gcc/genconfig.c

   1 /* Generate from machine description:
   2    - some #define configuration flags.
   3    Copyright (C) 1987, 1991, 1997, 1998, 1999, 2000, 2003, 2004
   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 2, 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 COPYING.  If not, write to the Free
  20 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
  21 02111-1307, USA.  */
  22
  23
  24 #include "bconfig.h"
  25 #include "system.h"
  26 #include "coretypes.h"
  27 #include "tm.h"
  28 #include "rtl.h"
  29 #include "errors.h"
  30 #include "gensupport.h"
  31
  32
  33 /* flags to determine output of machine description dependent #define's.  */
  34 static int max_recog_operands;  /* Largest operand number seen.  */
  35 static int max_dup_operands;    /* Largest number of match_dup in any insn.  */
  36 static int max_clobbers_per_insn;
  37 static int have_cc0_flag;
  38 static int have_cmove_flag;
  39 static int have_cond_exec_flag;
  40 static int have_lo_sum_flag;
  41 static int have_peephole_flag;
  42 static int have_peephole2_flag;
  43
  44 /* Maximum number of insns seen in a split.  */
  45 static int max_insns_per_split = 1;
  46
  47 /* Maximum number of input insns for peephole2.  */
  48 static int max_insns_per_peep2;
  49
  50 static int clobbers_seen_this_insn;
  51 static int dup_operands_seen_this_insn;
  52
  53 static void walk_insn_part (rtx, int, int);
  54 static void gen_insn (rtx);
  55 static void gen_expand (rtx);
  56 static void gen_split (rtx);
  57 static void gen_peephole (rtx);
  58 static void gen_peephole2 (rtx);
  59
  60 /* RECOG_P will be nonzero if this pattern was seen in a context where it will
  61    be used to recognize, rather than just generate an insn.
  62
  63    NON_PC_SET_SRC will be nonzero if this pattern was seen in a SET_SRC
  64    of a SET whose destination is not (pc).  */
  65
  66 static void
  67 walk_insn_part (rtx part, int recog_p, int non_pc_set_src)
  68 {
  69   int i, j;
  70   RTX_CODE code;
  71   const char *format_ptr;
  72
  73   if (part == 0)
  74     return;
  75
  76   code = GET_CODE (part);
  77   switch (code)
  78     {
  79     case CLOBBER:
  80       clobbers_seen_this_insn++;
  81       break;
  82
  83     case MATCH_OPERAND:
  84       if (XINT (part, 0) > max_recog_operands)
  85         max_recog_operands = XINT (part, 0);
  86       return;
  87
  88     case MATCH_OP_DUP:
  89     case MATCH_PAR_DUP:
  90       ++dup_operands_seen_this_insn;
  91     case MATCH_SCRATCH:
  92     case MATCH_PARALLEL:
  93     case MATCH_OPERATOR:
  94       if (XINT (part, 0) > max_recog_operands)
  95         max_recog_operands = XINT (part, 0);
  96       /* Now scan the rtl's in the vector inside the MATCH_OPERATOR or
  97          MATCH_PARALLEL.  */
  98       break;
  99
 100     case LABEL_REF:
 101       if (GET_CODE (XEXP (part, 0)) == MATCH_OPERAND
 102           || GET_CODE (XEXP (part, 0)) == MATCH_DUP)
 103         break;
 104       return;
 105
 106     case MATCH_DUP:
 107       ++dup_operands_seen_this_insn;
 108       if (XINT (part, 0) > max_recog_operands)
 109         max_recog_operands = XINT (part, 0);
 110       return;
 111
 112     case CC0:
 113       if (recog_p)
 114         have_cc0_flag = 1;
 115       return;
 116
 117     case LO_SUM:
 118       if (recog_p)
 119         have_lo_sum_flag = 1;
 120       return;
 121
 122     case SET:
 123       walk_insn_part (SET_DEST (part), 0, recog_p);
 124       walk_insn_part (SET_SRC (part), recog_p,
 125                       GET_CODE (SET_DEST (part)) != PC);
 126       return;
 127
 128     case IF_THEN_ELSE:
 129       /* Only consider this machine as having a conditional move if the
 130          two arms of the IF_THEN_ELSE are both MATCH_OPERAND.  Otherwise,
