gcc/genconfig.c

   1 /* Generate from machine description:
   2    - some #define configuration flags.
   3    Copyright (C) 1987, 1991, 1997, 1998, 1999 Free Software Foundation, Inc.
   4
   5 This file is part of GNU CC.
   6
   7 GNU CC is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 2, or (at your option)
  10 any later version.
  11
  12 GNU CC is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GNU CC; see the file COPYING.  If not, write to
  19 the Free Software Foundation, 59 Temple Place - Suite 330,
  20 Boston, MA 02111-1307, USA.  */
  21
  22
  23 #include "hconfig.h"
  24 #include "system.h"
  25 #include "rtl.h"
  26 #include "obstack.h"
  27 #include "errors.h"
  28
  29 static struct obstack obstack;
  30 struct obstack *rtl_obstack = &obstack;
  31
  32 #define obstack_chunk_alloc xmalloc
  33 #define obstack_chunk_free free
  34
  35 /* flags to determine output of machine description dependent #define's.  */
  36 static int max_recog_operands;  /* Largest operand number seen.  */
  37 static int max_dup_operands;    /* Largest number of match_dup in any insn.  */
  38 static int max_clobbers_per_insn;
  39 static int register_constraint_flag;
  40 static int have_cc0_flag;
  41 static int have_cmove_flag;
  42 static int have_cond_arith_flag;
  43 static int have_lo_sum_flag;
  44 static int have_peephole_flag;
  45 static int have_peephole2_flag;
  46
  47 /* Maximum number of insns seen in a split.  */
  48 static int max_insns_per_split = 1;
  49
  50 static int clobbers_seen_this_insn;
  51 static int dup_operands_seen_this_insn;
  52
  53 static void walk_insn_part PROTO((rtx, int, int));
  54 static void gen_insn PROTO((rtx));
  55 static void gen_expand PROTO((rtx));
  56 static void gen_split PROTO((rtx));
  57 static void gen_peephole PROTO((rtx));
  58
  59 /* RECOG_P will be non-zero if this pattern was seen in a context where it will
  60    be used to recognize, rather than just generate an insn.
  61
  62    NON_PC_SET_SRC will be non-zero if this pattern was seen in a SET_SRC
  63    of a SET whose destination is not (pc).  */
  64
  65 static void
  66 walk_insn_part (part, recog_p, non_pc_set_src)
  67      rtx part;
  68      int recog_p;
  69      int non_pc_set_src;
  70 {
  71   register int i, j;
  72   register RTX_CODE code;
  73   register const char *format_ptr;
  74
  75   if (part == 0)
  76     return;
  77
  78   code = GET_CODE (part);
  79   switch (code)
  80     {
  81     case CLOBBER:
  82       clobbers_seen_this_insn++;
  83       break;
  84
  85     case MATCH_OPERAND:
  86       if (XINT (part, 0) > max_recog_operands)
  87         max_recog_operands = XINT (part, 0);
  88       if (XSTR (part, 2) && *XSTR (part, 2))
  89         register_constraint_flag = 1;
  90       return;
  91
  92     case MATCH_OP_DUP:
  93     case MATCH_PAR_DUP:
  94       ++dup_operands_seen_this_insn;
  95     case MATCH_SCRATCH:
  96     case MATCH_PARALLEL:
  97     case MATCH_OPERATOR:
  98       if (XINT (part, 0) > max_recog_operands)
  99         max_recog_operands = XINT (part, 0);
 100       /* Now scan the rtl's in the vector inside the MATCH_OPERATOR or
 101          MATCH_PARALLEL.  */
 102       break;
 103
 104     case LABEL_REF:
 105       if (GET_CODE (XEXP (part, 0)) == MATCH_OPERAND)
 106         break;
 107       return;
 108
 109     case MATCH_DUP:
 110       ++dup_operands_seen_this_insn;
 111       if (XINT (part, 0) > max_recog_operands)
 112         max_recog_operands = XINT (part, 0);
 113       return;
 114
 115     case CC0:
 116       if (recog_p)
 117         have_cc0_flag = 1;
 118       return;
 119
 120     case LO_SUM:
 121       if (recog_p)
 122         have_lo_sum_flag = 1;
 123       return;
 124
 125     case SET:
 126       walk_insn_part (SET_DEST (part), 0, recog_p);
 127       walk_insn_part (SET_SRC (part), recog_p,
