gcc/rtl.c

   1 /* RTL utility routines.
   2    Copyright (C) 1987, 1988, 1991, 1994, 1997, 1998, 1999, 2000, 2001, 2002,
   3    2003, 2004 Free Software Foundation, Inc.
   4
   5 This file is part of GCC.
   6
   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.
  11
  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.
  16
  17 You should have received a copy of the GNU General Public License
  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.  */
  21
  22 #include "config.h"
  23 #include "system.h"
  24 #include "coretypes.h"
  25 #include "tm.h"
  26 #include "rtl.h"
  27 #include "real.h"
  28 #include "ggc.h"
  29 #include "errors.h"
  30
  31 \f
  32 /* Indexed by rtx code, gives number of operands for an rtx with that code.
  33    Does NOT include rtx header data (code and links).  */
  34
  35 #define DEF_RTL_EXPR(ENUM, NAME, FORMAT, CLASS)   sizeof FORMAT - 1 ,
  36
  37 const unsigned char rtx_length[NUM_RTX_CODE] = {
  38 #include "rtl.def"
  39 };
  40
  41 #undef DEF_RTL_EXPR
  42
  43 /* Indexed by rtx code, gives the name of that kind of rtx, as a C string.  */
  44
  45 #define DEF_RTL_EXPR(ENUM, NAME, FORMAT, CLASS)   NAME ,
  46
  47 const char * const rtx_name[NUM_RTX_CODE] = {
  48 #include "rtl.def"              /* rtl expressions are documented here */
  49 };
  50
  51 #undef DEF_RTL_EXPR
  52
  53 /* Indexed by rtx code, gives a sequence of operand-types for
  54    rtx's of that code.  The sequence is a C string in which
  55    each character describes one operand.  */
  56
  57 const char * const rtx_format[NUM_RTX_CODE] = {
  58   /* "*" undefined.
  59          can cause a warning message
  60      "0" field is unused (or used in a phase-dependent manner)
  61          prints nothing
  62      "i" an integer
  63          prints the integer
  64      "n" like "i", but prints entries from `note_insn_name'
  65      "w" an integer of width HOST_BITS_PER_WIDE_INT
  66          prints the integer
  67      "s" a pointer to a string
  68          prints the string
  69      "S" like "s", but optional:
  70          the containing rtx may end before this operand
  71      "T" like "s", but treated specially by the RTL reader;
  72          only found in machine description patterns.
  73      "e" a pointer to an rtl expression
  74          prints the expression
  75      "E" a pointer to a vector that points to a number of rtl expressions
  76          prints a list of the rtl expressions
  77      "V" like "E", but optional:
  78          the containing rtx may end before this operand
  79      "u" a pointer to another insn
  80          prints the uid of the insn.
  81      "b" is a pointer to a bitmap header.
  82      "B" is a basic block pointer.
  83      "t" is a tree pointer.  */
  84
  85 #define DEF_RTL_EXPR(ENUM, NAME, FORMAT, CLASS)   FORMAT ,
  86 #include "rtl.def"              /* rtl expressions are defined here */
  87 #undef DEF_RTL_EXPR
  88 };
  89
  90 /* Indexed by rtx code, gives a character representing the "class" of
  91    that rtx code.  See rtl.def for documentation on the defined classes.  */
  92
  93 const char rtx_class[NUM_RTX_CODE] = {
  94 #define DEF_RTL_EXPR(ENUM, NAME, FORMAT, CLASS)   CLASS,
  95 #include "rtl.def"              /* rtl expressions are defined here */
