Mercurial > hg > CbC > CbC_gcc
annotate gcc/web.c @ 55:77e2b8dfacca gcc-4.4.5
update it from 4.4.3 to 4.5.0
| author | ryoma <e075725@ie.u-ryukyu.ac.jp> |
|---|---|
| date | Fri, 12 Feb 2010 23:39:51 +0900 |
| parents | a06113de4d67 |
| children | b7f97abdc517 |
| rev | line source |
|---|---|
| 0 | 1 /* Web construction code for GNU compiler. |
| 2 Contributed by Jan Hubicka. | |
| 3 Copyright (C) 2001, 2002, 2004, 2006, 2007, 2008 | |
| 4 Free Software Foundation, Inc. | |
| 5 | |
| 6 This file is part of GCC. | |
| 7 | |
| 8 GCC is free software; you can redistribute it and/or modify it under | |
| 9 the terms of the GNU General Public License as published by the Free | |
| 10 Software Foundation; either version 3, or (at your option) any later | |
| 11 version. | |
| 12 | |
| 13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY | |
| 14 WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
| 15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
| 16 for more details. | |
| 17 | |
| 18 You should have received a copy of the GNU General Public License | |
| 19 along with GCC; see the file COPYING3. If not see | |
| 20 <http://www.gnu.org/licenses/>. */ | |
| 21 | |
| 22 /* Simple optimization pass that splits independent uses of each pseudo, | |
| 23 increasing effectiveness of other optimizations. The optimization can | |
| 24 serve as an example of use for the dataflow module. | |
| 25 | |
| 26 We don't split registers with REG_USERVAR set unless -fmessy-debugging | |
| 27 is specified, because debugging information about such split variables | |
| 28 is almost unusable. | |
| 29 | |
| 30 TODO | |
| 31 - Add code to keep debugging up-to-date after splitting user variable | |
| 32 pseudos. This can be done by keeping track of all the pseudos used | |
| 33 for the variable and using life analysis information before reload | |
| 34 to determine which one is live and, in case more than one are live, | |
| 35 choose the one with the latest definition. | |
| 36 | |
| 37 Other optimization passes can benefit from the infrastructure too. | |
| 38 | |
| 39 - We may use profile information and ignore infrequent use for the | |
| 40 purpose of web unifying, inserting the compensation code later to | |
| 41 implement full induction variable expansion for loops (currently | |
| 42 we expand only if the induction variable is dead afterward, which | |
| 43 is often the case). */ | |
| 44 | |
| 45 #include "config.h" | |
| 46 #include "system.h" | |
| 47 #include "coretypes.h" | |
| 48 #include "tm.h" | |
| 49 #include "toplev.h" | |
| 50 | |
| 51 #include "rtl.h" | |
| 52 #include "hard-reg-set.h" | |
| 53 #include "flags.h" | |
| 54 #include "obstack.h" | |
| 55 #include "basic-block.h" | |
| 56 #include "output.h" | |
| 57 #include "df.h" | |
| 58 #include "function.h" | |
| 59 #include "timevar.h" | |
| 60 #include "tree-pass.h" | |
| 61 | |
| 62 | |
| 63 static rtx entry_register (struct web_entry *, df_ref, char *); | |
| 64 static void replace_ref (df_ref, rtx); | |
| 65 | |
| 66 /* Find the root of unionfind tree (the representative of set). */ | |
| 67 | |
| 68 struct web_entry * | |
| 69 unionfind_root (struct web_entry *element) | |
| 70 { | |
| 71 struct web_entry *element1 = element, *element2; | |
| 72 | |
| 73 while (element->pred) | |
| 74 element = element->pred; | |
| 75 while (element1->pred) | |
| 76 { | |
| 77 element2 = element1->pred; | |
| 78 element1->pred = element; | |
