1/* Generate code from machine description to perform peephole optimizations. 2 Copyright (C) 1987, 89, 92, 97, 98, 1999 Free Software Foundation, Inc. 3 4This file is part of GNU CC. 5 6GNU CC is free software; you can redistribute it and/or modify 7it under the terms of the GNU General Public License as published by 8the Free Software Foundation; either version 2, or (at your option) 9any later version. 10 11GNU CC is distributed in the hope that it will be useful, 12but WITHOUT ANY WARRANTY; without even the implied warranty of 13MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14GNU General Public License for more details. 15 16You should have received a copy of the GNU General Public License 17along with GNU CC; see the file COPYING. If not, write to 18the Free Software Foundation, 59 Temple Place - Suite 330, 19Boston, MA 02111-1307, USA. */ 20 21 22#include "hconfig.h" 23#include "system.h" 24#include "rtl.h" 25#include "obstack.h" 26 27static struct obstack obstack; 28struct obstack *rtl_obstack = &obstack; 29 30#define obstack_chunk_alloc xmalloc 31#define obstack_chunk_free free 32 33/* Define this so we can link with print-rtl.o to get debug_rtx function. */ 34char **insn_name_ptr = 0; 35 36/* While tree-walking an instruction pattern, we keep a chain 37 of these `struct link's to record how to get down to the 38 current position. In each one, POS is the operand number, 39 and if the operand is a vector VEC is the element number. 40 VEC is -1 if the operand is not a vector. */ 41 42struct link 43{ 44 struct link *next; 45 int pos; 46 int vecelt; 47}; 48 49void fatal PVPROTO ((const char *, ...)) 50 ATTRIBUTE_PRINTF_1 ATTRIBUTE_NORETURN; 51void fancy_abort PROTO((void)) ATTRIBUTE_NORETURN; 52 53static int max_opno; 54 55/* Number of operands used in current peephole definition. */ 56 57static int n_operands; 58 59/* Peephole optimizations get insn codes just like insn patterns. 60 Count them so we know the code of the define_peephole we are handling. */ 61 62static int insn_code_number = 0; 63 64static void gen_peephole PROTO((rtx)); 65static void match_rtx PROTO((rtx, struct link *, int)); 66static void print_path PROTO((struct link *)); 67static void print_code PROTO((RTX_CODE)); 68 69static void 70gen_peephole (peep) 71 rtx peep; 72{ 73 int ninsns = XVECLEN (peep, 0); 74 int i; 75 76 n_operands = 0; 77 78 printf (" insn = ins1;\n"); 79#if 0 80 printf (" want_jump = 0;\n"); 81#endif 82 83 for (i = 0; i < ninsns; i++) 84 { 85 if (i > 0) 86 { 87 printf (" do { insn = NEXT_INSN (insn);\n"); 88 printf (" if (insn == 0) goto L%d; }\n", 89 insn_code_number); 90 printf (" while (GET_CODE (insn) == NOTE\n"); 91 printf ("\t || (GET_CODE (insn) == INSN\n"); 92 printf ("\t && (GET_CODE (PATTERN (insn)) == USE\n"); 93 printf ("\t\t || GET_CODE (PATTERN (insn)) == CLOBBER)));\n"); 94 95 printf (" if (GET_CODE (insn) == CODE_LABEL\n\ 96 || GET_CODE (insn) == BARRIER)\n goto L%d;\n", 97 insn_code_number); 98 } 99 100#if 0 101 printf (" if (GET_CODE (insn) == JUMP_INSN)\n"); 102 printf (" want_jump = JUMP_LABEL (insn);\n"); 103#endif 104 105 printf (" pat = PATTERN (insn);\n"); 106 107 /* Walk the insn's pattern, remembering at all times the path 108 down to the walking point. */ 109 110 match_rtx (XVECEXP (peep, 0, i), NULL_PTR, insn_code_number); 111 } 112 113 /* We get this far if the pattern matches. 