  96 #undef DEF_RTL_EXPR
  97 };
  98
  99 /* Indexed by rtx code, gives the size of the rtx in bytes.  */
 100
 101 const unsigned char rtx_size[NUM_RTX_CODE] = {
 102 #define DEF_RTL_EXPR(ENUM, NAME, FORMAT, CLASS)                         \
 103   ((ENUM) == CONST_INT || (ENUM) == CONST_DOUBLE                        \
 104    ? RTX_HDR_SIZE + (sizeof FORMAT - 1) * sizeof (HOST_WIDE_INT)        \
 105    : RTX_HDR_SIZE + (sizeof FORMAT - 1) * sizeof (rtunion)),
 106
 107 #include "rtl.def"
 108 #undef DEF_RTL_EXPR
 109 };
 110
 111 /* Names for kinds of NOTEs and REG_NOTEs.  */
 112
 113 const char * const note_insn_name[NOTE_INSN_MAX - NOTE_INSN_BIAS] =
 114 {
 115   "", "NOTE_INSN_DELETED",
 116   "NOTE_INSN_BLOCK_BEG", "NOTE_INSN_BLOCK_END",
 117   "NOTE_INSN_LOOP_BEG", "NOTE_INSN_LOOP_END",
 118   "NOTE_INSN_LOOP_CONT", "NOTE_INSN_LOOP_VTOP",
 119   "NOTE_INSN_LOOP_END_TOP_COND", "NOTE_INSN_FUNCTION_END",
 120   "NOTE_INSN_PROLOGUE_END", "NOTE_INSN_EPILOGUE_BEG",
 121   "NOTE_INSN_DELETED_LABEL", "NOTE_INSN_FUNCTION_BEG",
 122   "NOTE_INSN_EH_REGION_BEG", "NOTE_INSN_EH_REGION_END",
 123   "NOTE_INSN_REPEATED_LINE_NUMBER",
 124   "NOTE_INSN_BASIC_BLOCK", "NOTE_INSN_EXPECTED_VALUE",
 125   "NOTE_INSN_PREDICTION"
 126 };
 127
 128 const char * const reg_note_name[] =
 129 {
 130   "", "REG_DEAD", "REG_INC", "REG_EQUIV", "REG_EQUAL",
 131   "REG_RETVAL", "REG_LIBCALL", "REG_NONNEG",
 132   "REG_NO_CONFLICT", "REG_UNUSED", "REG_CC_SETTER", "REG_CC_USER",
 133   "REG_LABEL", "REG_DEP_ANTI", "REG_DEP_OUTPUT", "REG_BR_PROB",
 134   "REG_VALUE_PROFILE", "REG_NOALIAS", "REG_SAVE_AREA", "REG_BR_PRED",
 135   "REG_FRAME_RELATED_EXPR", "REG_EH_CONTEXT", "REG_EH_REGION",
 136   "REG_SAVE_NOTE", "REG_MAYBE_DEAD", "REG_NORETURN",
 137   "REG_NON_LOCAL_GOTO", "REG_SETJMP", "REG_ALWAYS_RETURN",
 138   "REG_VTABLE_REF"
 139 };
 140
 141
 142 #ifdef GATHER_STATISTICS
 143 static int rtx_alloc_counts[(int) LAST_AND_UNUSED_RTX_CODE];
 144 static int rtx_alloc_sizes[(int) LAST_AND_UNUSED_RTX_CODE];
 145 static int rtvec_alloc_counts;
 146 static int rtvec_alloc_sizes;
 147 #endif
 148
 149 \f
 150 /* Allocate an rtx vector of N elements.
 151    Store the length, and initialize all elements to zero.  */
 152
 153 rtvec
 154 rtvec_alloc (int n)
 155 {
 156   rtvec rt;
 157
 158   rt = ggc_alloc_rtvec (n);
 159   /* clear out the vector */
 160   memset (&rt->elem[0], 0, n * sizeof (rtx));
 161
 162   PUT_NUM_ELEM (rt, n);
 163
 164 #ifdef GATHER_STATISTICS
 165   rtvec_alloc_counts++;
 166   rtvec_alloc_sizes += n * sizeof (rtx);
 167 #endif
 168
 169   return rt;
 170 }
 171
 172 /* Allocate an rtx of code CODE.  The CODE is stored in the rtx;
 173    all the rest is initialized to zero.  */
 174
 175 rtx
 176 rtx_alloc (RTX_CODE code)
 177 {
 178   rtx rt;
 179
 180   rt = ggc_alloc_rtx (code);
 181
 182   /* We want to clear everything up to the FLD array.  Normally, this
 183      is one int, but we don't want to assume that and it isn't very
 184      portable anyway; this is.  */
 185
 186   memset (rt, 0, RTX_HDR_SIZE);
 187   PUT_CODE (rt, code);
 188
 189 #ifdef GATHER_STATISTICS
 190   rtx_alloc_counts[code]++;
 191   rtx_alloc_sizes[code] += RTX_SIZE (code);
 192 #endif
 193
 194   return rt;
 195 }
 196
 197 \f
 198 /* Create a new copy of an rtx.