| 79 element1 = element2; | |
| 80 } | |
| 81 return element; | |
| 82 } | |
| 83 | |
|
55
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
84 /* Union sets. |
| 0 | 85 Return true if FIRST and SECOND points to the same web entry structure and |
| 86 nothing is done. Otherwise, return false. */ | |
| 87 | |
| 88 bool | |
| 89 unionfind_union (struct web_entry *first, struct web_entry *second) | |
| 90 { | |
| 91 first = unionfind_root (first); | |
| 92 second = unionfind_root (second); | |
| 93 if (first == second) | |
| 94 return true; | |
| 95 second->pred = first; | |
| 96 return false; | |
| 97 } | |
| 98 | |
| 99 /* For each use, all possible defs reaching it must come in the same | |
| 100 register, union them. | |
| 101 FUN is the function that does the union. */ | |
| 102 | |
| 103 void | |
| 104 union_defs (df_ref use, struct web_entry *def_entry, | |
| 105 struct web_entry *use_entry, | |
| 106 bool (*fun) (struct web_entry *, struct web_entry *)) | |
| 107 { | |
| 108 struct df_insn_info *insn_info = DF_REF_INSN_INFO (use); | |
| 109 struct df_link *link = DF_REF_CHAIN (use); | |
| 110 df_ref *use_link; | |
| 111 df_ref *eq_use_link; | |
| 112 df_ref *def_link; | |
| 113 rtx set; | |
| 114 | |
| 115 if (insn_info) | |
| 116 { | |
| 117 rtx insn = insn_info->insn; | |
| 118 use_link = DF_INSN_INFO_USES (insn_info); | |
| 119 eq_use_link = DF_INSN_INFO_EQ_USES (insn_info); | |
| 120 def_link = DF_INSN_INFO_DEFS (insn_info); | |
| 121 set = single_set (insn); | |
| 122 } | |
| 123 else | |
| 124 { | |
| 125 /* An artificial use. It links up with nothing. */ | |
| 126 use_link = NULL; | |
| 127 eq_use_link = NULL; | |
| 128 def_link = NULL; | |
| 129 set = NULL; | |
| 130 } | |
| 131 | |
| 132 /* Some instructions may use match_dup for their operands. In case the | |
| 133 operands are dead, we will assign them different pseudos, creating | |
| 134 invalid instructions, so union all uses of the same operand for each | |
| 135 insn. */ | |
| 136 | |
| 137 if (use_link) | |
| 138 while (*use_link) | |
| 139 { | |
| 140 if (use != *use_link | |
| 141 && DF_REF_REAL_REG (use) == DF_REF_REAL_REG (*use_link)) | |
| 142 (*fun) (use_entry + DF_REF_ID (use), | |
| 143 use_entry + DF_REF_ID (*use_link)); | |
| 144 use_link++; | |
| 145 } | |
| 146 | |
| 147 if (eq_use_link) | |
| 148 while (*eq_use_link) | |
| 149 { | |
| 150 if (use != *eq_use_link | |
| 151 && DF_REF_REAL_REG (use) == DF_REF_REAL_REG (*eq_use_link)) | |
| 152 (*fun) (use_entry + DF_REF_ID (use), | |
| 153 use_entry + DF_REF_ID (*eq_use_link)); | |
| 154 eq_use_link++; | |
| 155 } | |
| 156 | |
| 157 /* Recognize trivial noop moves and attempt to keep them as noop. */ | |
| 158 | |
| 159 if (set | |
| 160 && SET_SRC (set) == DF_REF_REG (use) | |
| 161 && SET_SRC (set) == SET_DEST (set)) | |
| 162 { | |
| 163 if (def_link) | |
| 164 while (*def_link) | |
| 165 { | |
| 166 if (DF_REF_REAL_REG (use) == DF_REF_REAL_REG (*def_link)) | |
| 167 (*fun) (use_entry + DF_REF_ID (use), | |
| 168 def_entry + DF_REF_ID (*def_link)); | |
| 169 def_link++; | |
| 170 } | |
| 171 } | |
| 172 while (link) | |
| 173 { | |
| 174 (*fun) (use_entry + DF_REF_ID (use), | |
| 175 def_entry + DF_REF_ID (link->ref)); | |
| 176 link = link->next; | |
| 177 } | |
| 178 | |
| 179 /* A READ_WRITE use requires the corresponding def to be in the same | |
| 180 register. Find it and union. */ | |
| 181 if (DF_REF_FLAGS (use) & DF_REF_READ_WRITE) | |