114 Now test the extra condition. */ 115 116 if (XSTR (peep, 1) && XSTR (peep, 1)[0]) 117 printf (" if (! (%s)) goto L%d;\n", 118 XSTR (peep, 1), insn_code_number); 119 120 /* If that matches, construct new pattern and put it in the first insn. 121 This new pattern will never be matched. 122 It exists only so that insn-extract can get the operands back. 123 So use a simple regular form: a PARALLEL containing a vector 124 of all the operands. */ 125 126 printf (" PATTERN (ins1) = gen_rtx_PARALLEL (VOIDmode, gen_rtvec_v (%d, operands));\n", n_operands); 127 128#if 0 129 printf (" if (want_jump && GET_CODE (ins1) != JUMP_INSN)\n"); 130 printf (" {\n"); 131 printf (" rtx insn2 = emit_jump_insn_before (PATTERN (ins1), ins1);\n"); 132 printf (" delete_insn (ins1);\n"); 133 printf (" ins1 = ins2;\n"); 134 printf (" }\n"); 135#endif 136 137 /* Record this define_peephole's insn code in the insn, 138 as if it had been recognized to match this. */ 139 printf (" INSN_CODE (ins1) = %d;\n", 140 insn_code_number); 141 142 /* Delete the remaining insns. */ 143 if (ninsns > 1) 144 printf (" delete_for_peephole (NEXT_INSN (ins1), insn);\n"); 145 146 /* See reload1.c for insertion of NOTE which guarantees that this 147 cannot be zero. */ 148 printf (" return NEXT_INSN (insn);\n"); 149 150 printf (" L%d:\n\n", insn_code_number); 151} 152 153static void 154match_rtx (x, path, fail_label) 155 rtx x; 156 struct link *path; 157 int fail_label; 158{ 159 register RTX_CODE code; 160 register int i; 161 register int len; 162 register char *fmt; 163 struct link link; 164 165 if (x == 0) 166 return; 167 168 169 code = GET_CODE (x); 170 171 switch (code) 172 { 173 case MATCH_OPERAND: 174 if (XINT (x, 0) > max_opno) 175 max_opno = XINT (x, 0); 176 if (XINT (x, 0) >= n_operands) 177 n_operands = 1 + XINT (x, 0); 178 179 printf (" x = "); 180 print_path (path); 181 printf (";\n"); 182 183 printf (" operands[%d] = x;\n", XINT (x, 0)); 184 if (XSTR (x, 1) && XSTR (x, 1)[0]) 185 printf (" if (! %s (x, %smode)) goto L%d;\n", 186 XSTR (x, 1), GET_MODE_NAME (GET_MODE (x)), fail_label); 187 return; 188 189 case MATCH_DUP: 190 case MATCH_PAR_DUP: 191 printf (" x = "); 192 print_path (path); 193 printf (";\n"); 194 195 printf (" if (!rtx_equal_p (operands[%d], x)) goto L%d;\n", 196 XINT (x, 0), fail_label); 197 return; 198 199 case MATCH_OP_DUP: 200 printf (" x = "); 201 print_path (path); 202 printf (";\n"); 203 204 printf (" if (GET_CODE (operands[%d]) != GET_CODE (x)\n", XINT (x, 0)); 205 printf (" || GET_MODE (operands[%d]) != GET_MODE (x)) goto L%d;\n", 206 XINT (x, 0), fail_label); 207 printf (" operands[%d] = x;\n", XINT (x, 0)); 208 link.next = path; 209 link.vecelt = -1; 210 for (i = 0; i < XVECLEN (x, 1); i++) 211 { 212 link.pos = i; 213 match_rtx (XVECEXP (x, 1, i), &link, fail_label); 214 } 215 return; 216 217 case MATCH_OPERATOR: 218 if (XINT (x, 0) > max_opno) 219 max_opno = XINT (x, 0); 220 if (XINT (x, 0) >= n_operands) 221 n_operands = 1 + XINT (x, 0); 222 223 printf (" x = "); 224 print_path (path); 225 printf (";\n"); 226 227 printf (" operands[%d] = x;\n", XINT (x, 0)); 228 if (XSTR (x, 1) && XSTR (x, 1)[0]) 229 printf (" if (! %s (x, %smode)) goto L%d;\n", 230 XSTR (x, 1), GET_MODE_NAME (GET_MODE (x)), fail_label); 231 link.next = path; 