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 enum rtx_class 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_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_UNLIKELY_EXECUTED_CODE",
 126   "NOTE_INSN_VAR_LOCATION"
 127 };
 128
 129 const char * const reg_note_name[] =
 130 {
 131   "", "REG_DEAD", "REG_INC", "REG_EQUIV", "REG_EQUAL",
 132   "REG_RETVAL", "REG_LIBCALL", "REG_NONNEG",
 133   "REG_NO_CONFLICT", "REG_UNUSED", "REG_CC_SETTER", "REG_CC_USER",
 134   "REG_LABEL", "REG_DEP_ANTI", "REG_DEP_OUTPUT", "REG_BR_PROB",
 135   "REG_VALUE_PROFILE", "REG_NOALIAS", "REG_SAVE_AREA", "REG_BR_PRED",
 136   "REG_FRAME_RELATED_EXPR", "REG_EH_CONTEXT", "REG_EH_REGION",
 137   "REG_SAVE_NOTE", "REG_MAYBE_DEAD", "REG_NORETURN",
 138   "REG_NON_LOCAL_GOTO", "REG_CROSSING_JUMP", "REG_SETJMP", "REG_ALWAYS_RETURN"
 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_stat (RTX_CODE code MEM_STAT_DECL)
 177 {
 178   rtx rt;
 179
 180   rt = (rtx) ggc_alloc_typed_stat (gt_ggc_e_7rtx_def,
 181                                    RTX_SIZE (code) PASS_MEM_STAT);
 182
 183   /* We want to clear everything up to the FLD array.  Normally, this
 184      is one int, but we don't want to assume that and it isn't very
 185      portable anyway; this is.  */
 186
 187   memset (rt, 0, RTX_HDR_SIZE);
 188   PUT_CODE (rt, code);
 189
 190 #ifdef GATHER_STATISTICS
 191   rtx_alloc_counts[code]++;
 192   rtx_alloc_sizes[code] += RTX_SIZE (code);
 193 #endif
 194
 195   return rt;
 196 }
 197
 198 \f
 199 /* Create a new copy of an rtx.
 200    Recursively copies the operands of the rtx,
 201    except for those few rtx codes that are sharable.  */
 202
 203 rtx
 204 copy_rtx (rtx orig)
 205 {
 206   rtx copy;
 207   int i, j;
 208   RTX_CODE code;
 209   const char *format_ptr;
 210
 211   code = GET_CODE (orig);
 212
 213   switch (code)
 214     {
 215     case REG:
 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       return orig;
 226     case CLOBBER:
 227       if (REG_P (XEXP (orig, 0)) && REGNO (XEXP (orig, 0)) < FIRST_PSEUDO_REGISTER)
 228         return orig;
 229       break;
 230
 231     case CONST:
 232       /* CONST can be shared if it contains a SYMBOL_REF.  If it contains
 233          a LABEL_REF, it isn't sharable.  */
 234       if (GET_CODE (XEXP (orig, 0)) == PLUS
 235           && GET_CODE (XEXP (XEXP (orig, 0), 0)) == SYMBOL_REF
 236           && GET_CODE (XEXP (XEXP (orig, 0), 1)) == CONST_INT)
 237         return orig;
 238       break;
 239
 240       /* A MEM with a constant address is not sharable.  The problem is that
 241          the constant address may need to be reloaded.  If the mem is shared,
 242          then reloading one copy of this mem will cause all copies to appear
 243          to have been reloaded.  */
 244
 245     default:
 246       break;
 247     }
 248
 249   copy = rtx_alloc (code);
 250
 251   /* Copy the various flags, and other information.  We assume that
 252      all fields need copying, and then clear the fields that should
 253      not be copied.  That is the sensible default behavior, and forces
 254      us to explicitly document why we are *not* copying a flag.  */
 255   memcpy (copy, orig, RTX_HDR_SIZE);
 256
 257   /* We do not copy the USED flag, which is used as a mark bit during
 258      walks over the RTL.  */
 259   RTX_FLAG (copy, used) = 0;
 260
 261   /* We do not copy FRAME_RELATED for INSNs.  */
 262   if (INSN_P (orig))
 263     RTX_FLAG (copy, frame_related) = 0;
 264   RTX_FLAG (copy, jump) = RTX_FLAG (orig, jump);
 265   RTX_FLAG (copy, call) = RTX_FLAG (orig, call);
 266
 267   format_ptr = GET_RTX_FORMAT (GET_CODE (copy));
 268
 269   for (i = 0; i < GET_RTX_LENGTH (GET_CODE (copy)); i++)
 270     {
 271       copy->u.fld[i] = orig->u.fld[i];
 272       switch (*format_ptr++)
 273         {
 274         case 'e':
 275           if (XEXP (orig, i) != NULL)
 276             XEXP (copy, i) = copy_rtx (XEXP (orig, i));
 277           break;
 278
 279         case 'E':
 280         case 'V':
 281           if (XVEC (orig, i) != NULL)