| 182 { | |
| 183 df_ref *link; | |
| 184 | |
| 185 if (insn_info) | |
| 186 link = DF_INSN_INFO_DEFS (insn_info); | |
| 187 else | |
| 188 link = NULL; | |
| 189 | |
| 190 if (link) | |
| 191 while (*link) | |
| 192 { | |
| 193 if (DF_REF_REAL_REG (*link) == DF_REF_REAL_REG (use)) | |
| 194 (*fun) (use_entry + DF_REF_ID (use), | |
| 195 def_entry + DF_REF_ID (*link)); | |
| 196 link++; | |
| 197 } | |
| 198 } | |
| 199 } | |
| 200 | |
| 201 /* Find the corresponding register for the given entry. */ | |
| 202 | |
| 203 static rtx | |
| 204 entry_register (struct web_entry *entry, df_ref ref, char *used) | |
| 205 { | |
| 206 struct web_entry *root; | |
| 207 rtx reg, newreg; | |
| 208 | |
| 209 /* Find the corresponding web and see if it has been visited. */ | |
| 210 root = unionfind_root (entry); | |
| 211 if (root->reg) | |
| 212 return root->reg; | |
| 213 | |
| 214 /* We are seeing this web for the first time, do the assignment. */ | |
| 215 reg = DF_REF_REAL_REG (ref); | |
| 216 | |
| 217 /* In case the original register is already assigned, generate new one. */ | |
| 218 if (!used[REGNO (reg)]) | |
| 219 newreg = reg, used[REGNO (reg)] = 1; | |
| 220 else if (REG_USERVAR_P (reg) && 0/*&& !flag_messy_debugging*/) | |
| 221 { | |
| 222 newreg = reg; | |
| 223 if (dump_file) | |
| 224 fprintf (dump_file, | |
| 225 "New web forced to keep reg=%i (user variable)\n", | |
| 226 REGNO (reg)); | |
| 227 } | |
| 228 else | |
| 229 { | |
| 230 newreg = gen_reg_rtx (GET_MODE (reg)); | |
| 231 REG_USERVAR_P (newreg) = REG_USERVAR_P (reg); | |
| 232 REG_POINTER (newreg) = REG_POINTER (reg); | |
| 233 REG_ATTRS (newreg) = REG_ATTRS (reg); | |
| 234 if (dump_file) | |
| 235 fprintf (dump_file, "Web oldreg=%i newreg=%i\n", REGNO (reg), | |
| 236 REGNO (newreg)); | |
| 237 } | |
| 238 | |
| 239 root->reg = newreg; | |
| 240 return newreg; | |
| 241 } | |
| 242 | |
| 243 /* Replace the reference by REG. */ | |
| 244 | |
| 245 static void | |
| 246 replace_ref (df_ref ref, rtx reg) | |
| 247 { | |
| 248 rtx oldreg = DF_REF_REAL_REG (ref); | |
| 249 rtx *loc = DF_REF_REAL_LOC (ref); | |
| 250 unsigned int uid = DF_REF_INSN_UID (ref); | |
| 251 | |
| 252 if (oldreg == reg) | |
| 253 return; | |
| 254 if (dump_file) | |
| 255 fprintf (dump_file, "Updating insn %i (%i->%i)\n", | |
|
55
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
256 uid, REGNO (oldreg), REGNO (reg)); |
| 0 | 257 *loc = reg; |
| 258 df_insn_rescan (DF_REF_INSN (ref)); | |
| 259 } | |
| 260 | |
| 261 | |
| 262 static bool | |
| 263 gate_handle_web (void) | |
| 264 { | |
| 265 return (optimize > 0 && flag_web); | |
| 266 } | |
| 267 | |
| 268 /* Main entry point. */ | |
| 269 | |
| 270 static unsigned int | |
| 271 web_main (void) | |
| 272 { | |
| 273 struct web_entry *def_entry; | |
| 274 struct web_entry *use_entry; | |
| 275 unsigned int max = max_reg_num (); | |
| 276 char *used; | |
| 277 basic_block bb; | |
| 278 unsigned int uses_num = 0; | |
| 279 rtx insn; | |
| 280 | |
| 281 df_set_flags (DF_NO_HARD_REGS + DF_EQ_NOTES); | |
| 282 df_chain_add_problem (DF_UD_CHAIN); | |
| 283 df_analyze (); | |
| 284 df_set_flags (DF_DEFER_INSN_RESCAN); | |
| 285 | |
| 286 /* Assign ids to the uses. */ | |
| 287 FOR_ALL_BB (bb) | |
| 288 FOR_BB_INSNS (bb, insn) | |
| 289 { | |
| 290 unsigned int uid = INSN_UID (insn); | |
| 291 if (INSN_P (insn)) | |
| 292 { | |
| 293 df_ref *use_rec; | |
