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9ca8d59e | 1 | /* Generic partial redundancy elimination with lazy code motion support. |
b25a2bca | 2 | Copyright (C) 1998, 1999, 2000, 2001 Free Software Foundation, Inc. |
e48ba7af | 3 | |
4 | This file is part of GNU CC. | |
5 | ||
6 | GNU CC is free software; you can redistribute it and/or modify | |
7 | it under the terms of the GNU General Public License as published by | |
8 | the Free Software Foundation; either version 2, or (at your option) | |
9 | any later version. | |
10 | ||
11 | GNU CC is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | GNU General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
17 | along with GNU CC; see the file COPYING. If not, write to | |
18 | the Free Software Foundation, 59 Temple Place - Suite 330, | |
19 | Boston, MA 02111-1307, USA. */ | |
20 | ||
21 | /* These routines are meant to be used by various optimization | |
22 | passes which can be modeled as lazy code motion problems. | |
23 | Including, but not limited to: | |
24 | ||
25 | * Traditional partial redundancy elimination. | |
26 | ||
27 | * Placement of caller/caller register save/restores. | |
28 | ||
29 | * Load/store motion. | |
30 | ||
31 | * Copy motion. | |
32 | ||
33 | * Conversion of flat register files to a stacked register | |
34 | model. | |
35 | ||
36 | * Dead load/store elimination. | |
37 | ||
38 | These routines accept as input: | |
39 | ||
40 | * Basic block information (number of blocks, lists of | |
41 | predecessors and successors). Note the granularity | |
42 | does not need to be basic block, they could be statements | |
43 | or functions. | |
44 | ||
45 | * Bitmaps of local properties (computed, transparent and | |
46 | anticipatable expressions). | |
47 | ||
48 | The output of these routines is bitmap of redundant computations | |
49 | and a bitmap of optimal placement points. */ | |
50 | ||
51 | ||
52 | #include "config.h" | |
53 | #include "system.h" | |
e48ba7af | 54 | #include "rtl.h" |
55 | #include "regs.h" | |
56 | #include "hard-reg-set.h" | |
57 | #include "flags.h" | |
58 | #include "real.h" | |
59 | #include "insn-config.h" | |
60 | #include "recog.h" | |
61 | #include "basic-block.h" | |
18862b5a | 62 | #include "tm_p.h" |
9ca8d59e | 63 | |
18862b5a | 64 | /* We want target macros for the mode switching code to be able to refer |
65 | to instruction attribute values. */ | |
66 | #include "insn-attr.h" | |
e48ba7af | 67 | |
7bcd381b | 68 | /* Edge based LCM routines. */ |
9ca8d59e | 69 | static void compute_antinout_edge PARAMS ((sbitmap *, sbitmap *, |
70 | sbitmap *, sbitmap *)); | |
71 | static void compute_earliest PARAMS ((struct edge_list *, int, | |
72 | sbitmap *, sbitmap *, | |
73 | sbitmap *, sbitmap *, | |
74 | sbitmap *)); | |
75 | static void compute_laterin PARAMS ((struct edge_list *, sbitmap *, | |
76 | sbitmap *, sbitmap *, | |
77 | sbitmap *)); | |
78 | static void compute_insert_delete PARAMS ((struct edge_list *edge_list, | |
79 | sbitmap *, sbitmap *, | |
80 | sbitmap *, sbitmap *, | |
81 | sbitmap *)); | |
7bcd381b | 82 | |
83 | /* Edge based LCM routines on a reverse flowgraph. */ | |
9ca8d59e | 84 | static void compute_farthest PARAMS ((struct edge_list *, int, |
85 | sbitmap *, sbitmap *, | |
86 | sbitmap*, sbitmap *, | |
87 | sbitmap *)); | |
88 | static void compute_nearerout PARAMS ((struct edge_list *, sbitmap *, | |
89 | sbitmap *, sbitmap *, | |
90 | sbitmap *)); | |
91 | static void compute_rev_insert_delete PARAMS ((struct edge_list *edge_list, | |
92 | sbitmap *, sbitmap *, | |
93 | sbitmap *, sbitmap *, | |
94 | sbitmap *)); | |
7bcd381b | 95 | \f |
96 | /* Edge based lcm routines. */ | |
97 | ||
98 | /* Compute expression anticipatability at entrance and exit of each block. | |
99 | This is done based on the flow graph, and not on the pred-succ lists. | |
100 | Other than that, its pretty much identical to compute_antinout. */ | |
e48ba7af | 101 | |
102 | static void | |
7bcd381b | 103 | compute_antinout_edge (antloc, transp, antin, antout) |
e48ba7af | 104 | sbitmap *antloc; |
105 | sbitmap *transp; | |
106 | sbitmap *antin; | |
107 | sbitmap *antout; | |
108 | { | |
2325f0e2 | 109 | int bb; |
7bcd381b | 110 | edge e; |
2c59145b | 111 | basic_block *worklist, *qin, *qout, *qend; |
112 | unsigned int qlen; | |
e48ba7af | 113 | |
2325f0e2 | 114 | /* Allocate a worklist array/queue. Entries are only added to the |
115 | list if they were not already on the list. So the size is | |
116 | bounded by the number of basic blocks. */ | |
2c59145b | 117 | qin = qout = worklist |
9ca8d59e | 118 | = (basic_block *) xmalloc (sizeof (basic_block) * n_basic_blocks); |
e48ba7af | 119 | |
2325f0e2 | 120 | /* We want a maximal solution, so make an optimistic initialization of |
121 | ANTIN. */ | |
122 | sbitmap_vector_ones (antin, n_basic_blocks); | |
e48ba7af | 123 | |
5d6931e2 | 124 | /* Put every block on the worklist; this is necessary because of the |
125 | optimistic initialization of ANTIN above. */ | |
2c59145b | 126 | for (bb = n_basic_blocks - 1; bb >= 0; bb--) |
e48ba7af | 127 | { |
2c59145b | 128 | *qin++ = BASIC_BLOCK (bb); |
5d6931e2 | 129 | BASIC_BLOCK (bb)->aux = BASIC_BLOCK (bb); |
2325f0e2 | 130 | } |
2c59145b | 131 | |
132 | qin = worklist; | |
133 | qend = &worklist[n_basic_blocks]; | |
134 | qlen = n_basic_blocks; | |
e48ba7af | 135 | |
5d6931e2 | 136 | /* Mark blocks which are predecessors of the exit block so that we |
137 | can easily identify them below. */ | |
138 | for (e = EXIT_BLOCK_PTR->pred; e; e = e->pred_next) | |
139 | e->src->aux = EXIT_BLOCK_PTR; | |
140 | ||
2325f0e2 | 141 | /* Iterate until the worklist is empty. */ |
2c59145b | 142 | while (qlen) |
2325f0e2 | 143 | { |
144 | /* Take the first entry off the worklist. */ | |
2c59145b | 145 | basic_block b = *qout++; |
2325f0e2 | 146 | bb = b->index; |
2c59145b | 147 | qlen--; |
148 | ||
149 | if (qout >= qend) | |
150 | qout = worklist; | |
e48ba7af | 151 | |
2325f0e2 | 152 | if (b->aux == EXIT_BLOCK_PTR) |
9ca8d59e | 153 | /* Do not clear the aux field for blocks which are predecessors of |
154 | the EXIT block. That way we never add then to the worklist | |
155 | again. */ | |
156 | sbitmap_zero (antout[bb]); | |
2325f0e2 | 157 | else |
158 | { | |
159 | /* Clear the aux field of this block so that it can be added to | |
160 | the worklist again if necessary. */ | |
161 | b->aux = NULL; | |
162 | sbitmap_intersection_of_succs (antout[bb], antin, bb); | |
163 | } | |
7bcd381b | 164 | |
2325f0e2 | 165 | if (sbitmap_a_or_b_and_c (antin[bb], antloc[bb], transp[bb], antout[bb])) |
9ca8d59e | 166 | /* If the in state of this block changed, then we need |
167 | to add the predecessors of this block to the worklist | |
168 | if they are not already on the worklist. */ | |
169 | for (e = b->pred; e; e = e->pred_next) | |
170 | if (!e->src->aux && e->src != ENTRY_BLOCK_PTR) | |
e48ba7af | 171 | { |
2c59145b | 172 | *qin++ = e->src; |
9ca8d59e | 173 | e->src->aux = e; |
2c59145b | 174 | qlen++; |
175 | if (qin >= qend) | |