 199    Recursively copies the operands of the rtx,
 200    except for those few rtx codes that are sharable.  */
 201
 202 rtx
 203 copy_rtx (rtx orig)
 204 {
 205   rtx copy;
 206   int i, j;
 207   RTX_CODE code;
 208   const char *format_ptr;
 209
 210   code = GET_CODE (orig);
 211
 212   switch (code)
 213     {
 214     case REG:
 215     case QUEUED:
 216     case CONST_INT:
 217     case CONST_DOUBLE:
 218     case CONST_VECTOR:
 219     case SYMBOL_REF:
 220     case CODE_LABEL:
 221     case PC:
 222     case CC0:
 223     case SCRATCH:
 224       /* SCRATCH must be shared because they represent distinct values.  */
 225     case ADDRESSOF:
 226       return orig;
 227     case CLOBBER:
 228       if (REG_P (XEXP (orig, 0)) && REGNO (XEXP (orig, 0)) < FIRST_PSEUDO_REGISTER)
 229         return orig;
 230       break;
 231
 232     case CONST:
 233       /* CONST can be shared if it contains a SYMBOL_REF.  If it contains
 234          a LABEL_REF, it isn't sharable.  */
 235       if (GET_CODE (XEXP (orig, 0)) == PLUS
 236           && GET_CODE (XEXP (XEXP (orig, 0), 0)) == SYMBOL_REF
 237           && GET_CODE (XEXP (XEXP (orig, 0), 1)) == CONST_INT)
 238         return orig;
 239       break;
 240
 241       /* A MEM with a constant address is not sharable.  The problem is that
 242          the constant address may need to be reloaded.  If the mem is shared,
 243          then reloading one copy of this mem will cause all copies to appear
 244          to have been reloaded.  */
 245
 246     default:
 247       break;
 248     }
 249
 250   copy = rtx_alloc (code);
 251
 252   /* Copy the various flags, and other information.  We assume that
 253      all fields need copying, and then clear the fields that should
 254      not be copied.  That is the sensible default behavior, and forces
 255      us to explicitly document why we are *not* copying a flag.  */
 256   memcpy (copy, orig, RTX_HDR_SIZE);
 257
 258   /* We do not copy the USED flag, which is used as a mark bit during
 259      walks over the RTL.  */
 260   RTX_FLAG (copy, used) = 0;
 261
 262   /* We do not copy FRAME_RELATED for INSNs.  */
 263   if (GET_RTX_CLASS (code) == 'i')
 264     RTX_FLAG (copy, frame_related) = 0;
 265   RTX_FLAG (copy, jump) = RTX_FLAG (orig, jump);
 266   RTX_FLAG (copy, call) = RTX_FLAG (orig, call);
 267
 268   format_ptr = GET_RTX_FORMAT (GET_CODE (copy));
 269
 270   for (i = 0; i < GET_RTX_LENGTH (GET_CODE (copy)); i++)
 271     {
 272       copy->u.fld[i] = orig->u.fld[i];
 273       switch (*format_ptr++)
 274         {
 275         case 'e':
 276           if (XEXP (orig, i) != NULL)
 277             XEXP (copy, i) = copy_rtx (XEXP (orig, i));
 278           break;
 279
 280         case 'E':
 281         case 'V':
 282           if (XVEC (orig, i) != NULL)
 283             {
 284               XVEC (copy, i) = rtvec_alloc (XVECLEN (orig, i));
 285               for (j = 0; j < XVECLEN (copy, i); j++)
 286                 XVECEXP (copy, i, j) = copy_rtx (XVECEXP (orig, i, j));
 287             }
 288           break;
 289
 290         case 't':
 291         case 'w':
 292         case 'i':
 293         case 's':
 294         case 'S':
 295         case 'T':
 296         case 'u':
 297         case 'B':
 298         case '0':
 299           /* These are left unchanged.  */
 300           break;
 301
 302         default:
 303           abort ();
 304         }
 305     }
 306   return copy;
 307 }
 308
 309 /* Create a new copy of an rtx.  Only copy just one level.  */
 310
 311 rtx
 312 shallow_copy_rtx (rtx orig)
 313 {
 314   rtx copy;
 315
 316   copy = ggc_alloc_rtx (GET_CODE (orig));
 317   memcpy (copy, orig, RTX_SIZE (GET_CODE (orig)));
 318   return copy;
 319 }
 320 \f
 321 /* This is 1 until after the rtl generation pass.  */
 322 int rtx_equal_function_value_matters;
 323
 324 /* Nonzero when we are generating CONCATs.  */
 325 int generating_concat_p;
 326 \f
 327 /* Return 1 if X and Y are identical-looking rtx's.
