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b4ead7d4 BS |
1 | /* Instruction scheduling pass. |
2 | Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, | |
f759eb8b | 3 | 1999, 2000, 2001 Free Software Foundation, Inc. |
b4ead7d4 BS |
4 | Contributed by Michael Tiemann (tiemann@cygnus.com) Enhanced by, |
5 | and currently maintained by, Jim Wilson (wilson@cygnus.com) | |
6 | ||
1322177d | 7 | This file is part of GCC. |
b4ead7d4 | 8 | |
1322177d LB |
9 | GCC is free software; you can redistribute it and/or modify it under |
10 | the terms of the GNU General Public License as published by the Free | |
11 | Software Foundation; either version 2, or (at your option) any later | |
12 | version. | |
b4ead7d4 | 13 | |
1322177d LB |
14 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY |
15 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
b4ead7d4 BS |
16 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
17 | for more details. | |
18 | ||
19 | You should have received a copy of the GNU General Public License | |
47a1bd82 NC |
20 | along with GCC; see the file COPYING. If not, write to the Free |
21 | Software Foundation, 59 Temple Place - Suite 330, Boston, MA | |
b4ead7d4 BS |
22 | 02111-1307, USA. */ |
23 | ||
24 | /* This pass implements list scheduling within basic blocks. It is | |
25 | run twice: (1) after flow analysis, but before register allocation, | |
26 | and (2) after register allocation. | |
27 | ||
28 | The first run performs interblock scheduling, moving insns between | |
29 | different blocks in the same "region", and the second runs only | |
30 | basic block scheduling. | |
31 | ||
32 | Interblock motions performed are useful motions and speculative | |
33 | motions, including speculative loads. Motions requiring code | |
34 | duplication are not supported. The identification of motion type | |
35 | and the check for validity of speculative motions requires | |
36 | construction and analysis of the function's control flow graph. | |
37 | ||
38 | The main entry point for this pass is schedule_insns(), called for | |
39 | each function. The work of the scheduler is organized in three | |
40 | levels: (1) function level: insns are subject to splitting, | |
41 | control-flow-graph is constructed, regions are computed (after | |
42 | reload, each region is of one block), (2) region level: control | |
43 | flow graph attributes required for interblock scheduling are | |
44 | computed (dominators, reachability, etc.), data dependences and | |
45 | priorities are computed, and (3) block level: insns in the block | |
46 | are actually scheduled. */ | |
47 | \f | |
48 | #include "config.h" | |
49 | #include "system.h" | |
50 | #include "toplev.h" | |
51 | #include "rtl.h" | |
52 | #include "tm_p.h" | |
53 | #include "hard-reg-set.h" | |
54 | #include "basic-block.h" | |
55 | #include "regs.h" | |
56 | #include "function.h" | |
57 | #include "flags.h" | |
58 | #include "insn-config.h" | |
59 | #include "insn-attr.h" | |
60 | #include "except.h" | |
61 | #include "toplev.h" | |
62 | #include "recog.h" | |
63 | #include "sched-int.h" | |
64 | ||
f56887a7 | 65 | #ifdef INSN_SCHEDULING |
b4ead7d4 BS |
66 | /* Some accessor macros for h_i_d members only used within this file. */ |
67 | #define INSN_REF_COUNT(INSN) (h_i_d[INSN_UID (INSN)].ref_count) | |
68 | #define FED_BY_SPEC_LOAD(insn) (h_i_d[INSN_UID (insn)].fed_by_spec_load) | |
69 | #define IS_LOAD_INSN(insn) (h_i_d[INSN_UID (insn)].is_load_insn) | |
70 | ||
71 | #define MAX_RGN_BLOCKS 10 | |
72 | #define MAX_RGN_INSNS 100 | |
73 | ||
74 | /* nr_inter/spec counts interblock/speculative motion for the function. */ | |
75 | static int nr_inter, nr_spec; | |
76 | ||
77 | /* Control flow graph edges are kept in circular lists. */ | |
78 | typedef struct | |
79 | { | |
80 | int from_block; | |
81 | int to_block; | |
82 | int next_in; | |
83 | int next_out; | |
84 | } | |
85 | haifa_edge; | |
86 | static haifa_edge *edge_table; | |
87 | ||
88 | #define NEXT_IN(edge) (edge_table[edge].next_in) | |
89 | #define NEXT_OUT(edge) (edge_table[edge].next_out) | |
90 | #define FROM_BLOCK(edge) (edge_table[edge].from_block) | |
91 | #define TO_BLOCK(edge) (edge_table[edge].to_block) | |
92 | ||
93 | /* Number of edges in the control flow graph. (In fact, larger than | |
94 | that by 1, since edge 0 is unused.) */ | |
95 | static int nr_edges; | |
96 | ||
97 | /* Circular list of incoming/outgoing edges of a block. */ | |
98 | static int *in_edges; | |
99 | static int *out_edges; | |
100 | ||
101 | #define IN_EDGES(block) (in_edges[block]) | |
102 | #define OUT_EDGES(block) (out_edges[block]) | |
103 | ||
104 | static int is_cfg_nonregular PARAMS ((void)); | |
105 | static int build_control_flow PARAMS ((struct edge_list *)); | |
106 | static void new_edge PARAMS ((int, int)); | |
107 | ||
108 | /* A region is the main entity for interblock scheduling: insns | |
109 | are allowed to move between blocks in the same region, along | |
110 | control flow graph edges, in the 'up' direction. */ | |
111 | typedef struct | |
112 | { | |
113 | int rgn_nr_blocks; /* Number of blocks in region. */ | |
114 | int rgn_blocks; /* cblocks in the region (actually index in rgn_bb_table). */ | |
115 | } | |
116 | region; | |
117 | ||
118 | /* Number of regions in the procedure. */ | |
119 | static int nr_regions; | |
120 | ||
121 | /* Table of region descriptions. */ | |
122 | static region *rgn_table; | |
123 | ||
124 | /* Array of lists of regions' blocks. */ | |
125 | static int *rgn_bb_table; | |
126 | ||
127 | /* Topological order of blocks in the region (if b2 is reachable from | |
128 | b1, block_to_bb[b2] > block_to_bb[b1]). Note: A basic block is | |
129 | always referred to by either block or b, while its topological | |
130 | order name (in the region) is refered to by bb. */ | |
131 | static int *block_to_bb; | |
132 | ||
133 | /* The number of the region containing a block. */ | |
134 | static int *containing_rgn; | |
135 | ||
136 | #define RGN_NR_BLOCKS(rgn) (rgn_table[rgn].rgn_nr_blocks) | |
137 | #define RGN_BLOCKS(rgn) (rgn_table[rgn].rgn_blocks) | |
138 | #define BLOCK_TO_BB(block) (block_to_bb[block]) | |
139 | #define CONTAINING_RGN(block) (containing_rgn[block]) | |
140 | ||
141 | void debug_regions PARAMS ((void)); | |
142 | static void find_single_block_region PARAMS ((void)); | |
143 | static void find_rgns PARAMS ((struct edge_list *, sbitmap *)); | |
144 | static int too_large PARAMS ((int, int *, int *)); | |
145 | ||
146 | extern void debug_live PARAMS ((int, int)); | |
147 | ||
148 | /* Blocks of the current region being scheduled. */ | |
149 | static int current_nr_blocks; | |
150 | static int current_blocks; | |
151 | ||
152 | /* The mapping from bb to block. */ | |
153 | #define BB_TO_BLOCK(bb) (rgn_bb_table[current_blocks + (bb)]) | |
154 | ||
155 | /* Bit vectors and bitset operations are needed for computations on | |
156 | the control flow graph. */ | |
157 | ||
158 | typedef unsigned HOST_WIDE_INT *bitset; | |
159 | typedef struct | |
160 | { | |
161 | int *first_member; /* Pointer to the list start in bitlst_table. */ | |
162 | int nr_members; /* The number of members of the bit list. */ | |
163 | } | |
164 | bitlst; | |
165 | ||
166 | static int bitlst_table_last; | |
167 | static int bitlst_table_size; | |
168 | static int *bitlst_table; | |
169 | ||
170 | static char bitset_member PARAMS ((bitset, int, int)); | |
171 | static void extract_bitlst PARAMS ((bitset, int, int, bitlst *)); | |
172 | ||
173 | /* Target info declarations. | |
174 | ||
175 | The block currently being scheduled is referred to as the "target" block, | |
176 | while other blocks in the region from which insns can be moved to the | |
177 | target are called "source" blocks. The candidate structure holds info | |
178 | about such sources: are they valid? Speculative? Etc. */ | |
179 | typedef bitlst bblst; | |
180 | typedef struct | |
181 | { | |
182 | char is_valid; | |
183 | char is_speculative; | |
184 | int src_prob; | |
185 | bblst split_bbs; | |
186 | bblst update_bbs; | |
187 | } | |
188 | candidate; | |
189 | ||
190 | static candidate *candidate_table; | |
191 | ||
192 | /* A speculative motion requires checking live information on the path | |
193 | from 'source' to 'target'. The split blocks are those to be checked. | |
194 | After a speculative motion, live information should be modified in | |
195 | the 'update' blocks. | |
196 | ||
197 | Lists of split and update blocks for each candidate of the current | |
198 | target are in array bblst_table. */ | |
199 | static int *bblst_table, bblst_size, bblst_last; | |
200 | ||
201 | #define IS_VALID(src) ( candidate_table[src].is_valid ) | |
202 | #define IS_SPECULATIVE(src) ( candidate_table[src].is_speculative ) | |
203 | #define SRC_PROB(src) ( candidate_table[src].src_prob ) | |
204 | ||
205 | /* The bb being currently scheduled. */ | |
206 | static int target_bb; | |
207 | ||
208 | /* List of edges. */ | |
209 | typedef bitlst edgelst; | |
210 | ||
211 | /* Target info functions. */ | |
212 | static void split_edges PARAMS ((int, int, edgelst *)); | |
213 | static void compute_trg_info PARAMS ((int)); | |
214 | void debug_candidate PARAMS ((int)); | |
215 | void debug_candidates PARAMS ((int)); | |
216 | ||
217 | /* Bit-set of bbs, where bit 'i' stands for bb 'i'. */ | |
218 | typedef bitset bbset; | |
219 | ||
220 | /* Number of words of the bbset. */ | |
221 | static int bbset_size; | |
222 | ||
223 | /* Dominators array: dom[i] contains the bbset of dominators of | |
224 | bb i in the region. */ | |
225 | static bbset *dom; | |
226 | ||
227 | /* bb 0 is the only region entry. */ | |
228 | #define IS_RGN_ENTRY(bb) (!bb) | |
229 | ||
230 | /* Is bb_src dominated by bb_trg. */ | |
231 | #define IS_DOMINATED(bb_src, bb_trg) \ | |
232 | ( bitset_member (dom[bb_src], bb_trg, bbset_size) ) | |
233 | ||
234 | /* Probability: Prob[i] is a float in [0, 1] which is the probability | |
235 | of bb i relative to the region entry. */ | |
236 | static float *prob; | |
237 | ||
238 | /* The probability of bb_src, relative to bb_trg. Note, that while the | |
239 | 'prob[bb]' is a float in [0, 1], this macro returns an integer | |
240 | in [0, 100]. */ | |
241 | #define GET_SRC_PROB(bb_src, bb_trg) ((int) (100.0 * (prob[bb_src] / \ | |
242 | prob[bb_trg]))) | |
243 | ||
244 | /* Bit-set of edges, where bit i stands for edge i. */ | |
245 | typedef bitset edgeset; | |
246 | ||
247 | /* Number of edges in the region. */ | |
248 | static int rgn_nr_edges; | |
249 | ||
250 | /* Array of size rgn_nr_edges. */ | |
251 | static int *rgn_edges; | |
252 | ||
253 | /* Number of words in an edgeset. */ | |
254 | static int edgeset_size; | |
255 | ||
256 | /* Number of bits in an edgeset. */ | |
257 | static int edgeset_bitsize; | |
258 | ||
259 | /* Mapping from each edge in the graph to its number in the rgn. */ | |
260 | static int *edge_to_bit; | |
261 | #define EDGE_TO_BIT(edge) (edge_to_bit[edge]) | |
262 | ||
263 | /* The split edges of a source bb is different for each target | |
264 | bb. In order to compute this efficiently, the 'potential-split edges' | |
265 | are computed for each bb prior to scheduling a region. This is actually | |
266 | the split edges of each bb relative to the region entry. | |
267 | ||
268 | pot_split[bb] is the set of potential split edges of bb. */ | |
269 | static edgeset *pot_split; | |
270 | ||
271 | /* For every bb, a set of its ancestor edges. */ | |
272 | static edgeset *ancestor_edges; | |
273 | ||
274 | static void compute_dom_prob_ps PARAMS ((int)); | |
275 | ||
276 | #define ABS_VALUE(x) (((x)<0)?(-(x)):(x)) | |
277 | #define INSN_PROBABILITY(INSN) (SRC_PROB (BLOCK_TO_BB (BLOCK_NUM (INSN)))) | |
278 | #define IS_SPECULATIVE_INSN(INSN) (IS_SPECULATIVE (BLOCK_TO_BB (BLOCK_NUM (INSN)))) | |
279 | #define INSN_BB(INSN) (BLOCK_TO_BB (BLOCK_NUM (INSN))) | |
280 | ||
281 | /* Parameters affecting the decision of rank_for_schedule(). | |
282 | ??? Nope. But MIN_PROBABILITY is used in copmute_trg_info. */ | |
283 | #define MIN_DIFF_PRIORITY 2 | |
284 | #define MIN_PROBABILITY 40 | |
285 | #define MIN_PROB_DIFF 10 | |
286 | ||
287 | /* Speculative scheduling functions. */ | |
288 | static int check_live_1 PARAMS ((int, rtx)); | |
289 | static void update_live_1 PARAMS ((int, rtx)); | |
290 | static int check_live PARAMS ((rtx, int)); | |
291 | static void update_live PARAMS ((rtx, int)); | |
292 | static void set_spec_fed PARAMS ((rtx)); | |
293 | static int is_pfree PARAMS ((rtx, int, int)); | |
294 | static int find_conditional_protection PARAMS ((rtx, int)); | |
295 | static int is_conditionally_protected PARAMS ((rtx, int, int)); | |
296 | static int may_trap_exp PARAMS ((rtx, int)); | |
297 | static int haifa_classify_insn PARAMS ((rtx)); | |
298 | static int is_prisky PARAMS ((rtx, int, int)); | |
299 | static int is_exception_free PARAMS ((rtx, int, int)); | |
300 | ||
301 | static void add_branch_dependences PARAMS ((rtx, rtx)); | |
302 | static void compute_block_backward_dependences PARAMS ((int)); | |
303 | void debug_dependencies PARAMS ((void)); | |
304 | ||
305 | static void init_regions PARAMS ((void)); | |
306 | static void schedule_region PARAMS ((int)); | |
4ba478b8 | 307 | static void propagate_deps PARAMS ((int, struct deps *)); |
b4ead7d4 BS |
308 | static void free_pending_lists PARAMS ((void)); |
309 | ||
310 | /* Functions for construction of the control flow graph. */ | |
311 | ||
312 | /* Return 1 if control flow graph should not be constructed, 0 otherwise. | |
313 | ||
314 | We decide not to build the control flow graph if there is possibly more | |
315 | than one entry to the function, if computed branches exist, of if we | |
316 | have nonlocal gotos. */ | |
317 | ||
318 | static int | |
319 | is_cfg_nonregular () | |
320 | { | |
321 | int b; | |
322 | rtx insn; | |
323 | RTX_CODE code; | |
324 | ||
325 | /* If we have a label that could be the target of a nonlocal goto, then | |
326 | the cfg is not well structured. */ | |
327 | if (nonlocal_goto_handler_labels) | |
328 | return 1; | |
329 | ||
330 | /* If we have any forced labels, then the cfg is not well structured. */ | |
331 | if (forced_labels) | |
332 | return 1; | |
333 | ||
334 | /* If this function has a computed jump, then we consider the cfg | |