 128                       GET_CODE (SET_DEST (part)) != PC);
 129       return;
 130
 131     case IF_THEN_ELSE:
 132       /* Only consider this machine as having a conditional move if the
 133          two arms of the IF_THEN_ELSE are both MATCH_OPERAND.  Otherwise,
 134          we have some specific IF_THEN_ELSE construct (like the doz
 135          instruction on the RS/6000) that can't be used in the general
 136          context we want it for.  If the first operand is an arithmetic
 137          operation and the second is a MATCH_OPERNAND, show we have
 138          conditional arithmetic.  */
 139
 140       if (recog_p && non_pc_set_src
 141           && GET_CODE (XEXP (part, 1)) == MATCH_OPERAND
 142           && GET_CODE (XEXP (part, 2)) == MATCH_OPERAND)
 143         have_cmove_flag = 1;
 144       else if (recog_p && non_pc_set_src
 145                && (GET_RTX_CLASS (GET_CODE (XEXP (part, 1))) == '1'
 146                    || GET_RTX_CLASS (GET_CODE (XEXP (part, 1))) == '2'
 147                    || GET_RTX_CLASS (GET_CODE (XEXP (part, 1))) == 'c')
 148                && GET_CODE (XEXP (XEXP (part, 1), 0)) == MATCH_OPERAND
 149                && GET_CODE (XEXP (part, 2)) == MATCH_OPERAND)
 150         have_cond_arith_flag = 1;
 151       break;
 152
 153     case REG: case CONST_INT: case SYMBOL_REF:
 154     case PC:
 155       return;
 156
 157     default:
 158       break;
 159     }
 160
 161   format_ptr = GET_RTX_FORMAT (GET_CODE (part));
 162
 163   for (i = 0; i < GET_RTX_LENGTH (GET_CODE (part)); i++)
 164     switch (*format_ptr++)
 165       {
 166       case 'e':
 167       case 'u':
 168         walk_insn_part (XEXP (part, i), recog_p, non_pc_set_src);
 169         break;
 170       case 'E':
 171         if (XVEC (part, i) != NULL)
 172           for (j = 0; j < XVECLEN (part, i); j++)
 173             walk_insn_part (XVECEXP (part, i, j), recog_p, non_pc_set_src);
 174         break;
 175       }
 176 }
 177
 178 static void
 179 gen_insn (insn)
 180      rtx insn;
 181 {
 182   int i;
 183
 184   /* Walk the insn pattern to gather the #define's status.  */
 185   clobbers_seen_this_insn = 0;
 186   dup_operands_seen_this_insn = 0;
 187   if (XVEC (insn, 1) != 0)
 188     for (i = 0; i < XVECLEN (insn, 1); i++)
 189       walk_insn_part (XVECEXP (insn, 1, i), 1, 0);
 190
 191   if (clobbers_seen_this_insn > max_clobbers_per_insn)
 192     max_clobbers_per_insn = clobbers_seen_this_insn;
 193   if (dup_operands_seen_this_insn > max_dup_operands)
 194     max_dup_operands = dup_operands_seen_this_insn;
 195 }
 196
 197 /* Similar but scan a define_expand.  */
 198
 199 static void
 200 gen_expand (insn)
 201      rtx insn;
 202 {
 203   int i;
 204
 205   /* Walk the insn pattern to gather the #define's status.  */
 206
 207   /* Note that we don't bother recording the number of MATCH_DUPs
 208      that occur in a gen_expand, because only reload cares about that.  */
 209   if (XVEC (insn, 1) != 0)
 210     for (i = 0; i < XVECLEN (insn, 1); i++)
 211       {
 212         /* Compute the maximum SETs and CLOBBERS
 213            in any one of the sub-insns;
 214            don't sum across all of them.  */
 215         clobbers_seen_this_insn = 0;
 216
 217         walk_insn_part (XVECEXP (insn, 1, i), 0, 0);
 218
 219         if (clobbers_seen_this_insn > max_clobbers_per_insn)
 220           max_clobbers_per_insn = clobbers_seen_this_insn;
 221       }
 222 }
 223
 224 /* Similar but scan a define_split.  */
 225
 226 static void
 227 gen_split (split)
 228      rtx split;
 229 {
 230   int i;
 231
 232   /* Look through the patterns that are matched
 233      to compute the maximum operand number.  */
 234   for (i = 0; i < XVECLEN (split, 0); i++)
 235     walk_insn_part (XVECEXP (split, 0, i), 1, 0);
 236   /* Look at the number of insns this insn could split into.  */