 282             {
 283               XVEC (copy, i) = rtvec_alloc (XVECLEN (orig, i));
 284               for (j = 0; j < XVECLEN (copy, i); j++)
 285                 XVECEXP (copy, i, j) = copy_rtx (XVECEXP (orig, i, j));
 286             }
 287           break;
 288
 289         case 't':
 290         case 'w':
 291         case 'i':
 292         case 's':
 293         case 'S':
 294         case 'T':
 295         case 'u':
 296         case 'B':
 297         case '0':
 298           /* These are left unchanged.  */
 299           break;
 300
 301         default:
 302           abort ();
 303         }
 304     }
 305   return copy;
 306 }
 307
 308 /* Create a new copy of an rtx.  Only copy just one level.  */
 309
 310 rtx
 311 shallow_copy_rtx_stat (rtx orig MEM_STAT_DECL)
 312 {
 313   rtx copy;
 314
 315   copy = (rtx) ggc_alloc_typed_stat (gt_ggc_e_7rtx_def,
 316                                      RTX_SIZE (GET_CODE (orig)) PASS_MEM_STAT);
 317   memcpy (copy, orig, RTX_SIZE (GET_CODE (orig)));
 318   return copy;
 319 }
 320 \f
 321 /* Nonzero when we are generating CONCATs.  */
 322 int generating_concat_p;
 323 \f
 324 /* Return 1 if X and Y are identical-looking rtx's.
 325    This is the Lisp function EQUAL for rtx arguments.  */
 326
 327 int
 328 rtx_equal_p (rtx x, rtx y)
 329 {
 330   int i;
 331   int j;
 332   enum rtx_code code;
 333   const char *fmt;
 334
 335   if (x == y)
 336     return 1;
 337   if (x == 0 || y == 0)
 338     return 0;
 339
 340   code = GET_CODE (x);
 341   /* Rtx's of different codes cannot be equal.  */
 342   if (code != GET_CODE (y))
 343     return 0;
 344
 345   /* (MULT:SI x y) and (MULT:HI x y) are NOT equivalent.
 346      (REG:SI x) and (REG:HI x) are NOT equivalent.  */
 347
 348   if (GET_MODE (x) != GET_MODE (y))
 349     return 0;
 350
 351   /* Some RTL can be compared nonrecursively.  */
 352   switch (code)
 353     {
 354     case REG:
 355       return (REGNO (x) == REGNO (y));
 356
 357     case LABEL_REF:
 358       return XEXP (x, 0) == XEXP (y, 0);
 359
 360     case SYMBOL_REF:
 361       return XSTR (x, 0) == XSTR (y, 0);
 362
 363     case SCRATCH:
 364     case CONST_DOUBLE:
 365     case CONST_INT:
 366     case CONST_VECTOR:
 367       return 0;
 368
 369     default:
 370       break;
 371     }
 372
 373   /* Compare the elements.  If any pair of corresponding elements
 374      fail to match, return 0 for the whole thing.  */
 375
 376   fmt = GET_RTX_FORMAT (code);
 377   for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
 378     {
 379       switch (fmt[i])
 380         {
 381         case 'w':
 382           if (XWINT (x, i) != XWINT (y, i))
 383             return 0;
 384           break;
 385
 386         case 'n':
 387         case 'i':
 388           if (XINT (x, i) != XINT (y, i))
 389             return 0;
 390           break;
 391
 392         case 'V':
 393         case 'E':
 394           /* Two vectors must have the same length.  */
 395           if (XVECLEN (x, i) != XVECLEN (y, i))
 396             return 0;
 397
 398           /* And the corresponding elements must match.  */
 399           for (j = 0; j < XVECLEN (x, i); j++)
 400             if (rtx_equal_p (XVECEXP (x, i, j), XVECEXP (y, i, j)) == 0)
 401               return 0;
 402           break;
 403
 404         case 'e':
 405           if (rtx_equal_p (XEXP (x, i), XEXP (y, i)) == 0)
 406             return 0;
 407           break;
 408
 409         case 'S':
 410         case 's':
 411           if ((XSTR (x, i) || XSTR (y, i))
 412               && (! XSTR (x, i) || ! XSTR (y, i)
 413                   || strcmp (XSTR (x, i), XSTR (y, i))))
 414             return 0;
 415           break;
 416
 417         case 'u':
 418           /* These are just backpointers, so they don't matter.  */
 419           break;
 420
 421         case '0':
 422         case 't':
 423           break;
 424
 425           /* It is believed that rtx's at this level will never
 426              contain anything but integers and other rtx's,