335 | not well structured. */ | |
336 | if (current_function_has_computed_jump) | |
337 | return 1; | |
338 | ||
339 | /* If we have exception handlers, then we consider the cfg not well | |
340 | structured. ?!? We should be able to handle this now that flow.c | |
341 | computes an accurate cfg for EH. */ | |
342 | if (exception_handler_labels) | |
343 | return 1; | |
344 | ||
345 | /* If we have non-jumping insns which refer to labels, then we consider | |
346 | the cfg not well structured. */ | |
347 | /* Check for labels referred to other thn by jumps. */ | |
348 | for (b = 0; b < n_basic_blocks; b++) | |
349 | for (insn = BLOCK_HEAD (b);; insn = NEXT_INSN (insn)) | |
350 | { | |
351 | code = GET_CODE (insn); | |
f759eb8b | 352 | if (GET_RTX_CLASS (code) == 'i' && code != JUMP_INSN) |
b4ead7d4 | 353 | { |
cabf3891 | 354 | rtx note = find_reg_note (insn, REG_LABEL, NULL_RTX); |
f759eb8b AO |
355 | |
356 | if (note | |
357 | && ! (GET_CODE (NEXT_INSN (insn)) == JUMP_INSN | |
cabf3891 | 358 | && find_reg_note (NEXT_INSN (insn), REG_LABEL, |
f759eb8b AO |
359 | XEXP (note, 0)))) |
360 | return 1; | |
b4ead7d4 BS |
361 | } |
362 | ||
363 | if (insn == BLOCK_END (b)) | |
364 | break; | |
365 | } | |
366 | ||
367 | /* All the tests passed. Consider the cfg well structured. */ | |
368 | return 0; | |
369 | } | |
370 | ||
371 | /* Build the control flow graph and set nr_edges. | |
372 | ||
373 | Instead of trying to build a cfg ourselves, we rely on flow to | |
374 | do it for us. Stamp out useless code (and bug) duplication. | |
375 | ||
376 | Return nonzero if an irregularity in the cfg is found which would | |
377 | prevent cross block scheduling. */ | |
378 | ||
379 | static int | |
380 | build_control_flow (edge_list) | |
381 | struct edge_list *edge_list; | |
382 | { | |
383 | int i, unreachable, num_edges; | |
384 | ||
385 | /* This already accounts for entry/exit edges. */ | |
386 | num_edges = NUM_EDGES (edge_list); | |
387 | ||
388 | /* Unreachable loops with more than one basic block are detected | |
389 | during the DFS traversal in find_rgns. | |
390 | ||
391 | Unreachable loops with a single block are detected here. This | |
392 | test is redundant with the one in find_rgns, but it's much | |
393 | cheaper to go ahead and catch the trivial case here. */ | |
394 | unreachable = 0; | |
395 | for (i = 0; i < n_basic_blocks; i++) | |
396 | { | |
397 | basic_block b = BASIC_BLOCK (i); | |
398 | ||
399 | if (b->pred == NULL | |
400 | || (b->pred->src == b | |
401 | && b->pred->pred_next == NULL)) | |
402 | unreachable = 1; | |
403 | } | |
404 | ||
405 | /* ??? We can kill these soon. */ | |
406 | in_edges = (int *) xcalloc (n_basic_blocks, sizeof (int)); | |
407 | out_edges = (int *) xcalloc (n_basic_blocks, sizeof (int)); | |
408 | edge_table = (haifa_edge *) xcalloc (num_edges, sizeof (haifa_edge)); | |
409 | ||
410 | nr_edges = 0; | |
411 | for (i = 0; i < num_edges; i++) | |
412 | { | |
413 | edge e = INDEX_EDGE (edge_list, i); | |
414 | ||
415 | if (e->dest != EXIT_BLOCK_PTR | |
416 | && e->src != ENTRY_BLOCK_PTR) | |
417 | new_edge (e->src->index, e->dest->index); | |
418 | } | |
419 | ||
420 | /* Increment by 1, since edge 0 is unused. */ | |
421 | nr_edges++; | |
422 | ||
423 | return unreachable; | |
424 | } | |
425 | ||
426 | /* Record an edge in the control flow graph from SOURCE to TARGET. | |
427 | ||
428 | In theory, this is redundant with the s_succs computed above, but | |
429 | we have not converted all of haifa to use information from the | |
430 | integer lists. */ | |
431 | ||
432 | static void | |
433 | new_edge (source, target) | |
434 | int source, target; | |
435 | { | |
436 | int e, next_edge; | |
437 | int curr_edge, fst_edge; | |
438 | ||
439 | /* Check for duplicates. */ | |
440 | fst_edge = curr_edge = OUT_EDGES (source); | |
441 | while (curr_edge) | |
442 | { | |
443 | if (FROM_BLOCK (curr_edge) == source | |
444 | && TO_BLOCK (curr_edge) == target) | |
445 | { | |
446 | return; | |
447 | } | |
448 | ||
449 | curr_edge = NEXT_OUT (curr_edge); | |
450 | ||
451 | if (fst_edge == curr_edge) | |
452 | break; | |
453 | } | |
454 | ||
455 | e = ++nr_edges; | |
456 | ||
457 | FROM_BLOCK (e) = source; | |
458 | TO_BLOCK (e) = target; | |
459 | ||
460 | if (OUT_EDGES (source)) | |
461 | { | |
462 | next_edge = NEXT_OUT (OUT_EDGES (source)); | |
463 | NEXT_OUT (OUT_EDGES (source)) = e; | |
464 | NEXT_OUT (e) = next_edge; | |
465 | } | |
466 | else | |
467 | { | |
468 | OUT_EDGES (source) = e; | |
469 | NEXT_OUT (e) = e; | |
470 | } | |
471 | ||
472 | if (IN_EDGES (target)) | |
473 | { | |
474 | next_edge = NEXT_IN (IN_EDGES (target)); | |
475 | NEXT_IN (IN_EDGES (target)) = e; | |
476 | NEXT_IN (e) = next_edge; | |
477 | } | |
478 | else | |
479 | { | |
480 | IN_EDGES (target) = e; | |
481 | NEXT_IN (e) = e; | |
482 | } | |
483 | } | |
484 | ||
485 | /* BITSET macros for operations on the control flow graph. */ | |
486 | ||
487 | /* Compute bitwise union of two bitsets. */ | |
488 | #define BITSET_UNION(set1, set2, len) \ | |
b3694847 SS |
489 | do { bitset tp = set1, sp = set2; \ |
490 | int i; \ | |
b4ead7d4 BS |
491 | for (i = 0; i < len; i++) \ |
492 | *(tp++) |= *(sp++); } while (0) | |
493 | ||
494 | /* Compute bitwise intersection of two bitsets. */ | |
495 | #define BITSET_INTER(set1, set2, len) \ | |
b3694847 SS |
496 | do { bitset tp = set1, sp = set2; \ |
497 | int i; \ | |
b4ead7d4 BS |
498 | for (i = 0; i < len; i++) \ |
499 | *(tp++) &= *(sp++); } while (0) | |
500 | ||
501 | /* Compute bitwise difference of two bitsets. */ | |
502 | #define BITSET_DIFFER(set1, set2, len) \ | |
b3694847 SS |
503 | do { bitset tp = set1, sp = set2; \ |
504 | int i; \ | |
b4ead7d4 BS |
505 | for (i = 0; i < len; i++) \ |
506 | *(tp++) &= ~*(sp++); } while (0) | |
507 | ||
508 | /* Inverts every bit of bitset 'set'. */ | |
509 | #define BITSET_INVERT(set, len) \ | |
b3694847 SS |
510 | do { bitset tmpset = set; \ |
511 | int i; \ | |
b4ead7d4 BS |
512 | for (i = 0; i < len; i++, tmpset++) \ |
513 | *tmpset = ~*tmpset; } while (0) | |
514 | ||
515 | /* Turn on the index'th bit in bitset set. */ | |
516 | #define BITSET_ADD(set, index, len) \ | |
517 | { \ | |
518 | if (index >= HOST_BITS_PER_WIDE_INT * len) \ | |
519 | abort (); \ | |
520 | else \ | |
521 | set[index/HOST_BITS_PER_WIDE_INT] |= \ | |
9c8fad33 | 522 | ((unsigned HOST_WIDE_INT) 1) << (index % HOST_BITS_PER_WIDE_INT); \ |
b4ead7d4 BS |
523 | } |
524 | ||
525 | /* Turn off the index'th bit in set. */ | |
526 | #define BITSET_REMOVE(set, index, len) \ | |
527 | { \ | |
528 | if (index >= HOST_BITS_PER_WIDE_INT * len) \ | |
529 | abort (); \ | |
530 | else \ | |
531 | set[index/HOST_BITS_PER_WIDE_INT] &= \ | |
9c8fad33 | 532 | ~(((unsigned HOST_WIDE_INT) 1) << (index % HOST_BITS_PER_WIDE_INT)); \ |
b4ead7d4 BS |
533 | } |
534 | ||
535 | /* Check if the index'th bit in bitset set is on. */ | |
536 | ||
537 | static char | |
538 | bitset_member (set, index, len) | |
539 | bitset set; | |
540 | int index, len; | |
541 | { | |
542 | if (index >= HOST_BITS_PER_WIDE_INT * len) | |
543 | abort (); | |
9c8fad33 JW |
544 | return ((set[index / HOST_BITS_PER_WIDE_INT] & |
545 | ((unsigned HOST_WIDE_INT) 1) << (index % HOST_BITS_PER_WIDE_INT)) | |
546 | ? 1 : 0); | |
b4ead7d4 BS |
547 | } |
548 | ||
549 | /* Translate a bit-set SET to a list BL of the bit-set members. */ | |
550 | ||
551 | static void | |
552 | extract_bitlst (set, len, bitlen, bl) | |
553 | bitset set; | |
554 | int len; | |
555 | int bitlen; | |
556 | bitlst *bl; | |
557 | { | |
558 | int i, j, offset; | |
559 | unsigned HOST_WIDE_INT word; | |
560 | ||
561 | /* bblst table space is reused in each call to extract_bitlst. */ | |
562 | bitlst_table_last = 0; | |
563 | ||
564 | bl->first_member = &bitlst_table[bitlst_table_last]; | |
565 | bl->nr_members = 0; | |
566 | ||
567 | /* Iterate over each word in the bitset. */ | |
568 | for (i = 0; i < len; i++) | |
569 | { | |
570 | word = set[i]; | |
571 | offset = i * HOST_BITS_PER_WIDE_INT; | |
572 | ||
573 | /* Iterate over each bit in the word, but do not | |
574 | go beyond the end of the defined bits. */ | |
575 | for (j = 0; offset < bitlen && word; j++) | |
576 | { | |
577 | if (word & 1) | |
578 | { | |
579 | bitlst_table[bitlst_table_last++] = offset; | |
580 | (bl->nr_members)++; | |
581 | } | |
582 | word >>= 1; | |
583 | ++offset; | |
584 | } | |
585 | } | |
586 | ||
587 | } | |
588 | ||
589 | /* Functions for the construction of regions. */ | |
590 | ||
591 | /* Print the regions, for debugging purposes. Callable from debugger. */ | |
592 | ||
593 | void | |
594 | debug_regions () | |
595 | { | |
596 | int rgn, bb; | |
597 | ||
598 | fprintf (sched_dump, "\n;; ------------ REGIONS ----------\n\n"); | |
599 | for (rgn = 0; rgn < nr_regions; rgn++) | |
600 | { | |
601 | fprintf (sched_dump, ";;\trgn %d nr_blocks %d:\n", rgn, | |
602 | rgn_table[rgn].rgn_nr_blocks); | |
603 | fprintf (sched_dump, ";;\tbb/block: "); | |
604 | ||
605 | for (bb = 0; bb < rgn_table[rgn].rgn_nr_blocks; bb++) | |
606 | { | |
607 | current_blocks = RGN_BLOCKS (rgn); | |
608 | ||
609 | if (bb != BLOCK_TO_BB (BB_TO_BLOCK (bb))) | |
610 | abort (); | |
611 | ||
612 | fprintf (sched_dump, " %d/%d ", bb, BB_TO_BLOCK (bb)); | |
613 | } | |
614 | ||
615 | fprintf (sched_dump, "\n\n"); | |
616 | } | |
617 | } | |
618 | ||
619 | /* Build a single block region for each basic block in the function. | |
620 | This allows for using the same code for interblock and basic block | |
621 | scheduling. */ | |
622 | ||
623 | static void | |
624 | find_single_block_region () | |
625 | { | |
626 | int i; | |
627 | ||
628 | for (i = 0; i < n_basic_blocks; i++) | |
629 | { | |
630 | rgn_bb_table[i] = i; | |
631 | RGN_NR_BLOCKS (i) = 1; | |
632 | RGN_BLOCKS (i) = i; | |
633 | CONTAINING_RGN (i) = i; | |
634 | BLOCK_TO_BB (i) = 0; | |
635 | } | |
636 | nr_regions = n_basic_blocks; | |
637 | } | |
638 | ||
639 | /* Update number of blocks and the estimate for number of insns | |
640 | in the region. Return 1 if the region is "too large" for interblock | |
641 | scheduling (compile time considerations), otherwise return 0. */ | |
642 | ||
643 | static int | |
644 | too_large (block, num_bbs, num_insns) | |
645 | int block, *num_bbs, *num_insns; | |
646 | { | |
647 | (*num_bbs)++; | |
648 | (*num_insns) += (INSN_LUID (BLOCK_END (block)) - | |
649 | INSN_LUID (BLOCK_HEAD (block))); | |
650 | if ((*num_bbs > MAX_RGN_BLOCKS) || (*num_insns > MAX_RGN_INSNS)) | |
651 | return 1; | |
652 | else | |
653 | return 0; | |
654 | } | |
655 | ||
656 | /* Update_loop_relations(blk, hdr): Check if the loop headed by max_hdr[blk] | |
657 | is still an inner loop. Put in max_hdr[blk] the header of the most inner | |
658 | loop containing blk. */ | |
659 | #define UPDATE_LOOP_RELATIONS(blk, hdr) \ | |
660 | { \ | |
661 | if (max_hdr[blk] == -1) \ | |
662 | max_hdr[blk] = hdr; \ | |
663 | else if (dfs_nr[max_hdr[blk]] > dfs_nr[hdr]) \ | |
664 | RESET_BIT (inner, hdr); \ | |
665 | else if (dfs_nr[max_hdr[blk]] < dfs_nr[hdr]) \ | |
666 | { \ | |
667 | RESET_BIT (inner,max_hdr[blk]); \ | |
668 | max_hdr[blk] = hdr; \ | |
669 | } \ | |
670 | } | |
671 | ||
672 | /* Find regions for interblock scheduling. | |
673 | ||
674 | A region for scheduling can be: | |
675 | ||
676 | * A loop-free procedure, or | |
677 | ||
678 | * A reducible inner loop, or | |
679 | ||
680 | * A basic block not contained in any other region. | |
681 | ||
682 | ?!? In theory we could build other regions based on extended basic | |
683 | blocks or reverse extended basic blocks. Is it worth the trouble? | |
684 | ||
685 | Loop blocks that form a region are put into the region's block list | |
686 | in topological order. | |
687 | ||
688 | This procedure stores its results into the following global (ick) variables | |
689 | ||
690 | * rgn_nr | |
691 | * rgn_table | |
692 | * rgn_bb_table | |
693 | * block_to_bb | |
694 | * containing region | |
695 | ||
696 | We use dominator relationships to avoid making regions out of non-reducible | |
697 | loops. | |
698 | ||
699 | This procedure needs to be converted to work on pred/succ lists instead | |
700 | of edge tables. That would simplify it somewhat. */ | |
701 | ||
702 | static void | |
703 | find_rgns (edge_list, dom) | |
704 | struct edge_list *edge_list; | |
705 | sbitmap *dom; | |
706 | { | |
707 | int *max_hdr, *dfs_nr, *stack, *degree; | |
708 | char no_loops = 1; | |
709 | int node, child, loop_head, i, head, tail; | |
710 | int count = 0, sp, idx = 0, current_edge = out_edges[0]; | |
711 | int num_bbs, num_insns, unreachable; | |
712 | int too_large_failure; | |
713 | ||
714 | /* Note if an edge has been passed. */ | |
715 | sbitmap passed; | |
716 | ||
717 | /* Note if a block is a natural loop header. */ | |
718 | sbitmap header; | |
719 | ||
720 | /* Note if a block is an natural inner loop header. */ | |
721 | sbitmap inner; | |
722 | ||
723 | /* Note if a block is in the block queue. */ | |
724 | sbitmap in_queue; | |
725 | ||
726 | /* Note if a block is in the block queue. */ | |
727 | sbitmap in_stack; | |
728 | ||
729 | int num_edges = NUM_EDGES (edge_list); | |
730 | ||
731 | /* Perform a DFS traversal of the cfg. Identify loop headers, inner loops | |
732 | and a mapping from block to its loop header (if the block is contained | |
733 | in a loop, else -1). | |
734 | ||
735 | Store results in HEADER, INNER, and MAX_HDR respectively, these will | |
736 | be used as inputs to the second traversal. | |
737 | ||
738 | STACK, SP and DFS_NR are only used during the first traversal. */ | |
739 | ||
740 | /* Allocate and initialize variables for the first traversal. */ | |
741 | max_hdr = (int *) xmalloc (n_basic_blocks * sizeof (int)); | |
742 | dfs_nr = (int *) xcalloc (n_basic_blocks, sizeof (int)); | |
743 | stack = (int *) xmalloc (nr_edges * sizeof (int)); | |
744 | ||
745 | inner = sbitmap_alloc (n_basic_blocks); | |
746 | sbitmap_ones (inner); | |
747 | ||
748 | header = sbitmap_alloc (n_basic_blocks); | |
749 | sbitmap_zero (header); | |
750 | ||
751 | passed = sbitmap_alloc (nr_edges); | |
752 | sbitmap_zero (passed); | |
753 | ||
754 | in_queue = sbitmap_alloc (n_basic_blocks); | |
755 | sbitmap_zero (in_queue); | |
756 | ||
757 | in_stack = sbitmap_alloc (n_basic_blocks); | |
758 | sbitmap_zero (in_stack); | |