176 | qin = worklist; | |
e48ba7af | 177 | } |
e48ba7af | 178 | } |
9ca8d59e | 179 | |
2c59145b | 180 | free (worklist); |
e48ba7af | 181 | } |
182 | ||
7bcd381b | 183 | /* Compute the earliest vector for edge based lcm. */ |
9ca8d59e | 184 | |
e48ba7af | 185 | static void |
7bcd381b | 186 | compute_earliest (edge_list, n_exprs, antin, antout, avout, kill, earliest) |
187 | struct edge_list *edge_list; | |
e48ba7af | 188 | int n_exprs; |
7bcd381b | 189 | sbitmap *antin, *antout, *avout, *kill, *earliest; |
e48ba7af | 190 | { |
7bcd381b | 191 | sbitmap difference, temp_bitmap; |
192 | int x, num_edges; | |
193 | basic_block pred, succ; | |
e48ba7af | 194 | |
7bcd381b | 195 | num_edges = NUM_EDGES (edge_list); |
e48ba7af | 196 | |
7bcd381b | 197 | difference = sbitmap_alloc (n_exprs); |
198 | temp_bitmap = sbitmap_alloc (n_exprs); | |
e48ba7af | 199 | |
7bcd381b | 200 | for (x = 0; x < num_edges; x++) |
e48ba7af | 201 | { |
7bcd381b | 202 | pred = INDEX_EDGE_PRED_BB (edge_list, x); |
203 | succ = INDEX_EDGE_SUCC_BB (edge_list, x); | |
204 | if (pred == ENTRY_BLOCK_PTR) | |
205 | sbitmap_copy (earliest[x], antin[succ->index]); | |
206 | else | |
207 | { | |
1287c919 | 208 | /* We refer to the EXIT_BLOCK index, instead of testing for |
209 | EXIT_BLOCK_PTR, so that EXIT_BLOCK_PTR's index can be | |
210 | changed so as to pretend it's a regular block, so that | |
211 | its antin can be taken into account. */ | |
212 | if (succ->index == EXIT_BLOCK) | |
9ca8d59e | 213 | sbitmap_zero (earliest[x]); |
7bcd381b | 214 | else |
e48ba7af | 215 | { |
7bcd381b | 216 | sbitmap_difference (difference, antin[succ->index], |
217 | avout[pred->index]); | |
218 | sbitmap_not (temp_bitmap, antout[pred->index]); | |
9ca8d59e | 219 | sbitmap_a_and_b_or_c (earliest[x], difference, |
220 | kill[pred->index], temp_bitmap); | |
e48ba7af | 221 | } |
222 | } | |
e48ba7af | 223 | } |
9ca8d59e | 224 | |
e48ba7af | 225 | free (temp_bitmap); |
7bcd381b | 226 | free (difference); |
e48ba7af | 227 | } |
228 | ||
2325f0e2 | 229 | /* later(p,s) is dependent on the calculation of laterin(p). |
230 | laterin(p) is dependent on the calculation of later(p2,p). | |
231 | ||
232 | laterin(ENTRY) is defined as all 0's | |
233 | later(ENTRY, succs(ENTRY)) are defined using laterin(ENTRY) | |
234 | laterin(succs(ENTRY)) is defined by later(ENTRY, succs(ENTRY)). | |
235 | ||
236 | If we progress in this manner, starting with all basic blocks | |
237 | in the work list, anytime we change later(bb), we need to add | |
238 | succs(bb) to the worklist if they are not already on the worklist. | |
239 | ||
240 | Boundary conditions: | |
241 | ||
242 | We prime the worklist all the normal basic blocks. The ENTRY block can | |
243 | never be added to the worklist since it is never the successor of any | |
244 | block. We explicitly prevent the EXIT block from being added to the | |
245 | worklist. | |
246 | ||
247 | We optimistically initialize LATER. That is the only time this routine | |
248 | will compute LATER for an edge out of the entry block since the entry | |
249 | block is never on the worklist. Thus, LATERIN is neither used nor | |
250 | computed for the ENTRY block. | |
251 | ||
252 | Since the EXIT block is never added to the worklist, we will neither | |
253 | use nor compute LATERIN for the exit block. Edges which reach the | |
254 | EXIT block are handled in the normal fashion inside the loop. However, | |
255 | the insertion/deletion computation needs LATERIN(EXIT), so we have | |
256 | to compute it. */ | |
257 | ||
e48ba7af | 258 | static void |
2325f0e2 | 259 | compute_laterin (edge_list, earliest, antloc, later, laterin) |
7bcd381b | 260 | struct edge_list *edge_list; |
7bcd381b | 261 | sbitmap *earliest, *antloc, *later, *laterin; |
e48ba7af | 262 | { |
2325f0e2 | 263 | int bb, num_edges, i; |
264 | edge e; | |
2c59145b | 265 | basic_block *worklist, *qin, *qout, *qend; |
266 | unsigned int qlen; | |
e48ba7af | 267 | |
7bcd381b | 268 | num_edges = NUM_EDGES (edge_list); |
e48ba7af | 269 | |
2325f0e2 | 270 | /* Allocate a worklist array/queue. Entries are only added to the |
271 | list if they were not already on the list. So the size is | |
272 | bounded by the number of basic blocks. */ | |
2c59145b | 273 | qin = qout = worklist |
9ca8d59e | 274 | = (basic_block *) xmalloc (sizeof (basic_block) * (n_basic_blocks + 1)); |
2325f0e2 | 275 | |
276 | /* Initialize a mapping from each edge to its index. */ | |
277 | for (i = 0; i < num_edges; i++) | |
9ffd5d6d | 278 | INDEX_EDGE (edge_list, i)->aux = (void *) (size_t) i; |
2325f0e2 | 279 | |
280 | /* We want a maximal solution, so initially consider LATER true for | |
281 | all edges. This allows propagation through a loop since the incoming | |
282 | loop edge will have LATER set, so if all the other incoming edges | |
283 | to the loop are set, then LATERIN will be set for the head of the | |
284 | loop. | |
285 | ||
286 | If the optimistic setting of LATER on that edge was incorrect (for | |
287 | example the expression is ANTLOC in a block within the loop) then | |
288 | this algorithm will detect it when we process the block at the head | |
289 | of the optimistic edge. That will requeue the affected blocks. */ | |
290 | sbitmap_vector_ones (later, num_edges); | |
291 | ||
048599b9 | 292 | /* Note that even though we want an optimistic setting of LATER, we |
293 | do not want to be overly optimistic. Consider an outgoing edge from | |
294 | the entry block. That edge should always have a LATER value the | |
295 | same as EARLIEST for that edge. */ | |
296 | for (e = ENTRY_BLOCK_PTR->succ; e; e = e->succ_next) | |
9ca8d59e | 297 | sbitmap_copy (later[(size_t) e->aux], earliest[(size_t) e->aux]); |
048599b9 | 298 | |
2325f0e2 | 299 | /* Add all the blocks to the worklist. This prevents an early exit from |
300 | the loop given our optimistic initialization of LATER above. */ | |
2c59145b | 301 | for (bb = 0; bb < n_basic_blocks; bb++) |
e48ba7af | 302 | { |
2325f0e2 | 303 | basic_block b = BASIC_BLOCK (bb); |
2c59145b | 304 | *qin++ = b; |
2325f0e2 | 305 | b->aux = b; |
7bcd381b | 306 | } |
2c59145b | 307 | qin = worklist; |
308 | /* Note that we do not use the last allocated element for our queue, | |
309 | as EXIT_BLOCK is never inserted into it. In fact the above allocation | |
310 | of n_basic_blocks + 1 elements is not encessary. */ | |
311 | qend = &worklist[n_basic_blocks]; | |
312 | qlen = n_basic_blocks; | |
7bcd381b | 313 | |
2325f0e2 | 314 | /* Iterate until the worklist is empty. */ |
2c59145b | 315 | while (qlen) |
7bcd381b | 316 | { |
2325f0e2 | 317 | /* Take the first entry off the worklist. */ |
2c59145b | 318 | basic_block b = *qout++; |
2325f0e2 | 319 | b->aux = NULL; |
2c59145b | 320 | qlen--; |
321 | if (qout >= qend) | |
322 | qout = worklist; | |
2325f0e2 | 323 | |
324 | /* Compute the intersection of LATERIN for each incoming edge to B. */ | |
325 | bb = b->index; | |
326 | sbitmap_ones (laterin[bb]); | |
327 | for (e = b->pred; e != NULL; e = e->pred_next) | |