| 294 for (use_rec = DF_INSN_UID_USES (uid); *use_rec; use_rec++) | |
| 295 { | |
| 296 df_ref use = *use_rec; | |
| 297 if (DF_REF_REGNO (use) >= FIRST_PSEUDO_REGISTER) | |
| 298 DF_REF_ID (use) = uses_num++; | |
| 299 } | |
| 300 for (use_rec = DF_INSN_UID_EQ_USES (uid); *use_rec; use_rec++) | |
| 301 { | |
| 302 df_ref use = *use_rec; | |
| 303 if (DF_REF_REGNO (use) >= FIRST_PSEUDO_REGISTER) | |
| 304 DF_REF_ID (use) = uses_num++; | |
| 305 } | |
| 306 } | |
| 307 } | |
| 308 | |
| 309 /* Record the number of uses and defs at the beginning of the optimization. */ | |
| 310 def_entry = XCNEWVEC (struct web_entry, DF_DEFS_TABLE_SIZE()); | |
| 311 used = XCNEWVEC (char, max); | |
| 312 use_entry = XCNEWVEC (struct web_entry, uses_num); | |
| 313 | |
| 314 /* Produce the web. */ | |
| 315 FOR_ALL_BB (bb) | |
| 316 FOR_BB_INSNS (bb, insn) | |
| 317 { | |
| 318 unsigned int uid = INSN_UID (insn); | |
| 319 if (INSN_P (insn)) | |
| 320 { | |
| 321 df_ref *use_rec; | |
| 322 for (use_rec = DF_INSN_UID_USES (uid); *use_rec; use_rec++) | |
| 323 { | |
| 324 df_ref use = *use_rec; | |
| 325 if (DF_REF_REGNO (use) >= FIRST_PSEUDO_REGISTER) | |
| 326 union_defs (use, def_entry, use_entry, unionfind_union); | |
| 327 } | |
| 328 for (use_rec = DF_INSN_UID_EQ_USES (uid); *use_rec; use_rec++) | |
| 329 { | |
| 330 df_ref use = *use_rec; | |
| 331 if (DF_REF_REGNO (use) >= FIRST_PSEUDO_REGISTER) | |
| 332 union_defs (use, def_entry, use_entry, unionfind_union); | |
| 333 } | |
| 334 } | |
| 335 } | |
| 336 | |
| 337 /* Update the instruction stream, allocating new registers for split pseudos | |
| 338 in progress. */ | |
| 339 FOR_ALL_BB (bb) | |
| 340 FOR_BB_INSNS (bb, insn) | |
| 341 { | |
| 342 unsigned int uid = INSN_UID (insn); | |
| 343 if (INSN_P (insn)) | |
| 344 { | |
| 345 df_ref *use_rec; | |
| 346 df_ref *def_rec; | |
| 347 for (use_rec = DF_INSN_UID_USES (uid); *use_rec; use_rec++) | |
| 348 { | |
| 349 df_ref use = *use_rec; | |
| 350 if (DF_REF_REGNO (use) >= FIRST_PSEUDO_REGISTER) | |
| 351 replace_ref (use, entry_register (use_entry + DF_REF_ID (use), use, used)); | |
| 352 } | |
| 353 for (use_rec = DF_INSN_UID_EQ_USES (uid); *use_rec; use_rec++) | |
| 354 { | |
| 355 df_ref use = *use_rec; | |
| 356 if (DF_REF_REGNO (use) >= FIRST_PSEUDO_REGISTER) | |
| 357 replace_ref (use, entry_register (use_entry + DF_REF_ID (use), use, used)); | |
| 358 } | |
| 359 for (def_rec = DF_INSN_UID_DEFS (uid); *def_rec; def_rec++) | |
| 360 { | |
| 361 df_ref def = *def_rec; | |
| 362 if (DF_REF_REGNO (def) >= FIRST_PSEUDO_REGISTER) | |
| 363 replace_ref (def, entry_register (def_entry + DF_REF_ID (def), def, used)); | |
| 364 } | |
| 365 } | |
| 366 } | |
| 367 | |
| 368 free (def_entry); | |
| 369 free (use_entry); | |
| 370 free (used); | |
| 371 return 0; | |
| 372 } | |
| 373 | |
| 374 struct rtl_opt_pass pass_web = | |
| 375 { | |
| 376 { | |
| 377 RTL_PASS, | |
| 378 "web", /* name */ | |
| 379 gate_handle_web, /* gate */ | |
| 380 web_main, /* execute */ | |
| 381 NULL, /* sub */ | |
| 382 NULL, /* next */ | |
| 383 0, /* static_pass_number */ | |
| 384 TV_WEB, /* tv_id */ | |
| 385 0, /* properties_required */ | |
| 386 0, /* properties_provided */ | |
| 387 0, /* properties_destroyed */ | |
| 388 0, /* todo_flags_start */ | |
|
55
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
389 TODO_df_finish | TODO_verify_rtl_sharing | |
| 0 | 390 TODO_dump_func /* todo_flags_finish */ |
| 391 } | |
| 392 }; | |
| 393 |