]>
Commit | Line | Data |
---|---|---|
9ca8d59e | 1 | /* Generic partial redundancy elimination with lazy code motion support. |
0364c2b4 | 2 | Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004 |
3ad4992f | 3 | Free Software Foundation, Inc. |
e48ba7af | 4 | |
f12b58b3 | 5 | This file is part of GCC. |
e48ba7af | 6 | |
f12b58b3 | 7 | GCC is free software; you can redistribute it and/or modify it under |
8 | the terms of the GNU General Public License as published by the Free | |
9 | Software Foundation; either version 2, or (at your option) any later | |
10 | version. | |
e48ba7af | 11 | |
f12b58b3 | 12 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY |
13 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
14 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
15 | for more details. | |
e48ba7af | 16 | |
17 | You should have received a copy of the GNU General Public License | |
f12b58b3 | 18 | along with GCC; see the file COPYING. If not, write to the Free |
19 | Software Foundation, 59 Temple Place - Suite 330, Boston, MA | |
20 | 02111-1307, USA. */ | |
e48ba7af | 21 | |
22 | /* These routines are meant to be used by various optimization | |
5ab08585 | 23 | passes which can be modeled as lazy code motion problems. |
e48ba7af | 24 | Including, but not limited to: |
25 | ||
26 | * Traditional partial redundancy elimination. | |
27 | ||
28 | * Placement of caller/caller register save/restores. | |
29 | ||
30 | * Load/store motion. | |
31 | ||
32 | * Copy motion. | |
33 | ||
34 | * Conversion of flat register files to a stacked register | |
35 | model. | |
36 | ||
37 | * Dead load/store elimination. | |
38 | ||
39 | These routines accept as input: | |
40 | ||
41 | * Basic block information (number of blocks, lists of | |
42 | predecessors and successors). Note the granularity | |
43 | does not need to be basic block, they could be statements | |
44 | or functions. | |
45 | ||
46 | * Bitmaps of local properties (computed, transparent and | |
47 | anticipatable expressions). | |
48 | ||
49 | The output of these routines is bitmap of redundant computations | |
50 | and a bitmap of optimal placement points. */ | |
51 | ||
52 | ||
53 | #include "config.h" | |
54 | #include "system.h" | |
805e22b2 | 55 | #include "coretypes.h" |
56 | #include "tm.h" | |
e48ba7af | 57 | #include "rtl.h" |
58 | #include "regs.h" | |
59 | #include "hard-reg-set.h" | |
60 | #include "flags.h" | |
61 | #include "real.h" | |
62 | #include "insn-config.h" | |
63 | #include "recog.h" | |
64 | #include "basic-block.h" | |
742ee135 | 65 | #include "output.h" |
18862b5a | 66 | #include "tm_p.h" |
6ce54148 | 67 | #include "function.h" |
9ca8d59e | 68 | |
18862b5a | 69 | /* We want target macros for the mode switching code to be able to refer |
70 | to instruction attribute values. */ | |
71 | #include "insn-attr.h" | |
e48ba7af | 72 | |
7bcd381b | 73 | /* Edge based LCM routines. */ |
3ad4992f | 74 | static void compute_antinout_edge (sbitmap *, sbitmap *, sbitmap *, sbitmap *); |
75 | static void compute_earliest (struct edge_list *, int, sbitmap *, sbitmap *, | |
76 | sbitmap *, sbitmap *, sbitmap *); | |
77 | static void compute_laterin (struct edge_list *, sbitmap *, sbitmap *, | |
78 | sbitmap *, sbitmap *); | |
79 | static void compute_insert_delete (struct edge_list *edge_list, sbitmap *, | |
80 | sbitmap *, sbitmap *, sbitmap *, sbitmap *); | |
7bcd381b | 81 | |
82 | /* Edge based LCM routines on a reverse flowgraph. */ | |
3ad4992f | 83 | static void compute_farthest (struct edge_list *, int, sbitmap *, sbitmap *, |
84 | sbitmap*, sbitmap *, sbitmap *); | |
85 | static void compute_nearerout (struct edge_list *, sbitmap *, sbitmap *, | |
86 | sbitmap *, sbitmap *); | |
87 | static void compute_rev_insert_delete (struct edge_list *edge_list, sbitmap *, | |
88 | sbitmap *, sbitmap *, sbitmap *, | |
89 | sbitmap *); | |
7bcd381b | 90 | \f |
91 | /* Edge based lcm routines. */ | |
3b7e1f27 | 92 | |
5ab08585 | 93 | /* Compute expression anticipatability at entrance and exit of each block. |
94 | This is done based on the flow graph, and not on the pred-succ lists. | |
7bcd381b | 95 | Other than that, its pretty much identical to compute_antinout. */ |
e48ba7af | 96 | |
97 | static void | |
3ad4992f | 98 | compute_antinout_edge (sbitmap *antloc, sbitmap *transp, sbitmap *antin, |
99 | sbitmap *antout) | |
e48ba7af | 100 | { |
4c26117a | 101 | basic_block bb; |
7bcd381b | 102 | edge e; |
2c59145b | 103 | basic_block *worklist, *qin, *qout, *qend; |
104 | unsigned int qlen; | |
3b7e1f27 | 105 | |
2325f0e2 | 106 | /* Allocate a worklist array/queue. Entries are only added to the |
107 | list if they were not already on the list. So the size is | |
108 | bounded by the number of basic blocks. */ | |
f0af5a88 | 109 | qin = qout = worklist = xmalloc (sizeof (basic_block) * n_basic_blocks); |
e48ba7af | 110 | |
2325f0e2 | 111 | /* We want a maximal solution, so make an optimistic initialization of |
112 | ANTIN. */ | |
f20183e6 | 113 | sbitmap_vector_ones (antin, last_basic_block); |
e48ba7af | 114 | |
5d6931e2 | 115 | /* Put every block on the worklist; this is necessary because of the |
116 | optimistic initialization of ANTIN above. */ | |
4c26117a | 117 | FOR_EACH_BB_REVERSE (bb) |
e48ba7af | 118 | { |
ea0041f4 | 119 | *qin++ = bb; |
4c26117a | 120 | bb->aux = bb; |
2325f0e2 | 121 | } |
5ab08585 | 122 | |
2c59145b | 123 | qin = worklist; |
b3d6de89 | 124 | qend = &worklist[n_basic_blocks]; |
125 | qlen = n_basic_blocks; | |
e48ba7af | 126 | |
5d6931e2 | 127 | /* Mark blocks which are predecessors of the exit block so that we |
128 | can easily identify them below. */ | |
129 | for (e = EXIT_BLOCK_PTR->pred; e; e = e->pred_next) | |
130 | e->src->aux = EXIT_BLOCK_PTR; | |
131 | ||
2325f0e2 | 132 | /* Iterate until the worklist is empty. */ |
2c59145b | 133 | while (qlen) |
2325f0e2 | 134 | { |
135 | /* Take the first entry off the worklist. */ | |
4c26117a | 136 | bb = *qout++; |
2c59145b | 137 | qlen--; |
3b7e1f27 | 138 | |
2c59145b | 139 | if (qout >= qend) |
8851e806 | 140 | qout = worklist; |
e48ba7af | 141 | |
4c26117a | 142 | if (bb->aux == EXIT_BLOCK_PTR) |
9ca8d59e | 143 | /* Do not clear the aux field for blocks which are predecessors of |
144 | the EXIT block. That way we never add then to the worklist | |
145 | again. */ | |
4c26117a | 146 | sbitmap_zero (antout[bb->index]); |
2325f0e2 | 147 | else |
148 | { | |
149 | /* Clear the aux field of this block so that it can be added to | |
150 | the worklist again if necessary. */ | |
4c26117a | 151 | bb->aux = NULL; |
152 | sbitmap_intersection_of_succs (antout[bb->index], antin, bb->index); | |
2325f0e2 | 153 | } |
7bcd381b | 154 | |
4c26117a | 155 | if (sbitmap_a_or_b_and_c_cg (antin[bb->index], antloc[bb->index], |
156 | transp[bb->index], antout[bb->index])) | |
9ca8d59e | 157 | /* If the in state of this block changed, then we need |
158 | to add the predecessors of this block to the worklist | |
159 | if they are not already on the worklist. */ | |