9ffd5d6d | 328 | sbitmap_a_and_b (laterin[bb], laterin[bb], later[(size_t)e->aux]); |
2325f0e2 | 329 | |
330 | /* Calculate LATER for all outgoing edges. */ | |
331 | for (e = b->succ; e != NULL; e = e->succ_next) | |
9ca8d59e | 332 | if (sbitmap_union_of_diff (later[(size_t) e->aux], |
333 | earliest[(size_t) e->aux], | |
334 | laterin[e->src->index], | |
335 | antloc[e->src->index]) | |
336 | /* If LATER for an outgoing edge was changed, then we need | |
337 | to add the target of the outgoing edge to the worklist. */ | |
338 | && e->dest != EXIT_BLOCK_PTR && e->dest->aux == 0) | |
339 | { | |
2c59145b | 340 | *qin++ = e->dest; |
9ca8d59e | 341 | e->dest->aux = e; |
2c59145b | 342 | qlen++; |
343 | if (qin >= qend) | |
344 | qin = worklist; | |
9ca8d59e | 345 | } |
e48ba7af | 346 | } |
347 | ||
2325f0e2 | 348 | /* Computation of insertion and deletion points requires computing LATERIN |
349 | for the EXIT block. We allocated an extra entry in the LATERIN array | |
350 | for just this purpose. */ | |
351 | sbitmap_ones (laterin[n_basic_blocks]); | |
352 | for (e = EXIT_BLOCK_PTR->pred; e != NULL; e = e->pred_next) | |
353 | sbitmap_a_and_b (laterin[n_basic_blocks], | |
354 | laterin[n_basic_blocks], | |
9ffd5d6d | 355 | later[(size_t) e->aux]); |
2325f0e2 | 356 | |
2c59145b | 357 | free (worklist); |
e48ba7af | 358 | } |
359 | ||
7bcd381b | 360 | /* Compute the insertion and deletion points for edge based LCM. */ |
9ca8d59e | 361 | |
7bcd381b | 362 | static void |
363 | compute_insert_delete (edge_list, antloc, later, laterin, | |
364 | insert, delete) | |
365 | struct edge_list *edge_list; | |
366 | sbitmap *antloc, *later, *laterin, *insert, *delete; | |
367 | { | |
368 | int x; | |
e48ba7af | 369 | |
7bcd381b | 370 | for (x = 0; x < n_basic_blocks; x++) |
371 | sbitmap_difference (delete[x], antloc[x], laterin[x]); | |
372 | ||
373 | for (x = 0; x < NUM_EDGES (edge_list); x++) | |
374 | { | |
375 | basic_block b = INDEX_EDGE_SUCC_BB (edge_list, x); | |
9ca8d59e | 376 | |
7bcd381b | 377 | if (b == EXIT_BLOCK_PTR) |
378 | sbitmap_difference (insert[x], later[x], laterin[n_basic_blocks]); | |
379 | else | |
380 | sbitmap_difference (insert[x], later[x], laterin[b->index]); | |
381 | } | |
382 | } | |
e48ba7af | 383 | |
9ca8d59e | 384 | /* Given local properties TRANSP, ANTLOC, AVOUT, KILL return the insert and |
385 | delete vectors for edge based LCM. Returns an edgelist which is used to | |
386 | map the insert vector to what edge an expression should be inserted on. */ | |
e48ba7af | 387 | |
7bcd381b | 388 | struct edge_list * |
389 | pre_edge_lcm (file, n_exprs, transp, avloc, antloc, kill, insert, delete) | |
27548a74 | 390 | FILE *file ATTRIBUTE_UNUSED; |
e48ba7af | 391 | int n_exprs; |
7bcd381b | 392 | sbitmap *transp; |
393 | sbitmap *avloc; | |
e48ba7af | 394 | sbitmap *antloc; |
7bcd381b | 395 | sbitmap *kill; |
396 | sbitmap **insert; | |
397 | sbitmap **delete; | |
e48ba7af | 398 | { |
7bcd381b | 399 | sbitmap *antin, *antout, *earliest; |
400 | sbitmap *avin, *avout; | |
401 | sbitmap *later, *laterin; | |
402 | struct edge_list *edge_list; | |
403 | int num_edges; | |
e48ba7af | 404 | |
7bcd381b | 405 | edge_list = create_edge_list (); |
406 | num_edges = NUM_EDGES (edge_list); | |
e48ba7af | 407 | |
7bcd381b | 408 | #ifdef LCM_DEBUG_INFO |
409 | if (file) | |
e48ba7af | 410 | { |
7bcd381b | 411 | fprintf (file, "Edge List:\n"); |
412 | verify_edge_list (file, edge_list); | |
413 | print_edge_list (file, edge_list); | |
414 | dump_sbitmap_vector (file, "transp", "", transp, n_basic_blocks); | |
415 | dump_sbitmap_vector (file, "antloc", "", antloc, n_basic_blocks); | |
416 | dump_sbitmap_vector (file, "avloc", "", avloc, n_basic_blocks); | |
417 | dump_sbitmap_vector (file, "kill", "", kill, n_basic_blocks); | |
e48ba7af | 418 | } |
7bcd381b | 419 | #endif |
e48ba7af | 420 | |
7bcd381b | 421 | /* Compute global availability. */ |
422 | avin = sbitmap_vector_alloc (n_basic_blocks, n_exprs); | |
423 | avout = sbitmap_vector_alloc (n_basic_blocks, n_exprs); | |
424 | compute_available (avloc, kill, avout, avin); | |
cca23eb2 | 425 | sbitmap_vector_free (avin); |
e48ba7af | 426 | |
7bcd381b | 427 | /* Compute global anticipatability. */ |
428 | antin = sbitmap_vector_alloc (n_basic_blocks, n_exprs); | |
429 | antout = sbitmap_vector_alloc (n_basic_blocks, n_exprs); | |
430 | compute_antinout_edge (antloc, transp, antin, antout); | |
e48ba7af | 431 | |
7bcd381b | 432 | #ifdef LCM_DEBUG_INFO |
433 | if (file) | |
e48ba7af | 434 | { |
7bcd381b | 435 | dump_sbitmap_vector (file, "antin", "", antin, n_basic_blocks); |
436 | dump_sbitmap_vector (file, "antout", "", antout, n_basic_blocks); | |
e48ba7af | 437 | } |
7bcd381b | 438 | #endif |
e48ba7af | 439 | |
7bcd381b | 440 | /* Compute earliestness. */ |
441 | earliest = sbitmap_vector_alloc (num_edges, n_exprs); | |
442 | compute_earliest (edge_list, n_exprs, antin, antout, avout, kill, earliest); | |
e48ba7af | 443 | |
7bcd381b | 444 | #ifdef LCM_DEBUG_INFO |
445 | if (file) | |
446 | dump_sbitmap_vector (file, "earliest", "", earliest, num_edges); | |
447 | #endif | |
e48ba7af | 448 | |
cca23eb2 | 449 | sbitmap_vector_free (antout); |
450 | sbitmap_vector_free (antin); | |
451 | sbitmap_vector_free (avout); | |
e48ba7af | 452 | |
7bcd381b | 453 | later = sbitmap_vector_alloc (num_edges, n_exprs); |
9ca8d59e | 454 | |
7bcd381b | 455 | /* Allocate an extra element for the exit block in the laterin vector. */ |
456 | laterin = sbitmap_vector_alloc (n_basic_blocks + 1, n_exprs); | |
2325f0e2 | 457 | compute_laterin (edge_list, earliest, antloc, later, laterin); |
458 | ||
7bcd381b | 459 | #ifdef LCM_DEBUG_INFO |
460 | if (file) | |
461 | { | |
462 | dump_sbitmap_vector (file, "laterin", "", laterin, n_basic_blocks + 1); | |
463 | dump_sbitmap_vector (file, "later", "", later, num_edges); | |
464 | } | |
465 | #endif | |
e48ba7af | 466 | |
cca23eb2 | 467 | sbitmap_vector_free (earliest); |
7bcd381b | 468 | |
469 | *insert = sbitmap_vector_alloc (num_edges, n_exprs); | |
470 | *delete = sbitmap_vector_alloc (n_basic_blocks, n_exprs); | |
471 | compute_insert_delete (edge_list, antloc, later, laterin, *insert, *delete); | |
e48ba7af | 472 | |
cca23eb2 | 473 | sbitmap_vector_free (laterin); |
474 | sbitmap_vector_free (later); | |
7bcd381b | 475 | |
476 | #ifdef LCM_DEBUG_INFO | |
477 | if (file) | |
e48ba7af | 478 | { |
7bcd381b | 479 | dump_sbitmap_vector (file, "pre_insert_map", "", *insert, num_edges); |
9ca8d59e | 480 | dump_sbitmap_vector (file, "pre_delete_map", "", *delete, |
481 | n_basic_blocks); | |
e48ba7af | 482 | } |
7bcd381b | 483 | #endif |
e48ba7af | 484 | |
7bcd381b | 485 | return edge_list; |
486 | } | |
e48ba7af | 487 | |
7bcd381b | 488 | /* Compute the AVIN and AVOUT vectors from the AVLOC and KILL vectors. |
489 | Return the number of passes we performed to iterate to a solution. */ | |
9ca8d59e | 490 | |
2325f0e2 | 491 | void |
7bcd381b | 492 | compute_available (avloc, kill, avout, avin) |
493 | sbitmap *avloc, *kill, *avout, *avin; | |
