gcc/genconfig.c

   1 /* Generate from machine description:
   2    - some #define configuration flags.
   3    Copyright (C) 1987, 1991, 1997, 1998,
   4    1999, 2000 Free Software Foundation, Inc.
   5
   6 This file is part of GNU CC.
   7
   8 GNU CC is free software; you can redistribute it and/or modify
   9 it under the terms of the GNU General Public License as published by
  10 the Free Software Foundation; either version 2, or (at your option)
  11 any later version.
  12
  13 GNU CC is distributed in the hope that it will be useful,
  14 but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 GNU General Public License for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with GNU CC; see the file COPYING.  If not, write to
  20 the Free Software Foundation, 59 Temple Place - Suite 330,
  21 Boston, MA 02111-1307, USA.  */
  22
  23
  24 #include "hconfig.h"
  25 #include "system.h"
  26 #include "rtl.h"
  27 #include "errors.h"
  28 #include "gensupport.h"
  29
  30
  31 /* flags to determine output of machine description dependent #define's.  */
  32 static int max_recog_operands;  /* Largest operand number seen.  */
  33 static int max_dup_operands;    /* Largest number of match_dup in any insn.  */
  34 static int max_clobbers_per_insn;
  35 static int have_cc0_flag;
  36 static int have_cmove_flag;
  37 static int have_cond_exec_flag;
  38 static int have_lo_sum_flag;
  39 static int have_peephole_flag;
  40 static int have_peephole2_flag;
  41
  42 /* Maximum number of insns seen in a split.  */
  43 static int max_insns_per_split = 1;
  44
  45 /* Maximum number of input insns for peephole2.  */
  46 static int max_insns_per_peep2;
  47
  48 static int clobbers_seen_this_insn;
  49 static int dup_operands_seen_this_insn;
  50
  51 static void walk_insn_part PARAMS ((rtx, int, int));
  52 static void gen_insn PARAMS ((rtx));
  53 static void gen_expand PARAMS ((rtx));
  54 static void gen_split PARAMS ((rtx));
  55 static void gen_peephole PARAMS ((rtx));
  56 static void gen_peephole2 PARAMS ((rtx));
  57
  58 /* RECOG_P will be non-zero if this pattern was seen in a context where it will
  59    be used to recognize, rather than just generate an insn.
  60
  61    NON_PC_SET_SRC will be non-zero if this pattern was seen in a SET_SRC
  62    of a SET whose destination is not (pc).  */
  63
  64 static void
  65 walk_insn_part (part, recog_p, non_pc_set_src)
  66      rtx part;
  67      int recog_p;
  68      int non_pc_set_src;
  69 {
  70   register int i, j;
  71   register RTX_CODE code;
  72   register const char *format_ptr;
  73
  74   if (part == 0)
  75     return;
  76
  77   code = GET_CODE (part);
  78   switch (code)
  79     {
  80     case CLOBBER:
  81       clobbers_seen_this_insn++;
  82       break;
  83
  84     case MATCH_OPERAND:
  85       if (XINT (part, 0) > max_recog_operands)
  86         max_recog_operands = XINT (part, 0);
  87       return;
  88
  89     case MATCH_OP_DUP:
  90     case MATCH_PAR_DUP:
  91       ++dup_operands_seen_this_insn;
  92     case MATCH_SCRATCH:
  93     case MATCH_PARALLEL:
  94     case MATCH_OPERATOR:
  95       if (XINT (part, 0) > max_recog_operands)
  96         max_recog_operands = XINT (part, 0);
  97       /* Now scan the rtl's in the vector inside the MATCH_OPERATOR or
  98          MATCH_PARALLEL.  */
  99       break;
 100
 101     case LABEL_REF:
 102       if (GET_CODE (XEXP (part, 0)) == MATCH_OPERAND)
 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 (insn)
 173      rtx insn;
 174 {
 175   int i;
 176
 177   /* Walk the insn pattern to gather the #define's status.  */
 178   clobbers_seen_this_insn = 0;
 179   dup_operands_seen_this_insn = 0;
 180   if (XVEC (insn, 1) != 0)
 181     for (i = 0; i < XVECLEN (insn, 1); i++)
 182       walk_insn_part (XVECEXP (insn, 1, i), 1, 0);
 183
 184   if (clobbers_seen_this_insn > max_clobbers_per_insn)
 185     max_clobbers_per_insn = clobbers_seen_this_insn;
 186   if (dup_operands_seen_this_insn > max_dup_operands)
 187     max_dup_operands = dup_operands_seen_this_insn;
 188 }
 189
 190 /* Similar but scan a define_expand.  */
 191
 192 static void
 193 gen_expand (insn)
 194      rtx insn;
 195 {
 196   int i;
 197
 198   /* Walk the insn pattern to gather the #define's status.  */
 199
 200   /* Note that we don't bother recording the number of MATCH_DUPs
 201      that occur in a gen_expand, because only reload cares about that.  */
 202   if (XVEC (insn, 1) != 0)
 203     for (i = 0; i < XVECLEN (insn, 1); i++)
 204       {
 205         /* Compute the maximum SETs and CLOBBERS
 206            in any one of the sub-insns;
 207            don't sum across all of them.  */
 208         clobbers_seen_this_insn = 0;