 131          we have some specific IF_THEN_ELSE construct (like the doz
 132          instruction on the RS/6000) that can't be used in the general
 133          context we want it for.  */
 134
 135       if (recog_p && non_pc_set_src
 136           && GET_CODE (XEXP (part, 1)) == MATCH_OPERAND
 137           && GET_CODE (XEXP (part, 2)) == MATCH_OPERAND)
 138         have_cmove_flag = 1;
 139       break;
 140
 141     case COND_EXEC:
 142       if (recog_p)
 143         have_cond_exec_flag = 1;
 144       break;
 145
 146     case REG: case CONST_INT: case SYMBOL_REF:
 147     case PC:
 148       return;
 149
 150     default:
 151       break;
 152     }
 153
 154   format_ptr = GET_RTX_FORMAT (GET_CODE (part));
 155
 156   for (i = 0; i < GET_RTX_LENGTH (GET_CODE (part)); i++)
 157     switch (*format_ptr++)
 158       {
 159       case 'e':
 160       case 'u':
 161         walk_insn_part (XEXP (part, i), recog_p, non_pc_set_src);
 162         break;
 163       case 'E':
 164         if (XVEC (part, i) != NULL)
 165           for (j = 0; j < XVECLEN (part, i); j++)
 166             walk_insn_part (XVECEXP (part, i, j), recog_p, non_pc_set_src);
 167         break;
 168       }
 169 }
 170
 171 static void
 172 gen_insn (rtx insn)
 173 {
 174   int i;
 175
 176   /* Walk the insn pattern to gather the #define's status.  */
 177   clobbers_seen_this_insn = 0;
 178   dup_operands_seen_this_insn = 0;
 179   if (XVEC (insn, 1) != 0)
 180     for (i = 0; i < XVECLEN (insn, 1); i++)
 181       walk_insn_part (XVECEXP (insn, 1, i), 1, 0);
 182
 183   if (clobbers_seen_this_insn > max_clobbers_per_insn)
 184     max_clobbers_per_insn = clobbers_seen_this_insn;
 185   if (dup_operands_seen_this_insn > max_dup_operands)
 186     max_dup_operands = dup_operands_seen_this_insn;
 187 }
 188
 189 /* Similar but scan a define_expand.  */
 190
 191 static void
 192 gen_expand (rtx insn)
 193 {
 194   int i;
 195
 196   /* Walk the insn pattern to gather the #define's status.  */
 197
 198   /* Note that we don't bother recording the number of MATCH_DUPs
 199      that occur in a gen_expand, because only reload cares about that.  */
 200   if (XVEC (insn, 1) != 0)
 201     for (i = 0; i < XVECLEN (insn, 1); i++)
 202       {
 203         /* Compute the maximum SETs and CLOBBERS
 204            in any one of the sub-insns;
 205            don't sum across all of them.  */
 206         clobbers_seen_this_insn = 0;
 207
 208         walk_insn_part (XVECEXP (insn, 1, i), 0, 0);
 209
 210         if (clobbers_seen_this_insn > max_clobbers_per_insn)
 211           max_clobbers_per_insn = clobbers_seen_this_insn;
 212       }
 213 }
 214
 215 /* Similar but scan a define_split.  */
 216
 217 static void
 218 gen_split (rtx split)
 219 {
 220   int i;
 221
 222   /* Look through the patterns that are matched
 223      to compute the maximum operand number.  */
 224   for (i = 0; i < XVECLEN (split, 0); i++)
 225     walk_insn_part (XVECEXP (split, 0, i), 1, 0);
 226   /* Look at the number of insns this insn could split into.  */
 227   if (XVECLEN (split, 2) > max_insns_per_split)
 228     max_insns_per_split = XVECLEN (split, 2);
 229 }
 230
 231 static void
 232 gen_peephole (rtx peep)
 233 {
 234   int i;
 235
 236   /* Look through the patterns that are matched
 237      to compute the maximum operand number.  */
 238   for (i = 0; i < XVECLEN (peep, 0); i++)
 239     walk_insn_part (XVECEXP (peep, 0, i), 1, 0);
 240 }
 241
 242 static void
 243 gen_peephole2 (rtx peep)
 244 {
 245   int i, n;
 246
 247   /* Look through the patterns that are matched
 248      to compute the maximum operand number.  */
 249   for (i = XVECLEN (peep, 0) - 1; i >= 0; --i)
 250     walk_insn_part (XVECEXP (peep, 0, i), 1, 0);