e48ba7af | 494 | { |
2325f0e2 | 495 | int bb; |
496 | edge e; | |
2c59145b | 497 | basic_block *worklist, *qin, *qout, *qend; |
498 | unsigned int qlen; | |
e48ba7af | 499 | |
2325f0e2 | 500 | /* Allocate a worklist array/queue. Entries are only added to the |
501 | list if they were not already on the list. So the size is | |
502 | bounded by the number of basic blocks. */ | |
2c59145b | 503 | qin = qout = worklist |
9ca8d59e | 504 | = (basic_block *) xmalloc (sizeof (basic_block) * n_basic_blocks); |
e48ba7af | 505 | |
2325f0e2 | 506 | /* We want a maximal solution. */ |
507 | sbitmap_vector_ones (avout, n_basic_blocks); | |
508 | ||
5d6931e2 | 509 | /* Put every block on the worklist; this is necessary because of the |
510 | optimistic initialization of AVOUT above. */ | |
2c59145b | 511 | for (bb = 0; bb < n_basic_blocks; bb++) |
e48ba7af | 512 | { |
2c59145b | 513 | *qin++ = BASIC_BLOCK (bb); |
5d6931e2 | 514 | BASIC_BLOCK (bb)->aux = BASIC_BLOCK (bb); |
e48ba7af | 515 | } |
2c59145b | 516 | |
517 | qin = worklist; | |
518 | qend = &worklist[n_basic_blocks]; | |
519 | qlen = n_basic_blocks; | |
2325f0e2 | 520 | |
5d6931e2 | 521 | /* Mark blocks which are successors of the entry block so that we |
522 | can easily identify them below. */ | |
523 | for (e = ENTRY_BLOCK_PTR->succ; e; e = e->succ_next) | |
524 | e->dest->aux = ENTRY_BLOCK_PTR; | |
525 | ||
2325f0e2 | 526 | /* Iterate until the worklist is empty. */ |
2c59145b | 527 | while (qlen) |
2325f0e2 | 528 | { |
529 | /* Take the first entry off the worklist. */ | |
2c59145b | 530 | basic_block b = *qout++; |
2325f0e2 | 531 | bb = b->index; |
2c59145b | 532 | qlen--; |
533 | ||
534 | if (qout >= qend) | |
535 | qout = worklist; | |
2325f0e2 | 536 | |
537 | /* If one of the predecessor blocks is the ENTRY block, then the | |
538 | intersection of avouts is the null set. We can identify such blocks | |
539 | by the special value in the AUX field in the block structure. */ | |
540 | if (b->aux == ENTRY_BLOCK_PTR) | |
9ca8d59e | 541 | /* Do not clear the aux field for blocks which are successors of the |
542 | ENTRY block. That way we never add then to the worklist again. */ | |
543 | sbitmap_zero (avin[bb]); | |
2325f0e2 | 544 | else |
545 | { | |
546 | /* Clear the aux field of this block so that it can be added to | |
547 | the worklist again if necessary. */ | |
548 | b->aux = NULL; | |
549 | sbitmap_intersection_of_preds (avin[bb], avout, bb); | |
550 | } | |
551 | ||
552 | if (sbitmap_union_of_diff (avout[bb], avloc[bb], avin[bb], kill[bb])) | |
9ca8d59e | 553 | /* If the out state of this block changed, then we need |
554 | to add the successors of this block to the worklist | |
555 | if they are not already on the worklist. */ | |
556 | for (e = b->succ; e; e = e->succ_next) | |
557 | if (!e->dest->aux && e->dest != EXIT_BLOCK_PTR) | |
2325f0e2 | 558 | { |
2c59145b | 559 | *qin++ = e->dest; |
9ca8d59e | 560 | e->dest->aux = e; |
2c59145b | 561 | qlen++; |
562 | ||
563 | if (qin >= qend) | |
564 | qin = worklist; | |
2325f0e2 | 565 | } |
2325f0e2 | 566 | } |
9ca8d59e | 567 | |
2c59145b | 568 | free (worklist); |
e48ba7af | 569 | } |
570 | ||
7bcd381b | 571 | /* Compute the farthest vector for edge based lcm. */ |
9ca8d59e | 572 | |
e48ba7af | 573 | static void |
7bcd381b | 574 | compute_farthest (edge_list, n_exprs, st_avout, st_avin, st_antin, |
575 | kill, farthest) | |
576 | struct edge_list *edge_list; | |
e48ba7af | 577 | int n_exprs; |
7bcd381b | 578 | sbitmap *st_avout, *st_avin, *st_antin, *kill, *farthest; |
e48ba7af | 579 | { |
7bcd381b | 580 | sbitmap difference, temp_bitmap; |
581 | int x, num_edges; | |
582 | basic_block pred, succ; | |
e48ba7af | 583 | |
7bcd381b | 584 | num_edges = NUM_EDGES (edge_list); |
e48ba7af | 585 | |
7bcd381b | 586 | difference = sbitmap_alloc (n_exprs); |
587 | temp_bitmap = sbitmap_alloc (n_exprs); | |
e48ba7af | 588 | |
7bcd381b | 589 | for (x = 0; x < num_edges; x++) |
e48ba7af | 590 | { |
7bcd381b | 591 | pred = INDEX_EDGE_PRED_BB (edge_list, x); |
592 | succ = INDEX_EDGE_SUCC_BB (edge_list, x); | |
593 | if (succ == EXIT_BLOCK_PTR) | |
594 | sbitmap_copy (farthest[x], st_avout[pred->index]); | |
595 | else | |
e48ba7af | 596 | { |
7bcd381b | 597 | if (pred == ENTRY_BLOCK_PTR) |
9ca8d59e | 598 | sbitmap_zero (farthest[x]); |
7bcd381b | 599 | else |
600 | { | |
601 | sbitmap_difference (difference, st_avout[pred->index], | |
602 | st_antin[succ->index]); | |
603 | sbitmap_not (temp_bitmap, st_avin[succ->index]); | |
604 | sbitmap_a_and_b_or_c (farthest[x], difference, | |
605 | kill[succ->index], temp_bitmap); | |
606 | } | |
e48ba7af | 607 | } |
e48ba7af | 608 | } |
9ca8d59e | 609 | |
e48ba7af | 610 | free (temp_bitmap); |
7bcd381b | 611 | free (difference); |
e48ba7af | 612 | } |
613 | ||
2325f0e2 | 614 | /* Compute nearer and nearerout vectors for edge based lcm. |
615 | ||
616 | This is the mirror of compute_laterin, additional comments on the | |
617 | implementation can be found before compute_laterin. */ | |
618 | ||
e48ba7af | 619 | static void |
2325f0e2 | 620 | compute_nearerout (edge_list, farthest, st_avloc, nearer, nearerout) |
7bcd381b | 621 | struct edge_list *edge_list; |
7bcd381b | 622 | sbitmap *farthest, *st_avloc, *nearer, *nearerout; |
e48ba7af | 623 | { |
2325f0e2 | 624 | int bb, num_edges, i; |
625 | edge e; | |
626 | basic_block *worklist, *tos; | |
e48ba7af | 627 | |
7bcd381b | 628 | num_edges = NUM_EDGES (edge_list); |
e48ba7af | 629 | |
2325f0e2 | 630 | /* Allocate a worklist array/queue. Entries are only added to the |
631 | list if they were not already on the list. So the size is | |
632 | bounded by the number of basic blocks. */ | |
9ca8d59e | 633 | tos = worklist |
634 | = (basic_block *) xmalloc (sizeof (basic_block) * (n_basic_blocks + 1)); | |
e48ba7af | 635 | |
2325f0e2 | 636 | /* Initialize NEARER for each edge and build a mapping from an edge to |
637 | its index. */ | |
638 | for (i = 0; i < num_edges; i++) | |
9ffd5d6d | 639 | INDEX_EDGE (edge_list, i)->aux = (void *) (size_t) i; |
7bcd381b | 640 | |
2325f0e2 | 641 | /* We want a maximal solution. */ |
642 | sbitmap_vector_ones (nearer, num_edges); | |
643 | ||
048599b9 | 644 | /* Note that even though we want an optimistic setting of NEARER, we |
645 | do not want to be overly optimistic. Consider an incoming edge to | |
646 | the exit block. That edge should always have a NEARER value the | |
647 | same as FARTHEST for that edge. */ | |
648 | for (e = EXIT_BLOCK_PTR->pred; e; e = e->pred_next) | |
8b863f57 | 649 | sbitmap_copy (nearer[(size_t)e->aux], farthest[(size_t)e->aux]); |
048599b9 | 650 | |
2325f0e2 | 651 | /* Add all the blocks to the worklist. This prevents an early exit |
652 | from the loop given our optimistic initialization of NEARER. */ | |
653 | for (bb = 0; bb < n_basic_blocks; bb++) | |
e48ba7af | 654 | { |
2325f0e2 | 655 | basic_block b = BASIC_BLOCK (bb); |
656 | *tos++ = b; | |
657 | b->aux = b; | |
7bcd381b | 658 | } |
2325f0e2 | 659 | |
660 | /* Iterate until the worklist is empty. */ | |