759 | ||
760 | for (i = 0; i < n_basic_blocks; i++) | |
761 | max_hdr[i] = -1; | |
762 | ||
763 | /* DFS traversal to find inner loops in the cfg. */ | |
764 | ||
765 | sp = -1; | |
766 | while (1) | |
767 | { | |
768 | if (current_edge == 0 || TEST_BIT (passed, current_edge)) | |
769 | { | |
770 | /* We have reached a leaf node or a node that was already | |
771 | processed. Pop edges off the stack until we find | |
772 | an edge that has not yet been processed. */ | |
773 | while (sp >= 0 | |
774 | && (current_edge == 0 || TEST_BIT (passed, current_edge))) | |
775 | { | |
776 | /* Pop entry off the stack. */ | |
777 | current_edge = stack[sp--]; | |
778 | node = FROM_BLOCK (current_edge); | |
779 | child = TO_BLOCK (current_edge); | |
780 | RESET_BIT (in_stack, child); | |
781 | if (max_hdr[child] >= 0 && TEST_BIT (in_stack, max_hdr[child])) | |
782 | UPDATE_LOOP_RELATIONS (node, max_hdr[child]); | |
783 | current_edge = NEXT_OUT (current_edge); | |
784 | } | |
785 | ||
786 | /* See if have finished the DFS tree traversal. */ | |
787 | if (sp < 0 && TEST_BIT (passed, current_edge)) | |
788 | break; | |
789 | ||
790 | /* Nope, continue the traversal with the popped node. */ | |
791 | continue; | |
792 | } | |
793 | ||
794 | /* Process a node. */ | |
795 | node = FROM_BLOCK (current_edge); | |
796 | child = TO_BLOCK (current_edge); | |
797 | SET_BIT (in_stack, node); | |
798 | dfs_nr[node] = ++count; | |
799 | ||
800 | /* If the successor is in the stack, then we've found a loop. | |
801 | Mark the loop, if it is not a natural loop, then it will | |
802 | be rejected during the second traversal. */ | |
803 | if (TEST_BIT (in_stack, child)) | |
804 | { | |
805 | no_loops = 0; | |
806 | SET_BIT (header, child); | |
807 | UPDATE_LOOP_RELATIONS (node, child); | |
808 | SET_BIT (passed, current_edge); | |
809 | current_edge = NEXT_OUT (current_edge); | |
810 | continue; | |
811 | } | |
812 | ||
813 | /* If the child was already visited, then there is no need to visit | |
814 | it again. Just update the loop relationships and restart | |
815 | with a new edge. */ | |
816 | if (dfs_nr[child]) | |
817 | { | |
818 | if (max_hdr[child] >= 0 && TEST_BIT (in_stack, max_hdr[child])) | |
819 | UPDATE_LOOP_RELATIONS (node, max_hdr[child]); | |
820 | SET_BIT (passed, current_edge); | |
821 | current_edge = NEXT_OUT (current_edge); | |
822 | continue; | |
823 | } | |
824 | ||
825 | /* Push an entry on the stack and continue DFS traversal. */ | |
826 | stack[++sp] = current_edge; | |
827 | SET_BIT (passed, current_edge); | |
828 | current_edge = OUT_EDGES (child); | |
829 | ||
830 | /* This is temporary until haifa is converted to use rth's new | |
831 | cfg routines which have true entry/exit blocks and the | |
832 | appropriate edges from/to those blocks. | |
833 | ||
834 | Generally we update dfs_nr for a node when we process its | |
835 | out edge. However, if the node has no out edge then we will | |
836 | not set dfs_nr for that node. This can confuse the scheduler | |
837 | into thinking that we have unreachable blocks, which in turn | |
838 | disables cross block scheduling. | |
839 | ||
840 | So, if we have a node with no out edges, go ahead and mark it | |
841 | as reachable now. */ | |
842 | if (current_edge == 0) | |
843 | dfs_nr[child] = ++count; | |
844 | } | |
845 | ||
846 | /* Another check for unreachable blocks. The earlier test in | |
847 | is_cfg_nonregular only finds unreachable blocks that do not | |
848 | form a loop. | |
849 | ||
850 | The DFS traversal will mark every block that is reachable from | |
851 | the entry node by placing a nonzero value in dfs_nr. Thus if | |
852 | dfs_nr is zero for any block, then it must be unreachable. */ | |
853 | unreachable = 0; | |
854 | for (i = 0; i < n_basic_blocks; i++) | |
855 | if (dfs_nr[i] == 0) | |
856 | { | |
857 | unreachable = 1; | |
858 | break; | |
859 | } | |
860 | ||
861 | /* Gross. To avoid wasting memory, the second pass uses the dfs_nr array | |
862 | to hold degree counts. */ | |
863 | degree = dfs_nr; | |
864 | ||
865 | for (i = 0; i < n_basic_blocks; i++) | |
866 | degree[i] = 0; | |
867 | for (i = 0; i < num_edges; i++) | |
868 | { | |
869 | edge e = INDEX_EDGE (edge_list, i); | |
870 | ||
871 | if (e->dest != EXIT_BLOCK_PTR) | |
872 | degree[e->dest->index]++; | |
873 | } | |
874 | ||
875 | /* Do not perform region scheduling if there are any unreachable | |
876 | blocks. */ | |
877 | if (!unreachable) | |
878 | { | |
879 | int *queue; | |
880 | ||
881 | if (no_loops) | |
882 | SET_BIT (header, 0); | |
883 | ||
884 | /* Second travsersal:find reducible inner loops and topologically sort | |
885 | block of each region. */ | |
886 | ||
887 | queue = (int *) xmalloc (n_basic_blocks * sizeof (int)); | |
888 | ||
889 | /* Find blocks which are inner loop headers. We still have non-reducible | |
890 | loops to consider at this point. */ | |
891 | for (i = 0; i < n_basic_blocks; i++) | |
892 | { | |
893 | if (TEST_BIT (header, i) && TEST_BIT (inner, i)) | |
894 | { | |
895 | edge e; | |
896 | int j; | |
897 | ||
898 | /* Now check that the loop is reducible. We do this separate | |
899 | from finding inner loops so that we do not find a reducible | |
900 | loop which contains an inner non-reducible loop. | |
901 | ||
902 | A simple way to find reducible/natural loops is to verify | |
903 | that each block in the loop is dominated by the loop | |
904 | header. | |
905 | ||
906 | If there exists a block that is not dominated by the loop | |
907 | header, then the block is reachable from outside the loop | |
908 | and thus the loop is not a natural loop. */ | |
909 | for (j = 0; j < n_basic_blocks; j++) | |
910 | { | |
911 | /* First identify blocks in the loop, except for the loop | |
912 | entry block. */ | |
913 | if (i == max_hdr[j] && i != j) | |
914 | { | |
915 | /* Now verify that the block is dominated by the loop | |
916 | header. */ | |
917 | if (!TEST_BIT (dom[j], i)) | |
918 | break; | |
919 | } | |
920 | } | |
921 | ||
922 | /* If we exited the loop early, then I is the header of | |
923 | a non-reducible loop and we should quit processing it | |
924 | now. */ | |
925 | if (j != n_basic_blocks) | |
926 | continue; | |
927 | ||
928 | /* I is a header of an inner loop, or block 0 in a subroutine | |
929 | with no loops at all. */ | |
930 | head = tail = -1; | |
931 | too_large_failure = 0; | |
932 | loop_head = max_hdr[i]; | |
933 | ||
934 | /* Decrease degree of all I's successors for topological | |
935 | ordering. */ | |
936 | for (e = BASIC_BLOCK (i)->succ; e; e = e->succ_next) | |
937 | if (e->dest != EXIT_BLOCK_PTR) | |
938 | --degree[e->dest->index]; | |
939 | ||
940 | /* Estimate # insns, and count # blocks in the region. */ | |
941 | num_bbs = 1; | |
942 | num_insns = (INSN_LUID (BLOCK_END (i)) | |
943 | - INSN_LUID (BLOCK_HEAD (i))); | |
944 | ||
945 | /* Find all loop latches (blocks with back edges to the loop | |
946 | header) or all the leaf blocks in the cfg has no loops. | |
947 | ||
948 | Place those blocks into the queue. */ | |
949 | if (no_loops) | |
950 | { | |
951 | for (j = 0; j < n_basic_blocks; j++) | |
952 | /* Leaf nodes have only a single successor which must | |
953 | be EXIT_BLOCK. */ | |
954 | if (BASIC_BLOCK (j)->succ | |
955 | && BASIC_BLOCK (j)->succ->dest == EXIT_BLOCK_PTR | |
956 | && BASIC_BLOCK (j)->succ->succ_next == NULL) | |
957 | { | |
958 | queue[++tail] = j; | |
959 | SET_BIT (in_queue, j); | |
960 | ||
961 | if (too_large (j, &num_bbs, &num_insns)) | |
962 | { | |
963 | too_large_failure = 1; | |
964 | break; | |
965 | } | |
966 | } | |
967 | } | |
968 | else | |
969 | { | |
970 | edge e; | |
971 | ||
972 | for (e = BASIC_BLOCK (i)->pred; e; e = e->pred_next) | |
973 | { | |
974 | if (e->src == ENTRY_BLOCK_PTR) | |
975 | continue; | |
976 | ||
977 | node = e->src->index; | |
978 | ||
979 | if (max_hdr[node] == loop_head && node != i) | |
980 | { | |
981 | /* This is a loop latch. */ | |
982 | queue[++tail] = node; | |
983 | SET_BIT (in_queue, node); | |
984 | ||
985 | if (too_large (node, &num_bbs, &num_insns)) | |
986 | { | |
987 | too_large_failure = 1; | |
988 | break; | |
989 | } | |
990 | } | |
991 | } | |
992 | } | |
993 | ||
994 | /* Now add all the blocks in the loop to the queue. | |
995 | ||
996 | We know the loop is a natural loop; however the algorithm | |
997 | above will not always mark certain blocks as being in the | |
998 | loop. Consider: | |
999 | node children | |
1000 | a b,c | |
1001 | b c | |
1002 | c a,d | |
1003 | d b | |
1004 | ||
1005 | The algorithm in the DFS traversal may not mark B & D as part | |
1006 | of the loop (ie they will not have max_hdr set to A). | |
1007 | ||
1008 | We know they can not be loop latches (else they would have | |
1009 | had max_hdr set since they'd have a backedge to a dominator | |
1010 | block). So we don't need them on the initial queue. | |
1011 | ||
1012 | We know they are part of the loop because they are dominated | |
1013 | by the loop header and can be reached by a backwards walk of | |
1014 | the edges starting with nodes on the initial queue. | |
1015 | ||
1016 | It is safe and desirable to include those nodes in the | |
1017 | loop/scheduling region. To do so we would need to decrease | |
1018 | the degree of a node if it is the target of a backedge | |
1019 | within the loop itself as the node is placed in the queue. | |
1020 | ||
1021 | We do not do this because I'm not sure that the actual | |
1022 | scheduling code will properly handle this case. ?!? */ | |
1023 | ||
1024 | while (head < tail && !too_large_failure) | |
1025 | { | |
1026 | edge e; | |
1027 | child = queue[++head]; | |
1028 | ||
1029 | for (e = BASIC_BLOCK (child)->pred; e; e = e->pred_next) | |
1030 | { | |
1031 | node = e->src->index; | |
1032 | ||
1033 | /* See discussion above about nodes not marked as in | |
1034 | this loop during the initial DFS traversal. */ | |
1035 | if (e->src == ENTRY_BLOCK_PTR | |
1036 | || max_hdr[node] != loop_head) | |
1037 | { | |
1038 | tail = -1; | |
1039 | break; | |
1040 | } | |
1041 | else if (!TEST_BIT (in_queue, node) && node != i) | |
1042 | { | |
1043 | queue[++tail] = node; | |
1044 | SET_BIT (in_queue, node); | |
1045 | ||
1046 | if (too_large (node, &num_bbs, &num_insns)) | |
1047 | { | |
1048 | too_large_failure = 1; | |
1049 | break; | |
1050 | } | |
1051 | } | |
1052 | } | |
1053 | } | |
1054 | ||
1055 | if (tail >= 0 && !too_large_failure) | |
1056 | { | |
1057 | /* Place the loop header into list of region blocks. */ | |
1058 | degree[i] = -1; | |
1059 | rgn_bb_table[idx] = i; | |
1060 | RGN_NR_BLOCKS (nr_regions) = num_bbs; | |
1061 | RGN_BLOCKS (nr_regions) = idx++; | |
1062 | CONTAINING_RGN (i) = nr_regions; | |
1063 | BLOCK_TO_BB (i) = count = 0; | |
1064 | ||
1065 | /* Remove blocks from queue[] when their in degree | |
1066 | becomes zero. Repeat until no blocks are left on the | |
1067 | list. This produces a topological list of blocks in | |
1068 | the region. */ | |
1069 | while (tail >= 0) | |
1070 | { | |
1071 | if (head < 0) | |
1072 | head = tail; | |
1073 | child = queue[head]; | |
1074 | if (degree[child] == 0) | |
1075 | { | |
1076 | edge e; | |
1077 | ||
1078 | degree[child] = -1; | |
1079 | rgn_bb_table[idx++] = child; | |
1080 | BLOCK_TO_BB (child) = ++count; | |
1081 | CONTAINING_RGN (child) = nr_regions; | |
1082 | queue[head] = queue[tail--]; | |
1083 | ||
1084 | for (e = BASIC_BLOCK (child)->succ; | |
1085 | e; | |
1086 | e = e->succ_next) | |
1087 | if (e->dest != EXIT_BLOCK_PTR) | |
1088 | --degree[e->dest->index]; | |
1089 | } | |
1090 | else | |
1091 | --head; | |
1092 | } | |
1093 | ++nr_regions; | |
1094 | } | |
1095 | } | |
1096 | } | |
1097 | free (queue); | |
1098 | } | |
1099 | ||
1100 | /* Any block that did not end up in a region is placed into a region | |
1101 | by itself. */ | |
1102 | for (i = 0; i < n_basic_blocks; i++) | |
1103 | if (degree[i] >= 0) | |
1104 | { | |
1105 | rgn_bb_table[idx] = i; | |
1106 | RGN_NR_BLOCKS (nr_regions) = 1; | |
1107 | RGN_BLOCKS (nr_regions) = idx++; | |
1108 | CONTAINING_RGN (i) = nr_regions++; | |
1109 | BLOCK_TO_BB (i) = 0; | |
1110 | } | |
1111 | ||
1112 | free (max_hdr); | |
1113 | free (dfs_nr); | |
1114 | free (stack); | |
1115 | free (passed); | |
1116 | free (header); | |
1117 | free (inner); | |
1118 | free (in_queue); | |
1119 | free (in_stack); | |
1120 | } | |
1121 | ||
1122 | /* Functions for regions scheduling information. */ | |
1123 | ||
1124 | /* Compute dominators, probability, and potential-split-edges of bb. | |
1125 | Assume that these values were already computed for bb's predecessors. */ | |
1126 | ||
1127 | static void | |
1128 | compute_dom_prob_ps (bb) | |
1129 | int bb; | |
1130 | { | |
1131 | int nxt_in_edge, fst_in_edge, pred; | |
1132 | int fst_out_edge, nxt_out_edge, nr_out_edges, nr_rgn_out_edges; | |
1133 | ||
1134 | prob[bb] = 0.0; | |
1135 | if (IS_RGN_ENTRY (bb)) | |
1136 | { | |
1137 | BITSET_ADD (dom[bb], 0, bbset_size); | |
1138 | prob[bb] = 1.0; | |
1139 | return; | |
1140 | } | |
1141 | ||
1142 | fst_in_edge = nxt_in_edge = IN_EDGES (BB_TO_BLOCK (bb)); | |
1143 | ||
1144 | /* Intialize dom[bb] to '111..1'. */ | |
1145 | BITSET_INVERT (dom[bb], bbset_size); | |
1146 | ||
1147 | do | |
1148 | { | |
1149 | pred = FROM_BLOCK (nxt_in_edge); | |
1150 | BITSET_INTER (dom[bb], dom[BLOCK_TO_BB (pred)], bbset_size); | |
1151 | ||
1152 | BITSET_UNION (ancestor_edges[bb], ancestor_edges[BLOCK_TO_BB (pred)], | |
1153 | edgeset_size); | |
1154 | ||
1155 | BITSET_ADD (ancestor_edges[bb], EDGE_TO_BIT (nxt_in_edge), edgeset_size); | |
1156 | ||
1157 | nr_out_edges = 1; | |
1158 | nr_rgn_out_edges = 0; | |
1159 | fst_out_edge = OUT_EDGES (pred); | |
1160 | nxt_out_edge = NEXT_OUT (fst_out_edge); | |
1161 | BITSET_UNION (pot_split[bb], pot_split[BLOCK_TO_BB (pred)], | |
1162 | edgeset_size); | |
1163 | ||
1164 | BITSET_ADD (pot_split[bb], EDGE_TO_BIT (fst_out_edge), edgeset_size); | |
1165 | ||
1166 | /* The successor doesn't belong in the region? */ | |
1167 | if (CONTAINING_RGN (TO_BLOCK (fst_out_edge)) != | |
1168 | CONTAINING_RGN (BB_TO_BLOCK (bb))) | |
1169 | ++nr_rgn_out_edges; | |
1170 | ||
1171 | while (fst_out_edge != nxt_out_edge) | |
1172 | { | |
1173 | ++nr_out_edges; | |
1174 | /* The successor doesn't belong in the region? */ | |
