH |
1049 | { |
1050 | bool can_fallthru; | |
1051 | new_bb = expand_gimple_tailcall (bb, stmt, &can_fallthru); | |
1052 | if (new_bb) | |
1053 | { | |
1054 | if (can_fallthru) | |
1055 | bb = new_bb; | |
1056 | else | |
1057 | return new_bb; | |
1058 | } | |
1059 | } | |
80c7a9eb RH |
1060 | else |
1061 | expand_expr_stmt (stmt); | |
242229bb JH |
1062 | } |
1063 | } | |
1064 | ||
1065 | do_pending_stack_adjust (); | |
1066 | ||
1067 | /* Find the the block tail. The last insn is the block is the insn | |
1068 | before a barrier and/or table jump insn. */ | |
1069 | last = get_last_insn (); | |
4b4bf941 | 1070 | if (BARRIER_P (last)) |
242229bb JH |
1071 | last = PREV_INSN (last); |
1072 | if (JUMP_TABLE_DATA_P (last)) | |
1073 | last = PREV_INSN (PREV_INSN (last)); | |
1074 | BB_END (bb) = last; | |
caf93cb0 | 1075 | |
242229bb JH |
1076 | if (dump_file) |
1077 | dump_bb (bb, dump_file, 0); | |
1078 | update_bb_for_insn (bb); | |
80c7a9eb | 1079 | |
242229bb JH |
1080 | return bb; |
1081 | } | |
1082 | ||
1083 | ||
1084 | /* Create a basic block for initialization code. */ | |
1085 | ||
1086 | static basic_block | |
1087 | construct_init_block (void) | |
1088 | { | |
1089 | basic_block init_block, first_block; | |
1090 | edge e; | |
1091 | ||
242229bb JH |
1092 | for (e = ENTRY_BLOCK_PTR->succ; e; e = e->succ_next) |
1093 | if (e->dest == ENTRY_BLOCK_PTR->next_bb) | |
1094 | break; | |
1095 | ||
1096 | init_block = create_basic_block (NEXT_INSN (get_insns ()), | |
1097 | get_last_insn (), | |
1098 | ENTRY_BLOCK_PTR); | |
1099 | init_block->frequency = ENTRY_BLOCK_PTR->frequency; | |
1100 | init_block->count = ENTRY_BLOCK_PTR->count; | |
1101 | if (e) | |
1102 | { | |
1103 | first_block = e->dest; | |
1104 | redirect_edge_succ (e, init_block); | |
1105 | e = make_edge (init_block, first_block, EDGE_FALLTHRU); | |
1106 | } | |
1107 | else | |
1108 | e = make_edge (init_block, EXIT_BLOCK_PTR, EDGE_FALLTHRU); | |
1109 | e->probability = REG_BR_PROB_BASE; | |
1110 | e->count = ENTRY_BLOCK_PTR->count; | |
1111 | ||
1112 | update_bb_for_insn (init_block); | |
1113 | return init_block; | |
1114 | } | |
1115 | ||
1116 | ||
1117 | /* Create a block containing landing pads and similar stuff. */ | |
1118 | ||
1119 | static void | |
1120 | construct_exit_block (void) | |
1121 | { | |
1122 | rtx head = get_last_insn (); | |
1123 | rtx end; | |
1124 | basic_block exit_block; | |
1125 | edge e, e2, next; | |
1126 | ||
caf93cb0 | 1127 | /* Make sure the locus is set to the end of the function, so that |
242229bb | 1128 | epilogue line numbers and warnings are set properly. */ |
6773e15f PB |
1129 | #ifdef USE_MAPPED_LOCATION |
1130 | if (cfun->function_end_locus != UNKNOWN_LOCATION) | |
1131 | #else | |
242229bb | 1132 | if (cfun->function_end_locus.file) |
6773e15f | 1133 | #endif |
242229bb JH |
1134 | input_location = cfun->function_end_locus; |
1135 | ||
1136 | /* The following insns belong to the top scope. */ | |
1137 | record_block_change (DECL_INITIAL (current_function_decl)); | |
1138 | ||
242229bb JH |
1139 | /* Generate rtl for function exit. */ |
1140 | expand_function_end (); | |
1141 | ||
1142 | end = get_last_insn (); | |
1143 | if (head == end) | |
1144 | return; | |
4b4bf941 | 1145 | while (NEXT_INSN (head) && NOTE_P (NEXT_INSN (head))) |
242229bb | 1146 | head = NEXT_INSN (head); |
80c7a9eb RH |
1147 | exit_block = create_basic_block (NEXT_INSN (head), end, |
1148 | EXIT_BLOCK_PTR->prev_bb); | |
242229bb JH |
1149 | exit_block->frequency = EXIT_BLOCK_PTR->frequency; |
1150 | exit_block->count = EXIT_BLOCK_PTR->count; | |
1151 | for (e = EXIT_BLOCK_PTR->pred; e; e = next) | |
1152 | { | |
1153 | next = e->pred_next; | |
1154 | if (!(e->flags & EDGE_ABNORMAL)) | |
1155 | redirect_edge_succ (e, exit_block); | |
1156 | } | |
1157 | e = make_edge (exit_block, EXIT_BLOCK_PTR, EDGE_FALLTHRU); | |
1158 | e->probability = REG_BR_PROB_BASE; | |
1159 | e->count = EXIT_BLOCK_PTR->count; | |
1160 | for (e2 = EXIT_BLOCK_PTR->pred; e2; e2 = e2->pred_next) | |
1161 | if (e2 != e) | |
1162 | { | |
1163 | e->count -= e2->count; | |
1164 | exit_block->count -= e2->count; | |
1165 | exit_block->frequency -= EDGE_FREQUENCY (e2); | |