661 | while (tos != worklist) | |
7bcd381b | 662 | { |
2325f0e2 | 663 | /* Take the first entry off the worklist. */ |
664 | basic_block b = *--tos; | |
665 | b->aux = NULL; | |
666 | ||
667 | /* Compute the intersection of NEARER for each outgoing edge from B. */ | |
668 | bb = b->index; | |
669 | sbitmap_ones (nearerout[bb]); | |
670 | for (e = b->succ; e != NULL; e = e->succ_next) | |
9ffd5d6d | 671 | sbitmap_a_and_b (nearerout[bb], nearerout[bb], |
672 | nearer[(size_t) e->aux]); | |
2325f0e2 | 673 | |
674 | /* Calculate NEARER for all incoming edges. */ | |
675 | for (e = b->pred; e != NULL; e = e->pred_next) | |
9ca8d59e | 676 | if (sbitmap_union_of_diff (nearer[(size_t) e->aux], |
677 | farthest[(size_t) e->aux], | |
678 | nearerout[e->dest->index], | |
679 | st_avloc[e->dest->index]) | |
680 | /* If NEARER for an incoming edge was changed, then we need | |
681 | to add the source of the incoming edge to the worklist. */ | |
682 | && e->src != ENTRY_BLOCK_PTR && e->src->aux == 0) | |
683 | { | |
684 | *tos++ = e->src; | |
685 | e->src->aux = e; | |
686 | } | |
7bcd381b | 687 | } |
e48ba7af | 688 | |
2325f0e2 | 689 | /* Computation of insertion and deletion points requires computing NEAREROUT |
690 | for the ENTRY block. We allocated an extra entry in the NEAREROUT array | |
691 | for just this purpose. */ | |
692 | sbitmap_ones (nearerout[n_basic_blocks]); | |
693 | for (e = ENTRY_BLOCK_PTR->succ; e != NULL; e = e->succ_next) | |
694 | sbitmap_a_and_b (nearerout[n_basic_blocks], | |
695 | nearerout[n_basic_blocks], | |
9ffd5d6d | 696 | nearer[(size_t) e->aux]); |
2325f0e2 | 697 | |
698 | free (tos); | |
7bcd381b | 699 | } |
e48ba7af | 700 | |
7bcd381b | 701 | /* Compute the insertion and deletion points for edge based LCM. */ |
9ca8d59e | 702 | |
e48ba7af | 703 | static void |
7bcd381b | 704 | compute_rev_insert_delete (edge_list, st_avloc, nearer, nearerout, |
705 | insert, delete) | |
706 | struct edge_list *edge_list; | |
707 | sbitmap *st_avloc, *nearer, *nearerout, *insert, *delete; | |
e48ba7af | 708 | { |
7bcd381b | 709 | int x; |
e48ba7af | 710 | |
7bcd381b | 711 | for (x = 0; x < n_basic_blocks; x++) |
712 | sbitmap_difference (delete[x], st_avloc[x], nearerout[x]); | |
713 | ||
714 | for (x = 0; x < NUM_EDGES (edge_list); x++) | |
e48ba7af | 715 | { |
7bcd381b | 716 | basic_block b = INDEX_EDGE_PRED_BB (edge_list, x); |
717 | if (b == ENTRY_BLOCK_PTR) | |
718 | sbitmap_difference (insert[x], nearer[x], nearerout[n_basic_blocks]); | |
e48ba7af | 719 | else |
7bcd381b | 720 | sbitmap_difference (insert[x], nearer[x], nearerout[b->index]); |
e48ba7af | 721 | } |
e48ba7af | 722 | } |
723 | ||
7bcd381b | 724 | /* Given local properties TRANSP, ST_AVLOC, ST_ANTLOC, KILL return the |
725 | insert and delete vectors for edge based reverse LCM. Returns an | |
726 | edgelist which is used to map the insert vector to what edge | |
727 | an expression should be inserted on. */ | |
e48ba7af | 728 | |
7bcd381b | 729 | struct edge_list * |
730 | pre_edge_rev_lcm (file, n_exprs, transp, st_avloc, st_antloc, kill, | |
731 | insert, delete) | |
27548a74 | 732 | FILE *file ATTRIBUTE_UNUSED; |
7bcd381b | 733 | int n_exprs; |
734 | sbitmap *transp; | |
735 | sbitmap *st_avloc; | |
736 | sbitmap *st_antloc; | |
737 | sbitmap *kill; | |
738 | sbitmap **insert; | |
739 | sbitmap **delete; | |
e48ba7af | 740 | { |
7bcd381b | 741 | sbitmap *st_antin, *st_antout; |
742 | sbitmap *st_avout, *st_avin, *farthest; | |
743 | sbitmap *nearer, *nearerout; | |
744 | struct edge_list *edge_list; | |
27548a74 | 745 | int num_edges; |
7bcd381b | 746 | |
747 | edge_list = create_edge_list (); | |
748 | num_edges = NUM_EDGES (edge_list); | |
749 | ||
750 | st_antin = (sbitmap *) sbitmap_vector_alloc (n_basic_blocks, n_exprs); | |
751 | st_antout = (sbitmap *) sbitmap_vector_alloc (n_basic_blocks, n_exprs); | |
752 | sbitmap_vector_zero (st_antin, n_basic_blocks); | |
753 | sbitmap_vector_zero (st_antout, n_basic_blocks); | |
754 | compute_antinout_edge (st_antloc, transp, st_antin, st_antout); | |
755 | ||
756 | /* Compute global anticipatability. */ | |
757 | st_avout = sbitmap_vector_alloc (n_basic_blocks, n_exprs); | |
758 | st_avin = sbitmap_vector_alloc (n_basic_blocks, n_exprs); | |
759 | compute_available (st_avloc, kill, st_avout, st_avin); | |
760 | ||
761 | #ifdef LCM_DEBUG_INFO | |
762 | if (file) | |
763 | { | |
764 | fprintf (file, "Edge List:\n"); | |
765 | verify_edge_list (file, edge_list); | |
766 | print_edge_list (file, edge_list); | |
767 | dump_sbitmap_vector (file, "transp", "", transp, n_basic_blocks); | |
768 | dump_sbitmap_vector (file, "st_avloc", "", st_avloc, n_basic_blocks); | |
769 | dump_sbitmap_vector (file, "st_antloc", "", st_antloc, n_basic_blocks); | |
770 | dump_sbitmap_vector (file, "st_antin", "", st_antin, n_basic_blocks); | |
771 | dump_sbitmap_vector (file, "st_antout", "", st_antout, n_basic_blocks); | |
772 | dump_sbitmap_vector (file, "st_kill", "", kill, n_basic_blocks); | |
773 | } | |
774 | #endif | |
e48ba7af | 775 | |
7bcd381b | 776 | #ifdef LCM_DEBUG_INFO |
777 | if (file) | |
778 | { | |
779 | dump_sbitmap_vector (file, "st_avout", "", st_avout, n_basic_blocks); | |
780 | dump_sbitmap_vector (file, "st_avin", "", st_avin, n_basic_blocks); | |
781 | } | |
782 | #endif | |
e48ba7af | 783 | |
7bcd381b | 784 | /* Compute farthestness. */ |
785 | farthest = sbitmap_vector_alloc (num_edges, n_exprs); | |
786 | compute_farthest (edge_list, n_exprs, st_avout, st_avin, st_antin, | |
787 | kill, farthest); | |
788 | ||
789 | #ifdef LCM_DEBUG_INFO | |
790 | if (file) | |
791 | dump_sbitmap_vector (file, "farthest", "", farthest, num_edges); | |
792 | #endif | |
793 | ||
cca23eb2 | 794 | sbitmap_vector_free (st_antin); |
795 | sbitmap_vector_free (st_antout); | |
796 | ||
797 | sbitmap_vector_free (st_avin); | |
798 | sbitmap_vector_free (st_avout); | |
7bcd381b | 799 | |
800 | nearer = sbitmap_vector_alloc (num_edges, n_exprs); | |
9ca8d59e | 801 | |
7bcd381b | 802 | /* Allocate an extra element for the entry block. */ |
803 | nearerout = sbitmap_vector_alloc (n_basic_blocks + 1, n_exprs); | |
2325f0e2 | 804 | compute_nearerout (edge_list, farthest, st_avloc, nearer, nearerout); |
7bcd381b | 805 | |
806 | #ifdef LCM_DEBUG_INFO | |
807 | if (file) | |
e48ba7af | 808 | { |
7bcd381b | 809 | dump_sbitmap_vector (file, "nearerout", "", nearerout, |
810 | n_basic_blocks + 1); | |
811 | dump_sbitmap_vector (file, "nearer", "", nearer, num_edges); | |
e48ba7af | 812 | } |
7bcd381b | 813 | #endif |
814 | ||
cca23eb2 | 815 | sbitmap_vector_free (farthest); |
7bcd381b | 816 | |
817 | *insert = sbitmap_vector_alloc (num_edges, n_exprs); | |
818 | *delete = sbitmap_vector_alloc (n_basic_blocks, n_exprs); | |
9ca8d59e | 819 | compute_rev_insert_delete (edge_list, st_avloc, nearer, nearerout, |
820 | *insert, *delete); | |
7bcd381b | 821 | |
cca23eb2 | 822 | sbitmap_vector_free (nearerout); |
823 | sbitmap_vector_free (nearer); | |
7bcd381b | 824 | |
825 | #ifdef LCM_DEBUG_INFO | |
826 | if (file) | |
827 | { | |