1175 | if (CONTAINING_RGN (TO_BLOCK (nxt_out_edge)) != | |
1176 | CONTAINING_RGN (BB_TO_BLOCK (bb))) | |
1177 | ++nr_rgn_out_edges; | |
1178 | BITSET_ADD (pot_split[bb], EDGE_TO_BIT (nxt_out_edge), edgeset_size); | |
1179 | nxt_out_edge = NEXT_OUT (nxt_out_edge); | |
1180 | ||
1181 | } | |
1182 | ||
1183 | /* Now nr_rgn_out_edges is the number of region-exit edges from | |
1184 | pred, and nr_out_edges will be the number of pred out edges | |
1185 | not leaving the region. */ | |
1186 | nr_out_edges -= nr_rgn_out_edges; | |
1187 | if (nr_rgn_out_edges > 0) | |
1188 | prob[bb] += 0.9 * prob[BLOCK_TO_BB (pred)] / nr_out_edges; | |
1189 | else | |
1190 | prob[bb] += prob[BLOCK_TO_BB (pred)] / nr_out_edges; | |
1191 | nxt_in_edge = NEXT_IN (nxt_in_edge); | |
1192 | } | |
1193 | while (fst_in_edge != nxt_in_edge); | |
1194 | ||
1195 | BITSET_ADD (dom[bb], bb, bbset_size); | |
1196 | BITSET_DIFFER (pot_split[bb], ancestor_edges[bb], edgeset_size); | |
1197 | ||
1198 | if (sched_verbose >= 2) | |
1199 | fprintf (sched_dump, ";; bb_prob(%d, %d) = %3d\n", bb, BB_TO_BLOCK (bb), | |
1200 | (int) (100.0 * prob[bb])); | |
1201 | } | |
1202 | ||
1203 | /* Functions for target info. */ | |
1204 | ||
1205 | /* Compute in BL the list of split-edges of bb_src relatively to bb_trg. | |
1206 | Note that bb_trg dominates bb_src. */ | |
1207 | ||
1208 | static void | |
1209 | split_edges (bb_src, bb_trg, bl) | |
1210 | int bb_src; | |
1211 | int bb_trg; | |
1212 | edgelst *bl; | |
1213 | { | |
1214 | int es = edgeset_size; | |
1215 | edgeset src = (edgeset) xcalloc (es, sizeof (HOST_WIDE_INT)); | |
1216 | ||
1217 | while (es--) | |
1218 | src[es] = (pot_split[bb_src])[es]; | |
1219 | BITSET_DIFFER (src, pot_split[bb_trg], edgeset_size); | |
1220 | extract_bitlst (src, edgeset_size, edgeset_bitsize, bl); | |
1221 | free (src); | |
1222 | } | |
1223 | ||
1224 | /* Find the valid candidate-source-blocks for the target block TRG, compute | |
1225 | their probability, and check if they are speculative or not. | |
1226 | For speculative sources, compute their update-blocks and split-blocks. */ | |
1227 | ||
1228 | static void | |
1229 | compute_trg_info (trg) | |
1230 | int trg; | |
1231 | { | |
b3694847 | 1232 | candidate *sp; |
b4ead7d4 BS |
1233 | edgelst el; |
1234 | int check_block, update_idx; | |
1235 | int i, j, k, fst_edge, nxt_edge; | |
1236 | ||
1237 | /* Define some of the fields for the target bb as well. */ | |
1238 | sp = candidate_table + trg; | |
1239 | sp->is_valid = 1; | |
1240 | sp->is_speculative = 0; | |
1241 | sp->src_prob = 100; | |
1242 | ||
1243 | for (i = trg + 1; i < current_nr_blocks; i++) | |
1244 | { | |
1245 | sp = candidate_table + i; | |
1246 | ||
1247 | sp->is_valid = IS_DOMINATED (i, trg); | |
1248 | if (sp->is_valid) | |
1249 | { | |
1250 | sp->src_prob = GET_SRC_PROB (i, trg); | |
1251 | sp->is_valid = (sp->src_prob >= MIN_PROBABILITY); | |
1252 | } | |
1253 | ||
1254 | if (sp->is_valid) | |
1255 | { | |
1256 | split_edges (i, trg, &el); | |
1257 | sp->is_speculative = (el.nr_members) ? 1 : 0; | |
1258 | if (sp->is_speculative && !flag_schedule_speculative) | |
1259 | sp->is_valid = 0; | |
1260 | } | |
1261 | ||
1262 | if (sp->is_valid) | |
1263 | { | |
1264 | char *update_blocks; | |
1265 | ||
1266 | /* Compute split blocks and store them in bblst_table. | |
1267 | The TO block of every split edge is a split block. */ | |
1268 | sp->split_bbs.first_member = &bblst_table[bblst_last]; | |
1269 | sp->split_bbs.nr_members = el.nr_members; | |
1270 | for (j = 0; j < el.nr_members; bblst_last++, j++) | |
1271 | bblst_table[bblst_last] = | |
1272 | TO_BLOCK (rgn_edges[el.first_member[j]]); | |
1273 | sp->update_bbs.first_member = &bblst_table[bblst_last]; | |
1274 | ||
1275 | /* Compute update blocks and store them in bblst_table. | |
1276 | For every split edge, look at the FROM block, and check | |
1277 | all out edges. For each out edge that is not a split edge, | |
1278 | add the TO block to the update block list. This list can end | |
1279 | up with a lot of duplicates. We need to weed them out to avoid | |
1280 | overrunning the end of the bblst_table. */ | |
1281 | update_blocks = (char *) alloca (n_basic_blocks); | |
1282 | memset (update_blocks, 0, n_basic_blocks); | |
1283 | ||
1284 | update_idx = 0; | |
1285 | for (j = 0; j < el.nr_members; j++) | |
1286 | { | |
1287 | check_block = FROM_BLOCK (rgn_edges[el.first_member[j]]); | |
1288 | fst_edge = nxt_edge = OUT_EDGES (check_block); | |
1289 | do | |
1290 | { | |
1291 | if (! update_blocks[TO_BLOCK (nxt_edge)]) | |
1292 | { | |
1293 | for (k = 0; k < el.nr_members; k++) | |
1294 | if (EDGE_TO_BIT (nxt_edge) == el.first_member[k]) | |
1295 | break; | |
1296 | ||
1297 | if (k >= el.nr_members) | |
1298 | { | |
1299 | bblst_table[bblst_last++] = TO_BLOCK (nxt_edge); | |
1300 | update_blocks[TO_BLOCK (nxt_edge)] = 1; | |
1301 | update_idx++; | |
1302 | } | |
1303 | } | |
1304 | ||
1305 | nxt_edge = NEXT_OUT (nxt_edge); | |
1306 | } | |
1307 | while (fst_edge != nxt_edge); | |
1308 | } | |
1309 | sp->update_bbs.nr_members = update_idx; | |
1310 | ||
1311 | /* Make sure we didn't overrun the end of bblst_table. */ | |
1312 | if (bblst_last > bblst_size) | |
1313 | abort (); | |
1314 | } | |
1315 | else | |
1316 | { | |
1317 | sp->split_bbs.nr_members = sp->update_bbs.nr_members = 0; | |
1318 | ||
1319 | sp->is_speculative = 0; | |
1320 | sp->src_prob = 0; | |
1321 | } | |
1322 | } | |
1323 | } | |
1324 | ||
1325 | /* Print candidates info, for debugging purposes. Callable from debugger. */ | |
1326 | ||
1327 | void | |
1328 | debug_candidate (i) | |
1329 | int i; | |
1330 | { | |
1331 | if (!candidate_table[i].is_valid) | |
1332 | return; | |
1333 | ||
1334 | if (candidate_table[i].is_speculative) | |
1335 | { | |
1336 | int j; | |
1337 | fprintf (sched_dump, "src b %d bb %d speculative \n", BB_TO_BLOCK (i), i); | |
1338 | ||
1339 | fprintf (sched_dump, "split path: "); | |
1340 | for (j = 0; j < candidate_table[i].split_bbs.nr_members; j++) | |
1341 | { | |
1342 | int b = candidate_table[i].split_bbs.first_member[j]; | |
1343 | ||
1344 | fprintf (sched_dump, " %d ", b); | |
1345 | } | |
1346 | fprintf (sched_dump, "\n"); | |
1347 | ||
1348 | fprintf (sched_dump, "update path: "); | |
1349 | for (j = 0; j < candidate_table[i].update_bbs.nr_members; j++) | |
1350 | { | |
1351 | int b = candidate_table[i].update_bbs.first_member[j]; | |
1352 | ||
1353 | fprintf (sched_dump, " %d ", b); | |
1354 | } | |
1355 | fprintf (sched_dump, "\n"); | |
1356 | } | |
1357 | else | |
1358 | { | |
1359 | fprintf (sched_dump, " src %d equivalent\n", BB_TO_BLOCK (i)); | |
1360 | } | |
1361 | } | |
1362 | ||
1363 | /* Print candidates info, for debugging purposes. Callable from debugger. */ | |
1364 | ||
1365 | void | |
1366 | debug_candidates (trg) | |
1367 | int trg; | |
1368 | { | |
1369 | int i; | |
1370 | ||
1371 | fprintf (sched_dump, "----------- candidate table: target: b=%d bb=%d ---\n", | |
1372 | BB_TO_BLOCK (trg), trg); | |
1373 | for (i = trg + 1; i < current_nr_blocks; i++) | |
1374 | debug_candidate (i); | |
1375 | } | |
1376 | ||
1377 | /* Functions for speculative scheduing. */ | |
1378 | ||
1379 | /* Return 0 if x is a set of a register alive in the beginning of one | |
1380 | of the split-blocks of src, otherwise return 1. */ | |
1381 | ||
1382 | static int | |
1383 | check_live_1 (src, x) | |
1384 | int src; | |
1385 | rtx x; | |
1386 | { | |
b3694847 SS |
1387 | int i; |
1388 | int regno; | |
1389 | rtx reg = SET_DEST (x); | |
b4ead7d4 BS |
1390 | |
1391 | if (reg == 0) | |
1392 | return 1; | |
1393 | ||
1394 | while (GET_CODE (reg) == SUBREG || GET_CODE (reg) == ZERO_EXTRACT | |
1395 | || GET_CODE (reg) == SIGN_EXTRACT | |
1396 | || GET_CODE (reg) == STRICT_LOW_PART) | |
1397 | reg = XEXP (reg, 0); | |
1398 | ||
7193d1dc | 1399 | if (GET_CODE (reg) == PARALLEL) |
b4ead7d4 | 1400 | { |
b3694847 | 1401 | int i; |
90d036a0 | 1402 | |
b4ead7d4 | 1403 | for (i = XVECLEN (reg, 0) - 1; i >= 0; i--) |
7193d1dc RK |
1404 | if (XEXP (XVECEXP (reg, 0, i), 0) != 0) |
1405 | if (check_live_1 (src, XEXP (XVECEXP (reg, 0, i), 0))) | |
90d036a0 | 1406 | return 1; |
90d036a0 | 1407 | |
b4ead7d4 BS |
1408 | return 0; |
1409 | } | |
1410 | ||
1411 | if (GET_CODE (reg) != REG) | |
1412 | return 1; | |
1413 | ||
1414 | regno = REGNO (reg); | |
1415 | ||
1416 | if (regno < FIRST_PSEUDO_REGISTER && global_regs[regno]) | |
1417 | { | |
1418 | /* Global registers are assumed live. */ | |
1419 | return 0; | |
1420 | } | |
1421 | else | |
1422 | { | |
1423 | if (regno < FIRST_PSEUDO_REGISTER) | |
1424 | { | |
1425 | /* Check for hard registers. */ | |
1426 | int j = HARD_REGNO_NREGS (regno, GET_MODE (reg)); | |
1427 | while (--j >= 0) | |
1428 | { | |
1429 | for (i = 0; i < candidate_table[src].split_bbs.nr_members; i++) | |
1430 | { | |
1431 | int b = candidate_table[src].split_bbs.first_member[i]; | |
1432 | ||
1433 | if (REGNO_REG_SET_P (BASIC_BLOCK (b)->global_live_at_start, | |
1434 | regno + j)) | |
1435 | { | |
1436 | return 0; | |
1437 | } | |
1438 | } | |
1439 | } | |
1440 | } | |
1441 | else | |
1442 | { | |
1443 | /* Check for psuedo registers. */ | |
1444 | for (i = 0; i < candidate_table[src].split_bbs.nr_members; i++) | |
1445 | { | |
1446 | int b = candidate_table[src].split_bbs.first_member[i]; | |
1447 | ||
1448 | if (REGNO_REG_SET_P (BASIC_BLOCK (b)->global_live_at_start, regno)) | |
1449 | { | |
1450 | return 0; | |
1451 | } | |
1452 | } | |
1453 | } | |
1454 | } | |
1455 | ||
1456 | return 1; | |
1457 | } | |
1458 | ||
1459 | /* If x is a set of a register R, mark that R is alive in the beginning | |
1460 | of every update-block of src. */ | |
1461 | ||
1462 | static void | |
1463 | update_live_1 (src, x) | |
1464 | int src; | |
1465 | rtx x; | |
1466 | { | |
b3694847 SS |
1467 | int i; |
1468 | int regno; | |
1469 | rtx reg = SET_DEST (x); | |
b4ead7d4 BS |
1470 | |
1471 | if (reg == 0) | |
1472 | return; | |
1473 | ||
1474 | while (GET_CODE (reg) == SUBREG || GET_CODE (reg) == ZERO_EXTRACT | |
1475 | || GET_CODE (reg) == SIGN_EXTRACT | |
1476 | || GET_CODE (reg) == STRICT_LOW_PART) | |
1477 | reg = XEXP (reg, 0); | |
1478 | ||
7193d1dc | 1479 | if (GET_CODE (reg) == PARALLEL) |
b4ead7d4 | 1480 | { |
b3694847 | 1481 | int i; |
90d036a0 | 1482 | |
b4ead7d4 | 1483 | for (i = XVECLEN (reg, 0) - 1; i >= 0; i--) |
7193d1dc RK |
1484 | if (XEXP (XVECEXP (reg, 0, i), 0) != 0) |
1485 | update_live_1 (src, XEXP (XVECEXP (reg, 0, i), 0)); | |
90d036a0 | 1486 | |
b4ead7d4 BS |
1487 | return; |
1488 | } | |
1489 | ||
1490 | if (GET_CODE (reg) != REG) | |
1491 | return; | |
1492 | ||
1493 | /* Global registers are always live, so the code below does not apply | |
1494 | to them. */ | |
1495 | ||
1496 | regno = REGNO (reg); | |
1497 | ||
1498 | if (regno >= FIRST_PSEUDO_REGISTER || !global_regs[regno]) | |
1499 | { | |
1500 | if (regno < FIRST_PSEUDO_REGISTER) | |
1501 | { | |
1502 | int j = HARD_REGNO_NREGS (regno, GET_MODE (reg)); | |
1503 | while (--j >= 0) | |
1504 | { | |
1505 | for (i = 0; i < candidate_table[src].update_bbs.nr_members; i++) | |
1506 | { | |
1507 | int b = candidate_table[src].update_bbs.first_member[i]; | |
1508 | ||
1509 | SET_REGNO_REG_SET (BASIC_BLOCK (b)->global_live_at_start, | |
1510 | regno + j); | |
1511 | } | |
1512 | } | |
1513 | } | |
1514 | else | |
1515 | { | |
1516 | for (i = 0; i < candidate_table[src].update_bbs.nr_members; i++) | |
1517 | { | |
1518 | int b = candidate_table[src].update_bbs.first_member[i]; | |
1519 | ||
1520 | SET_REGNO_REG_SET (BASIC_BLOCK (b)->global_live_at_start, regno); | |
1521 | } | |
1522 | } | |
1523 | } | |
1524 | } | |
1525 | ||
1526 | /* Return 1 if insn can be speculatively moved from block src to trg, | |
1527 | otherwise return 0. Called before first insertion of insn to | |
1528 | ready-list or before the scheduling. */ | |
1529 | ||
1530 | static int | |
1531 | check_live (insn, src) | |
1532 | rtx insn; | |
1533 | int src; | |
1534 | { | |
1535 | /* Find the registers set by instruction. */ | |
1536 | if (GET_CODE (PATTERN (insn)) == SET | |
1537 | || GET_CODE (PATTERN (insn)) == CLOBBER) | |
1538 | return check_live_1 (src, PATTERN (insn)); | |
1539 | else if (GET_CODE (PATTERN (insn)) == PARALLEL) | |
1540 | { | |
1541 | int j; | |
1542 | for (j = XVECLEN (PATTERN (insn), 0) - 1; j >= 0; j--) | |
1543 | if ((GET_CODE (XVECEXP (PATTERN (insn), 0, j)) == SET | |
1544 | || GET_CODE (XVECEXP (PATTERN (insn), 0, j)) == CLOBBER) | |
1545 | && !check_live_1 (src, XVECEXP (PATTERN (insn), 0, j))) | |
1546 | return 0; | |
1547 | ||
1548 | return 1; | |
1549 | } | |
1550 | ||
1551 | return 1; | |
1552 | } | |
1553 | ||
1554 | /* Update the live registers info after insn was moved speculatively from | |
1555 | block src to trg. */ | |
1556 | ||
1557 | static void | |
1558 | update_live (insn, src) | |
1559 | rtx insn; | |
1560 | int src; | |
1561 | { | |
1562 | /* Find the registers set by instruction. */ | |
1563 | if (GET_CODE (PATTERN (insn)) == SET | |
1564 | || GET_CODE (PATTERN (insn)) == CLOBBER) | |
1565 | update_live_1 (src, PATTERN (insn)); | |
1566 | else if (GET_CODE (PATTERN (insn)) == PARALLEL) | |
1567 | { | |
1568 | int j; | |
1569 | for (j = XVECLEN (PATTERN (insn), 0) - 1; j >= 0; j--) | |
1570 | if (GET_CODE (XVECEXP (PATTERN (insn), 0, j)) == SET | |
1571 | || GET_CODE (XVECEXP (PATTERN (insn), 0, j)) == CLOBBER) | |
1572 | update_live_1 (src, XVECEXP (PATTERN (insn), 0, j)); | |
1573 | } | |
1574 | } | |
1575 | ||
1576 | /* Exception Free Loads: | |
1577 | ||
1578 | We define five classes of speculative loads: IFREE, IRISKY, | |
1579 | PFREE, PRISKY, and MFREE. | |
1580 | ||
1581 | IFREE loads are loads that are proved to be exception-free, just | |
1582 | by examining the load insn. Examples for such loads are loads | |
1583 | from TOC and loads of global data. | |
1584 | ||
1585 | IRISKY loads are loads that are proved to be exception-risky, | |
1586 | just by examining the load insn. Examples for such loads are | |
1587 | volatile loads and loads from shared memory. | |
1588 | ||
1589 | PFREE loads are loads for which we can prove, by examining other | |
1590 | insns, that they are exception-free. Currently, this class consists | |
1591 | of loads for which we are able to find a "similar load", either in | |
1592 | the target block, or, if only one split-block exists, in that split | |