4c26117a | 160 | for (e = bb->pred; e; e = e->pred_next) |
9ca8d59e | 161 | if (!e->src->aux && e->src != ENTRY_BLOCK_PTR) |
e48ba7af | 162 | { |
2c59145b | 163 | *qin++ = e->src; |
9ca8d59e | 164 | e->src->aux = e; |
2c59145b | 165 | qlen++; |
166 | if (qin >= qend) | |
8851e806 | 167 | qin = worklist; |
e48ba7af | 168 | } |
e48ba7af | 169 | } |
9ca8d59e | 170 | |
82f7392b | 171 | clear_aux_for_edges (); |
172 | clear_aux_for_blocks (); | |
2c59145b | 173 | free (worklist); |
e48ba7af | 174 | } |
175 | ||
7bcd381b | 176 | /* Compute the earliest vector for edge based lcm. */ |
9ca8d59e | 177 | |
e48ba7af | 178 | static void |
3ad4992f | 179 | compute_earliest (struct edge_list *edge_list, int n_exprs, sbitmap *antin, |
180 | sbitmap *antout, sbitmap *avout, sbitmap *kill, | |
181 | sbitmap *earliest) | |
e48ba7af | 182 | { |
7bcd381b | 183 | sbitmap difference, temp_bitmap; |
5ab08585 | 184 | int x, num_edges; |
7bcd381b | 185 | basic_block pred, succ; |
e48ba7af | 186 | |
7bcd381b | 187 | num_edges = NUM_EDGES (edge_list); |
e48ba7af | 188 | |
7bcd381b | 189 | difference = sbitmap_alloc (n_exprs); |
190 | temp_bitmap = sbitmap_alloc (n_exprs); | |
e48ba7af | 191 | |
7bcd381b | 192 | for (x = 0; x < num_edges; x++) |
e48ba7af | 193 | { |
7bcd381b | 194 | pred = INDEX_EDGE_PRED_BB (edge_list, x); |
195 | succ = INDEX_EDGE_SUCC_BB (edge_list, x); | |
196 | if (pred == ENTRY_BLOCK_PTR) | |
b3d6de89 | 197 | sbitmap_copy (earliest[x], antin[succ->index]); |
7bcd381b | 198 | else |
8851e806 | 199 | { |
742ee135 | 200 | if (succ == EXIT_BLOCK_PTR) |
9ca8d59e | 201 | sbitmap_zero (earliest[x]); |
7bcd381b | 202 | else |
e48ba7af | 203 | { |
b3d6de89 | 204 | sbitmap_difference (difference, antin[succ->index], |
205 | avout[pred->index]); | |
206 | sbitmap_not (temp_bitmap, antout[pred->index]); | |
9ca8d59e | 207 | sbitmap_a_and_b_or_c (earliest[x], difference, |
b3d6de89 | 208 | kill[pred->index], temp_bitmap); |
e48ba7af | 209 | } |
210 | } | |
e48ba7af | 211 | } |
9ca8d59e | 212 | |
f5123ed5 | 213 | sbitmap_free (temp_bitmap); |
214 | sbitmap_free (difference); | |
e48ba7af | 215 | } |
216 | ||
2325f0e2 | 217 | /* later(p,s) is dependent on the calculation of laterin(p). |
218 | laterin(p) is dependent on the calculation of later(p2,p). | |
219 | ||
220 | laterin(ENTRY) is defined as all 0's | |
221 | later(ENTRY, succs(ENTRY)) are defined using laterin(ENTRY) | |
222 | laterin(succs(ENTRY)) is defined by later(ENTRY, succs(ENTRY)). | |
223 | ||
224 | If we progress in this manner, starting with all basic blocks | |
225 | in the work list, anytime we change later(bb), we need to add | |
226 | succs(bb) to the worklist if they are not already on the worklist. | |
227 | ||
228 | Boundary conditions: | |
229 | ||
230 | We prime the worklist all the normal basic blocks. The ENTRY block can | |
231 | never be added to the worklist since it is never the successor of any | |
232 | block. We explicitly prevent the EXIT block from being added to the | |
233 | worklist. | |
234 | ||
235 | We optimistically initialize LATER. That is the only time this routine | |
236 | will compute LATER for an edge out of the entry block since the entry | |
237 | block is never on the worklist. Thus, LATERIN is neither used nor | |
238 | computed for the ENTRY block. | |
239 | ||
240 | Since the EXIT block is never added to the worklist, we will neither | |
241 | use nor compute LATERIN for the exit block. Edges which reach the | |
242 | EXIT block are handled in the normal fashion inside the loop. However, | |
243 | the insertion/deletion computation needs LATERIN(EXIT), so we have | |
244 | to compute it. */ | |
5ab08585 | 245 | |
e48ba7af | 246 | static void |
3ad4992f | 247 | compute_laterin (struct edge_list *edge_list, sbitmap *earliest, |
248 | sbitmap *antloc, sbitmap *later, sbitmap *laterin) | |
e48ba7af | 249 | { |
4c26117a | 250 | int num_edges, i; |
2325f0e2 | 251 | edge e; |
4c26117a | 252 | basic_block *worklist, *qin, *qout, *qend, bb; |
2c59145b | 253 | unsigned int qlen; |
e48ba7af | 254 | |
7bcd381b | 255 | num_edges = NUM_EDGES (edge_list); |
e48ba7af | 256 | |
2325f0e2 | 257 | /* Allocate a worklist array/queue. Entries are only added to the |
258 | list if they were not already on the list. So the size is | |
259 | bounded by the number of basic blocks. */ | |
2c59145b | 260 | qin = qout = worklist |
f0af5a88 | 261 | = xmalloc (sizeof (basic_block) * (n_basic_blocks + 1)); |
2325f0e2 | 262 | |
263 | /* Initialize a mapping from each edge to its index. */ | |
264 | for (i = 0; i < num_edges; i++) | |
9ffd5d6d | 265 | INDEX_EDGE (edge_list, i)->aux = (void *) (size_t) i; |
2325f0e2 | 266 | |
267 | /* We want a maximal solution, so initially consider LATER true for | |
268 | all edges. This allows propagation through a loop since the incoming | |
269 | loop edge will have LATER set, so if all the other incoming edges | |
270 | to the loop are set, then LATERIN will be set for the head of the | |
271 | loop. | |
272 | ||
273 | If the optimistic setting of LATER on that edge was incorrect (for | |
274 | example the expression is ANTLOC in a block within the loop) then | |
275 | this algorithm will detect it when we process the block at the head | |
276 | of the optimistic edge. That will requeue the affected blocks. */ | |
277 | sbitmap_vector_ones (later, num_edges); | |
278 | ||
048599b9 | 279 | /* Note that even though we want an optimistic setting of LATER, we |
280 | do not want to be overly optimistic. Consider an outgoing edge from | |
281 | the entry block. That edge should always have a LATER value the | |
282 | same as EARLIEST for that edge. */ | |
283 | for (e = ENTRY_BLOCK_PTR->succ; e; e = e->succ_next) | |
9ca8d59e | 284 | sbitmap_copy (later[(size_t) e->aux], earliest[(size_t) e->aux]); |
048599b9 | 285 | |
2325f0e2 | 286 | /* Add all the blocks to the worklist. This prevents an early exit from |
287 | the loop given our optimistic initialization of LATER above. */ | |
4c26117a | 288 | FOR_EACH_BB (bb) |
e48ba7af | 289 | { |
4c26117a | 290 | *qin++ = bb; |
291 | bb->aux = bb; | |
7bcd381b | 292 | } |
d4d93ea0 | 293 | |
2c59145b | 294 | /* Note that we do not use the last allocated element for our queue, |
295 | as EXIT_BLOCK is never inserted into it. In fact the above allocation | |
b903337a | 296 | of n_basic_blocks + 1 elements is not necessary. */ |
d4d93ea0 | 297 | qin = worklist; |
b3d6de89 | 298 | qend = &worklist[n_basic_blocks]; |
299 | qlen = n_basic_blocks; | |
7bcd381b | 300 | |
2325f0e2 | 301 | /* Iterate until the worklist is empty. */ |
2c59145b | 302 | while (qlen) |
7bcd381b | 303 | { |
2325f0e2 | 304 | /* Take the first entry off the worklist. */ |
4c26117a | 305 | bb = *qout++; |
306 | bb->aux = NULL; | |
2c59145b | 307 | qlen--; |
308 | if (qout >= qend) | |
8851e806 | 309 | qout = worklist; |
2325f0e2 | 310 | |
311 | /* Compute the intersection of LATERIN for each incoming edge to B. */ | |
4c26117a | 312 | sbitmap_ones (laterin[bb->index]); |
313 | for (e = bb->pred; e != NULL; e = e->pred_next) | |