 427              except for within LABEL_REFs and SYMBOL_REFs.  */
 428         default:
 429           abort ();
 430         }
 431     }
 432   return 1;
 433 }
 434
 435 void dump_rtx_statistics (void)
 436 {
 437 #ifdef GATHER_STATISTICS
 438   int i;
 439   int total_counts = 0;
 440   int total_sizes = 0;
 441   fprintf (stderr, "\nRTX Kind               Count      Bytes\n");
 442   fprintf (stderr, "---------------------------------------\n");
 443   for (i = 0; i < LAST_AND_UNUSED_RTX_CODE; i++)
 444     if (rtx_alloc_counts[i])
 445       {
 446         fprintf (stderr, "%-20s %7d %10d\n", GET_RTX_NAME (i),
 447                  rtx_alloc_counts[i], rtx_alloc_sizes[i]);
 448         total_counts += rtx_alloc_counts[i];
 449         total_sizes += rtx_alloc_sizes[i];
 450       }
 451   if (rtvec_alloc_counts)
 452     {
 453       fprintf (stderr, "%-20s %7d %10d\n", "rtvec",
 454                rtvec_alloc_counts, rtvec_alloc_sizes);
 455       total_counts += rtvec_alloc_counts;
 456       total_sizes += rtvec_alloc_sizes;
 457     }
 458   fprintf (stderr, "---------------------------------------\n");
 459   fprintf (stderr, "%-20s %7d %10d\n",
 460            "Total", total_counts, total_sizes);
 461   fprintf (stderr, "---------------------------------------\n");
 462 #endif
 463 }
 464 \f
 465 #if defined ENABLE_RTL_CHECKING && (GCC_VERSION >= 2007)
 466 void
 467 rtl_check_failed_bounds (rtx r, int n, const char *file, int line,
 468                          const char *func)
 469 {
 470   internal_error
 471     ("RTL check: access of elt %d of `%s' with last elt %d in %s, at %s:%d",
 472      n, GET_RTX_NAME (GET_CODE (r)), GET_RTX_LENGTH (GET_CODE (r)) - 1,
 473      func, trim_filename (file), line);
 474 }
 475
 476 void
 477 rtl_check_failed_type1 (rtx r, int n, int c1, const char *file, int line,
 478                         const char *func)
 479 {
 480   internal_error
 481     ("RTL check: expected elt %d type '%c', have '%c' (rtx %s) in %s, at %s:%d",
 482      n, c1, GET_RTX_FORMAT (GET_CODE (r))[n], GET_RTX_NAME (GET_CODE (r)),
 483      func, trim_filename (file), line);
 484 }
 485
 486 void
 487 rtl_check_failed_type2 (rtx r, int n, int c1, int c2, const char *file,
 488                         int line, const char *func)
 489 {
 490   internal_error
 491     ("RTL check: expected elt %d type '%c' or '%c', have '%c' (rtx %s) in %s, at %s:%d",
 492      n, c1, c2, 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_code1 (rtx r, enum rtx_code code, const char *file,
 498                         int line, const char *func)
 499 {
 500   internal_error ("RTL check: expected code `%s', have `%s' in %s, at %s:%d",
 501                   GET_RTX_NAME (code), GET_RTX_NAME (GET_CODE (r)), func,
 502                   trim_filename (file), line);
 503 }
 504
 505 void
 506 rtl_check_failed_code2 (rtx r, enum rtx_code code1, enum rtx_code code2,
 507                         const char *file, int line, const char *func)
 508 {
 509   internal_error
 510     ("RTL check: expected code `%s' or `%s', have `%s' in %s, at %s:%d",
 511      GET_RTX_NAME (code1), GET_RTX_NAME (code2), GET_RTX_NAME (GET_CODE (r)),
 512      func, trim_filename (file), line);
 513 }
 514
 515 /* XXX Maybe print the vector?  */
 516 void
 517 rtvec_check_failed_bounds (rtvec r, int n, const char *file, int line,
 518                            const char *func)
 519 {
 520   internal_error
 521     ("RTL check: access of elt %d of vector with last elt %d in %s, at %s:%d",
 522      n, GET_NUM_ELEM (r) - 1, func, trim_filename (file), line);
 523 }
 524 #endif /* ENABLE_RTL_CHECKING */
 525
 526 #if defined ENABLE_RTL_FLAG_CHECKING
 527 void
 528 rtl_check_failed_flag (const char *name, rtx r, const char *file,
 529                        int line, const char *func)
 530 {
 531   internal_error
 532     ("RTL flag check: %s used with unexpected rtx code `%s' in %s, at %s:%d",
 533      name, GET_RTX_NAME (GET_CODE (r)), func, trim_filename (file), line);
 534 }
 535 #endif /* ENABLE_RTL_FLAG_CHECKING */