1593 | block. Load2 is similar to load1 if both have same single base | |
1594 | register. We identify only part of the similar loads, by finding | |
1595 | an insn upon which both load1 and load2 have a DEF-USE dependence. | |
1596 | ||
1597 | PRISKY loads are loads for which we can prove, by examining other | |
1598 | insns, that they are exception-risky. Currently we have two proofs for | |
1599 | such loads. The first proof detects loads that are probably guarded by a | |
1600 | test on the memory address. This proof is based on the | |
1601 | backward and forward data dependence information for the region. | |
1602 | Let load-insn be the examined load. | |
1603 | Load-insn is PRISKY iff ALL the following hold: | |
1604 | ||
1605 | - insn1 is not in the same block as load-insn | |
1606 | - there is a DEF-USE dependence chain (insn1, ..., load-insn) | |
1607 | - test-insn is either a compare or a branch, not in the same block | |
1608 | as load-insn | |
1609 | - load-insn is reachable from test-insn | |
1610 | - there is a DEF-USE dependence chain (insn1, ..., test-insn) | |
1611 | ||
1612 | This proof might fail when the compare and the load are fed | |
1613 | by an insn not in the region. To solve this, we will add to this | |
1614 | group all loads that have no input DEF-USE dependence. | |
1615 | ||
1616 | The second proof detects loads that are directly or indirectly | |
1617 | fed by a speculative load. This proof is affected by the | |
1618 | scheduling process. We will use the flag fed_by_spec_load. | |
1619 | Initially, all insns have this flag reset. After a speculative | |
1620 | motion of an insn, if insn is either a load, or marked as | |
1621 | fed_by_spec_load, we will also mark as fed_by_spec_load every | |
1622 | insn1 for which a DEF-USE dependence (insn, insn1) exists. A | |
1623 | load which is fed_by_spec_load is also PRISKY. | |
1624 | ||
1625 | MFREE (maybe-free) loads are all the remaining loads. They may be | |
1626 | exception-free, but we cannot prove it. | |
1627 | ||
1628 | Now, all loads in IFREE and PFREE classes are considered | |
1629 | exception-free, while all loads in IRISKY and PRISKY classes are | |
1630 | considered exception-risky. As for loads in the MFREE class, | |
1631 | these are considered either exception-free or exception-risky, | |
1632 | depending on whether we are pessimistic or optimistic. We have | |
1633 | to take the pessimistic approach to assure the safety of | |
1634 | speculative scheduling, but we can take the optimistic approach | |
1635 | by invoking the -fsched_spec_load_dangerous option. */ | |
1636 | ||
1637 | enum INSN_TRAP_CLASS | |
1638 | { | |
1639 | TRAP_FREE = 0, IFREE = 1, PFREE_CANDIDATE = 2, | |
1640 | PRISKY_CANDIDATE = 3, IRISKY = 4, TRAP_RISKY = 5 | |
1641 | }; | |
1642 | ||
1643 | #define WORST_CLASS(class1, class2) \ | |
1644 | ((class1 > class2) ? class1 : class2) | |
1645 | ||
1646 | /* Non-zero if block bb_to is equal to, or reachable from block bb_from. */ | |
1647 | #define IS_REACHABLE(bb_from, bb_to) \ | |
1648 | (bb_from == bb_to \ | |
1649 | || IS_RGN_ENTRY (bb_from) \ | |
1650 | || (bitset_member (ancestor_edges[bb_to], \ | |
1651 | EDGE_TO_BIT (IN_EDGES (BB_TO_BLOCK (bb_from))), \ | |
1652 | edgeset_size))) | |
1653 | ||
1654 | /* Non-zero iff the address is comprised from at most 1 register. */ | |
1655 | #define CONST_BASED_ADDRESS_P(x) \ | |
1656 | (GET_CODE (x) == REG \ | |
1657 | || ((GET_CODE (x) == PLUS || GET_CODE (x) == MINUS \ | |
1658 | || (GET_CODE (x) == LO_SUM)) \ | |
1659 | && (GET_CODE (XEXP (x, 0)) == CONST_INT \ | |
1660 | || GET_CODE (XEXP (x, 1)) == CONST_INT))) | |
1661 | ||
1662 | /* Turns on the fed_by_spec_load flag for insns fed by load_insn. */ | |
1663 | ||
1664 | static void | |
1665 | set_spec_fed (load_insn) | |
1666 | rtx load_insn; | |
1667 | { | |
1668 | rtx link; | |
1669 | ||
1670 | for (link = INSN_DEPEND (load_insn); link; link = XEXP (link, 1)) | |
1671 | if (GET_MODE (link) == VOIDmode) | |
1672 | FED_BY_SPEC_LOAD (XEXP (link, 0)) = 1; | |
1673 | } /* set_spec_fed */ | |
1674 | ||
1675 | /* On the path from the insn to load_insn_bb, find a conditional | |
1676 | branch depending on insn, that guards the speculative load. */ | |
1677 | ||
1678 | static int | |
1679 | find_conditional_protection (insn, load_insn_bb) | |
1680 | rtx insn; | |
1681 | int load_insn_bb; | |
1682 | { | |
1683 | rtx link; | |
1684 | ||
1685 | /* Iterate through DEF-USE forward dependences. */ | |
1686 | for (link = INSN_DEPEND (insn); link; link = XEXP (link, 1)) | |
1687 | { | |
1688 | rtx next = XEXP (link, 0); | |
1689 | if ((CONTAINING_RGN (BLOCK_NUM (next)) == | |
1690 | CONTAINING_RGN (BB_TO_BLOCK (load_insn_bb))) | |
1691 | && IS_REACHABLE (INSN_BB (next), load_insn_bb) | |
1692 | && load_insn_bb != INSN_BB (next) | |
1693 | && GET_MODE (link) == VOIDmode | |
1694 | && (GET_CODE (next) == JUMP_INSN | |
1695 | || find_conditional_protection (next, load_insn_bb))) | |
1696 | return 1; | |
1697 | } | |
1698 | return 0; | |
1699 | } /* find_conditional_protection */ | |
1700 | ||
1701 | /* Returns 1 if the same insn1 that participates in the computation | |
1702 | of load_insn's address is feeding a conditional branch that is | |
1703 | guarding on load_insn. This is true if we find a the two DEF-USE | |
1704 | chains: | |
1705 | insn1 -> ... -> conditional-branch | |
1706 | insn1 -> ... -> load_insn, | |
1707 | and if a flow path exist: | |
1708 | insn1 -> ... -> conditional-branch -> ... -> load_insn, | |
1709 | and if insn1 is on the path | |
1710 | region-entry -> ... -> bb_trg -> ... load_insn. | |
1711 | ||
1712 | Locate insn1 by climbing on LOG_LINKS from load_insn. | |
1713 | Locate the branch by following INSN_DEPEND from insn1. */ | |
1714 | ||
1715 | static int | |
1716 | is_conditionally_protected (load_insn, bb_src, bb_trg) | |
1717 | rtx load_insn; | |
1718 | int bb_src, bb_trg; | |
1719 | { | |
1720 | rtx link; | |
1721 | ||
1722 | for (link = LOG_LINKS (load_insn); link; link = XEXP (link, 1)) | |
1723 | { | |
1724 | rtx insn1 = XEXP (link, 0); | |
1725 | ||
1726 | /* Must be a DEF-USE dependence upon non-branch. */ | |
1727 | if (GET_MODE (link) != VOIDmode | |
1728 | || GET_CODE (insn1) == JUMP_INSN) | |
1729 | continue; | |
1730 | ||
1731 | /* Must exist a path: region-entry -> ... -> bb_trg -> ... load_insn. */ | |
1732 | if (INSN_BB (insn1) == bb_src | |
1733 | || (CONTAINING_RGN (BLOCK_NUM (insn1)) | |
1734 | != CONTAINING_RGN (BB_TO_BLOCK (bb_src))) | |
1735 | || (!IS_REACHABLE (bb_trg, INSN_BB (insn1)) | |
1736 | && !IS_REACHABLE (INSN_BB (insn1), bb_trg))) | |
1737 | continue; | |
1738 | ||
1739 | /* Now search for the conditional-branch. */ | |
1740 | if (find_conditional_protection (insn1, bb_src)) | |
1741 | return 1; | |
1742 | ||
1743 | /* Recursive step: search another insn1, "above" current insn1. */ | |
1744 | return is_conditionally_protected (insn1, bb_src, bb_trg); | |
1745 | } | |
1746 | ||
1747 | /* The chain does not exist. */ | |
1748 | return 0; | |
1749 | } /* is_conditionally_protected */ | |
1750 | ||
1751 | /* Returns 1 if a clue for "similar load" 'insn2' is found, and hence | |
1752 | load_insn can move speculatively from bb_src to bb_trg. All the | |
1753 | following must hold: | |
1754 | ||
1755 | (1) both loads have 1 base register (PFREE_CANDIDATEs). | |
1756 | (2) load_insn and load1 have a def-use dependence upon | |
1757 | the same insn 'insn1'. | |
1758 | (3) either load2 is in bb_trg, or: | |
1759 | - there's only one split-block, and | |
1760 | - load1 is on the escape path, and | |
1761 | ||
1762 | From all these we can conclude that the two loads access memory | |
1763 | addresses that differ at most by a constant, and hence if moving | |
1764 | load_insn would cause an exception, it would have been caused by | |
1765 | load2 anyhow. */ | |
1766 | ||
1767 | static int | |
1768 | is_pfree (load_insn, bb_src, bb_trg) | |
1769 | rtx load_insn; | |
1770 | int bb_src, bb_trg; | |
1771 | { | |
1772 | rtx back_link; | |
b3694847 | 1773 | candidate *candp = candidate_table + bb_src; |
b4ead7d4 BS |
1774 | |
1775 | if (candp->split_bbs.nr_members != 1) | |
1776 | /* Must have exactly one escape block. */ | |
1777 | return 0; | |
1778 | ||
1779 | for (back_link = LOG_LINKS (load_insn); | |
1780 | back_link; back_link = XEXP (back_link, 1)) | |
1781 | { | |
1782 | rtx insn1 = XEXP (back_link, 0); | |
1783 | ||
1784 | if (GET_MODE (back_link) == VOIDmode) | |
1785 | { | |
1786 | /* Found a DEF-USE dependence (insn1, load_insn). */ | |
1787 | rtx fore_link; | |
1788 | ||
1789 | for (fore_link = INSN_DEPEND (insn1); | |
1790 | fore_link; fore_link = XEXP (fore_link, 1)) | |
1791 | { | |
1792 | rtx insn2 = XEXP (fore_link, 0); | |
1793 | if (GET_MODE (fore_link) == VOIDmode) | |
1794 | { | |
1795 | /* Found a DEF-USE dependence (insn1, insn2). */ | |
1796 | if (haifa_classify_insn (insn2) != PFREE_CANDIDATE) | |
1797 | /* insn2 not guaranteed to be a 1 base reg load. */ | |
1798 | continue; | |
1799 | ||
1800 | if (INSN_BB (insn2) == bb_trg) | |
1801 | /* insn2 is the similar load, in the target block. */ | |
1802 | return 1; | |
1803 | ||
1804 | if (*(candp->split_bbs.first_member) == BLOCK_NUM (insn2)) | |
1805 | /* insn2 is a similar load, in a split-block. */ | |
1806 | return 1; | |
1807 | } | |
1808 | } | |
1809 | } | |
1810 | } | |
1811 | ||
1812 | /* Couldn't find a similar load. */ | |
1813 | return 0; | |
1814 | } /* is_pfree */ | |
1815 | ||
1816 | /* Returns a class that insn with GET_DEST(insn)=x may belong to, | |
1817 | as found by analyzing insn's expression. */ | |
1818 | ||
1819 | static int | |
1820 | may_trap_exp (x, is_store) | |
1821 | rtx x; | |
1822 | int is_store; | |
1823 | { | |
1824 | enum rtx_code code; | |
1825 | ||
1826 | if (x == 0) | |
1827 | return TRAP_FREE; | |
1828 | code = GET_CODE (x); | |
1829 | if (is_store) | |
1830 | { | |
1831 | if (code == MEM) | |
1832 | return TRAP_RISKY; | |
1833 | else | |
1834 | return TRAP_FREE; | |
1835 | } | |
1836 | if (code == MEM) | |
1837 | { | |
1838 | /* The insn uses memory: a volatile load. */ | |
1839 | if (MEM_VOLATILE_P (x)) | |
1840 | return IRISKY; | |
1841 | /* An exception-free load. */ | |
1842 | if (!may_trap_p (x)) | |
1843 | return IFREE; | |
1844 | /* A load with 1 base register, to be further checked. */ | |
1845 | if (CONST_BASED_ADDRESS_P (XEXP (x, 0))) | |
1846 | return PFREE_CANDIDATE; | |
1847 | /* No info on the load, to be further checked. */ | |
1848 | return PRISKY_CANDIDATE; | |
1849 | } | |
1850 | else | |
1851 | { | |
1852 | const char *fmt; | |
1853 | int i, insn_class = TRAP_FREE; | |
1854 | ||
1855 | /* Neither store nor load, check if it may cause a trap. */ | |
1856 | if (may_trap_p (x)) | |
1857 | return TRAP_RISKY; | |
1858 | /* Recursive step: walk the insn... */ | |
1859 | fmt = GET_RTX_FORMAT (code); | |
1860 | for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
1861 | { | |
1862 | if (fmt[i] == 'e') | |
1863 | { | |
1864 | int tmp_class = may_trap_exp (XEXP (x, i), is_store); | |
1865 | insn_class = WORST_CLASS (insn_class, tmp_class); | |
1866 | } | |
1867 | else if (fmt[i] == 'E') | |
1868 | { | |
1869 | int j; | |
1870 | for (j = 0; j < XVECLEN (x, i); j++) | |
1871 | { | |
1872 | int tmp_class = may_trap_exp (XVECEXP (x, i, j), is_store); | |
1873 | insn_class = WORST_CLASS (insn_class, tmp_class); | |
1874 | if (insn_class == TRAP_RISKY || insn_class == IRISKY) | |
1875 | break; | |
1876 | } | |
1877 | } | |
1878 | if (insn_class == TRAP_RISKY || insn_class == IRISKY) | |
1879 | break; | |
1880 | } | |
1881 | return insn_class; | |
1882 | } | |
1883 | } | |
1884 | ||
1885 | /* Classifies insn for the purpose of verifying that it can be | |
1886 | moved speculatively, by examining it's patterns, returning: | |
1887 | TRAP_RISKY: store, or risky non-load insn (e.g. division by variable). | |
1888 | TRAP_FREE: non-load insn. | |
1889 | IFREE: load from a globaly safe location. | |
1890 | IRISKY: volatile load. | |
1891 | PFREE_CANDIDATE, PRISKY_CANDIDATE: load that need to be checked for | |
1892 | being either PFREE or PRISKY. */ | |
1893 | ||
1894 | static int | |
1895 | haifa_classify_insn (insn) | |
1896 | rtx insn; | |
1897 | { | |
1898 | rtx pat = PATTERN (insn); | |
1899 | int tmp_class = TRAP_FREE; | |
1900 | int insn_class = TRAP_FREE; | |
1901 | enum rtx_code code; | |
1902 | ||
1903 | if (GET_CODE (pat) == PARALLEL) | |
1904 | { | |
1905 | int i, len = XVECLEN (pat, 0); | |
1906 | ||
1907 | for (i = len - 1; i >= 0; i--) | |
1908 | { | |
1909 | code = GET_CODE (XVECEXP (pat, 0, i)); | |
1910 | switch (code) | |
1911 | { | |
1912 | case CLOBBER: | |
1913 | /* Test if it is a 'store'. */ | |
1914 | tmp_class = may_trap_exp (XEXP (XVECEXP (pat, 0, i), 0), 1); | |
1915 | break; | |
1916 | case SET: | |
1917 | /* Test if it is a store. */ | |
1918 | tmp_class = may_trap_exp (SET_DEST (XVECEXP (pat, 0, i)), 1); | |
1919 | if (tmp_class == TRAP_RISKY) | |
1920 | break; | |
1921 | /* Test if it is a load. */ | |
90d036a0 RK |
1922 | tmp_class |
1923 | = WORST_CLASS (tmp_class, | |
1924 | may_trap_exp (SET_SRC (XVECEXP (pat, 0, i)), | |
1925 | 0)); | |
b4ead7d4 BS |
1926 | break; |
1927 | case COND_EXEC: | |
1928 | case TRAP_IF: | |
1929 | tmp_class = TRAP_RISKY; | |
1930 | break; | |
90d036a0 RK |
1931 | default: |
1932 | ; | |
b4ead7d4 BS |
1933 | } |
1934 | insn_class = WORST_CLASS (insn_class, tmp_class); | |
1935 | if (insn_class == TRAP_RISKY || insn_class == IRISKY) | |
1936 | break; | |
1937 | } | |
1938 | } | |
1939 | else | |
1940 | { | |
1941 | code = GET_CODE (pat); | |
1942 | switch (code) | |
1943 | { | |
1944 | case CLOBBER: | |
1945 | /* Test if it is a 'store'. */ | |
1946 | tmp_class = may_trap_exp (XEXP (pat, 0), 1); | |
1947 | break; | |
1948 | case SET: | |
1949 | /* Test if it is a store. */ | |
1950 | tmp_class = may_trap_exp (SET_DEST (pat), 1); | |
1951 | if (tmp_class == TRAP_RISKY) | |
1952 | break; | |
1953 | /* Test if it is a load. */ | |
1954 | tmp_class = | |
1955 | WORST_CLASS (tmp_class, | |
1956 | may_trap_exp (SET_SRC (pat), 0)); | |
1957 | break; | |
1958 | case COND_EXEC: | |
1959 | case TRAP_IF: | |
1960 | tmp_class = TRAP_RISKY; | |
1961 | break; | |
1962 | default:; | |
1963 | } | |
1964 | insn_class = tmp_class; | |