d4d93ea0 | 314 | sbitmap_a_and_b (laterin[bb->index], laterin[bb->index], |
315 | later[(size_t)e->aux]); | |
2325f0e2 | 316 | |
317 | /* Calculate LATER for all outgoing edges. */ | |
4c26117a | 318 | for (e = bb->succ; e != NULL; e = e->succ_next) |
739c050b | 319 | if (sbitmap_union_of_diff_cg (later[(size_t) e->aux], |
b3d6de89 | 320 | earliest[(size_t) e->aux], |
321 | laterin[e->src->index], | |
322 | antloc[e->src->index]) | |
9ca8d59e | 323 | /* If LATER for an outgoing edge was changed, then we need |
324 | to add the target of the outgoing edge to the worklist. */ | |
325 | && e->dest != EXIT_BLOCK_PTR && e->dest->aux == 0) | |
326 | { | |
2c59145b | 327 | *qin++ = e->dest; |
9ca8d59e | 328 | e->dest->aux = e; |
2c59145b | 329 | qlen++; |
330 | if (qin >= qend) | |
331 | qin = worklist; | |
9ca8d59e | 332 | } |
e48ba7af | 333 | } |
334 | ||
2325f0e2 | 335 | /* Computation of insertion and deletion points requires computing LATERIN |
336 | for the EXIT block. We allocated an extra entry in the LATERIN array | |
337 | for just this purpose. */ | |
f20183e6 | 338 | sbitmap_ones (laterin[last_basic_block]); |
2325f0e2 | 339 | for (e = EXIT_BLOCK_PTR->pred; e != NULL; e = e->pred_next) |
f20183e6 | 340 | sbitmap_a_and_b (laterin[last_basic_block], |
341 | laterin[last_basic_block], | |
9ffd5d6d | 342 | later[(size_t) e->aux]); |
2325f0e2 | 343 | |
82f7392b | 344 | clear_aux_for_edges (); |
2c59145b | 345 | free (worklist); |
e48ba7af | 346 | } |
347 | ||
7bcd381b | 348 | /* Compute the insertion and deletion points for edge based LCM. */ |
9ca8d59e | 349 | |
7bcd381b | 350 | static void |
3ad4992f | 351 | compute_insert_delete (struct edge_list *edge_list, sbitmap *antloc, |
352 | sbitmap *later, sbitmap *laterin, sbitmap *insert, | |
353 | sbitmap *delete) | |
7bcd381b | 354 | { |
355 | int x; | |
4c26117a | 356 | basic_block bb; |
e48ba7af | 357 | |
4c26117a | 358 | FOR_EACH_BB (bb) |
d4d93ea0 | 359 | sbitmap_difference (delete[bb->index], antloc[bb->index], |
360 | laterin[bb->index]); | |
5ab08585 | 361 | |
7bcd381b | 362 | for (x = 0; x < NUM_EDGES (edge_list); x++) |
363 | { | |
364 | basic_block b = INDEX_EDGE_SUCC_BB (edge_list, x); | |
9ca8d59e | 365 | |
7bcd381b | 366 | if (b == EXIT_BLOCK_PTR) |
f20183e6 | 367 | sbitmap_difference (insert[x], later[x], laterin[last_basic_block]); |
7bcd381b | 368 | else |
b3d6de89 | 369 | sbitmap_difference (insert[x], later[x], laterin[b->index]); |
7bcd381b | 370 | } |
371 | } | |
e48ba7af | 372 | |
9ca8d59e | 373 | /* Given local properties TRANSP, ANTLOC, AVOUT, KILL return the insert and |
374 | delete vectors for edge based LCM. Returns an edgelist which is used to | |
375 | map the insert vector to what edge an expression should be inserted on. */ | |
e48ba7af | 376 | |
7bcd381b | 377 | struct edge_list * |
3ad4992f | 378 | pre_edge_lcm (FILE *file ATTRIBUTE_UNUSED, int n_exprs, sbitmap *transp, |
379 | sbitmap *avloc, sbitmap *antloc, sbitmap *kill, | |
380 | sbitmap **insert, sbitmap **delete) | |
e48ba7af | 381 | { |
7bcd381b | 382 | sbitmap *antin, *antout, *earliest; |
383 | sbitmap *avin, *avout; | |
384 | sbitmap *later, *laterin; | |
385 | struct edge_list *edge_list; | |
386 | int num_edges; | |
e48ba7af | 387 | |
7bcd381b | 388 | edge_list = create_edge_list (); |
389 | num_edges = NUM_EDGES (edge_list); | |
e48ba7af | 390 | |
7bcd381b | 391 | #ifdef LCM_DEBUG_INFO |
392 | if (file) | |
e48ba7af | 393 | { |
7bcd381b | 394 | fprintf (file, "Edge List:\n"); |
395 | verify_edge_list (file, edge_list); | |
396 | print_edge_list (file, edge_list); | |
f20183e6 | 397 | dump_sbitmap_vector (file, "transp", "", transp, last_basic_block); |
398 | dump_sbitmap_vector (file, "antloc", "", antloc, last_basic_block); | |
399 | dump_sbitmap_vector (file, "avloc", "", avloc, last_basic_block); | |
400 | dump_sbitmap_vector (file, "kill", "", kill, last_basic_block); | |
e48ba7af | 401 | } |
7bcd381b | 402 | #endif |
e48ba7af | 403 | |
7bcd381b | 404 | /* Compute global availability. */ |
f20183e6 | 405 | avin = sbitmap_vector_alloc (last_basic_block, n_exprs); |
406 | avout = sbitmap_vector_alloc (last_basic_block, n_exprs); | |
7bcd381b | 407 | compute_available (avloc, kill, avout, avin); |
cca23eb2 | 408 | sbitmap_vector_free (avin); |
e48ba7af | 409 | |
7bcd381b | 410 | /* Compute global anticipatability. */ |
f20183e6 | 411 | antin = sbitmap_vector_alloc (last_basic_block, n_exprs); |
412 | antout = sbitmap_vector_alloc (last_basic_block, n_exprs); | |
7bcd381b | 413 | compute_antinout_edge (antloc, transp, antin, antout); |
e48ba7af | 414 | |
7bcd381b | 415 | #ifdef LCM_DEBUG_INFO |
416 | if (file) | |
e48ba7af | 417 | { |
f20183e6 | 418 | dump_sbitmap_vector (file, "antin", "", antin, last_basic_block); |
419 | dump_sbitmap_vector (file, "antout", "", antout, last_basic_block); | |
e48ba7af | 420 | } |
7bcd381b | 421 | #endif |
e48ba7af | 422 | |
7bcd381b | 423 | /* Compute earliestness. */ |
424 | earliest = sbitmap_vector_alloc (num_edges, n_exprs); | |
425 | compute_earliest (edge_list, n_exprs, antin, antout, avout, kill, earliest); | |
e48ba7af | 426 | |
7bcd381b | 427 | #ifdef LCM_DEBUG_INFO |
428 | if (file) | |
429 | dump_sbitmap_vector (file, "earliest", "", earliest, num_edges); | |
430 | #endif | |
e48ba7af | 431 | |
cca23eb2 | 432 | sbitmap_vector_free (antout); |
433 | sbitmap_vector_free (antin); | |
434 | sbitmap_vector_free (avout); | |
e48ba7af | 435 | |
7bcd381b | 436 | later = sbitmap_vector_alloc (num_edges, n_exprs); |
9ca8d59e | 437 | |
7bcd381b | 438 | /* Allocate an extra element for the exit block in the laterin vector. */ |
f20183e6 | 439 | laterin = sbitmap_vector_alloc (last_basic_block + 1, n_exprs); |
2325f0e2 | 440 | compute_laterin (edge_list, earliest, antloc, later, laterin); |
441 | ||
7bcd381b | 442 | #ifdef LCM_DEBUG_INFO |
443 | if (file) | |
444 | { | |
f20183e6 | 445 | dump_sbitmap_vector (file, "laterin", "", laterin, last_basic_block + 1); |
7bcd381b | 446 | dump_sbitmap_vector (file, "later", "", later, num_edges); |
447 | } | |
448 | #endif | |
e48ba7af | 449 | |
cca23eb2 | 450 | sbitmap_vector_free (earliest); |
7bcd381b | 451 | |
452 | *insert = sbitmap_vector_alloc (num_edges, n_exprs); | |
f20183e6 | 453 | *delete = sbitmap_vector_alloc (last_basic_block, n_exprs); |
7bcd381b | 454 | compute_insert_delete (edge_list, antloc, later, laterin, *insert, *delete); |
e48ba7af | 455 | |
cca23eb2 | 456 | sbitmap_vector_free (laterin); |
457 | sbitmap_vector_free (later); | |
7bcd381b | 458 | |
459 | #ifdef LCM_DEBUG_INFO | |
460 | if (file) | |
e48ba7af | 461 | { |
7bcd381b | 462 | dump_sbitmap_vector (file, "pre_insert_map", "", *insert, num_edges); |
9ca8d59e | 463 | dump_sbitmap_vector (file, "pre_delete_map", "", *delete, |
f20183e6 | 464 | last_basic_block); |
e48ba7af | 465 | } |
7bcd381b | 466 | #endif |
e48ba7af | 467 | |
7bcd381b | 468 | return edge_list; |
469 | } | |
3b7e1f27 | 470 | |
471 | /* Compute the AVIN and AVOUT vectors from the AVLOC and KILL vectors. | |
472 | Return the number of passes we performed to iterate to a solution. */ | |