 209
 210         walk_insn_part (XVECEXP (insn, 1, i), 0, 0);
 211
 212         if (clobbers_seen_this_insn > max_clobbers_per_insn)
 213           max_clobbers_per_insn = clobbers_seen_this_insn;
 214       }
 215 }
 216
 217 /* Similar but scan a define_split.  */
 218
 219 static void
 220 gen_split (split)
 221      rtx split;
 222 {
 223   int i;
 224
 225   /* Look through the patterns that are matched
 226      to compute the maximum operand number.  */
 227   for (i = 0; i < XVECLEN (split, 0); i++)
 228     walk_insn_part (XVECEXP (split, 0, i), 1, 0);
 229   /* Look at the number of insns this insn could split into.  */
 230   if (XVECLEN (split, 2) > max_insns_per_split)
 231     max_insns_per_split = XVECLEN (split, 2);
 232 }
 233
 234 static void
 235 gen_peephole (peep)
 236      rtx peep;
 237 {
 238   int i;
 239
 240   /* Look through the patterns that are matched
 241      to compute the maximum operand number.  */
 242   for (i = 0; i < XVECLEN (peep, 0); i++)
 243     walk_insn_part (XVECEXP (peep, 0, i), 1, 0);
 244 }
 245
 246 static void
 247 gen_peephole2 (peep)
 248      rtx peep;
 249 {
 250   int i, n;
 251
 252   /* Look through the patterns that are matched
 253      to compute the maximum operand number.  */
 254   for (i = XVECLEN (peep, 0) - 1; i >= 0; --i)
 255     walk_insn_part (XVECEXP (peep, 0, i), 1, 0);
 256
 257   /* Look at the number of insns this insn can be matched from.  */
 258   for (i = XVECLEN (peep, 0) - 1, n = 0; i >= 0; --i)
 259     if (GET_CODE (XVECEXP (peep, 0, i)) != MATCH_DUP
 260         && GET_CODE (XVECEXP (peep, 0, i)) != MATCH_SCRATCH)
 261       n++;
 262   if (n > max_insns_per_peep2)
 263     max_insns_per_peep2 = n;
 264 }
 265
 266 extern int main PARAMS ((int, char **));
 267
 268 int
 269 main (argc, argv)
 270      int argc;
 271      char **argv;
 272 {
 273   rtx desc;
 274
 275   progname = "genconfig";
 276
 277   if (argc <= 1)
 278     fatal ("No input file name.");
 279
 280   if (init_md_reader (argv[1]) != SUCCESS_EXIT_CODE)
 281     return (FATAL_EXIT_CODE);
 282
 283   printf ("/* Generated automatically by the program `genconfig'\n\
 284 from the machine description file `md'.  */\n\n");
 285
 286   /* Allow at least 10 operands for the sake of asm constructs.  */
 287   max_recog_operands = 9;  /* We will add 1 later.  */
 288   max_dup_operands = 1;
 289
 290   /* Read the machine description.  */
 291
 292   while (1)
 293     {
 294       int line_no, insn_code_number = 0;
 295
 296       desc = read_md_rtx (&line_no, &insn_code_number);
 297       if (desc == NULL)
 298         break;
 299
 300       switch (GET_CODE (desc))
 301         {
 302           case DEFINE_INSN:
 303             gen_insn (desc);
 304             break;
 305
 306           case DEFINE_EXPAND:
 307             gen_expand (desc);
 308             break;
 309
 310           case DEFINE_SPLIT:
 311             gen_split (desc);
 312             break;
 313
 314           case DEFINE_PEEPHOLE2:
 315             have_peephole2_flag = 1;
 316             gen_peephole2 (desc);
 317             break;
 318
 319           case DEFINE_PEEPHOLE:
 320             have_peephole_flag = 1;
 321             gen_peephole (desc);
 322             break;
 323
 324           default:
 325             break;
 326         }
 327     }
 328
 329   printf ("#define MAX_RECOG_OPERANDS %d\n", max_recog_operands + 1);
 330   printf ("#define MAX_DUP_OPERANDS %d\n", max_dup_operands);
 331
 332   /* This is conditionally defined, in case the user writes code which emits
 333      more splits than we can readily see (and knows s/he does it).  */
 334   printf ("#ifndef MAX_INSNS_PER_SPLIT\n");
 335   printf ("#define MAX_INSNS_PER_SPLIT %d\n", max_insns_per_split);
 336   printf ("#endif\n");
 337
 338   if (have_cc0_flag)
 339     printf ("#define HAVE_cc0 1\n");
 340
 341   if (have_cmove_flag)
 342     printf ("#define HAVE_conditional_move 1\n");
 343
 344   if (have_cond_exec_flag)
 345     printf ("#define HAVE_conditional_execution 1\n");
 346
 347   if (have_lo_sum_flag)
 348     printf ("#define HAVE_lo_sum 1\n");
 349
 350   if (have_peephole_flag)
 351     printf ("#define HAVE_peephole 1\n");
 352
 353   if (have_peephole2_flag)
 354     {
 355       printf ("#define HAVE_peephole2 1\n");
 356       printf ("#define MAX_INSNS_PER_PEEP2 %d\n", max_insns_per_peep2);
 357     }
 358
 359   fflush (stdout);
 360   return (ferror (stdout) != 0 ? FATAL_EXIT_CODE : SUCCESS_EXIT_CODE);
 361 }
 362
 363 /* Define this so we can link with print-rtl.o to get debug_rtx function.  */
 364 const char *
 365 get_insn_name (code)
 366      int code ATTRIBUTE_UNUSED;
 367 {
 368   return NULL;
 369 }