1965 | } | |
1966 | ||
1967 | return insn_class; | |
1968 | } | |
1969 | ||
1970 | /* Return 1 if load_insn is prisky (i.e. if load_insn is fed by | |
1971 | a load moved speculatively, or if load_insn is protected by | |
1972 | a compare on load_insn's address). */ | |
1973 | ||
1974 | static int | |
1975 | is_prisky (load_insn, bb_src, bb_trg) | |
1976 | rtx load_insn; | |
1977 | int bb_src, bb_trg; | |
1978 | { | |
1979 | if (FED_BY_SPEC_LOAD (load_insn)) | |
1980 | return 1; | |
1981 | ||
1982 | if (LOG_LINKS (load_insn) == NULL) | |
1983 | /* Dependence may 'hide' out of the region. */ | |
1984 | return 1; | |
1985 | ||
1986 | if (is_conditionally_protected (load_insn, bb_src, bb_trg)) | |
1987 | return 1; | |
1988 | ||
1989 | return 0; | |
1990 | } | |
1991 | ||
1992 | /* Insn is a candidate to be moved speculatively from bb_src to bb_trg. | |
1993 | Return 1 if insn is exception-free (and the motion is valid) | |
1994 | and 0 otherwise. */ | |
1995 | ||
1996 | static int | |
1997 | is_exception_free (insn, bb_src, bb_trg) | |
1998 | rtx insn; | |
1999 | int bb_src, bb_trg; | |
2000 | { | |
2001 | int insn_class = haifa_classify_insn (insn); | |
2002 | ||
2003 | /* Handle non-load insns. */ | |
2004 | switch (insn_class) | |
2005 | { | |
2006 | case TRAP_FREE: | |
2007 | return 1; | |
2008 | case TRAP_RISKY: | |
2009 | return 0; | |
2010 | default:; | |
2011 | } | |
2012 | ||
2013 | /* Handle loads. */ | |
2014 | if (!flag_schedule_speculative_load) | |
2015 | return 0; | |
2016 | IS_LOAD_INSN (insn) = 1; | |
2017 | switch (insn_class) | |
2018 | { | |
2019 | case IFREE: | |
2020 | return (1); | |
2021 | case IRISKY: | |
2022 | return 0; | |
2023 | case PFREE_CANDIDATE: | |
2024 | if (is_pfree (insn, bb_src, bb_trg)) | |
2025 | return 1; | |
2026 | /* Don't 'break' here: PFREE-candidate is also PRISKY-candidate. */ | |
2027 | case PRISKY_CANDIDATE: | |
2028 | if (!flag_schedule_speculative_load_dangerous | |
2029 | || is_prisky (insn, bb_src, bb_trg)) | |
2030 | return 0; | |
2031 | break; | |
2032 | default:; | |
2033 | } | |
2034 | ||
2035 | return flag_schedule_speculative_load_dangerous; | |
2036 | } | |
2037 | \f | |
2038 | /* The number of insns from the current block scheduled so far. */ | |
2039 | static int sched_target_n_insns; | |
2040 | /* The number of insns from the current block to be scheduled in total. */ | |
2041 | static int target_n_insns; | |
2042 | /* The number of insns from the entire region scheduled so far. */ | |
2043 | static int sched_n_insns; | |
79c2ffde BS |
2044 | /* Nonzero if the last scheduled insn was a jump. */ |
2045 | static int last_was_jump; | |
b4ead7d4 BS |
2046 | |
2047 | /* Implementations of the sched_info functions for region scheduling. */ | |
2048 | static void init_ready_list PARAMS ((struct ready_list *)); | |
2049 | static int can_schedule_ready_p PARAMS ((rtx)); | |
2050 | static int new_ready PARAMS ((rtx)); | |
2051 | static int schedule_more_p PARAMS ((void)); | |
2052 | static const char *rgn_print_insn PARAMS ((rtx, int)); | |
2053 | static int rgn_rank PARAMS ((rtx, rtx)); | |
18e720b3 BS |
2054 | static int contributes_to_priority PARAMS ((rtx, rtx)); |
2055 | static void compute_jump_reg_dependencies PARAMS ((rtx, regset)); | |
b4ead7d4 BS |
2056 | |
2057 | /* Return nonzero if there are more insns that should be scheduled. */ | |
2058 | ||
2059 | static int | |
2060 | schedule_more_p () | |
2061 | { | |
79c2ffde | 2062 | return ! last_was_jump && sched_target_n_insns < target_n_insns; |
b4ead7d4 BS |
2063 | } |
2064 | ||
2065 | /* Add all insns that are initially ready to the ready list READY. Called | |
2066 | once before scheduling a set of insns. */ | |
2067 | ||
2068 | static void | |
2069 | init_ready_list (ready) | |
2070 | struct ready_list *ready; | |
2071 | { | |
2072 | rtx prev_head = current_sched_info->prev_head; | |
2073 | rtx next_tail = current_sched_info->next_tail; | |
2074 | int bb_src; | |
2075 | rtx insn; | |
2076 | ||
2077 | target_n_insns = 0; | |
2078 | sched_target_n_insns = 0; | |
2079 | sched_n_insns = 0; | |
79c2ffde | 2080 | last_was_jump = 0; |
b4ead7d4 BS |
2081 | |
2082 | /* Print debugging information. */ | |
2083 | if (sched_verbose >= 5) | |
2084 | debug_dependencies (); | |
2085 | ||
2086 | /* Prepare current target block info. */ | |
2087 | if (current_nr_blocks > 1) | |
2088 | { | |
2089 | candidate_table = (candidate *) xmalloc (current_nr_blocks | |
2090 | * sizeof (candidate)); | |
2091 | ||
2092 | bblst_last = 0; | |
2093 | /* bblst_table holds split blocks and update blocks for each block after | |
2094 | the current one in the region. split blocks and update blocks are | |
2095 | the TO blocks of region edges, so there can be at most rgn_nr_edges | |
2096 | of them. */ | |
2097 | bblst_size = (current_nr_blocks - target_bb) * rgn_nr_edges; | |
2098 | bblst_table = (int *) xmalloc (bblst_size * sizeof (int)); | |
2099 | ||
2100 | bitlst_table_last = 0; | |
2101 | bitlst_table_size = rgn_nr_edges; | |
2102 | bitlst_table = (int *) xmalloc (rgn_nr_edges * sizeof (int)); | |
2103 | ||
2104 | compute_trg_info (target_bb); | |
2105 | } | |
2106 | ||
2107 | /* Initialize ready list with all 'ready' insns in target block. | |
2108 | Count number of insns in the target block being scheduled. */ | |
2109 | for (insn = NEXT_INSN (prev_head); insn != next_tail; insn = NEXT_INSN (insn)) | |
2110 | { | |
2111 | rtx next; | |
2112 | ||
2113 | if (! INSN_P (insn)) | |
2114 | continue; | |
2115 | next = NEXT_INSN (insn); | |
2116 | ||
2117 | if (INSN_DEP_COUNT (insn) == 0 | |
2118 | && (SCHED_GROUP_P (next) == 0 || ! INSN_P (next))) | |
2119 | ready_add (ready, insn); | |
2120 | if (!(SCHED_GROUP_P (insn))) | |
2121 | target_n_insns++; | |
2122 | } | |
2123 | ||
2124 | /* Add to ready list all 'ready' insns in valid source blocks. | |
2125 | For speculative insns, check-live, exception-free, and | |
2126 | issue-delay. */ | |
2127 | for (bb_src = target_bb + 1; bb_src < current_nr_blocks; bb_src++) | |
2128 | if (IS_VALID (bb_src)) | |
2129 | { | |
2130 | rtx src_head; | |
2131 | rtx src_next_tail; | |
2132 | rtx tail, head; | |
2133 | ||
2134 | get_block_head_tail (BB_TO_BLOCK (bb_src), &head, &tail); | |
2135 | src_next_tail = NEXT_INSN (tail); | |
2136 | src_head = head; | |
2137 | ||
2138 | for (insn = src_head; insn != src_next_tail; insn = NEXT_INSN (insn)) | |
2139 | { | |
2140 | if (! INSN_P (insn)) | |
2141 | continue; | |
2142 | ||
2143 | if (!CANT_MOVE (insn) | |
2144 | && (!IS_SPECULATIVE_INSN (insn) | |
b8ec5764 | 2145 | || (insn_issue_delay (insn) <= 3 |
b4ead7d4 BS |
2146 | && check_live (insn, bb_src) |
2147 | && is_exception_free (insn, bb_src, target_bb)))) | |
2148 | { | |
2149 | rtx next; | |
2150 | ||
e3aafbad | 2151 | /* Note that we havn't squirreled away the notes for |
b4ead7d4 BS |
2152 | blocks other than the current. So if this is a |
2153 | speculative insn, NEXT might otherwise be a note. */ | |
2154 | next = next_nonnote_insn (insn); | |
2155 | if (INSN_DEP_COUNT (insn) == 0 | |
2156 | && (! next | |
2157 | || SCHED_GROUP_P (next) == 0 | |
2158 | || ! INSN_P (next))) | |
2159 | ready_add (ready, insn); | |
2160 | } | |
2161 | } | |
2162 | } | |
2163 | } | |
2164 | ||
2165 | /* Called after taking INSN from the ready list. Returns nonzero if this | |
2166 | insn can be scheduled, nonzero if we should silently discard it. */ | |
2167 | ||
2168 | static int | |
2169 | can_schedule_ready_p (insn) | |
2170 | rtx insn; | |
2171 | { | |
79c2ffde BS |
2172 | if (GET_CODE (insn) == JUMP_INSN) |
2173 | last_was_jump = 1; | |
2174 | ||
b4ead7d4 BS |
2175 | /* An interblock motion? */ |
2176 | if (INSN_BB (insn) != target_bb) | |
2177 | { | |
2178 | rtx temp; | |
2179 | basic_block b1; | |
2180 | ||
2181 | if (IS_SPECULATIVE_INSN (insn)) | |
2182 | { | |
2183 | if (!check_live (insn, INSN_BB (insn))) | |
2184 | return 0; | |
2185 | update_live (insn, INSN_BB (insn)); | |
2186 | ||
2187 | /* For speculative load, mark insns fed by it. */ | |
2188 | if (IS_LOAD_INSN (insn) || FED_BY_SPEC_LOAD (insn)) | |
2189 | set_spec_fed (insn); | |
2190 | ||
2191 | nr_spec++; | |
2192 | } | |
2193 | nr_inter++; | |
2194 | ||
2195 | /* Find the beginning of the scheduling group. */ | |
2196 | /* ??? Ought to update basic block here, but later bits of | |
2197 | schedule_block assumes the original insn block is | |
2198 | still intact. */ | |
2199 | ||
2200 | temp = insn; | |
2201 | while (SCHED_GROUP_P (temp)) | |
2202 | temp = PREV_INSN (temp); | |
2203 | ||
6d2f8887 | 2204 | /* Update source block boundaries. */ |
b4ead7d4 BS |
2205 | b1 = BLOCK_FOR_INSN (temp); |
2206 | if (temp == b1->head && insn == b1->end) | |
2207 | { | |
2208 | /* We moved all the insns in the basic block. | |
2209 | Emit a note after the last insn and update the | |
2210 | begin/end boundaries to point to the note. */ | |
2211 | rtx note = emit_note_after (NOTE_INSN_DELETED, insn); | |
2212 | b1->head = note; | |
2213 | b1->end = note; | |
2214 | } | |
2215 | else if (insn == b1->end) | |
2216 | { | |
2217 | /* We took insns from the end of the basic block, | |
2218 | so update the end of block boundary so that it | |
2219 | points to the first insn we did not move. */ | |
2220 | b1->end = PREV_INSN (temp); | |
2221 | } | |
2222 | else if (temp == b1->head) | |
2223 | { | |
2224 | /* We took insns from the start of the basic block, | |
2225 | so update the start of block boundary so that | |
2226 | it points to the first insn we did not move. */ | |
2227 | b1->head = NEXT_INSN (insn); | |
2228 | } | |
2229 | } | |
2230 | else | |
2231 | { | |
2232 | /* In block motion. */ | |
2233 | sched_target_n_insns++; | |
2234 | } | |
2235 | sched_n_insns++; | |
2236 | ||
2237 | return 1; | |
2238 | } | |
2239 | ||
2240 | /* Called after INSN has all its dependencies resolved. Return nonzero | |
2241 | if it should be moved to the ready list or the queue, or zero if we | |
2242 | should silently discard it. */ | |
2243 | static int | |
2244 | new_ready (next) | |
2245 | rtx next; | |
2246 | { | |
2247 | /* For speculative insns, before inserting to ready/queue, | |
2248 | check live, exception-free, and issue-delay. */ | |
2249 | if (INSN_BB (next) != target_bb | |
2250 | && (!IS_VALID (INSN_BB (next)) | |
2251 | || CANT_MOVE (next) | |
2252 | || (IS_SPECULATIVE_INSN (next) | |
b8ec5764 | 2253 | && (insn_issue_delay (next) > 3 |
b4ead7d4 BS |
2254 | || !check_live (next, INSN_BB (next)) |
2255 | || !is_exception_free (next, INSN_BB (next), target_bb))))) | |
2256 | return 0; | |
2257 | return 1; | |
2258 | } | |
2259 | ||
2260 | /* Return a string that contains the insn uid and optionally anything else | |
2261 | necessary to identify this insn in an output. It's valid to use a | |
2262 | static buffer for this. The ALIGNED parameter should cause the string | |
2263 | to be formatted so that multiple output lines will line up nicely. */ | |
2264 | ||
2265 | static const char * | |
2266 | rgn_print_insn (insn, aligned) | |
2267 | rtx insn; | |
2268 | int aligned; | |
2269 | { | |
2270 | static char tmp[80]; | |
2271 | ||
2272 | if (aligned) | |
2273 | sprintf (tmp, "b%3d: i%4d", INSN_BB (insn), INSN_UID (insn)); | |
2274 | else | |
2275 | { | |
b4ead7d4 | 2276 | if (current_nr_blocks > 1 && INSN_BB (insn) != target_bb) |
f56887a7 BS |
2277 | sprintf (tmp, "%d/b%d", INSN_UID (insn), INSN_BB (insn)); |
2278 | else | |
2279 | sprintf (tmp, "%d", INSN_UID (insn)); | |
b4ead7d4 BS |
2280 | } |
2281 | return tmp; | |
2282 | } | |
2283 | ||
2284 | /* Compare priority of two insns. Return a positive number if the second | |
2285 | insn is to be preferred for scheduling, and a negative one if the first | |
2286 | is to be preferred. Zero if they are equally good. */ | |
2287 | ||
2288 | static int | |
2289 | rgn_rank (insn1, insn2) | |
2290 | rtx insn1, insn2; | |
2291 | { | |
2292 | /* Some comparison make sense in interblock scheduling only. */ | |
2293 | if (INSN_BB (insn1) != INSN_BB (insn2)) | |
2294 | { | |
2295 | int spec_val, prob_val; | |
2296 | ||
2297 | /* Prefer an inblock motion on an interblock motion. */ | |
2298 | if ((INSN_BB (insn2) == target_bb) && (INSN_BB (insn1) != target_bb)) | |
2299 | return 1; | |
2300 | if ((INSN_BB (insn1) == target_bb) && (INSN_BB (insn2) != target_bb)) | |
2301 | return -1; | |
2302 | ||
2303 | /* Prefer a useful motion on a speculative one. */ | |
2304 | spec_val = IS_SPECULATIVE_INSN (insn1) - IS_SPECULATIVE_INSN (insn2); | |
2305 | if (spec_val) | |
2306 | return spec_val; | |
2307 | ||
2308 | /* Prefer a more probable (speculative) insn. */ | |
2309 | prob_val = INSN_PROBABILITY (insn2) - INSN_PROBABILITY (insn1); | |
2310 | if (prob_val) | |
2311 | return prob_val; | |
2312 | } | |
2313 | return 0; | |
2314 | } | |
2315 | ||
18e720b3 BS |
2316 | /* NEXT is an instruction that depends on INSN (a backward dependence); |
2317 | return nonzero if we should include this dependence in priority | |
2318 | calculations. */ | |
2319 | ||
2320 | static int | |
2321 | contributes_to_priority (next, insn) | |
2322 | rtx next, insn; | |
2323 | { | |
2324 | return BLOCK_NUM (next) == BLOCK_NUM (insn); | |
2325 | } | |
2326 | ||
2327 | /* INSN is a JUMP_INSN. Store the set of registers that must be considered | |
2328 | to be set by this jump in SET. */ | |
2329 | ||
2330 | static void | |
2331 | compute_jump_reg_dependencies (insn, set) | |
2332 | rtx insn ATTRIBUTE_UNUSED; | |
2333 | regset set ATTRIBUTE_UNUSED; | |
2334 | { | |
2335 | /* Nothing to do here, since we postprocess jumps in | |
2336 | add_branch_dependences. */ | |
2337 | } | |
2338 | ||
b4ead7d4 BS |
2339 | /* Used in schedule_insns to initialize current_sched_info for scheduling |
2340 | regions (or single basic blocks). */ | |
2341 | ||
2342 | static struct sched_info region_sched_info = | |
2343 | { | |
2344 | init_ready_list, | |
2345 | can_schedule_ready_p, | |
2346 | schedule_more_p, | |
2347 | new_ready, | |
2348 | rgn_rank, | |
2349 | rgn_print_insn, | |
18e720b3 BS |
2350 | contributes_to_priority, |
2351 | compute_jump_reg_dependencies, | |
b4ead7d4 BS |
2352 | |
2353 | NULL, NULL, | |
2354 | NULL, NULL, | |
4b6c5340 | 2355 | 0, 0 |
b4ead7d4 BS |
2356 | }; |
2357 | ||
2358 | /* Add dependences so that branches are scheduled to run last in their | |
2359 | block. */ | |
2360 | ||