473 | ||
2325f0e2 | 474 | void |
3ad4992f | 475 | compute_available (sbitmap *avloc, sbitmap *kill, sbitmap *avout, |
476 | sbitmap *avin) | |
e48ba7af | 477 | { |
3b7e1f27 | 478 | edge e; |
4c26117a | 479 | basic_block *worklist, *qin, *qout, *qend, bb; |
3b7e1f27 | 480 | unsigned int qlen; |
481 | ||
482 | /* Allocate a worklist array/queue. Entries are only added to the | |
483 | list if they were not already on the list. So the size is | |
484 | bounded by the number of basic blocks. */ | |
f0af5a88 | 485 | qin = qout = worklist = xmalloc (sizeof (basic_block) * n_basic_blocks); |
3b7e1f27 | 486 | |
487 | /* We want a maximal solution. */ | |
f20183e6 | 488 | sbitmap_vector_ones (avout, last_basic_block); |
3b7e1f27 | 489 | |
490 | /* Put every block on the worklist; this is necessary because of the | |
491 | optimistic initialization of AVOUT above. */ | |
4c26117a | 492 | FOR_EACH_BB (bb) |
3b7e1f27 | 493 | { |
4c26117a | 494 | *qin++ = bb; |
495 | bb->aux = bb; | |
3b7e1f27 | 496 | } |
497 | ||
498 | qin = worklist; | |
b3d6de89 | 499 | qend = &worklist[n_basic_blocks]; |
500 | qlen = n_basic_blocks; | |
3b7e1f27 | 501 | |
502 | /* Mark blocks which are successors of the entry block so that we | |
503 | can easily identify them below. */ | |
504 | for (e = ENTRY_BLOCK_PTR->succ; e; e = e->succ_next) | |
505 | e->dest->aux = ENTRY_BLOCK_PTR; | |
506 | ||
507 | /* Iterate until the worklist is empty. */ | |
508 | while (qlen) | |
509 | { | |
510 | /* Take the first entry off the worklist. */ | |
4c26117a | 511 | bb = *qout++; |
3b7e1f27 | 512 | qlen--; |
513 | ||
514 | if (qout >= qend) | |
8851e806 | 515 | qout = worklist; |
3b7e1f27 | 516 | |
517 | /* If one of the predecessor blocks is the ENTRY block, then the | |
518 | intersection of avouts is the null set. We can identify such blocks | |
519 | by the special value in the AUX field in the block structure. */ | |
4c26117a | 520 | if (bb->aux == ENTRY_BLOCK_PTR) |
3b7e1f27 | 521 | /* Do not clear the aux field for blocks which are successors of the |
522 | ENTRY block. That way we never add then to the worklist again. */ | |
4c26117a | 523 | sbitmap_zero (avin[bb->index]); |
3b7e1f27 | 524 | else |
525 | { | |
526 | /* Clear the aux field of this block so that it can be added to | |
527 | the worklist again if necessary. */ | |
4c26117a | 528 | bb->aux = NULL; |
529 | sbitmap_intersection_of_preds (avin[bb->index], avout, bb->index); | |
3b7e1f27 | 530 | } |
531 | ||
d4d93ea0 | 532 | if (sbitmap_union_of_diff_cg (avout[bb->index], avloc[bb->index], |
533 | avin[bb->index], kill[bb->index])) | |
3b7e1f27 | 534 | /* If the out state of this block changed, then we need |
535 | to add the successors of this block to the worklist | |
536 | if they are not already on the worklist. */ | |
4c26117a | 537 | for (e = bb->succ; e; e = e->succ_next) |
3b7e1f27 | 538 | if (!e->dest->aux && e->dest != EXIT_BLOCK_PTR) |
539 | { | |
540 | *qin++ = e->dest; | |
541 | e->dest->aux = e; | |
542 | qlen++; | |
543 | ||
544 | if (qin >= qend) | |
8851e806 | 545 | qin = worklist; |
3b7e1f27 | 546 | } |
547 | } | |
548 | ||
549 | clear_aux_for_edges (); | |
550 | clear_aux_for_blocks (); | |
551 | free (worklist); | |
e48ba7af | 552 | } |
553 | ||
7bcd381b | 554 | /* Compute the farthest vector for edge based lcm. */ |
9ca8d59e | 555 | |
e48ba7af | 556 | static void |
3ad4992f | 557 | compute_farthest (struct edge_list *edge_list, int n_exprs, |
558 | sbitmap *st_avout, sbitmap *st_avin, sbitmap *st_antin, | |
559 | sbitmap *kill, sbitmap *farthest) | |
e48ba7af | 560 | { |
7bcd381b | 561 | sbitmap difference, temp_bitmap; |
5ab08585 | 562 | int x, num_edges; |
7bcd381b | 563 | basic_block pred, succ; |
e48ba7af | 564 | |
7bcd381b | 565 | num_edges = NUM_EDGES (edge_list); |
e48ba7af | 566 | |
7bcd381b | 567 | difference = sbitmap_alloc (n_exprs); |
568 | temp_bitmap = sbitmap_alloc (n_exprs); | |
e48ba7af | 569 | |
7bcd381b | 570 | for (x = 0; x < num_edges; x++) |
e48ba7af | 571 | { |
7bcd381b | 572 | pred = INDEX_EDGE_PRED_BB (edge_list, x); |
573 | succ = INDEX_EDGE_SUCC_BB (edge_list, x); | |
574 | if (succ == EXIT_BLOCK_PTR) | |
b3d6de89 | 575 | sbitmap_copy (farthest[x], st_avout[pred->index]); |
7bcd381b | 576 | else |
e48ba7af | 577 | { |
7bcd381b | 578 | if (pred == ENTRY_BLOCK_PTR) |
9ca8d59e | 579 | sbitmap_zero (farthest[x]); |
7bcd381b | 580 | else |
581 | { | |
b3d6de89 | 582 | sbitmap_difference (difference, st_avout[pred->index], |
583 | st_antin[succ->index]); | |
584 | sbitmap_not (temp_bitmap, st_avin[succ->index]); | |
5ab08585 | 585 | sbitmap_a_and_b_or_c (farthest[x], difference, |
b3d6de89 | 586 | kill[succ->index], temp_bitmap); |
7bcd381b | 587 | } |
e48ba7af | 588 | } |
e48ba7af | 589 | } |
9ca8d59e | 590 | |
f5123ed5 | 591 | sbitmap_free (temp_bitmap); |
592 | sbitmap_free (difference); | |
e48ba7af | 593 | } |
594 | ||
2325f0e2 | 595 | /* Compute nearer and nearerout vectors for edge based lcm. |
596 | ||
597 | This is the mirror of compute_laterin, additional comments on the | |
598 | implementation can be found before compute_laterin. */ | |
599 | ||
e48ba7af | 600 | static void |
3ad4992f | 601 | compute_nearerout (struct edge_list *edge_list, sbitmap *farthest, |
602 | sbitmap *st_avloc, sbitmap *nearer, sbitmap *nearerout) | |
e48ba7af | 603 | { |
4c26117a | 604 | int num_edges, i; |
2325f0e2 | 605 | edge e; |
4c26117a | 606 | basic_block *worklist, *tos, bb; |
e48ba7af | 607 | |
7bcd381b | 608 | num_edges = NUM_EDGES (edge_list); |
e48ba7af | 609 | |
2325f0e2 | 610 | /* Allocate a worklist array/queue. Entries are only added to the |
611 | list if they were not already on the list. So the size is | |
612 | bounded by the number of basic blocks. */ | |
f0af5a88 | 613 | tos = worklist = xmalloc (sizeof (basic_block) * (n_basic_blocks + 1)); |
e48ba7af | 614 | |
2325f0e2 | 615 | /* Initialize NEARER for each edge and build a mapping from an edge to |
616 | its index. */ | |
617 | for (i = 0; i < num_edges; i++) | |
9ffd5d6d | 618 | INDEX_EDGE (edge_list, i)->aux = (void *) (size_t) i; |
7bcd381b | 619 | |
2325f0e2 | 620 | /* We want a maximal solution. */ |
621 | sbitmap_vector_ones (nearer, num_edges); | |
622 | ||
048599b9 | 623 | /* Note that even though we want an optimistic setting of NEARER, we |
624 | do not want to be overly optimistic. Consider an incoming edge to | |
625 | the exit block. That edge should always have a NEARER value the | |
626 | same as FARTHEST for that edge. */ | |
627 | for (e = EXIT_BLOCK_PTR->pred; e; e = e->pred_next) | |
8b863f57 | 628 | sbitmap_copy (nearer[(size_t)e->aux], farthest[(size_t)e->aux]); |
048599b9 | 629 | |
2325f0e2 | 630 | /* Add all the blocks to the worklist. This prevents an early exit |
631 | from the loop given our optimistic initialization of NEARER. */ | |
4c26117a | 632 | FOR_EACH_BB (bb) |
e48ba7af | 633 | { |
4c26117a | 634 | *tos++ = bb; |
635 | bb->aux = bb; | |
7bcd381b | 636 | } |
5ab08585 | 637 | |
2325f0e2 | 638 | /* Iterate until the worklist is empty. */ |