828 | dump_sbitmap_vector (file, "pre_insert_map", "", *insert, num_edges); | |
9ca8d59e | 829 | dump_sbitmap_vector (file, "pre_delete_map", "", *delete, |
830 | n_basic_blocks); | |
7bcd381b | 831 | } |
832 | #endif | |
7bcd381b | 833 | return edge_list; |
e48ba7af | 834 | } |
18862b5a | 835 | |
9ca8d59e | 836 | /* Mode switching: |
837 | ||
838 | The algorithm for setting the modes consists of scanning the insn list | |
18862b5a | 839 | and finding all the insns which require a specific mode. Each insn gets |
840 | a unique struct seginfo element. These structures are inserted into a list | |
841 | for each basic block. For each entity, there is an array of bb_info over | |
842 | the flow graph basic blocks (local var 'bb_info'), and contains a list | |
843 | of all insns within that basic block, in the order they are encountered. | |
844 | ||
845 | For each entity, any basic block WITHOUT any insns requiring a specific | |
846 | mode are given a single entry, without a mode. (Each basic block | |
847 | in the flow graph must have at least one entry in the segment table.) | |
848 | ||
849 | The LCM algorithm is then run over the flow graph to determine where to | |
850 | place the sets to the highest-priority value in respect of first the first | |
851 | insn in any one block. Any adjustments required to the transparancy | |
852 | vectors are made, then the next iteration starts for the next-lower | |
853 | priority mode, till for each entity all modes are exhasted. | |
854 | ||
855 | More details are located in the code for optimize_mode_switching(). */ | |
856 | ||
857 | /* This structure contains the information for each insn which requires | |
858 | either single or double mode to be set. | |
859 | MODE is the mode this insn must be executed in. | |
f913e47c | 860 | INSN_PTR is the insn to be executed (may be the note that marks the |
861 | beginning of a basic block). | |
18862b5a | 862 | BBNUM is the flow graph basic block this insn occurs in. |
863 | NEXT is the next insn in the same basic block. */ | |
864 | struct seginfo | |
865 | { | |
866 | int mode; | |
867 | rtx insn_ptr; | |
868 | int bbnum; | |
869 | struct seginfo *next; | |
870 | HARD_REG_SET regs_live; | |
871 | }; | |
872 | ||
873 | struct bb_info | |
874 | { | |
875 | struct seginfo *seginfo; | |
876 | int computing; | |
877 | }; | |
878 | ||
879 | /* These bitmaps are used for the LCM algorithm. */ | |
880 | ||
29768226 | 881 | #ifdef OPTIMIZE_MODE_SWITCHING |
18862b5a | 882 | static sbitmap *antic; |
883 | static sbitmap *transp; | |
884 | static sbitmap *comp; | |
885 | static sbitmap *delete; | |
886 | static sbitmap *insert; | |
887 | ||
7dff60c8 | 888 | static struct seginfo * new_seginfo PARAMS ((int, rtx, int, HARD_REG_SET)); |
18862b5a | 889 | static void add_seginfo PARAMS ((struct bb_info *, struct seginfo *)); |
18862b5a | 890 | static void reg_dies PARAMS ((rtx, HARD_REG_SET)); |
891 | static void reg_becomes_live PARAMS ((rtx, rtx, void *)); | |
29768226 | 892 | static void make_preds_opaque PARAMS ((basic_block, int)); |
893 | #endif | |
894 | \f | |
895 | #ifdef OPTIMIZE_MODE_SWITCHING | |
18862b5a | 896 | |
897 | /* This function will allocate a new BBINFO structure, initialized | |
7dff60c8 | 898 | with the MODE, INSN, and basic block BB parameters. */ |
29768226 | 899 | |
18862b5a | 900 | static struct seginfo * |
901 | new_seginfo (mode, insn, bb, regs_live) | |
902 | int mode; | |
903 | rtx insn; | |
904 | int bb; | |
905 | HARD_REG_SET regs_live; | |
906 | { | |
907 | struct seginfo *ptr; | |
908 | ptr = xmalloc (sizeof (struct seginfo)); | |
909 | ptr->mode = mode; | |
910 | ptr->insn_ptr = insn; | |
911 | ptr->bbnum = bb; | |
912 | ptr->next = NULL; | |
913 | COPY_HARD_REG_SET (ptr->regs_live, regs_live); | |
914 | return ptr; | |
915 | } | |
916 | ||
917 | /* Add a seginfo element to the end of a list. | |
918 | HEAD is a pointer to the list beginning. | |
919 | INFO is the structure to be linked in. */ | |
29768226 | 920 | |
18862b5a | 921 | static void |
922 | add_seginfo (head, info) | |
923 | struct bb_info *head; | |
924 | struct seginfo *info; | |
925 | { | |
926 | struct seginfo *ptr; | |
927 | ||
928 | if (head->seginfo == NULL) | |
929 | head->seginfo = info; | |
930 | else | |
931 | { | |
932 | ptr = head->seginfo; | |
933 | while (ptr->next != NULL) | |
934 | ptr = ptr->next; | |
935 | ptr->next = info; | |
936 | } | |
937 | } | |
938 | ||
939 | /* Make all predecessors of basic block B opaque, recursively, till we hit | |
940 | some that are already non-transparent, or an edge where aux is set; that | |
941 | denotes that a mode set is to be done on that edge. | |
942 | J is the bit number in the bitmaps that corresponds to the entity that | |
943 | we are currently handling mode-switching for. */ | |
29768226 | 944 | |
18862b5a | 945 | static void |
946 | make_preds_opaque (b, j) | |
947 | basic_block b; | |
948 | int j; | |
949 | { | |
950 | edge e; | |
951 | ||
952 | for (e = b->pred; e; e = e->pred_next) | |
953 | { | |
954 | basic_block pb = e->src; | |
9ca8d59e | 955 | |
18862b5a | 956 | if (e->aux || ! TEST_BIT (transp[pb->index], j)) |
957 | continue; | |
9ca8d59e | 958 | |
18862b5a | 959 | RESET_BIT (transp[pb->index], j); |
960 | make_preds_opaque (pb, j); | |
961 | } | |
962 | } | |
963 | ||
964 | /* Record in LIVE that register REG died. */ | |
29768226 | 965 | |
18862b5a | 966 | static void |
967 | reg_dies (reg, live) | |
968 | rtx reg; | |
969 | HARD_REG_SET live; | |
970 | { | |
9ca8d59e | 971 | int regno, nregs; |
18862b5a | 972 | |
973 | if (GET_CODE (reg) != REG) | |
974 | return; | |
9ca8d59e | 975 | |
18862b5a | 976 | regno = REGNO (reg); |
977 | if (regno < FIRST_PSEUDO_REGISTER) | |
9ca8d59e | 978 | for (nregs = HARD_REGNO_NREGS (regno, GET_MODE (reg)) - 1; nregs >= 0; |
979 | nregs--) | |
980 | CLEAR_HARD_REG_BIT (live, regno + nregs); | |
18862b5a | 981 | } |
982 | ||
983 | /* Record in LIVE that register REG became live. | |
984 | This is called via note_stores. */ | |
29768226 | 985 | |
18862b5a | 986 | static void |
987 | reg_becomes_live (reg, setter, live) | |
988 | rtx reg; | |
989 | rtx setter ATTRIBUTE_UNUSED; | |
990 | void *live; | |
991 | { | |
9ca8d59e | 992 | int regno, nregs; |
18862b5a | 993 | |
994 | if (GET_CODE (reg) == SUBREG) | |
995 | reg = SUBREG_REG (reg); | |
996 | ||
997 | if (GET_CODE (reg) != REG) | |
998 | return; | |
999 | ||
1000 | regno = REGNO (reg); | |
1001 | if (regno < FIRST_PSEUDO_REGISTER) | |
9ca8d59e | 1002 | for (nregs = HARD_REGNO_NREGS (regno, GET_MODE (reg)) - 1; nregs >= 0; |
1003 | nregs--) | |
1004 | SET_HARD_REG_BIT (* (HARD_REG_SET *) live, regno + nregs); | |
18862b5a | 1005 | } |
1006 | ||
b78e14a8 | 1007 | /* Find all insns that need a particular mode setting, and insert the |
1008 | necessary mode switches. Return true if we did work. */ | |
9ca8d59e | 1009 | |
b78e14a8 | 1010 | int |
18862b5a | 1011 | optimize_mode_switching (file) |
b78e14a8 | 1012 | FILE *file; |
18862b5a | 1013 | { |
18862b5a | 1014 | rtx insn; |