2361 | static void | |
2362 | add_branch_dependences (head, tail) | |
2363 | rtx head, tail; | |
2364 | { | |
2365 | rtx insn, last; | |
2366 | ||
2367 | /* For all branches, calls, uses, clobbers, and cc0 setters, force them | |
2368 | to remain in order at the end of the block by adding dependencies and | |
2369 | giving the last a high priority. There may be notes present, and | |
2370 | prev_head may also be a note. | |
2371 | ||
2372 | Branches must obviously remain at the end. Calls should remain at the | |
2373 | end since moving them results in worse register allocation. Uses remain | |
2374 | at the end to ensure proper register allocation. cc0 setters remaim | |
2375 | at the end because they can't be moved away from their cc0 user. */ | |
2376 | insn = tail; | |
2377 | last = 0; | |
2378 | while (GET_CODE (insn) == CALL_INSN | |
2379 | || GET_CODE (insn) == JUMP_INSN | |
2380 | || (GET_CODE (insn) == INSN | |
2381 | && (GET_CODE (PATTERN (insn)) == USE | |
2382 | || GET_CODE (PATTERN (insn)) == CLOBBER | |
2383 | #ifdef HAVE_cc0 | |
2384 | || sets_cc0_p (PATTERN (insn)) | |
2385 | #endif | |
2386 | )) | |
2387 | || GET_CODE (insn) == NOTE) | |
2388 | { | |
2389 | if (GET_CODE (insn) != NOTE) | |
2390 | { | |
2391 | if (last != 0 | |
2392 | && !find_insn_list (insn, LOG_LINKS (last))) | |
2393 | { | |
2394 | add_dependence (last, insn, REG_DEP_ANTI); | |
2395 | INSN_REF_COUNT (insn)++; | |
2396 | } | |
2397 | ||
2398 | CANT_MOVE (insn) = 1; | |
2399 | ||
2400 | last = insn; | |
2401 | /* Skip over insns that are part of a group. | |
2402 | Make each insn explicitly depend on the previous insn. | |
2403 | This ensures that only the group header will ever enter | |
2404 | the ready queue (and, when scheduled, will automatically | |
2405 | schedule the SCHED_GROUP_P block). */ | |
2406 | while (SCHED_GROUP_P (insn)) | |
2407 | { | |
2408 | rtx temp = prev_nonnote_insn (insn); | |
2409 | add_dependence (insn, temp, REG_DEP_ANTI); | |
2410 | insn = temp; | |
2411 | } | |
2412 | } | |
2413 | ||
2414 | /* Don't overrun the bounds of the basic block. */ | |
2415 | if (insn == head) | |
2416 | break; | |
2417 | ||
2418 | insn = PREV_INSN (insn); | |
2419 | } | |
2420 | ||
2421 | /* Make sure these insns are scheduled last in their block. */ | |
2422 | insn = last; | |
2423 | if (insn != 0) | |
2424 | while (insn != head) | |
2425 | { | |
2426 | insn = prev_nonnote_insn (insn); | |
2427 | ||
2428 | if (INSN_REF_COUNT (insn) != 0) | |
2429 | continue; | |
2430 | ||
2431 | add_dependence (last, insn, REG_DEP_ANTI); | |
2432 | INSN_REF_COUNT (insn) = 1; | |
2433 | ||
2434 | /* Skip over insns that are part of a group. */ | |
2435 | while (SCHED_GROUP_P (insn)) | |
2436 | insn = prev_nonnote_insn (insn); | |
2437 | } | |
2438 | } | |
2439 | ||
2440 | /* Data structures for the computation of data dependences in a regions. We | |
2441 | keep one `deps' structure for every basic block. Before analyzing the | |
2442 | data dependences for a bb, its variables are initialized as a function of | |
2443 | the variables of its predecessors. When the analysis for a bb completes, | |
2444 | we save the contents to the corresponding bb_deps[bb] variable. */ | |
2445 | ||
2446 | static struct deps *bb_deps; | |
2447 | ||
2448 | /* After computing the dependencies for block BB, propagate the dependencies | |
4ba478b8 | 2449 | found in TMP_DEPS to the successors of the block. */ |
b4ead7d4 | 2450 | static void |
4ba478b8 | 2451 | propagate_deps (bb, tmp_deps) |
b4ead7d4 BS |
2452 | int bb; |
2453 | struct deps *tmp_deps; | |
b4ead7d4 BS |
2454 | { |
2455 | int b = BB_TO_BLOCK (bb); | |
2456 | int e, first_edge; | |
2457 | int reg; | |
2458 | rtx link_insn, link_mem; | |
2459 | rtx u; | |
2460 | ||
2461 | /* These lists should point to the right place, for correct | |
2462 | freeing later. */ | |
2463 | bb_deps[bb].pending_read_insns = tmp_deps->pending_read_insns; | |
2464 | bb_deps[bb].pending_read_mems = tmp_deps->pending_read_mems; | |
2465 | bb_deps[bb].pending_write_insns = tmp_deps->pending_write_insns; | |
2466 | bb_deps[bb].pending_write_mems = tmp_deps->pending_write_mems; | |
2467 | ||
2468 | /* bb's structures are inherited by its successors. */ | |
2469 | first_edge = e = OUT_EDGES (b); | |
2470 | if (e <= 0) | |
2471 | return; | |
2472 | ||
2473 | do | |
2474 | { | |
2475 | rtx x; | |
2476 | int b_succ = TO_BLOCK (e); | |
2477 | int bb_succ = BLOCK_TO_BB (b_succ); | |
2478 | struct deps *succ_deps = bb_deps + bb_succ; | |
2479 | ||
2480 | /* Only bbs "below" bb, in the same region, are interesting. */ | |
2481 | if (CONTAINING_RGN (b) != CONTAINING_RGN (b_succ) | |
2482 | || bb_succ <= bb) | |
2483 | { | |
2484 | e = NEXT_OUT (e); | |
2485 | continue; | |
2486 | } | |
2487 | ||
4ba478b8 RH |
2488 | /* The reg_last lists are inherited by bb_succ. */ |
2489 | EXECUTE_IF_SET_IN_REG_SET (&tmp_deps->reg_last_in_use, 0, reg, | |
b4ead7d4 | 2490 | { |
4ba478b8 RH |
2491 | struct deps_reg *tmp_deps_reg = &tmp_deps->reg_last[reg]; |
2492 | struct deps_reg *succ_deps_reg = &succ_deps->reg_last[reg]; | |
2493 | ||
2494 | for (u = tmp_deps_reg->uses; u; u = XEXP (u, 1)) | |
2495 | if (! find_insn_list (XEXP (u, 0), succ_deps_reg->uses)) | |
2496 | succ_deps_reg->uses | |
2497 | = alloc_INSN_LIST (XEXP (u, 0), succ_deps_reg->uses); | |
2498 | ||
2499 | for (u = tmp_deps_reg->sets; u; u = XEXP (u, 1)) | |
2500 | if (! find_insn_list (XEXP (u, 0), succ_deps_reg->sets)) | |
2501 | succ_deps_reg->sets | |
2502 | = alloc_INSN_LIST (XEXP (u, 0), succ_deps_reg->sets); | |
2503 | ||
2504 | for (u = tmp_deps_reg->clobbers; u; u = XEXP (u, 1)) | |
2505 | if (! find_insn_list (XEXP (u, 0), succ_deps_reg->clobbers)) | |
2506 | succ_deps_reg->clobbers | |
2507 | = alloc_INSN_LIST (XEXP (u, 0), succ_deps_reg->clobbers); | |
2508 | }); | |
2509 | IOR_REG_SET (&succ_deps->reg_last_in_use, &tmp_deps->reg_last_in_use); | |
b4ead7d4 BS |
2510 | |
2511 | /* Mem read/write lists are inherited by bb_succ. */ | |
2512 | link_insn = tmp_deps->pending_read_insns; | |
2513 | link_mem = tmp_deps->pending_read_mems; | |
2514 | while (link_insn) | |
2515 | { | |
2516 | if (!(find_insn_mem_list (XEXP (link_insn, 0), | |
2517 | XEXP (link_mem, 0), | |
2518 | succ_deps->pending_read_insns, | |
2519 | succ_deps->pending_read_mems))) | |
2520 | add_insn_mem_dependence (succ_deps, &succ_deps->pending_read_insns, | |
2521 | &succ_deps->pending_read_mems, | |
2522 | XEXP (link_insn, 0), XEXP (link_mem, 0)); | |
2523 | link_insn = XEXP (link_insn, 1); | |
2524 | link_mem = XEXP (link_mem, 1); | |
2525 | } | |
2526 | ||
2527 | link_insn = tmp_deps->pending_write_insns; | |
2528 | link_mem = tmp_deps->pending_write_mems; | |
2529 | while (link_insn) | |
2530 | { | |
2531 | if (!(find_insn_mem_list (XEXP (link_insn, 0), | |
2532 | XEXP (link_mem, 0), | |
2533 | succ_deps->pending_write_insns, | |
2534 | succ_deps->pending_write_mems))) | |
2535 | add_insn_mem_dependence (succ_deps, | |
2536 | &succ_deps->pending_write_insns, | |
2537 | &succ_deps->pending_write_mems, | |
2538 | XEXP (link_insn, 0), XEXP (link_mem, 0)); | |
2539 | ||
2540 | link_insn = XEXP (link_insn, 1); | |
2541 | link_mem = XEXP (link_mem, 1); | |
2542 | } | |
2543 | ||
2544 | /* last_function_call is inherited by bb_succ. */ | |
2545 | for (u = tmp_deps->last_function_call; u; u = XEXP (u, 1)) | |
4ba478b8 | 2546 | if (! find_insn_list (XEXP (u, 0), succ_deps->last_function_call)) |
b4ead7d4 | 2547 | succ_deps->last_function_call |
4ba478b8 | 2548 | = alloc_INSN_LIST (XEXP (u, 0), succ_deps->last_function_call); |
b4ead7d4 BS |
2549 | |
2550 | /* last_pending_memory_flush is inherited by bb_succ. */ | |
2551 | for (u = tmp_deps->last_pending_memory_flush; u; u = XEXP (u, 1)) | |
4ba478b8 | 2552 | if (! find_insn_list (XEXP (u, 0), |
b4ead7d4 | 2553 | succ_deps->last_pending_memory_flush)) |
b4ead7d4 BS |
2554 | succ_deps->last_pending_memory_flush |
2555 | = alloc_INSN_LIST (XEXP (u, 0), | |
2556 | succ_deps->last_pending_memory_flush); | |
b4ead7d4 BS |
2557 | |
2558 | /* sched_before_next_call is inherited by bb_succ. */ | |
2559 | x = LOG_LINKS (tmp_deps->sched_before_next_call); | |
2560 | for (; x; x = XEXP (x, 1)) | |
2561 | add_dependence (succ_deps->sched_before_next_call, | |
2562 | XEXP (x, 0), REG_DEP_ANTI); | |
2563 | ||
2564 | e = NEXT_OUT (e); | |
2565 | } | |
2566 | while (e != first_edge); | |
2567 | } | |
2568 | ||
2569 | /* Compute backward dependences inside bb. In a multiple blocks region: | |
2570 | (1) a bb is analyzed after its predecessors, and (2) the lists in | |
2571 | effect at the end of bb (after analyzing for bb) are inherited by | |
2572 | bb's successrs. | |
2573 | ||
2574 | Specifically for reg-reg data dependences, the block insns are | |
2575 | scanned by sched_analyze () top-to-bottom. Two lists are | |
4ba478b8 RH |
2576 | maintained by sched_analyze (): reg_last[].sets for register DEFs, |
2577 | and reg_last[].uses for register USEs. | |
b4ead7d4 BS |
2578 | |
2579 | When analysis is completed for bb, we update for its successors: | |
2580 | ; - DEFS[succ] = Union (DEFS [succ], DEFS [bb]) | |
2581 | ; - USES[succ] = Union (USES [succ], DEFS [bb]) | |
2582 | ||
2583 | The mechanism for computing mem-mem data dependence is very | |
2584 | similar, and the result is interblock dependences in the region. */ | |
2585 | ||
2586 | static void | |
2587 | compute_block_backward_dependences (bb) | |
2588 | int bb; | |
2589 | { | |
2590 | rtx head, tail; | |
b4ead7d4 BS |
2591 | struct deps tmp_deps; |
2592 | ||
2593 | tmp_deps = bb_deps[bb]; | |
2594 | ||
2595 | /* Do the analysis for this block. */ | |
2596 | get_block_head_tail (BB_TO_BLOCK (bb), &head, &tail); | |
2597 | sched_analyze (&tmp_deps, head, tail); | |
2598 | add_branch_dependences (head, tail); | |
2599 | ||
2600 | if (current_nr_blocks > 1) | |
4ba478b8 | 2601 | propagate_deps (bb, &tmp_deps); |
b4ead7d4 BS |
2602 | |
2603 | /* Free up the INSN_LISTs. */ | |
2604 | free_deps (&tmp_deps); | |
b4ead7d4 | 2605 | } |
4ba478b8 | 2606 | |
b4ead7d4 BS |
2607 | /* Remove all INSN_LISTs and EXPR_LISTs from the pending lists and add |
2608 | them to the unused_*_list variables, so that they can be reused. */ | |
2609 | ||
2610 | static void | |
2611 | free_pending_lists () | |
2612 | { | |
2613 | int bb; | |
2614 | ||
2615 | for (bb = 0; bb < current_nr_blocks; bb++) | |
2616 | { | |
2617 | free_INSN_LIST_list (&bb_deps[bb].pending_read_insns); | |
2618 | free_INSN_LIST_list (&bb_deps[bb].pending_write_insns); | |
2619 | free_EXPR_LIST_list (&bb_deps[bb].pending_read_mems); | |
2620 | free_EXPR_LIST_list (&bb_deps[bb].pending_write_mems); | |
2621 | } | |
2622 | } | |
2623 | \f | |
2624 | /* Print dependences for debugging, callable from debugger. */ | |
2625 | ||
2626 | void | |
2627 | debug_dependencies () | |
2628 | { | |
2629 | int bb; | |
2630 | ||
2631 | fprintf (sched_dump, ";; --------------- forward dependences: ------------ \n"); | |
2632 | for (bb = 0; bb < current_nr_blocks; bb++) | |
2633 | { | |
2634 | if (1) | |
2635 | { | |
2636 | rtx head, tail; | |
2637 | rtx next_tail; | |
2638 | rtx insn; | |
2639 | ||
2640 | get_block_head_tail (BB_TO_BLOCK (bb), &head, &tail); | |
2641 | next_tail = NEXT_INSN (tail); | |
2642 | fprintf (sched_dump, "\n;; --- Region Dependences --- b %d bb %d \n", | |
2643 | BB_TO_BLOCK (bb), bb); | |
2644 | ||
b8ec5764 VM |
2645 | fprintf (sched_dump, ";; %7s%6s%6s%6s%6s%6s%11s%6s\n", |
2646 | "insn", "code", "bb", "dep", "prio", "cost", "blockage", "units"); | |
2647 | fprintf (sched_dump, ";; %7s%6s%6s%6s%6s%6s%11s%6s\n", | |
2648 | "----", "----", "--", "---", "----", "----", "--------", "-----"); | |
b4ead7d4 BS |
2649 | for (insn = head; insn != next_tail; insn = NEXT_INSN (insn)) |
2650 | { | |
2651 | rtx link; | |
b8ec5764 | 2652 | int unit, range; |
b4ead7d4 BS |
2653 | |
2654 | if (! INSN_P (insn)) | |
2655 | { | |
2656 | int n; | |
2657 | fprintf (sched_dump, ";; %6d ", INSN_UID (insn)); | |
2658 | if (GET_CODE (insn) == NOTE) | |
2659 | { | |
2660 | n = NOTE_LINE_NUMBER (insn); | |
2661 | if (n < 0) | |
2662 | fprintf (sched_dump, "%s\n", GET_NOTE_INSN_NAME (n)); | |
2663 | else | |
2664 | fprintf (sched_dump, "line %d, file %s\n", n, | |
2665 | NOTE_SOURCE_FILE (insn)); | |
2666 | } | |
2667 | else | |
2668 | fprintf (sched_dump, " {%s}\n", GET_RTX_NAME (GET_CODE (insn))); | |
2669 | continue; | |
2670 | } | |
2671 | ||
b8ec5764 VM |
2672 | unit = insn_unit (insn); |
2673 | range = (unit < 0 | |
2674 | || function_units[unit].blockage_range_function == 0) ? 0 : | |
2675 | function_units[unit].blockage_range_function (insn); | |
2676 | fprintf (sched_dump, | |
2677 | ";; %s%5d%6d%6d%6d%6d%6d %3d -%3d ", | |
2678 | (SCHED_GROUP_P (insn) ? "+" : " "), | |
2679 | INSN_UID (insn), | |
2680 | INSN_CODE (insn), | |
2681 | INSN_BB (insn), | |
2682 | INSN_DEP_COUNT (insn), | |
2683 | INSN_PRIORITY (insn), | |
2684 | insn_cost (insn, 0, 0), | |
2685 | (int) MIN_BLOCKAGE_COST (range), | |
2686 | (int) MAX_BLOCKAGE_COST (range)); | |
2687 | insn_print_units (insn); | |
b4ead7d4 BS |
2688 | fprintf (sched_dump, "\t: "); |
2689 | for (link = INSN_DEPEND (insn); link; link = XEXP (link, 1)) | |
2690 | fprintf (sched_dump, "%d ", INSN_UID (XEXP (link, 0))); | |
2691 | fprintf (sched_dump, "\n"); | |
2692 | } | |
2693 | } | |
2694 | } | |
2695 | fprintf (sched_dump, "\n"); | |
2696 | } | |
2697 | \f | |
2698 | /* Schedule a region. A region is either an inner loop, a loop-free | |
2699 | subroutine, or a single basic block. Each bb in the region is | |
2700 | scheduled after its flow predecessors. */ | |
2701 | ||
2702 | static void | |
2703 | schedule_region (rgn) | |
2704 | int rgn; | |
2705 | { | |
2706 | int bb; | |
2707 | int rgn_n_insns = 0; | |
2708 | int sched_rgn_n_insns = 0; | |
2709 | ||
2710 | /* Set variables for the current region. */ | |
2711 | current_nr_blocks = RGN_NR_BLOCKS (rgn); | |
2712 | current_blocks = RGN_BLOCKS (rgn); | |
2713 | ||
2714 | init_deps_global (); | |
2715 | ||
2716 | /* Initializations for region data dependence analyisis. */ | |
2717 | bb_deps = (struct deps *) xmalloc (sizeof (struct deps) * current_nr_blocks); | |
2718 | for (bb = 0; bb < current_nr_blocks; bb++) | |
2719 | init_deps (bb_deps + bb); | |
2720 | ||
2721 | /* Compute LOG_LINKS. */ | |
2722 | for (bb = 0; bb < current_nr_blocks; bb++) | |