 237   if (XVECLEN (split, 2) > max_insns_per_split)
 238     max_insns_per_split = XVECLEN (split, 2);
 239 }
 240
 241 static void
 242 gen_peephole (peep)
 243      rtx peep;
 244 {
 245   int i;
 246
 247   /* Look through the patterns that are matched
 248      to compute the maximum operand number.  */
 249   for (i = 0; i < XVECLEN (peep, 0); i++)
 250     walk_insn_part (XVECEXP (peep, 0, i), 1, 0);
 251 }
 252 \f
 253 PTR
 254 xmalloc (size)
 255   size_t size;
 256 {
 257   register PTR val = (PTR) malloc (size);
 258
 259   if (val == 0)
 260     fatal ("virtual memory exhausted");
 261
 262   return val;
 263 }
 264
 265 PTR
 266 xrealloc (old, size)
 267   PTR old;
 268   size_t size;
 269 {
 270   register PTR ptr;
 271   if (old)
 272     ptr = (PTR) realloc (old, size);
 273   else
 274     ptr = (PTR) malloc (size);
 275   if (!ptr)
 276     fatal ("virtual memory exhausted");
 277   return ptr;
 278 }
 279
 280 int
 281 main (argc, argv)
 282      int argc;
 283      char **argv;
 284 {
 285   rtx desc;
 286   FILE *infile;
 287   register int c;
 288
 289   progname = "genconfig";
 290   obstack_init (rtl_obstack);
 291
 292   if (argc <= 1)
 293     fatal ("No input file name.");
 294
 295   infile = fopen (argv[1], "r");
 296   if (infile == 0)
 297     {
 298       perror (argv[1]);
 299       exit (FATAL_EXIT_CODE);
 300     }
 301
 302   printf ("/* Generated automatically by the program `genconfig'\n\
 303 from the machine description file `md'.  */\n\n");
 304
 305   /* Allow at least 10 operands for the sake of asm constructs.  */
 306   max_recog_operands = 9;  /* We will add 1 later.  */
 307   max_dup_operands = 1;
 308
 309   /* Read the machine description.  */
 310
 311   while (1)
 312     {
 313       c = read_skip_spaces (infile);
 314       if (c == EOF)
 315         break;
 316       ungetc (c, infile);
 317
 318       desc = read_rtx (infile);
 319       if (GET_CODE (desc) == DEFINE_INSN)
 320         gen_insn (desc);
 321       if (GET_CODE (desc) == DEFINE_EXPAND)
 322         gen_expand (desc);
 323       if (GET_CODE (desc) == DEFINE_SPLIT)
 324         gen_split (desc);
 325       if (GET_CODE (desc) == DEFINE_PEEPHOLE2)
 326         {
 327           have_peephole2_flag = 1;
 328           gen_split (desc);
 329         }
 330       if (GET_CODE (desc) == DEFINE_PEEPHOLE)
 331         {
 332           have_peephole_flag = 1;
 333           gen_peephole (desc);
 334         }
 335     }
 336
 337   printf ("\n#define MAX_RECOG_OPERANDS %d\n", max_recog_operands + 1);
 338
 339   printf ("\n#define MAX_DUP_OPERANDS %d\n", max_dup_operands);
 340
 341   /* This is conditionally defined, in case the user writes code which emits
 342      more splits than we can readily see (and knows s/he does it).  */
 343   printf ("#ifndef MAX_INSNS_PER_SPLIT\n#define MAX_INSNS_PER_SPLIT %d\n#endif\n",
 344           max_insns_per_split);
 345
 346   if (register_constraint_flag)
 347     printf ("#define REGISTER_CONSTRAINTS\n");
 348
 349   if (have_cc0_flag)
 350     printf ("#define HAVE_cc0\n");
 351
 352   if (have_cmove_flag)
 353     printf ("#define HAVE_conditional_move\n");
 354
 355   if (have_cond_arith_flag)
 356     printf ("#define HAVE_conditional_arithmetic\n");
 357
 358   if (have_lo_sum_flag)
 359     printf ("#define HAVE_lo_sum\n");
 360
 361   if (have_peephole_flag)
 362     printf ("#define HAVE_peephole\n");
 363
 364   if (have_peephole2_flag)
 365     printf ("#define HAVE_peephole2\n");
 366
 367   fflush (stdout);
 368   exit (ferror (stdout) != 0 ? FATAL_EXIT_CODE : SUCCESS_EXIT_CODE);
 369   /* NOTREACHED */
 370   return 0;
 371 }
 372
 373 /* Define this so we can link with print-rtl.o to get debug_rtx function.  */
 374 const char *
 375 get_insn_name (code)
 376      int code;
 377 {
 378   return NULL;
 379 }