1015 | int bb, e; | |
1016 | edge eg; | |
1017 | int need_commit = 0; | |
1018 | sbitmap *kill; | |
1019 | struct edge_list *edge_list; | |
1020 | static int num_modes[] = NUM_MODES_FOR_MODE_SWITCHING; | |
1021 | #define N_ENTITIES (sizeof num_modes / sizeof (int)) | |
1022 | int entity_map[N_ENTITIES]; | |
1023 | struct bb_info *bb_info[N_ENTITIES]; | |
1024 | int i, j; | |
1025 | int n_entities; | |
1026 | int max_num_modes = 0; | |
1027 | ||
1287c919 | 1028 | #ifdef NORMAL_MODE |
1029 | /* Increment n_basic_blocks before allocating bb_info. */ | |
1030 | n_basic_blocks++; | |
1031 | #endif | |
1032 | ||
18862b5a | 1033 | for (e = N_ENTITIES - 1, n_entities = 0; e >= 0; e--) |
9ca8d59e | 1034 | if (OPTIMIZE_MODE_SWITCHING (e)) |
1035 | { | |
1036 | /* Create the list of segments within each basic block. */ | |
1037 | bb_info[n_entities] | |
1038 | = (struct bb_info *) xcalloc (n_basic_blocks, sizeof **bb_info); | |
1039 | entity_map[n_entities++] = e; | |
1040 | if (num_modes[e] > max_num_modes) | |
1041 | max_num_modes = num_modes[e]; | |
1042 | } | |
1043 | ||
1287c919 | 1044 | #ifdef NORMAL_MODE |
1045 | /* Decrement it back in case we return below. */ | |
1046 | n_basic_blocks--; | |
1047 | #endif | |
1048 | ||
18862b5a | 1049 | if (! n_entities) |
b78e14a8 | 1050 | return 0; |
18862b5a | 1051 | |
1287c919 | 1052 | #ifdef NORMAL_MODE |
1053 | /* We're going to pretend the EXIT_BLOCK is a regular basic block, | |
1054 | so that switching back to normal mode when entering the | |
1055 | EXIT_BLOCK isn't optimized away. We do this by incrementing the | |
1056 | basic block count, growing the VARRAY of basic_block_info and | |
1057 | appending the EXIT_BLOCK_PTR to it. */ | |
1058 | n_basic_blocks++; | |
1059 | if (VARRAY_SIZE (basic_block_info) < n_basic_blocks) | |
1060 | VARRAY_GROW (basic_block_info, n_basic_blocks); | |
1061 | BASIC_BLOCK (n_basic_blocks - 1) = EXIT_BLOCK_PTR; | |
1062 | EXIT_BLOCK_PTR->index = n_basic_blocks - 1; | |
1063 | #endif | |
1064 | ||
18862b5a | 1065 | /* Create the bitmap vectors. */ |
1066 | ||
1067 | antic = sbitmap_vector_alloc (n_basic_blocks, n_entities); | |
1068 | transp = sbitmap_vector_alloc (n_basic_blocks, n_entities); | |
1069 | comp = sbitmap_vector_alloc (n_basic_blocks, n_entities); | |
1070 | ||
1071 | sbitmap_vector_ones (transp, n_basic_blocks); | |
1072 | ||
1073 | for (j = n_entities - 1; j >= 0; j--) | |
1074 | { | |
1075 | int e = entity_map[j]; | |
1076 | int no_mode = num_modes[e]; | |
1077 | struct bb_info *info = bb_info[j]; | |
1078 | ||
1079 | /* Determine what the first use (if any) need for a mode of entity E is. | |
b78e14a8 | 1080 | This will be the mode that is anticipatable for this block. |
18862b5a | 1081 | Also compute the initial transparency settings. */ |
1082 | for (bb = 0 ; bb < n_basic_blocks; bb++) | |
1083 | { | |
1084 | struct seginfo *ptr; | |
1085 | int last_mode = no_mode; | |
1086 | HARD_REG_SET live_now; | |
1087 | ||
1088 | REG_SET_TO_HARD_REG_SET (live_now, | |
1089 | BASIC_BLOCK (bb)->global_live_at_start); | |
1090 | for (insn = BLOCK_HEAD (bb); | |
1091 | insn != NULL && insn != NEXT_INSN (BLOCK_END (bb)); | |
1092 | insn = NEXT_INSN (insn)) | |
1093 | { | |
9204e736 | 1094 | if (INSN_P (insn)) |
18862b5a | 1095 | { |
1096 | int mode = MODE_NEEDED (e, insn); | |
1097 | rtx link; | |
1098 | ||
1099 | if (mode != no_mode && mode != last_mode) | |
1100 | { | |
1101 | last_mode = mode; | |
1102 | ptr = new_seginfo (mode, insn, bb, live_now); | |
1103 | add_seginfo (info + bb, ptr); | |
1104 | RESET_BIT (transp[bb], j); | |
1105 | } | |
1106 | ||
1107 | /* Update LIVE_NOW. */ | |
1108 | for (link = REG_NOTES (insn); link; link = XEXP (link, 1)) | |
1109 | if (REG_NOTE_KIND (link) == REG_DEAD) | |
1110 | reg_dies (XEXP (link, 0), live_now); | |
9ca8d59e | 1111 | |
18862b5a | 1112 | note_stores (PATTERN (insn), reg_becomes_live, &live_now); |
1113 | for (link = REG_NOTES (insn); link; link = XEXP (link, 1)) | |
1114 | if (REG_NOTE_KIND (link) == REG_UNUSED) | |
1115 | reg_dies (XEXP (link, 0), live_now); | |
1116 | } | |
1117 | } | |
9ca8d59e | 1118 | |
18862b5a | 1119 | info[bb].computing = last_mode; |
1120 | /* Check for blocks without ANY mode requirements. */ | |
1121 | if (last_mode == no_mode) | |
1122 | { | |
1123 | ptr = new_seginfo (no_mode, insn, bb, live_now); | |
1124 | add_seginfo (info + bb, ptr); | |
1125 | } | |
1126 | } | |
7dff60c8 | 1127 | #ifdef NORMAL_MODE |
18862b5a | 1128 | { |
7dff60c8 | 1129 | int mode = NORMAL_MODE (e); |
9ca8d59e | 1130 | |
18862b5a | 1131 | if (mode != no_mode) |
1132 | { | |
1133 | for (eg = ENTRY_BLOCK_PTR->succ; eg; eg = eg->succ_next) | |
1134 | { | |
1135 | bb = eg->dest->index; | |
1136 | ||
1137 | /* By always making this nontransparent, we save | |
1138 | an extra check in make_preds_opaque. We also | |
1139 | need this to avoid confusing pre_edge_lcm when | |
1140 | antic is cleared but transp and comp are set. */ | |
1141 | RESET_BIT (transp[bb], j); | |
1142 | ||
1143 | /* If the block already has MODE, pretend it | |
1144 | has none (because we don't need to set it), | |
1145 | but retain whatever mode it computes. */ | |
1146 | if (info[bb].seginfo->mode == mode) | |
9ca8d59e | 1147 | info[bb].seginfo->mode = no_mode; |
1148 | ||
1149 | /* Insert a fake computing definition of MODE into entry | |
1150 | blocks which compute no mode. This represents the mode on | |
1151 | entry. */ | |
18862b5a | 1152 | else if (info[bb].computing == no_mode) |
1153 | { | |
1154 | info[bb].computing = mode; | |
1155 | info[bb].seginfo->mode = no_mode; | |
1156 | } | |
1157 | } | |
1287c919 | 1158 | |
1159 | bb = n_basic_blocks - 1; | |
1160 | info[bb].seginfo->mode = mode; | |
18862b5a | 1161 | } |
1162 | } | |
7dff60c8 | 1163 | #endif /* NORMAL_MODE */ |
18862b5a | 1164 | } |
1165 | ||
1166 | kill = sbitmap_vector_alloc (n_basic_blocks, n_entities); | |
1167 | for (i = 0; i < max_num_modes; i++) | |
1168 | { | |
1169 | int current_mode[N_ENTITIES]; | |
1170 | ||
1171 | /* Set the anticipatable and computing arrays. */ | |
1172 | sbitmap_vector_zero (antic, n_basic_blocks); | |
1173 | sbitmap_vector_zero (comp, n_basic_blocks); | |
1174 | for (j = n_entities - 1; j >= 0; j--) | |
1175 | { | |
1176 | int m = current_mode[j] = MODE_PRIORITY_TO_MODE (entity_map[j], i); | |
1177 | struct bb_info *info = bb_info[j]; | |
1178 | ||
1179 | for (bb = 0 ; bb < n_basic_blocks; bb++) | |
1180 | { | |
18862b5a | 1181 | if (info[bb].seginfo->mode == m) |
1182 | SET_BIT (antic[bb], j); | |
1183 | ||
1184 | if (info[bb].computing == m) | |
1185 | SET_BIT (comp[bb], j); | |
1186 | } | |
1187 | } | |
1188 | ||
1189 | /* Calculate the optimal locations for the | |
1190 | placement mode switches to modes with priority I. */ | |
1191 | ||
1192 | for (bb = n_basic_blocks - 1; bb >= 0; bb--) | |
1193 | sbitmap_not (kill[bb], transp[bb]); | |
1194 | edge_list = pre_edge_lcm (file, 1, transp, comp, antic, | |
1195 | kill, &insert, &delete); | |
1196 | ||
9ca8d59e | 1197 | for (j = n_entities - 1; j >= 0; j--) |