639 | while (tos != worklist) | |
7bcd381b | 640 | { |
2325f0e2 | 641 | /* Take the first entry off the worklist. */ |
4c26117a | 642 | bb = *--tos; |
643 | bb->aux = NULL; | |
2325f0e2 | 644 | |
645 | /* Compute the intersection of NEARER for each outgoing edge from B. */ | |
4c26117a | 646 | sbitmap_ones (nearerout[bb->index]); |
647 | for (e = bb->succ; e != NULL; e = e->succ_next) | |
648 | sbitmap_a_and_b (nearerout[bb->index], nearerout[bb->index], | |
9ffd5d6d | 649 | nearer[(size_t) e->aux]); |
2325f0e2 | 650 | |
651 | /* Calculate NEARER for all incoming edges. */ | |
4c26117a | 652 | for (e = bb->pred; e != NULL; e = e->pred_next) |
739c050b | 653 | if (sbitmap_union_of_diff_cg (nearer[(size_t) e->aux], |
b3d6de89 | 654 | farthest[(size_t) e->aux], |
655 | nearerout[e->dest->index], | |
656 | st_avloc[e->dest->index]) | |
9ca8d59e | 657 | /* If NEARER for an incoming edge was changed, then we need |
658 | to add the source of the incoming edge to the worklist. */ | |
659 | && e->src != ENTRY_BLOCK_PTR && e->src->aux == 0) | |
660 | { | |
661 | *tos++ = e->src; | |
662 | e->src->aux = e; | |
663 | } | |
7bcd381b | 664 | } |
e48ba7af | 665 | |
2325f0e2 | 666 | /* Computation of insertion and deletion points requires computing NEAREROUT |
667 | for the ENTRY block. We allocated an extra entry in the NEAREROUT array | |
668 | for just this purpose. */ | |
f20183e6 | 669 | sbitmap_ones (nearerout[last_basic_block]); |
2325f0e2 | 670 | for (e = ENTRY_BLOCK_PTR->succ; e != NULL; e = e->succ_next) |
f20183e6 | 671 | sbitmap_a_and_b (nearerout[last_basic_block], |
672 | nearerout[last_basic_block], | |
9ffd5d6d | 673 | nearer[(size_t) e->aux]); |
2325f0e2 | 674 | |
82f7392b | 675 | clear_aux_for_edges (); |
2325f0e2 | 676 | free (tos); |
7bcd381b | 677 | } |
e48ba7af | 678 | |
7bcd381b | 679 | /* Compute the insertion and deletion points for edge based LCM. */ |
9ca8d59e | 680 | |
e48ba7af | 681 | static void |
3ad4992f | 682 | compute_rev_insert_delete (struct edge_list *edge_list, sbitmap *st_avloc, |
683 | sbitmap *nearer, sbitmap *nearerout, | |
684 | sbitmap *insert, sbitmap *delete) | |
e48ba7af | 685 | { |
7bcd381b | 686 | int x; |
4c26117a | 687 | basic_block bb; |
e48ba7af | 688 | |
4c26117a | 689 | FOR_EACH_BB (bb) |
d4d93ea0 | 690 | sbitmap_difference (delete[bb->index], st_avloc[bb->index], |
691 | nearerout[bb->index]); | |
5ab08585 | 692 | |
7bcd381b | 693 | for (x = 0; x < NUM_EDGES (edge_list); x++) |
e48ba7af | 694 | { |
7bcd381b | 695 | basic_block b = INDEX_EDGE_PRED_BB (edge_list, x); |
696 | if (b == ENTRY_BLOCK_PTR) | |
f20183e6 | 697 | sbitmap_difference (insert[x], nearer[x], nearerout[last_basic_block]); |
e48ba7af | 698 | else |
b3d6de89 | 699 | sbitmap_difference (insert[x], nearer[x], nearerout[b->index]); |
e48ba7af | 700 | } |
e48ba7af | 701 | } |
702 | ||
5ab08585 | 703 | /* Given local properties TRANSP, ST_AVLOC, ST_ANTLOC, KILL return the |
7bcd381b | 704 | insert and delete vectors for edge based reverse LCM. Returns an |
705 | edgelist which is used to map the insert vector to what edge | |
706 | an expression should be inserted on. */ | |
e48ba7af | 707 | |
7bcd381b | 708 | struct edge_list * |
3ad4992f | 709 | pre_edge_rev_lcm (FILE *file ATTRIBUTE_UNUSED, int n_exprs, sbitmap *transp, |
710 | sbitmap *st_avloc, sbitmap *st_antloc, sbitmap *kill, | |
711 | sbitmap **insert, sbitmap **delete) | |
e48ba7af | 712 | { |
7bcd381b | 713 | sbitmap *st_antin, *st_antout; |
714 | sbitmap *st_avout, *st_avin, *farthest; | |
715 | sbitmap *nearer, *nearerout; | |
716 | struct edge_list *edge_list; | |
27548a74 | 717 | int num_edges; |
7bcd381b | 718 | |
719 | edge_list = create_edge_list (); | |
720 | num_edges = NUM_EDGES (edge_list); | |
721 | ||
f0af5a88 | 722 | st_antin = sbitmap_vector_alloc (last_basic_block, n_exprs); |
723 | st_antout = sbitmap_vector_alloc (last_basic_block, n_exprs); | |
f20183e6 | 724 | sbitmap_vector_zero (st_antin, last_basic_block); |
725 | sbitmap_vector_zero (st_antout, last_basic_block); | |
7bcd381b | 726 | compute_antinout_edge (st_antloc, transp, st_antin, st_antout); |
727 | ||
728 | /* Compute global anticipatability. */ | |
f20183e6 | 729 | st_avout = sbitmap_vector_alloc (last_basic_block, n_exprs); |
730 | st_avin = sbitmap_vector_alloc (last_basic_block, n_exprs); | |
7bcd381b | 731 | compute_available (st_avloc, kill, st_avout, st_avin); |
732 | ||
733 | #ifdef LCM_DEBUG_INFO | |
734 | if (file) | |
735 | { | |
736 | fprintf (file, "Edge List:\n"); | |
737 | verify_edge_list (file, edge_list); | |
738 | print_edge_list (file, edge_list); | |
f20183e6 | 739 | dump_sbitmap_vector (file, "transp", "", transp, last_basic_block); |
740 | dump_sbitmap_vector (file, "st_avloc", "", st_avloc, last_basic_block); | |
741 | dump_sbitmap_vector (file, "st_antloc", "", st_antloc, last_basic_block); | |
742 | dump_sbitmap_vector (file, "st_antin", "", st_antin, last_basic_block); | |
743 | dump_sbitmap_vector (file, "st_antout", "", st_antout, last_basic_block); | |
744 | dump_sbitmap_vector (file, "st_kill", "", kill, last_basic_block); | |
7bcd381b | 745 | } |
746 | #endif | |
e48ba7af | 747 | |
7bcd381b | 748 | #ifdef LCM_DEBUG_INFO |
749 | if (file) | |
750 | { | |
f20183e6 | 751 | dump_sbitmap_vector (file, "st_avout", "", st_avout, last_basic_block); |
752 | dump_sbitmap_vector (file, "st_avin", "", st_avin, last_basic_block); | |
7bcd381b | 753 | } |
754 | #endif | |
e48ba7af | 755 | |
7bcd381b | 756 | /* Compute farthestness. */ |
757 | farthest = sbitmap_vector_alloc (num_edges, n_exprs); | |
5ab08585 | 758 | compute_farthest (edge_list, n_exprs, st_avout, st_avin, st_antin, |
7bcd381b | 759 | kill, farthest); |
760 | ||
761 | #ifdef LCM_DEBUG_INFO | |
762 | if (file) | |
763 | dump_sbitmap_vector (file, "farthest", "", farthest, num_edges); | |
764 | #endif | |
765 | ||
cca23eb2 | 766 | sbitmap_vector_free (st_antin); |
767 | sbitmap_vector_free (st_antout); | |
768 | ||
769 | sbitmap_vector_free (st_avin); | |
770 | sbitmap_vector_free (st_avout); | |
7bcd381b | 771 | |
772 | nearer = sbitmap_vector_alloc (num_edges, n_exprs); | |
9ca8d59e | 773 | |
7bcd381b | 774 | /* Allocate an extra element for the entry block. */ |
f20183e6 | 775 | nearerout = sbitmap_vector_alloc (last_basic_block + 1, n_exprs); |
2325f0e2 | 776 | compute_nearerout (edge_list, farthest, st_avloc, nearer, nearerout); |
7bcd381b | 777 | |
778 | #ifdef LCM_DEBUG_INFO | |
779 | if (file) | |
e48ba7af | 780 | { |
5ab08585 | 781 | dump_sbitmap_vector (file, "nearerout", "", nearerout, |
f20183e6 | 782 | last_basic_block + 1); |
7bcd381b | 783 | dump_sbitmap_vector (file, "nearer", "", nearer, num_edges); |
e48ba7af | 784 | } |
7bcd381b | 785 | #endif |
786 | ||
cca23eb2 | 787 | sbitmap_vector_free (farthest); |
7bcd381b | 788 | |
789 | *insert = sbitmap_vector_alloc (num_edges, n_exprs); | |
f20183e6 | 790 | *delete = sbitmap_vector_alloc (last_basic_block, n_exprs); |
9ca8d59e | 791 | compute_rev_insert_delete (edge_list, st_avloc, nearer, nearerout, |