1166 | } | |
1167 | if (e->count < 0) | |
1168 | e->count = 0; | |
1169 | if (exit_block->count < 0) | |
1170 | exit_block->count = 0; | |
1171 | if (exit_block->frequency < 0) | |
1172 | exit_block->frequency = 0; | |
1173 | update_bb_for_insn (exit_block); | |
1174 | } | |
1175 | ||
242229bb JH |
1176 | /* Translate the intermediate representation contained in the CFG |
1177 | from GIMPLE trees to RTL. | |
1178 | ||
1179 | We do conversion per basic block and preserve/update the tree CFG. | |
1180 | This implies we have to do some magic as the CFG can simultaneously | |
1181 | consist of basic blocks containing RTL and GIMPLE trees. This can | |
61ada8ae | 1182 | confuse the CFG hooks, so be careful to not manipulate CFG during |
242229bb JH |
1183 | the expansion. */ |
1184 | ||
1185 | static void | |
1186 | tree_expand_cfg (void) | |
1187 | { | |
1188 | basic_block bb, init_block; | |
1189 | sbitmap blocks; | |
1190 | ||
878f99d2 JH |
1191 | profile_status = PROFILE_ABSENT; |
1192 | ||
4586b4ca SB |
1193 | /* Some backends want to know that we are expanding to RTL. */ |
1194 | currently_expanding_to_rtl = 1; | |
1195 | ||
6429e3be RH |
1196 | /* Prepare the rtl middle end to start recording block changes. */ |
1197 | reset_block_changes (); | |
1198 | ||
727a31fa | 1199 | /* Expand the variables recorded during gimple lowering. */ |
242229bb JH |
1200 | expand_used_vars (); |
1201 | ||
1202 | /* Set up parameters and prepare for return, for the function. */ | |
b79c5284 | 1203 | expand_function_start (current_function_decl); |
242229bb JH |
1204 | |
1205 | /* If this function is `main', emit a call to `__main' | |
1206 | to run global initializers, etc. */ | |
1207 | if (DECL_NAME (current_function_decl) | |
1208 | && MAIN_NAME_P (DECL_NAME (current_function_decl)) | |
1209 | && DECL_FILE_SCOPE_P (current_function_decl)) | |
1210 | expand_main_function (); | |
1211 | ||
3fbd86b1 | 1212 | /* Register rtl specific functions for cfg. */ |
242229bb JH |
1213 | rtl_register_cfg_hooks (); |
1214 | ||
1215 | init_block = construct_init_block (); | |
1216 | ||
1217 | FOR_BB_BETWEEN (bb, init_block->next_bb, EXIT_BLOCK_PTR, next_bb) | |
80c7a9eb | 1218 | bb = expand_gimple_basic_block (bb, dump_file); |
242229bb JH |
1219 | |
1220 | construct_exit_block (); | |
1221 | ||
4586b4ca SB |
1222 | /* We're done expanding trees to RTL. */ |
1223 | currently_expanding_to_rtl = 0; | |
1224 | ||
242229bb | 1225 | /* Convert from NOTE_INSN_EH_REGION style notes, and do other |
9f8628ba | 1226 | sorts of eh initialization. */ |
242229bb JH |
1227 | convert_from_eh_region_ranges (); |
1228 | ||
1229 | rebuild_jump_labels (get_insns ()); | |
1230 | find_exception_handler_labels (); | |
1231 | ||
1232 | blocks = sbitmap_alloc (last_basic_block); | |
1233 | sbitmap_ones (blocks); | |
1234 | find_many_sub_basic_blocks (blocks); | |
1235 | purge_all_dead_edges (0); | |
1236 | sbitmap_free (blocks); | |
1237 | ||
1238 | compact_blocks (); | |
1239 | #ifdef ENABLE_CHECKING | |
1240 | verify_flow_info(); | |
1241 | #endif | |
9f8628ba PB |
1242 | |
1243 | /* There's no need to defer outputting this function any more; we | |
1244 | know we want to output it. */ | |
1245 | DECL_DEFER_OUTPUT (current_function_decl) = 0; | |
1246 | ||
1247 | /* Now that we're done expanding trees to RTL, we shouldn't have any | |
1248 | more CONCATs anywhere. */ | |
1249 | generating_concat_p = 0; | |
1250 | ||
1251 | finalize_block_changes (); | |
242229bb JH |
1252 | } |
1253 | ||
1254 | struct tree_opt_pass pass_expand = | |
1255 | { | |
1256 | "expand", /* name */ | |
1257 | NULL, /* gate */ | |
1258 | tree_expand_cfg, /* execute */ | |
1259 | NULL, /* sub */ | |
1260 | NULL, /* next */ | |
1261 | 0, /* static_pass_number */ | |
1262 | TV_EXPAND, /* tv_id */ | |
1263 | /* ??? If TER is enabled, we actually receive GENERIC. */ | |
1264 | PROP_gimple_leh | PROP_cfg, /* properties_required */ | |
1265 | PROP_rtl, /* properties_provided */ | |
1266 | PROP_gimple_leh, /* properties_destroyed */ | |
1267 | 0, /* todo_flags_start */ | |
9f8628ba PB |
1268 | 0, /* todo_flags_finish */ |
1269 | 'r' /* letter */ | |
242229bb | 1270 | }; |