2723 | compute_block_backward_dependences (bb); | |
2724 | ||
2725 | /* Compute INSN_DEPEND. */ | |
2726 | for (bb = current_nr_blocks - 1; bb >= 0; bb--) | |
2727 | { | |
2728 | rtx head, tail; | |
2729 | get_block_head_tail (BB_TO_BLOCK (bb), &head, &tail); | |
2730 | ||
2731 | compute_forward_dependences (head, tail); | |
2732 | } | |
2733 | ||
2734 | /* Set priorities. */ | |
2735 | for (bb = 0; bb < current_nr_blocks; bb++) | |
79c2ffde BS |
2736 | { |
2737 | rtx head, tail; | |
2738 | get_block_head_tail (BB_TO_BLOCK (bb), &head, &tail); | |
2739 | ||
2740 | rgn_n_insns += set_priorities (head, tail); | |
2741 | } | |
b4ead7d4 BS |
2742 | |
2743 | /* Compute interblock info: probabilities, split-edges, dominators, etc. */ | |
2744 | if (current_nr_blocks > 1) | |
2745 | { | |
2746 | int i; | |
2747 | ||
2748 | prob = (float *) xmalloc ((current_nr_blocks) * sizeof (float)); | |
2749 | ||
2750 | bbset_size = current_nr_blocks / HOST_BITS_PER_WIDE_INT + 1; | |
2751 | dom = (bbset *) xmalloc (current_nr_blocks * sizeof (bbset)); | |
2752 | for (i = 0; i < current_nr_blocks; i++) | |
2753 | dom[i] = (bbset) xcalloc (bbset_size, sizeof (HOST_WIDE_INT)); | |
2754 | ||
2755 | /* Edge to bit. */ | |
2756 | rgn_nr_edges = 0; | |
2757 | edge_to_bit = (int *) xmalloc (nr_edges * sizeof (int)); | |
2758 | for (i = 1; i < nr_edges; i++) | |
2759 | if (CONTAINING_RGN (FROM_BLOCK (i)) == rgn) | |
2760 | EDGE_TO_BIT (i) = rgn_nr_edges++; | |
2761 | rgn_edges = (int *) xmalloc (rgn_nr_edges * sizeof (int)); | |
2762 | ||
2763 | rgn_nr_edges = 0; | |
2764 | for (i = 1; i < nr_edges; i++) | |
2765 | if (CONTAINING_RGN (FROM_BLOCK (i)) == (rgn)) | |
2766 | rgn_edges[rgn_nr_edges++] = i; | |
2767 | ||
2768 | /* Split edges. */ | |
2769 | edgeset_size = rgn_nr_edges / HOST_BITS_PER_WIDE_INT + 1; | |
2770 | edgeset_bitsize = rgn_nr_edges; | |
2771 | pot_split = (edgeset *) xmalloc (current_nr_blocks * sizeof (edgeset)); | |
2772 | ancestor_edges | |
2773 | = (edgeset *) xmalloc (current_nr_blocks * sizeof (edgeset)); | |
2774 | for (i = 0; i < current_nr_blocks; i++) | |
2775 | { | |
2776 | pot_split[i] = | |
2777 | (edgeset) xcalloc (edgeset_size, sizeof (HOST_WIDE_INT)); | |
2778 | ancestor_edges[i] = | |
2779 | (edgeset) xcalloc (edgeset_size, sizeof (HOST_WIDE_INT)); | |
2780 | } | |
2781 | ||
2782 | /* Compute probabilities, dominators, split_edges. */ | |
2783 | for (bb = 0; bb < current_nr_blocks; bb++) | |
2784 | compute_dom_prob_ps (bb); | |
2785 | } | |
2786 | ||
2787 | /* Now we can schedule all blocks. */ | |
2788 | for (bb = 0; bb < current_nr_blocks; bb++) | |
2789 | { | |
2790 | rtx head, tail; | |
2791 | int b = BB_TO_BLOCK (bb); | |
2792 | ||
2793 | get_block_head_tail (b, &head, &tail); | |
2794 | ||
2795 | if (no_real_insns_p (head, tail)) | |
2796 | continue; | |
2797 | ||
2798 | current_sched_info->prev_head = PREV_INSN (head); | |
2799 | current_sched_info->next_tail = NEXT_INSN (tail); | |
2800 | ||
2801 | if (write_symbols != NO_DEBUG) | |
2802 | { | |
79c2ffde BS |
2803 | save_line_notes (b, head, tail); |
2804 | rm_line_notes (head, tail); | |
b4ead7d4 BS |
2805 | } |
2806 | ||
2807 | /* rm_other_notes only removes notes which are _inside_ the | |
2808 | block---that is, it won't remove notes before the first real insn | |
2809 | or after the last real insn of the block. So if the first insn | |
2810 | has a REG_SAVE_NOTE which would otherwise be emitted before the | |
2811 | insn, it is redundant with the note before the start of the | |
570a98eb | 2812 | block, and so we have to take it out. */ |
b4ead7d4 BS |
2813 | if (INSN_P (head)) |
2814 | { | |
2815 | rtx note; | |
2816 | ||
2817 | for (note = REG_NOTES (head); note; note = XEXP (note, 1)) | |
2818 | if (REG_NOTE_KIND (note) == REG_SAVE_NOTE) | |
2819 | { | |
570a98eb JH |
2820 | remove_note (head, note); |
2821 | note = XEXP (note, 1); | |
2822 | remove_note (head, note); | |
b4ead7d4 BS |
2823 | } |
2824 | } | |
2825 | ||
2826 | /* Remove remaining note insns from the block, save them in | |
2827 | note_list. These notes are restored at the end of | |
2828 | schedule_block (). */ | |
2829 | rm_other_notes (head, tail); | |
2830 | ||
2831 | target_bb = bb; | |
2832 | ||
2833 | current_sched_info->queue_must_finish_empty | |
2834 | = current_nr_blocks > 1 && !flag_schedule_interblock; | |
2835 | ||
2836 | schedule_block (b, rgn_n_insns); | |
2837 | sched_rgn_n_insns += sched_n_insns; | |
2838 | ||
2839 | /* Update target block boundaries. */ | |
2840 | if (head == BLOCK_HEAD (b)) | |
2841 | BLOCK_HEAD (b) = current_sched_info->head; | |
2842 | if (tail == BLOCK_END (b)) | |
2843 | BLOCK_END (b) = current_sched_info->tail; | |
2844 | ||
2845 | /* Clean up. */ | |
2846 | if (current_nr_blocks > 1) | |
2847 | { | |
2848 | free (candidate_table); | |
2849 | free (bblst_table); | |
2850 | free (bitlst_table); | |
2851 | } | |
2852 | } | |
2853 | ||
2854 | /* Sanity check: verify that all region insns were scheduled. */ | |
2855 | if (sched_rgn_n_insns != rgn_n_insns) | |
2856 | abort (); | |
2857 | ||
2858 | /* Restore line notes. */ | |
2859 | if (write_symbols != NO_DEBUG) | |
2860 | { | |
2861 | for (bb = 0; bb < current_nr_blocks; bb++) | |
79c2ffde BS |
2862 | { |
2863 | rtx head, tail; | |
2864 | get_block_head_tail (BB_TO_BLOCK (bb), &head, &tail); | |
14052b68 | 2865 | restore_line_notes (head, tail); |
79c2ffde | 2866 | } |
b4ead7d4 BS |
2867 | } |
2868 | ||
2869 | /* Done with this region. */ | |
2870 | free_pending_lists (); | |
2871 | ||
2872 | finish_deps_global (); | |
2873 | ||
2874 | free (bb_deps); | |
2875 | ||
2876 | if (current_nr_blocks > 1) | |
2877 | { | |
2878 | int i; | |
2879 | ||
2880 | free (prob); | |
2881 | for (i = 0; i < current_nr_blocks; ++i) | |
2882 | { | |
2883 | free (dom[i]); | |
2884 | free (pot_split[i]); | |
2885 | free (ancestor_edges[i]); | |
2886 | } | |
2887 | free (dom); | |
2888 | free (edge_to_bit); | |
2889 | free (rgn_edges); | |
2890 | free (pot_split); | |
2891 | free (ancestor_edges); | |
2892 | } | |
2893 | } | |
2894 | ||
2895 | /* Indexed by region, holds the number of death notes found in that region. | |
2896 | Used for consistency checks. */ | |
2897 | static int *deaths_in_region; | |
2898 | ||
2899 | /* Initialize data structures for region scheduling. */ | |
2900 | ||
2901 | static void | |
2902 | init_regions () | |
2903 | { | |
2904 | sbitmap blocks; | |
2905 | int rgn; | |
2906 | ||
2907 | nr_regions = 0; | |
2908 | rgn_table = (region *) xmalloc ((n_basic_blocks) * sizeof (region)); | |
2909 | rgn_bb_table = (int *) xmalloc ((n_basic_blocks) * sizeof (int)); | |
2910 | block_to_bb = (int *) xmalloc ((n_basic_blocks) * sizeof (int)); | |
2911 | containing_rgn = (int *) xmalloc ((n_basic_blocks) * sizeof (int)); | |
2912 | ||
2913 | blocks = sbitmap_alloc (n_basic_blocks); | |
2914 | ||
2915 | /* Compute regions for scheduling. */ | |
2916 | if (reload_completed | |
2917 | || n_basic_blocks == 1 | |
2918 | || !flag_schedule_interblock) | |
2919 | { | |
2920 | find_single_block_region (); | |
2921 | } | |
2922 | else | |
2923 | { | |
2924 | /* Verify that a 'good' control flow graph can be built. */ | |
2925 | if (is_cfg_nonregular ()) | |
2926 | { | |
2927 | find_single_block_region (); | |
2928 | } | |
2929 | else | |
2930 | { | |
2931 | sbitmap *dom; | |
2932 | struct edge_list *edge_list; | |
2933 | ||
2934 | dom = sbitmap_vector_alloc (n_basic_blocks, n_basic_blocks); | |
2935 | ||
2936 | /* The scheduler runs after flow; therefore, we can't blindly call | |
2937 | back into find_basic_blocks since doing so could invalidate the | |
2938 | info in global_live_at_start. | |
2939 | ||
2940 | Consider a block consisting entirely of dead stores; after life | |
2941 | analysis it would be a block of NOTE_INSN_DELETED notes. If | |
2942 | we call find_basic_blocks again, then the block would be removed | |
2943 | entirely and invalidate our the register live information. | |
2944 | ||
2945 | We could (should?) recompute register live information. Doing | |
2946 | so may even be beneficial. */ | |
2947 | edge_list = create_edge_list (); | |
2948 | ||
2949 | /* Compute the dominators and post dominators. */ | |
2950 | calculate_dominance_info (NULL, dom, CDI_DOMINATORS); | |
2951 | ||
2952 | /* build_control_flow will return nonzero if it detects unreachable | |
2953 | blocks or any other irregularity with the cfg which prevents | |
2954 | cross block scheduling. */ | |
2955 | if (build_control_flow (edge_list) != 0) | |
2956 | find_single_block_region (); | |
2957 | else | |
2958 | find_rgns (edge_list, dom); | |
2959 | ||
2960 | if (sched_verbose >= 3) | |
2961 | debug_regions (); | |
2962 | ||
2963 | /* We are done with flow's edge list. */ | |
2964 | free_edge_list (edge_list); | |
2965 | ||
2966 | /* For now. This will move as more and more of haifa is converted | |
2967 | to using the cfg code in flow.c. */ | |
2968 | free (dom); | |
2969 | } | |
2970 | } | |
2971 | ||
2972 | deaths_in_region = (int *) xmalloc (sizeof (int) * nr_regions); | |
2973 | ||
2974 | /* Remove all death notes from the subroutine. */ | |
2975 | for (rgn = 0; rgn < nr_regions; rgn++) | |
2976 | { | |
2977 | int b; | |
2978 | ||
2979 | sbitmap_zero (blocks); | |
2980 | for (b = RGN_NR_BLOCKS (rgn) - 1; b >= 0; --b) | |
2981 | SET_BIT (blocks, rgn_bb_table[RGN_BLOCKS (rgn) + b]); | |
2982 | ||
2983 | deaths_in_region[rgn] = count_or_remove_death_notes (blocks, 1); | |
2984 | } | |
2985 | ||
2986 | sbitmap_free (blocks); | |
2987 | } | |
2988 | ||
2989 | /* The one entry point in this file. DUMP_FILE is the dump file for | |
2990 | this pass. */ | |
2991 | ||
2992 | void | |
2993 | schedule_insns (dump_file) | |
2994 | FILE *dump_file; | |
2995 | { | |
2996 | sbitmap large_region_blocks, blocks; | |
2997 | int rgn; | |
2998 | int any_large_regions; | |
2999 | ||
3000 | /* Taking care of this degenerate case makes the rest of | |
3001 | this code simpler. */ | |
3002 | if (n_basic_blocks == 0) | |
3003 | return; | |
3004 | ||
3005 | nr_inter = 0; | |
3006 | nr_spec = 0; | |
3007 | ||
3008 | sched_init (dump_file); | |
3009 | ||
3010 | init_regions (); | |
3011 | ||
3012 | current_sched_info = ®ion_sched_info; | |
3013 | ||
3014 | /* Schedule every region in the subroutine. */ | |
3015 | for (rgn = 0; rgn < nr_regions; rgn++) | |
3016 | schedule_region (rgn); | |
3017 | ||
3018 | /* Update life analysis for the subroutine. Do single block regions | |
3019 | first so that we can verify that live_at_start didn't change. Then | |
6d2f8887 | 3020 | do all other blocks. */ |
b4ead7d4 BS |
3021 | /* ??? There is an outside possibility that update_life_info, or more |
3022 | to the point propagate_block, could get called with non-zero flags | |
3023 | more than once for one basic block. This would be kinda bad if it | |
3024 | were to happen, since REG_INFO would be accumulated twice for the | |
3025 | block, and we'd have twice the REG_DEAD notes. | |
3026 | ||
3027 | I'm fairly certain that this _shouldn't_ happen, since I don't think | |
3028 | that live_at_start should change at region heads. Not sure what the | |
3029 | best way to test for this kind of thing... */ | |
3030 | ||
3031 | allocate_reg_life_data (); | |
3032 | compute_bb_for_insn (get_max_uid ()); | |
3033 | ||
3034 | any_large_regions = 0; | |
3035 | large_region_blocks = sbitmap_alloc (n_basic_blocks); | |
3036 | sbitmap_ones (large_region_blocks); | |
3037 | ||
3038 | blocks = sbitmap_alloc (n_basic_blocks); | |
3039 | ||
3040 | for (rgn = 0; rgn < nr_regions; rgn++) | |
3041 | if (RGN_NR_BLOCKS (rgn) > 1) | |
3042 | any_large_regions = 1; | |
3043 | else | |
3044 | { | |
3045 | sbitmap_zero (blocks); | |
3046 | SET_BIT (blocks, rgn_bb_table[RGN_BLOCKS (rgn)]); | |
3047 | RESET_BIT (large_region_blocks, rgn_bb_table[RGN_BLOCKS (rgn)]); | |
3048 | ||
3049 | /* Don't update reg info after reload, since that affects | |
3050 | regs_ever_live, which should not change after reload. */ | |
3051 | update_life_info (blocks, UPDATE_LIFE_LOCAL, | |
3052 | (reload_completed ? PROP_DEATH_NOTES | |
3053 | : PROP_DEATH_NOTES | PROP_REG_INFO)); | |
3054 | ||
3055 | #ifndef HAVE_conditional_execution | |
3056 | /* ??? REG_DEAD notes only exist for unconditional deaths. We need | |
3057 | a count of the conditional plus unconditional deaths for this to | |
3058 | work out. */ | |
3059 | /* In the single block case, the count of registers that died should | |
3060 | not have changed during the schedule. */ | |
3061 | if (count_or_remove_death_notes (blocks, 0) != deaths_in_region[rgn]) | |
3062 | abort (); | |
3063 | #endif | |
3064 | } | |
3065 | ||
3066 | if (any_large_regions) | |
3067 | { | |
3068 | update_life_info (large_region_blocks, UPDATE_LIFE_GLOBAL, | |
3069 | PROP_DEATH_NOTES | PROP_REG_INFO); | |
3070 | } | |
3071 | ||
3072 | /* Reposition the prologue and epilogue notes in case we moved the | |
3073 | prologue/epilogue insns. */ | |
3074 | if (reload_completed) | |
3075 | reposition_prologue_and_epilogue_notes (get_insns ()); | |
3076 | ||
3077 | /* Delete redundant line notes. */ | |
3078 | if (write_symbols != NO_DEBUG) | |
3079 | rm_redundant_line_notes (); | |
3080 | ||
3081 | if (sched_verbose) | |
3082 | { | |
3083 | if (reload_completed == 0 && flag_schedule_interblock) | |
3084 | { | |
3085 | fprintf (sched_dump, | |
3086 | "\n;; Procedure interblock/speculative motions == %d/%d \n", | |
3087 | nr_inter, nr_spec); | |
3088 | } | |
3089 | else | |
3090 | { | |
3091 | if (nr_inter > 0) | |
3092 | abort (); | |
3093 | } | |
3094 | fprintf (sched_dump, "\n\n"); | |
3095 | } | |
3096 | ||
3097 | /* Clean up. */ | |
3098 | free (rgn_table); | |
3099 | free (rgn_bb_table); | |
3100 | free (block_to_bb); | |
3101 | free (containing_rgn); | |
3102 | ||
3103 | sched_finish (); | |
3104 | ||
3105 | if (edge_table) | |
3106 | { | |
3107 | free (edge_table); | |
3108 | edge_table = NULL; | |
3109 | } | |
3110 | ||
3111 | if (in_edges) | |
3112 | { | |
3113 | free (in_edges); | |
3114 | in_edges = NULL; | |
3115 | } | |
3116 | if (out_edges) | |
3117 | { | |
3118 | free (out_edges); | |
3119 | out_edges = NULL; | |
3120 | } | |
3121 | ||
3122 | sbitmap_free (blocks); | |
3123 | sbitmap_free (large_region_blocks); | |
3124 | ||
3125 | free (deaths_in_region); | |
3126 | } | |
f56887a7 | 3127 | #endif |