792 | *insert, *delete); | |
7bcd381b | 793 | |
cca23eb2 | 794 | sbitmap_vector_free (nearerout); |
795 | sbitmap_vector_free (nearer); | |
7bcd381b | 796 | |
797 | #ifdef LCM_DEBUG_INFO | |
798 | if (file) | |
799 | { | |
800 | dump_sbitmap_vector (file, "pre_insert_map", "", *insert, num_edges); | |
9ca8d59e | 801 | dump_sbitmap_vector (file, "pre_delete_map", "", *delete, |
f20183e6 | 802 | last_basic_block); |
7bcd381b | 803 | } |
804 | #endif | |
7bcd381b | 805 | return edge_list; |
e48ba7af | 806 | } |
18862b5a | 807 | |
9ca8d59e | 808 | /* Mode switching: |
809 | ||
810 | The algorithm for setting the modes consists of scanning the insn list | |
18862b5a | 811 | and finding all the insns which require a specific mode. Each insn gets |
812 | a unique struct seginfo element. These structures are inserted into a list | |
813 | for each basic block. For each entity, there is an array of bb_info over | |
814 | the flow graph basic blocks (local var 'bb_info'), and contains a list | |
815 | of all insns within that basic block, in the order they are encountered. | |
816 | ||
817 | For each entity, any basic block WITHOUT any insns requiring a specific | |
818 | mode are given a single entry, without a mode. (Each basic block | |
819 | in the flow graph must have at least one entry in the segment table.) | |
820 | ||
821 | The LCM algorithm is then run over the flow graph to determine where to | |
822 | place the sets to the highest-priority value in respect of first the first | |
b903337a | 823 | insn in any one block. Any adjustments required to the transparency |
18862b5a | 824 | vectors are made, then the next iteration starts for the next-lower |
b903337a | 825 | priority mode, till for each entity all modes are exhausted. |
18862b5a | 826 | |
827 | More details are located in the code for optimize_mode_switching(). */ | |
828 | ||
829 | /* This structure contains the information for each insn which requires | |
5ab08585 | 830 | either single or double mode to be set. |
18862b5a | 831 | MODE is the mode this insn must be executed in. |
f913e47c | 832 | INSN_PTR is the insn to be executed (may be the note that marks the |
833 | beginning of a basic block). | |
18862b5a | 834 | BBNUM is the flow graph basic block this insn occurs in. |
835 | NEXT is the next insn in the same basic block. */ | |
5ab08585 | 836 | struct seginfo |
18862b5a | 837 | { |
838 | int mode; | |
839 | rtx insn_ptr; | |
840 | int bbnum; | |
841 | struct seginfo *next; | |
842 | HARD_REG_SET regs_live; | |
843 | }; | |
844 | ||
3b7e1f27 | 845 | struct bb_info |
18862b5a | 846 | { |
847 | struct seginfo *seginfo; | |
848 | int computing; | |
849 | }; | |
850 | ||
851 | /* These bitmaps are used for the LCM algorithm. */ | |
852 | ||
29768226 | 853 | #ifdef OPTIMIZE_MODE_SWITCHING |
18862b5a | 854 | static sbitmap *antic; |
855 | static sbitmap *transp; | |
856 | static sbitmap *comp; | |
857 | static sbitmap *delete; | |
858 | static sbitmap *insert; | |
859 | ||
3ad4992f | 860 | static struct seginfo * new_seginfo (int, rtx, int, HARD_REG_SET); |
861 | static void add_seginfo (struct bb_info *, struct seginfo *); | |
862 | static void reg_dies (rtx, HARD_REG_SET); | |
863 | static void reg_becomes_live (rtx, rtx, void *); | |
864 | static void make_preds_opaque (basic_block, int); | |
29768226 | 865 | #endif |
866 | \f | |
867 | #ifdef OPTIMIZE_MODE_SWITCHING | |
18862b5a | 868 | |
869 | /* This function will allocate a new BBINFO structure, initialized | |
7dff60c8 | 870 | with the MODE, INSN, and basic block BB parameters. */ |
29768226 | 871 | |
18862b5a | 872 | static struct seginfo * |
3ad4992f | 873 | new_seginfo (int mode, rtx insn, int bb, HARD_REG_SET regs_live) |
18862b5a | 874 | { |
875 | struct seginfo *ptr; | |
876 | ptr = xmalloc (sizeof (struct seginfo)); | |
877 | ptr->mode = mode; | |
878 | ptr->insn_ptr = insn; | |
879 | ptr->bbnum = bb; | |
880 | ptr->next = NULL; | |
881 | COPY_HARD_REG_SET (ptr->regs_live, regs_live); | |
882 | return ptr; | |
883 | } | |
884 | ||
5ab08585 | 885 | /* Add a seginfo element to the end of a list. |
18862b5a | 886 | HEAD is a pointer to the list beginning. |
887 | INFO is the structure to be linked in. */ | |
29768226 | 888 | |
18862b5a | 889 | static void |
3ad4992f | 890 | add_seginfo (struct bb_info *head, struct seginfo *info) |
18862b5a | 891 | { |
892 | struct seginfo *ptr; | |
893 | ||
894 | if (head->seginfo == NULL) | |
895 | head->seginfo = info; | |
896 | else | |
897 | { | |
898 | ptr = head->seginfo; | |
899 | while (ptr->next != NULL) | |
8851e806 | 900 | ptr = ptr->next; |
18862b5a | 901 | ptr->next = info; |
902 | } | |
903 | } | |
904 | ||
905 | /* Make all predecessors of basic block B opaque, recursively, till we hit | |
906 | some that are already non-transparent, or an edge where aux is set; that | |
907 | denotes that a mode set is to be done on that edge. | |
908 | J is the bit number in the bitmaps that corresponds to the entity that | |
909 | we are currently handling mode-switching for. */ | |
29768226 | 910 | |
18862b5a | 911 | static void |
3ad4992f | 912 | make_preds_opaque (basic_block b, int j) |
18862b5a | 913 | { |
914 | edge e; | |
915 | ||
916 | for (e = b->pred; e; e = e->pred_next) | |
917 | { | |
918 | basic_block pb = e->src; | |
9ca8d59e | 919 | |
b3d6de89 | 920 | if (e->aux || ! TEST_BIT (transp[pb->index], j)) |
18862b5a | 921 | continue; |
9ca8d59e | 922 | |
b3d6de89 | 923 | RESET_BIT (transp[pb->index], j); |
18862b5a | 924 | make_preds_opaque (pb, j); |
925 | } | |
926 | } | |
927 | ||
928 | /* Record in LIVE that register REG died. */ | |
29768226 | 929 | |
18862b5a | 930 | static void |
3ad4992f | 931 | reg_dies (rtx reg, HARD_REG_SET live) |
18862b5a | 932 | { |
9ca8d59e | 933 | int regno, nregs; |
18862b5a | 934 | |
8ad4c111 | 935 | if (!REG_P (reg)) |
18862b5a | 936 | return; |
9ca8d59e | 937 | |
18862b5a | 938 | regno = REGNO (reg); |
939 | if (regno < FIRST_PSEUDO_REGISTER) | |
67d6c12b | 940 | for (nregs = hard_regno_nregs[regno][GET_MODE (reg)] - 1; nregs >= 0; |
9ca8d59e | 941 | nregs--) |
942 | CLEAR_HARD_REG_BIT (live, regno + nregs); | |
18862b5a | 943 | } |
944 | ||
945 | /* Record in LIVE that register REG became live. | |
946 | This is called via note_stores. */ | |
29768226 | 947 | |
18862b5a | 948 | static void |
3ad4992f | 949 | reg_becomes_live (rtx reg, rtx setter ATTRIBUTE_UNUSED, void *live) |
18862b5a | 950 | { |
9ca8d59e | 951 | int regno, nregs; |
18862b5a | 952 | |
953 | if (GET_CODE (reg) == SUBREG) | |
954 | reg = SUBREG_REG (reg); | |
955 | ||
8ad4c111 | 956 | if (!REG_P (reg)) |
18862b5a | 957 | return; |
958 | ||
959 | regno = REGNO (reg); | |
960 | if (regno < FIRST_PSEUDO_REGISTER) | |
67d6c12b | 961 | for (nregs = hard_regno_nregs[regno][GET_MODE (reg)] - 1; nregs >= 0; |
9ca8d59e | 962 | nregs--) |
963 | SET_HARD_REG_BIT (* (HARD_REG_SET *) live, regno + nregs); | |
18862b5a | 964 | } |
965 | ||
894b8fd9 | 966 | /* Make sure if MODE_ENTRY is defined the MODE_EXIT is defined |
967 | and vice versa. */ | |