 328    This is the Lisp function EQUAL for rtx arguments.  */
 329
 330 int
 331 rtx_equal_p (rtx x, rtx y)
 332 {
 333   int i;
 334   int j;
 335   enum rtx_code code;
 336   const char *fmt;
 337
 338   if (x == y)
 339     return 1;
 340   if (x == 0 || y == 0)
 341     return 0;
 342
 343   code = GET_CODE (x);
 344   /* Rtx's of different codes cannot be equal.  */
 345   if (code != GET_CODE (y))
 346     return 0;
 347
 348   /* (MULT:SI x y) and (MULT:HI x y) are NOT equivalent.
 349      (REG:SI x) and (REG:HI x) are NOT equivalent.  */
 350
 351   if (GET_MODE (x) != GET_MODE (y))
 352     return 0;
 353
 354   /* Some RTL can be compared nonrecursively.  */
 355   switch (code)
 356     {
 357     case REG:
 358       /* Until rtl generation is complete, don't consider a reference
 359          to the return register of the current function the same as
 360          the return from a called function.  This eases the job of
 361          function integration.  Once the distinction is no longer
 362          needed, they can be considered equivalent.  */
 363       return (REGNO (x) == REGNO (y)
 364               && (! rtx_equal_function_value_matters
 365                   || REG_FUNCTION_VALUE_P (x) == REG_FUNCTION_VALUE_P (y)));
 366
 367     case LABEL_REF:
 368       return XEXP (x, 0) == XEXP (y, 0);
 369
 370     case SYMBOL_REF:
 371       return XSTR (x, 0) == XSTR (y, 0);
 372
 373     case SCRATCH:
 374     case CONST_DOUBLE:
 375     case CONST_INT:
 376     case CONST_VECTOR:
 377       return 0;
 378
 379     default:
 380       break;
 381     }
 382
 383   /* Compare the elements.  If any pair of corresponding elements
 384      fail to match, return 0 for the whole thing.  */
 385
 386   fmt = GET_RTX_FORMAT (code);
 387   for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
 388     {
 389       switch (fmt[i])
 390         {
 391         case 'w':
 392           if (XWINT (x, i) != XWINT (y, i))
 393             return 0;
 394           break;
 395
 396         case 'n':
 397         case 'i':
 398           if (XINT (x, i) != XINT (y, i))
 399             return 0;
 400           break;
 401
 402         case 'V':
 403         case 'E':
 404           /* Two vectors must have the same length.  */
 405           if (XVECLEN (x, i) != XVECLEN (y, i))
 406             return 0;
 407
 408           /* And the corresponding elements must match.  */
 409           for (j = 0; j < XVECLEN (x, i); j++)
 410             if (rtx_equal_p (XVECEXP (x, i, j), XVECEXP (y, i, j)) == 0)
 411               return 0;
 412           break;
 413
 414         case 'e':
 415           if (rtx_equal_p (XEXP (x, i), XEXP (y, i)) == 0)
 416             return 0;
 417           break;
 418
 419         case 'S':
 420         case 's':
 421           if ((XSTR (x, i) || XSTR (y, i))
 422               && (! XSTR (x, i) || ! XSTR (y, i)
 423                   || strcmp (XSTR (x, i), XSTR (y, i))))
 424             return 0;
 425           break;
 426
 427         case 'u':
 428           /* These are just backpointers, so they don't matter.  */
 429           break;
 430
 431         case '0':
 432         case 't':
 433           break;
 434
 435           /* It is believed that rtx's at this level will never
 436              contain anything but integers and other rtx's,
 437              except for within LABEL_REFs and SYMBOL_REFs.  */
 438         default:
 439           abort ();
 440         }
 441     }
 442   return 1;
 443 }
 444
 445 void dump_rtx_statistics (void)
 446 {
 447 #ifdef GATHER_STATISTICS
 448   int i;
 449   int total_counts = 0;
 450   int total_sizes = 0;
 451   fprintf (stderr, "\nRTX Kind               Count      Bytes\n");