232 link.vecelt = -1; 233 for (i = 0; i < XVECLEN (x, 2); i++) 234 { 235 link.pos = i; 236 match_rtx (XVECEXP (x, 2, i), &link, fail_label); 237 } 238 return; 239 240 case MATCH_PARALLEL: 241 if (XINT (x, 0) > max_opno) 242 max_opno = XINT (x, 0); 243 if (XINT (x, 0) >= n_operands) 244 n_operands = 1 + XINT (x, 0); 245 246 printf (" x = "); 247 print_path (path); 248 printf (";\n"); 249 250 printf (" if (GET_CODE (x) != PARALLEL) goto L%d;\n", fail_label); 251 printf (" operands[%d] = x;\n", XINT (x, 0)); 252 if (XSTR (x, 1) && XSTR (x, 1)[0]) 253 printf (" if (! %s (x, %smode)) goto L%d;\n", 254 XSTR (x, 1), GET_MODE_NAME (GET_MODE (x)), fail_label); 255 link.next = path; 256 link.pos = 0; 257 for (i = 0; i < XVECLEN (x, 2); i++) 258 { 259 link.vecelt = i; 260 match_rtx (XVECEXP (x, 2, i), &link, fail_label); 261 } 262 return; 263 264 case ADDRESS: 265 match_rtx (XEXP (x, 0), path, fail_label); 266 return; 267 268 default: 269 break; 270 } 271 272 printf (" x = "); 273 print_path (path); 274 printf (";\n"); 275 276 printf (" if (GET_CODE (x) != "); 277 print_code (code); 278 printf (") goto L%d;\n", fail_label); 279 280 if (GET_MODE (x) != VOIDmode) 281 { 282 printf (" if (GET_MODE (x) != %smode) goto L%d;\n", 283 GET_MODE_NAME (GET_MODE (x)), fail_label); 284 } 285 286 link.next = path; 287 link.vecelt = -1; 288 fmt = GET_RTX_FORMAT (code); 289 len = GET_RTX_LENGTH (code); 290 for (i = 0; i < len; i++) 291 { 292 link.pos = i; 293 if (fmt[i] == 'e' || fmt[i] == 'u') 294 match_rtx (XEXP (x, i), &link, fail_label); 295 else if (fmt[i] == 'E') 296 { 297 int j; 298 printf (" if (XVECLEN (x, %d) != %d) goto L%d;\n", 299 i, XVECLEN (x, i), fail_label); 300 for (j = 0; j < XVECLEN (x, i); j++) 301 { 302 link.vecelt = j; 303 match_rtx (XVECEXP (x, i, j), &link, fail_label); 304 } 305 } 306 else if (fmt[i] == 'i') 307 { 308 /* Make sure that at run time `x' is the RTX we want to test. */ 309 if (i != 0) 310 { 311 printf (" x = "); 312 print_path (path); 313 printf (";\n"); 314 } 315 316 printf (" if (XINT (x, %d) != %d) goto L%d;\n", 317 i, XINT (x, i), fail_label); 318 } 319 else if (fmt[i] == 'w') 320 { 321 /* Make sure that at run time `x' is the RTX we want to test. */ 322 if (i != 0) 323 { 324 printf (" x = "); 325 print_path (path); 326 printf (";\n"); 327 } 328 329 printf (" if (XWINT (x, %d) != ", i); 330 printf (HOST_WIDE_INT_PRINT_DEC, XWINT (x, i)); 331 printf (") goto L%d;\n", fail_label); 332 } 333 else if (fmt[i] == 's') 334 { 335 /* Make sure that at run time `x' is the RTX we want to test. */ 336 if (i != 0) 337 { 338 printf (" x = "); 339 print_path (path); 340 printf (";\n"); 341 } 342 343 printf (" if (strcmp (XSTR (x, %d), \"%s\")) goto L%d;\n", 344 i, XSTR (x, i), fail_label); 345 } 346 } 347} 348 349/* Given a PATH, representing a path down the instruction's 350 pattern from the root to a certain point, output code to 351 evaluate to the rtx at that point. */ 352 353static void 354print_path (path) 355 struct link *path; 356{ 357 if (path == 0) 358 printf ("pat"); 359 else if (path->vecelt >= 0) 360 { 361 printf ("XVECEXP ("); 362 print_path (path->next); 363 printf (", %d, %d)", path->pos, path->vecelt); 364 } 365 else 366 { 367 printf ("XEXP ("); 368 print_path (path->next); 369 printf (", %d)", path->pos); 370 } 371} 372 373static void 374print_code (code) 375 RTX_CODE code; 376{ 377 register char *p1; 378 for (p1 = GET_RTX_NAME (code); *p1; p1++) 379 { 380 if (*p1 >= 'a' && *p1 <= 'z') 381 putchar (*p1 + 'A' - 'a'); 382 else 383 putchar (*p1); 384 } 385} 386 387PTR 388xmalloc (size) 389 size_t size; 390{ 391 register PTR val = (PTR) malloc (size); 392 393 if (val == 0) 394 fatal ("virtual memory exhausted"); 395 return val; 396} 397 398PTR 399xrealloc (old, size) 400 PTR old; 401 size_t size; 402{ 403 register PTR ptr; 404 if (old) 405 ptr = (PTR) realloc (old, size); 406 else 407 ptr = (PTR) malloc (size); 408 if (!ptr) 409 fatal ("virtual memory exhausted"); 410 return ptr; 411} 412 413void 414fatal VPROTO ((const char *format, ...)) 415{ 416#ifndef ANSI_PROTOTYPES 417 const char *format; 418#endif 419 va_list ap; 420 421 VA_START (ap, format); 422 423#ifndef ANSI_PROTOTYPES 424 format = va_arg (ap, const char *); 425#endif 426 427 fprintf (stderr, "genpeep: "); 428 vfprintf (stderr, format, ap); 429 va_end (ap); 430 fprintf (stderr, "\n"); 431 exit (FATAL_EXIT_CODE); 432} 433 434/* More 'friendly' abort that prints the line and file. 435 config.h can #define abort fancy_abort if you like that sort of thing. */ 436 437void 438fancy_abort () 439{ 440 fatal ("Internal gcc abort."); 441} 442 443int 444main (argc, argv) 445 int argc; 446 char **argv; 447{ 448 rtx desc; 449 FILE *infile; 450 register int c; 451 452 max_opno = -1; 453 454 obstack_init (rtl_obstack); 455 456 if (argc <= 1) 457 fatal ("No input file name."); 458 459 infile = fopen (argv[1], "r"); 460 if (infile == 0) 461 { 462 perror (argv[1]); 463 exit (FATAL_EXIT_CODE); 464 } 465 466 init_rtl (); 467 468 printf ("/* Generated automatically by the program `genpeep'\n\ 469from the machine description file `md'. */\n\n"); 470 471 printf ("#include \"config.h\"\n"); 472 printf ("#include \"system.h\"\n"); 473 printf ("#include \"insn-config.h\"\n"); 474 printf ("#include \"rtl.h\"\n"); 475 printf ("#include \"regs.h\"\n"); 476 printf ("#include \"output.h\"\n"); 477 printf ("#include \"real.h\"\n"); 478 printf ("#include \"recog.h\"\n"); 479 printf ("#include \"except.h\"\n\n"); 480 481 printf ("extern rtx peep_operand[];\n\n"); 482 printf ("#define operands peep_operand\n\n"); 483 484 printf ("rtx\npeephole (ins1)\n rtx ins1;\n{\n"); 485 printf (" rtx insn ATTRIBUTE_UNUSED, x ATTRIBUTE_UNUSED, pat ATTRIBUTE_UNUSED;\n\n"); 486 487 /* Early out: no peepholes for insns followed by barriers. */ 488 printf (" if (NEXT_INSN (ins1)\n"); 489 printf (" && GET_CODE (NEXT_INSN (ins1)) == BARRIER)\n"); 490 printf (" return 0;\n\n"); 491 492 /* Read the machine description. */ 493 494 while (1) 495 { 496 c = read_skip_spaces (infile); 497 if (c == EOF) 498 break; 499 ungetc (c, infile); 500 501 desc = read_rtx (infile); 502 if (GET_CODE (desc) == DEFINE_PEEPHOLE) 503 { 504 gen_peephole (desc); 505 insn_code_number++; 506 } 507 if (GET_CODE (desc) == DEFINE_INSN 508 || GET_CODE (desc) == DEFINE_EXPAND 509 || GET_CODE (desc) == DEFINE_SPLIT) 510 { 511 insn_code_number++; 512 } 513 } 514 515 printf (" return 0;\n}\n\n"); 516 517 if (max_opno == -1) 518 max_opno = 1; 519 520 printf ("rtx peep_operand[%d];\n", max_opno + 1); 521 522 fflush (stdout); 523 exit (ferror (stdout) != 0 ? FATAL_EXIT_CODE : SUCCESS_EXIT_CODE); 524 /* NOTREACHED */ 525 return 0; 526} 527