968 | #if defined (MODE_ENTRY) != defined (MODE_EXIT) | |
969 | #error "Both MODE_ENTRY and MODE_EXIT must be defined" | |
970 | #endif | |
971 | ||
b78e14a8 | 972 | /* Find all insns that need a particular mode setting, and insert the |
973 | necessary mode switches. Return true if we did work. */ | |
9ca8d59e | 974 | |
b78e14a8 | 975 | int |
3ad4992f | 976 | optimize_mode_switching (FILE *file) |
18862b5a | 977 | { |
18862b5a | 978 | rtx insn; |
4c26117a | 979 | int e; |
980 | basic_block bb; | |
18862b5a | 981 | int need_commit = 0; |
982 | sbitmap *kill; | |
983 | struct edge_list *edge_list; | |
e99c3a1d | 984 | static const int num_modes[] = NUM_MODES_FOR_MODE_SWITCHING; |
3585dac7 | 985 | #define N_ENTITIES ARRAY_SIZE (num_modes) |
18862b5a | 986 | int entity_map[N_ENTITIES]; |
3b7e1f27 | 987 | struct bb_info *bb_info[N_ENTITIES]; |
18862b5a | 988 | int i, j; |
989 | int n_entities; | |
990 | int max_num_modes = 0; | |
7fb47f9f | 991 | bool emited = false; |
43b8e8ee | 992 | basic_block post_entry ATTRIBUTE_UNUSED, pre_exit ATTRIBUTE_UNUSED; |
18862b5a | 993 | |
308f9b79 | 994 | clear_bb_flags (); |
1287c919 | 995 | |
18862b5a | 996 | for (e = N_ENTITIES - 1, n_entities = 0; e >= 0; e--) |
9ca8d59e | 997 | if (OPTIMIZE_MODE_SWITCHING (e)) |
998 | { | |
742ee135 | 999 | int entry_exit_extra = 0; |
1000 | ||
1001 | /* Create the list of segments within each basic block. | |
1002 | If NORMAL_MODE is defined, allow for two extra | |
8851e806 | 1003 | blocks split from the entry and exit block. */ |
894b8fd9 | 1004 | #if defined (MODE_ENTRY) && defined (MODE_EXIT) |
742ee135 | 1005 | entry_exit_extra = 2; |
1006 | #endif | |
9ca8d59e | 1007 | bb_info[n_entities] |
f0af5a88 | 1008 | = xcalloc (last_basic_block + entry_exit_extra, sizeof **bb_info); |
9ca8d59e | 1009 | entity_map[n_entities++] = e; |
1010 | if (num_modes[e] > max_num_modes) | |
1011 | max_num_modes = num_modes[e]; | |
1012 | } | |
1013 | ||
18862b5a | 1014 | if (! n_entities) |
b78e14a8 | 1015 | return 0; |
18862b5a | 1016 | |
894b8fd9 | 1017 | #if defined (MODE_ENTRY) && defined (MODE_EXIT) |
742ee135 | 1018 | { |
1019 | /* Split the edge from the entry block and the fallthrough edge to the | |
1020 | exit block, so that we can note that there NORMAL_MODE is supplied / | |
1021 | required. */ | |
1022 | edge eg; | |
1023 | post_entry = split_edge (ENTRY_BLOCK_PTR->succ); | |
1024 | /* The only non-call predecessor at this stage is a block with a | |
1025 | fallthrough edge; there can be at most one, but there could be | |
1026 | none at all, e.g. when exit is called. */ | |
1027 | for (pre_exit = 0, eg = EXIT_BLOCK_PTR->pred; eg; eg = eg->pred_next) | |
1028 | if (eg->flags & EDGE_FALLTHRU) | |
1029 | { | |
1030 | regset live_at_end = eg->src->global_live_at_end; | |
1031 | ||
2045cdd4 | 1032 | if (pre_exit) |
1033 | abort (); | |
742ee135 | 1034 | pre_exit = split_edge (eg); |
1035 | COPY_REG_SET (pre_exit->global_live_at_start, live_at_end); | |
1036 | COPY_REG_SET (pre_exit->global_live_at_end, live_at_end); | |
1037 | } | |
1038 | } | |
1287c919 | 1039 | #endif |
1040 | ||
18862b5a | 1041 | /* Create the bitmap vectors. */ |
1042 | ||
f20183e6 | 1043 | antic = sbitmap_vector_alloc (last_basic_block, n_entities); |
1044 | transp = sbitmap_vector_alloc (last_basic_block, n_entities); | |
1045 | comp = sbitmap_vector_alloc (last_basic_block, n_entities); | |
18862b5a | 1046 | |
f20183e6 | 1047 | sbitmap_vector_ones (transp, last_basic_block); |
18862b5a | 1048 | |
1049 | for (j = n_entities - 1; j >= 0; j--) | |
1050 | { | |
1051 | int e = entity_map[j]; | |
1052 | int no_mode = num_modes[e]; | |
3b7e1f27 | 1053 | struct bb_info *info = bb_info[j]; |
18862b5a | 1054 | |
1055 | /* Determine what the first use (if any) need for a mode of entity E is. | |
b78e14a8 | 1056 | This will be the mode that is anticipatable for this block. |
18862b5a | 1057 | Also compute the initial transparency settings. */ |
4c26117a | 1058 | FOR_EACH_BB (bb) |
18862b5a | 1059 | { |
1060 | struct seginfo *ptr; | |
1061 | int last_mode = no_mode; | |
1062 | HARD_REG_SET live_now; | |
1063 | ||
1064 | REG_SET_TO_HARD_REG_SET (live_now, | |
4c26117a | 1065 | bb->global_live_at_start); |
5496dbfc | 1066 | for (insn = BB_HEAD (bb); |
1067 | insn != NULL && insn != NEXT_INSN (BB_END (bb)); | |
18862b5a | 1068 | insn = NEXT_INSN (insn)) |
1069 | { | |
9204e736 | 1070 | if (INSN_P (insn)) |
18862b5a | 1071 | { |
1072 | int mode = MODE_NEEDED (e, insn); | |
1073 | rtx link; | |
1074 | ||
1075 | if (mode != no_mode && mode != last_mode) | |
1076 | { | |
1077 | last_mode = mode; | |
4c26117a | 1078 | ptr = new_seginfo (mode, insn, bb->index, live_now); |
1079 | add_seginfo (info + bb->index, ptr); | |
1080 | RESET_BIT (transp[bb->index], j); | |
18862b5a | 1081 | } |
894b8fd9 | 1082 | #ifdef MODE_AFTER |
1083 | last_mode = MODE_AFTER (last_mode, insn); | |
1084 | #endif | |
18862b5a | 1085 | /* Update LIVE_NOW. */ |
1086 | for (link = REG_NOTES (insn); link; link = XEXP (link, 1)) | |
1087 | if (REG_NOTE_KIND (link) == REG_DEAD) | |
1088 | reg_dies (XEXP (link, 0), live_now); | |
9ca8d59e | 1089 | |
18862b5a | 1090 | note_stores (PATTERN (insn), reg_becomes_live, &live_now); |
1091 | for (link = REG_NOTES (insn); link; link = XEXP (link, 1)) | |
1092 | if (REG_NOTE_KIND (link) == REG_UNUSED) | |
1093 | reg_dies (XEXP (link, 0), live_now); | |
1094 | } | |
1095 | } | |
9ca8d59e | 1096 | |
4c26117a | 1097 | info[bb->index].computing = last_mode; |
18862b5a | 1098 | /* Check for blocks without ANY mode requirements. */ |
1099 | if (last_mode == no_mode) | |
1100 | { | |
5496dbfc | 1101 | ptr = new_seginfo (no_mode, BB_END (bb), bb->index, live_now); |
4c26117a | 1102 | add_seginfo (info + bb->index, ptr); |
18862b5a | 1103 | } |
1104 | } | |
894b8fd9 | 1105 | #if defined (MODE_ENTRY) && defined (MODE_EXIT) |
18862b5a | 1106 | { |
894b8fd9 | 1107 | int mode = MODE_ENTRY (e); |
9ca8d59e | 1108 | |
18862b5a | 1109 | if (mode != no_mode) |
1110 | { | |
742ee135 | 1111 | bb = post_entry; |
5ab08585 | 1112 | |
742ee135 | 1113 | /* By always making this nontransparent, we save |
1114 | an extra check in make_preds_opaque. We also | |
1115 | need this to avoid confusing pre_edge_lcm when | |
1116 | antic is cleared but transp and comp are set. */ | |
1117 | RESET_BIT (transp[bb->index], j); | |
1287c919 | 1118 | |
742ee135 | 1119 | /* Insert a fake computing definition of MODE into entry |
1120 | blocks which compute no mode. This represents the mode on | |
1121 | entry. */ | |
1122 | info[bb->index].computing = mode; | |
1123 | ||
1124 | if (pre_exit) | |
894b8fd9 | 1125 | info[pre_exit->index].seginfo->mode = MODE_EXIT (e); |
18862b5a | 1126 | } |
1127 | } | |
7dff60c8 | 1128 | #endif /* NORMAL_MODE */ |
18862b5a | 1129 | } |
1130 | ||
f20183e6 | 1131 | kill = sbitmap_vector_alloc (last_basic_block, n_entities); |
18862b5a | 1132 | for (i = 0; i < max_num_modes; i++) |
1133 | { | |
1134 | int current_mode[N_ENTITIES]; | |
1135 | ||
1136 | /* Set the anticipatable and computing arrays. */ | |