 452   fprintf (stderr, "---------------------------------------\n");
 453   for (i = 0; i < LAST_AND_UNUSED_RTX_CODE; i++)
 454     if (rtx_alloc_counts[i])
 455       {
 456         fprintf (stderr, "%-20s %7d %10d\n", GET_RTX_NAME (i),
 457                  rtx_alloc_counts[i], rtx_alloc_sizes[i]);
 458         total_counts += rtx_alloc_counts[i];
 459         total_sizes += rtx_alloc_sizes[i];
 460       }
 461   if (rtvec_alloc_counts)
 462     {
 463       fprintf (stderr, "%-20s %7d %10d\n", "rtvec",
 464                rtvec_alloc_counts, rtvec_alloc_sizes);
 465       total_counts += rtvec_alloc_counts;
 466       total_sizes += rtvec_alloc_sizes;
 467     }
 468   fprintf (stderr, "---------------------------------------\n");
 469   fprintf (stderr, "%-20s %7d %10d\n",
 470            "Total", total_counts, total_sizes);
 471   fprintf (stderr, "---------------------------------------\n");
 472 #endif
 473 }
 474 \f
 475 #if defined ENABLE_RTL_CHECKING && (GCC_VERSION >= 2007)
 476 void
 477 rtl_check_failed_bounds (rtx r, int n, const char *file, int line,
 478                          const char *func)
 479 {
 480   internal_error
 481     ("RTL check: access of elt %d of `%s' with last elt %d in %s, at %s:%d",
 482      n, GET_RTX_NAME (GET_CODE (r)), GET_RTX_LENGTH (GET_CODE (r)) - 1,
 483      func, trim_filename (file), line);
 484 }
 485
 486 void
 487 rtl_check_failed_type1 (rtx r, int n, int c1, const char *file, int line,
 488                         const char *func)
 489 {
 490   internal_error
 491     ("RTL check: expected elt %d type '%c', have '%c' (rtx %s) in %s, at %s:%d",
 492      n, c1, GET_RTX_FORMAT (GET_CODE (r))[n], GET_RTX_NAME (GET_CODE (r)),
 493      func, trim_filename (file), line);
 494 }
 495
 496 void
 497 rtl_check_failed_type2 (rtx r, int n, int c1, int c2, const char *file,
 498                         int line, const char *func)
 499 {
 500   internal_error
 501     ("RTL check: expected elt %d type '%c' or '%c', have '%c' (rtx %s) in %s, at %s:%d",
 502      n, c1, c2, GET_RTX_FORMAT (GET_CODE (r))[n], GET_RTX_NAME (GET_CODE (r)),
 503      func, trim_filename (file), line);
 504 }
 505
 506 void
 507 rtl_check_failed_code1 (rtx r, enum rtx_code code, const char *file,
 508                         int line, const char *func)
 509 {
 510   internal_error ("RTL check: expected code `%s', have `%s' in %s, at %s:%d",
 511                   GET_RTX_NAME (code), GET_RTX_NAME (GET_CODE (r)), func,
 512                   trim_filename (file), line);
 513 }
 514
 515 void
 516 rtl_check_failed_code2 (rtx r, enum rtx_code code1, enum rtx_code code2,
 517                         const char *file, int line, const char *func)
 518 {
 519   internal_error
 520     ("RTL check: expected code `%s' or `%s', have `%s' in %s, at %s:%d",
 521      GET_RTX_NAME (code1), GET_RTX_NAME (code2), GET_RTX_NAME (GET_CODE (r)),
 522      func, trim_filename (file), line);
 523 }
 524
 525 /* XXX Maybe print the vector?  */
 526 void
 527 rtvec_check_failed_bounds (rtvec r, int n, const char *file, int line,
 528                            const char *func)
 529 {
 530   internal_error
 531     ("RTL check: access of elt %d of vector with last elt %d in %s, at %s:%d",
 532      n, GET_NUM_ELEM (r) - 1, func, trim_filename (file), line);
 533 }
 534 #endif /* ENABLE_RTL_CHECKING */
 535
 536 #if defined ENABLE_RTL_FLAG_CHECKING
 537 void
 538 rtl_check_failed_flag (const char *name, rtx r, const char *file,
 539                        int line, const char *func)
 540 {
 541   internal_error
 542     ("RTL flag check: %s used with unexpected rtx code `%s' in %s, at %s:%d",
 543      name, GET_RTX_NAME (GET_CODE (r)), func, trim_filename (file), line);
 544 }
 545 #endif /* ENABLE_RTL_FLAG_CHECKING */