18862b5a | 1198 | { |
1199 | /* Insert all mode sets that have been inserted by lcm. */ | |
1200 | int no_mode = num_modes[entity_map[j]]; | |
9ca8d59e | 1201 | |
18862b5a | 1202 | /* Wherever we have moved a mode setting upwards in the flow graph, |
1203 | the blocks between the new setting site and the now redundant | |
1204 | computation ceases to be transparent for any lower-priority | |
1205 | mode of the same entity. First set the aux field of each | |
1206 | insertion site edge non-transparent, then propagate the new | |
1207 | non-transparency from the redundant computation upwards till | |
1208 | we hit an insertion site or an already non-transparent block. */ | |
1209 | for (e = NUM_EDGES (edge_list) - 1; e >= 0; e--) | |
1210 | { | |
1211 | edge eg = INDEX_EDGE (edge_list, e); | |
1212 | int mode; | |
1213 | basic_block src_bb; | |
1214 | HARD_REG_SET live_at_edge; | |
1215 | rtx mode_set; | |
1216 | ||
1217 | eg->aux = 0; | |
1218 | ||
1219 | if (! TEST_BIT (insert[e], j)) | |
1220 | continue; | |
1221 | ||
1222 | eg->aux = (void *)1; | |
1223 | ||
1224 | mode = current_mode[j]; | |
1225 | src_bb = eg->src; | |
1226 | ||
9ca8d59e | 1227 | REG_SET_TO_HARD_REG_SET (live_at_edge, |
1228 | src_bb->global_live_at_end); | |
1229 | ||
18862b5a | 1230 | start_sequence (); |
1231 | EMIT_MODE_SET (entity_map[j], mode, live_at_edge); | |
1232 | mode_set = gen_sequence (); | |
1233 | end_sequence (); | |
1234 | ||
1287c919 | 1235 | /* If this is an abnormal edge, we'll insert at the end |
1236 | of the previous block. */ | |
18862b5a | 1237 | if (eg->flags & EDGE_ABNORMAL) |
1238 | { | |
a24d0647 | 1239 | if (GET_CODE (src_bb->end) == JUMP_INSN) |
1240 | emit_insn_before (mode_set, src_bb->end); | |
1287c919 | 1241 | /* It doesn't make sense to switch to normal mode |
1242 | after a CALL_INSN, so we're going to abort if we | |
1243 | find one. The cases in which a CALL_INSN may | |
1244 | have an abnormal edge are sibcalls and EH edges. | |
1245 | In the case of sibcalls, the dest basic-block is | |
1246 | the EXIT_BLOCK, that runs in normal mode; it is | |
1247 | assumed that a sibcall insn requires normal mode | |
1248 | itself, so no mode switch would be required after | |
1249 | the call (it wouldn't make sense, anyway). In | |
1250 | the case of EH edges, EH entry points also start | |
1251 | in normal mode, so a similar reasoning applies. */ | |
1252 | else if (GET_CODE (src_bb->end) == INSN) | |
a24d0647 | 1253 | src_bb->end = emit_insn_after (mode_set, src_bb->end); |
1287c919 | 1254 | else |
1255 | abort (); | |
18862b5a | 1256 | bb_info[j][src_bb->index].computing = mode; |
1257 | RESET_BIT (transp[src_bb->index], j); | |
1258 | } | |
1259 | else | |
1260 | { | |
1261 | need_commit = 1; | |
1262 | insert_insn_on_edge (mode_set, eg); | |
1263 | } | |
18862b5a | 1264 | } |
1265 | ||
1266 | for (bb = n_basic_blocks - 1; bb >= 0; bb--) | |
9ca8d59e | 1267 | if (TEST_BIT (delete[bb], j)) |
1268 | { | |
1269 | make_preds_opaque (BASIC_BLOCK (bb), j); | |
1270 | /* Cancel the 'deleted' mode set. */ | |
1271 | bb_info[j][bb].seginfo->mode = no_mode; | |
1272 | } | |
18862b5a | 1273 | } |
9ca8d59e | 1274 | |
18862b5a | 1275 | free_edge_list (edge_list); |
1276 | } | |
1277 | ||
1287c919 | 1278 | #ifdef NORMAL_MODE |
1279 | /* Restore the special status of EXIT_BLOCK. */ | |
1280 | n_basic_blocks--; | |
1281 | VARRAY_POP (basic_block_info); | |
1282 | EXIT_BLOCK_PTR->index = EXIT_BLOCK; | |
1283 | #endif | |
1284 | ||
18862b5a | 1285 | /* Now output the remaining mode sets in all the segments. */ |
1286 | for (j = n_entities - 1; j >= 0; j--) | |
1287 | { | |
7dff60c8 | 1288 | int no_mode = num_modes[entity_map[j]]; |
1289 | ||
1287c919 | 1290 | #ifdef NORMAL_MODE |
1291 | if (bb_info[j][n_basic_blocks].seginfo->mode != no_mode) | |
1292 | { | |
1293 | edge eg; | |
1294 | struct seginfo *ptr = bb_info[j][n_basic_blocks].seginfo; | |
1295 | ||
1296 | for (eg = EXIT_BLOCK_PTR->pred; eg; eg = eg->pred_next) | |
1297 | { | |
1298 | rtx mode_set; | |
1299 | ||
1300 | if (bb_info[j][eg->src->index].computing == ptr->mode) | |
1301 | continue; | |
1302 | ||
1303 | start_sequence (); | |
1304 | EMIT_MODE_SET (entity_map[j], ptr->mode, ptr->regs_live); | |
1305 | mode_set = gen_sequence (); | |
1306 | end_sequence (); | |
1307 | ||
1308 | /* If this is an abnormal edge, we'll insert at the end of the | |
1309 | previous block. */ | |
1310 | if (eg->flags & EDGE_ABNORMAL) | |
1311 | { | |
1312 | if (GET_CODE (eg->src->end) == JUMP_INSN) | |
1313 | emit_insn_before (mode_set, eg->src->end); | |
1314 | else if (GET_CODE (eg->src->end) == INSN) | |
1315 | eg->src->end = emit_insn_after (mode_set, eg->src->end); | |
1316 | else | |
1317 | abort (); | |
1318 | } | |
1319 | else | |
1320 | { | |
1321 | need_commit = 1; | |
1322 | insert_insn_on_edge (mode_set, eg); | |
1323 | } | |
1324 | } | |
1325 | ||
1326 | } | |
1327 | #endif | |
1328 | ||
18862b5a | 1329 | for (bb = n_basic_blocks - 1; bb >= 0; bb--) |
1330 | { | |
1331 | struct seginfo *ptr, *next; | |
1332 | for (ptr = bb_info[j][bb].seginfo; ptr; ptr = next) | |
1333 | { | |
1334 | next = ptr->next; | |
7dff60c8 | 1335 | if (ptr->mode != no_mode) |
18862b5a | 1336 | { |
1337 | rtx mode_set; | |
1338 | ||
1339 | start_sequence (); | |
1340 | EMIT_MODE_SET (entity_map[j], ptr->mode, ptr->regs_live); | |
1341 | mode_set = gen_sequence (); | |
1342 | end_sequence (); | |
1343 | ||
6484cd39 | 1344 | if (GET_CODE (ptr->insn_ptr) == NOTE |
1345 | && (NOTE_LINE_NUMBER (ptr->insn_ptr) | |
1346 | == NOTE_INSN_BASIC_BLOCK)) | |
7dff60c8 | 1347 | emit_block_insn_after (mode_set, ptr->insn_ptr, |
1348 | BASIC_BLOCK (ptr->bbnum)); | |
1349 | else | |
1350 | emit_block_insn_before (mode_set, ptr->insn_ptr, | |
1351 | BASIC_BLOCK (ptr->bbnum)); | |
18862b5a | 1352 | } |
9ca8d59e | 1353 | |
18862b5a | 1354 | free (ptr); |
1355 | } | |
1356 | } | |
9ca8d59e | 1357 | |
18862b5a | 1358 | free (bb_info[j]); |
1359 | } | |
1360 | ||
1361 | /* Finished. Free up all the things we've allocated. */ | |
1362 | ||
1363 | sbitmap_vector_free (kill); | |
1364 | sbitmap_vector_free (antic); | |
1365 | sbitmap_vector_free (transp); | |
1366 | sbitmap_vector_free (comp); | |
1367 | sbitmap_vector_free (delete); | |
1368 | sbitmap_vector_free (insert); | |
1369 | ||
1370 | if (need_commit) | |
1371 | commit_edge_insertions (); | |
b78e14a8 | 1372 | |
1373 | /* Ideally we'd figure out what blocks were affected and start from | |
1374 | there, but this is enormously complicated by commit_edge_insertions, | |
1375 | which would screw up any indicies we'd collected, and also need to | |
1376 | be involved in the update. Bail and recompute global life info for | |
1377 | everything. */ | |
1378 | ||
1379 | allocate_reg_life_data (); | |
1380 | update_life_info (NULL, UPDATE_LIFE_GLOBAL_RM_NOTES, | |
1381 | (PROP_DEATH_NOTES | PROP_KILL_DEAD_CODE | |
1382 | | PROP_SCAN_DEAD_CODE | PROP_REG_INFO)); | |
1383 | ||
1384 | return 1; | |
18862b5a | 1385 | } |
b78e14a8 | 1386 | #endif /* OPTIMIZE_MODE_SWITCHING */ |