f20183e6 | 1137 | sbitmap_vector_zero (antic, last_basic_block); |
1138 | sbitmap_vector_zero (comp, last_basic_block); | |
18862b5a | 1139 | for (j = n_entities - 1; j >= 0; j--) |
1140 | { | |
1141 | int m = current_mode[j] = MODE_PRIORITY_TO_MODE (entity_map[j], i); | |
3b7e1f27 | 1142 | struct bb_info *info = bb_info[j]; |
5ab08585 | 1143 | |
4c26117a | 1144 | FOR_EACH_BB (bb) |
18862b5a | 1145 | { |
4c26117a | 1146 | if (info[bb->index].seginfo->mode == m) |
1147 | SET_BIT (antic[bb->index], j); | |
18862b5a | 1148 | |
4c26117a | 1149 | if (info[bb->index].computing == m) |
1150 | SET_BIT (comp[bb->index], j); | |
18862b5a | 1151 | } |
1152 | } | |
1153 | ||
1154 | /* Calculate the optimal locations for the | |
1155 | placement mode switches to modes with priority I. */ | |
1156 | ||
4c26117a | 1157 | FOR_EACH_BB (bb) |
1158 | sbitmap_not (kill[bb->index], transp[bb->index]); | |
18862b5a | 1159 | edge_list = pre_edge_lcm (file, 1, transp, comp, antic, |
1160 | kill, &insert, &delete); | |
1161 | ||
9ca8d59e | 1162 | for (j = n_entities - 1; j >= 0; j--) |
18862b5a | 1163 | { |
1164 | /* Insert all mode sets that have been inserted by lcm. */ | |
1165 | int no_mode = num_modes[entity_map[j]]; | |
9ca8d59e | 1166 | |
18862b5a | 1167 | /* Wherever we have moved a mode setting upwards in the flow graph, |
1168 | the blocks between the new setting site and the now redundant | |
1169 | computation ceases to be transparent for any lower-priority | |
1170 | mode of the same entity. First set the aux field of each | |
1171 | insertion site edge non-transparent, then propagate the new | |
1172 | non-transparency from the redundant computation upwards till | |
1173 | we hit an insertion site or an already non-transparent block. */ | |
1174 | for (e = NUM_EDGES (edge_list) - 1; e >= 0; e--) | |
1175 | { | |
1176 | edge eg = INDEX_EDGE (edge_list, e); | |
1177 | int mode; | |
1178 | basic_block src_bb; | |
1179 | HARD_REG_SET live_at_edge; | |
1180 | rtx mode_set; | |
1181 | ||
1182 | eg->aux = 0; | |
1183 | ||
1184 | if (! TEST_BIT (insert[e], j)) | |
1185 | continue; | |
1186 | ||
1187 | eg->aux = (void *)1; | |
1188 | ||
1189 | mode = current_mode[j]; | |
1190 | src_bb = eg->src; | |
1191 | ||
9ca8d59e | 1192 | REG_SET_TO_HARD_REG_SET (live_at_edge, |
1193 | src_bb->global_live_at_end); | |
1194 | ||
18862b5a | 1195 | start_sequence (); |
1196 | EMIT_MODE_SET (entity_map[j], mode, live_at_edge); | |
31d3e01c | 1197 | mode_set = get_insns (); |
18862b5a | 1198 | end_sequence (); |
1199 | ||
7fb47f9f | 1200 | /* Do not bother to insert empty sequence. */ |
31d3e01c | 1201 | if (mode_set == NULL_RTX) |
7fb47f9f | 1202 | continue; |
1203 | ||
1287c919 | 1204 | /* If this is an abnormal edge, we'll insert at the end |
1205 | of the previous block. */ | |
18862b5a | 1206 | if (eg->flags & EDGE_ABNORMAL) |
1207 | { | |
7fb47f9f | 1208 | emited = true; |
6d7dc5b9 | 1209 | if (JUMP_P (BB_END (src_bb))) |
5496dbfc | 1210 | emit_insn_before (mode_set, BB_END (src_bb)); |
2045cdd4 | 1211 | /* It doesn't make sense to switch to normal mode |
1212 | after a CALL_INSN, so we're going to abort if we | |
1213 | find one. The cases in which a CALL_INSN may | |
1214 | have an abnormal edge are sibcalls and EH edges. | |
1215 | In the case of sibcalls, the dest basic-block is | |
1216 | the EXIT_BLOCK, that runs in normal mode; it is | |
1217 | assumed that a sibcall insn requires normal mode | |
1218 | itself, so no mode switch would be required after | |
1219 | the call (it wouldn't make sense, anyway). In | |
1220 | the case of EH edges, EH entry points also start | |
1221 | in normal mode, so a similar reasoning applies. */ | |
1222 | else if (NONJUMP_INSN_P (BB_END (src_bb))) | |
1223 | emit_insn_after (mode_set, BB_END (src_bb)); | |
1287c919 | 1224 | else |
2045cdd4 | 1225 | abort (); |
b3d6de89 | 1226 | bb_info[j][src_bb->index].computing = mode; |
1227 | RESET_BIT (transp[src_bb->index], j); | |
18862b5a | 1228 | } |
1229 | else | |
1230 | { | |
1231 | need_commit = 1; | |
1232 | insert_insn_on_edge (mode_set, eg); | |
1233 | } | |
18862b5a | 1234 | } |
1235 | ||
4c26117a | 1236 | FOR_EACH_BB_REVERSE (bb) |
1237 | if (TEST_BIT (delete[bb->index], j)) | |
9ca8d59e | 1238 | { |
4c26117a | 1239 | make_preds_opaque (bb, j); |
9ca8d59e | 1240 | /* Cancel the 'deleted' mode set. */ |
4c26117a | 1241 | bb_info[j][bb->index].seginfo->mode = no_mode; |
9ca8d59e | 1242 | } |
18862b5a | 1243 | } |
9ca8d59e | 1244 | |
82f7392b | 1245 | clear_aux_for_edges (); |
18862b5a | 1246 | free_edge_list (edge_list); |
1247 | } | |
1248 | ||
1249 | /* Now output the remaining mode sets in all the segments. */ | |
1250 | for (j = n_entities - 1; j >= 0; j--) | |
1251 | { | |
7dff60c8 | 1252 | int no_mode = num_modes[entity_map[j]]; |
1253 | ||
4c26117a | 1254 | FOR_EACH_BB_REVERSE (bb) |
18862b5a | 1255 | { |
1256 | struct seginfo *ptr, *next; | |
4c26117a | 1257 | for (ptr = bb_info[j][bb->index].seginfo; ptr; ptr = next) |
18862b5a | 1258 | { |
1259 | next = ptr->next; | |
7dff60c8 | 1260 | if (ptr->mode != no_mode) |
18862b5a | 1261 | { |
1262 | rtx mode_set; | |
1263 | ||
1264 | start_sequence (); | |
1265 | EMIT_MODE_SET (entity_map[j], ptr->mode, ptr->regs_live); | |
31d3e01c | 1266 | mode_set = get_insns (); |
18862b5a | 1267 | end_sequence (); |
1268 | ||
7fb47f9f | 1269 | /* Do not bother to insert empty sequence. */ |
31d3e01c | 1270 | if (mode_set == NULL_RTX) |
7fb47f9f | 1271 | continue; |
1272 | ||
1273 | emited = true; | |
6d7dc5b9 | 1274 | if (NOTE_P (ptr->insn_ptr) |
6484cd39 | 1275 | && (NOTE_LINE_NUMBER (ptr->insn_ptr) |
1276 | == NOTE_INSN_BASIC_BLOCK)) | |
9dda7915 | 1277 | emit_insn_after (mode_set, ptr->insn_ptr); |
7dff60c8 | 1278 | else |
9dda7915 | 1279 | emit_insn_before (mode_set, ptr->insn_ptr); |
18862b5a | 1280 | } |
9ca8d59e | 1281 | |
18862b5a | 1282 | free (ptr); |
1283 | } | |
1284 | } | |
9ca8d59e | 1285 | |
18862b5a | 1286 | free (bb_info[j]); |
1287 | } | |
1288 | ||
1289 | /* Finished. Free up all the things we've allocated. */ | |
5ab08585 | 1290 | |
18862b5a | 1291 | sbitmap_vector_free (kill); |
1292 | sbitmap_vector_free (antic); | |
1293 | sbitmap_vector_free (transp); | |
1294 | sbitmap_vector_free (comp); | |
1295 | sbitmap_vector_free (delete); | |
1296 | sbitmap_vector_free (insert); | |
1297 | ||
1298 | if (need_commit) | |
1299 | commit_edge_insertions (); | |
b78e14a8 | 1300 | |
894b8fd9 | 1301 | #if defined (MODE_ENTRY) && defined (MODE_EXIT) |
742ee135 | 1302 | cleanup_cfg (CLEANUP_NO_INSN_DEL); |
1303 | #else | |
7fb47f9f | 1304 | if (!need_commit && !emited) |
1305 | return 0; | |
742ee135 | 1306 | #endif |
7fb47f9f | 1307 | |
308f9b79 | 1308 | max_regno = max_reg_num (); |
1309 | allocate_reg_info (max_regno, FALSE, FALSE); | |
1310 | update_life_info_in_dirty_blocks (UPDATE_LIFE_GLOBAL_RM_NOTES, | |
1311 | (PROP_DEATH_NOTES | PROP_KILL_DEAD_CODE | |
1312 | | PROP_SCAN_DEAD_CODE)); | |
b78e14a8 | 1313 | |
1314 | return 1; | |
18862b5a | 1315 | } |
b78e14a8 | 1316 | #endif /* OPTIMIZE_MODE_SWITCHING */ |