 251
 252   /* Look at the number of insns this insn can be matched from.  */
 253   for (i = XVECLEN (peep, 0) - 1, n = 0; i >= 0; --i)
 254     if (GET_CODE (XVECEXP (peep, 0, i)) != MATCH_DUP
 255         && GET_CODE (XVECEXP (peep, 0, i)) != MATCH_SCRATCH)
 256       n++;
 257   if (n > max_insns_per_peep2)
 258     max_insns_per_peep2 = n;
 259 }
 260
 261 int
 262 main (int argc, char **argv)
 263 {
 264   rtx desc;
 265
 266   progname = "genconfig";
 267
 268   if (init_md_reader_args (argc, argv) != SUCCESS_EXIT_CODE)
 269     return (FATAL_EXIT_CODE);
 270
 271   puts ("/* Generated automatically by the program `genconfig'");
 272   puts ("   from the machine description file `md'.  */\n");
 273   puts ("#ifndef GCC_INSN_CONFIG_H");
 274   puts ("#define GCC_INSN_CONFIG_H\n");
 275
 276   /* Allow at least 30 operands for the sake of asm constructs.  */
 277   /* ??? We *really* ought to reorganize things such that there
 278      is no fixed upper bound.  */
 279   max_recog_operands = 29;  /* We will add 1 later.  */
 280   max_dup_operands = 1;
 281
 282   /* Read the machine description.  */
 283
 284   while (1)
 285     {
 286       int line_no, insn_code_number = 0;
 287
 288       desc = read_md_rtx (&line_no, &insn_code_number);
 289       if (desc == NULL)
 290         break;
 291
 292       switch (GET_CODE (desc))
 293         {
 294           case DEFINE_INSN:
 295             gen_insn (desc);
 296             break;
 297
 298           case DEFINE_EXPAND:
 299             gen_expand (desc);
 300             break;
 301
 302           case DEFINE_SPLIT:
 303             gen_split (desc);
 304             break;
 305
 306           case DEFINE_PEEPHOLE2:
 307             have_peephole2_flag = 1;
 308             gen_peephole2 (desc);
 309             break;
 310
 311           case DEFINE_PEEPHOLE:
 312             have_peephole_flag = 1;
 313             gen_peephole (desc);
 314             break;
 315
 316           default:
 317             break;
 318         }
 319     }
 320
 321   printf ("#define MAX_RECOG_OPERANDS %d\n", max_recog_operands + 1);
 322   printf ("#define MAX_DUP_OPERANDS %d\n", max_dup_operands);
 323
 324   /* This is conditionally defined, in case the user writes code which emits
 325      more splits than we can readily see (and knows s/he does it).  */
 326   printf ("#ifndef MAX_INSNS_PER_SPLIT\n");
 327   printf ("#define MAX_INSNS_PER_SPLIT %d\n", max_insns_per_split);
 328   printf ("#endif\n");
 329
 330   if (have_cc0_flag)
 331     {
 332       printf ("#define HAVE_cc0 1\n");
 333       printf ("#define CC0_P(X) ((X) == cc0_rtx)\n");
 334     }
 335   else
 336     {
 337       /* We output CC0_P this way to make sure that X is declared
 338          somewhere.  */
 339       printf ("#define CC0_P(X) ((X) ? 0 : 0)\n");
 340     }
 341
 342   if (have_cmove_flag)
 343     printf ("#define HAVE_conditional_move 1\n");
 344
 345   if (have_cond_exec_flag)
 346     printf ("#define HAVE_conditional_execution 1\n");
 347
 348   if (have_lo_sum_flag)
 349     printf ("#define HAVE_lo_sum 1\n");
 350
 351   if (have_peephole_flag)
 352     printf ("#define HAVE_peephole 1\n");
 353
 354   if (have_peephole2_flag)
 355     {
 356       printf ("#define HAVE_peephole2 1\n");
 357       printf ("#define MAX_INSNS_PER_PEEP2 %d\n", max_insns_per_peep2);
 358     }
 359
 360   puts("\n#endif /* GCC_INSN_CONFIG_H */");
 361
 362   if (ferror (stdout) || fflush (stdout) || fclose (stdout))
 363     return FATAL_EXIT_CODE;
 364
 365   return SUCCESS_EXIT_CODE;
 366 }
 367
 368 /* Define this so we can link with print-rtl.o to get debug_rtx function.  */
 369 const char *
 370 get_insn_name (int ARG_UNUSED (code))
 371 {
 372   return NULL;
 373 }