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 /* Define this so we can link with print-rtl.o to get debug_rtx function.  */
  36 char **insn_name_ptr = 0;
  37
  38 /* flags to determine output of machine description dependent #define's.  */
  39 static int max_recog_operands;  /* Largest operand number seen.  */
  40 static int max_dup_operands;    /* Largest number of match_dup in any insn.  */
  41 static int max_clobbers_per_insn;
  42 static int register_constraint_flag;
  43 static int have_cc0_flag;
  44 static int have_cmove_flag;
  45 static int have_lo_sum_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.  */
 137
 138       if (recog_p && non_pc_set_src
 139           && GET_CODE (XEXP (part, 1)) == MATCH_OPERAND
 140           && GET_CODE (XEXP (part, 2)) == MATCH_OPERAND)
 141         have_cmove_flag = 1;
 142       break;
 143
 144     case REG: case CONST_INT: case SYMBOL_REF:
 145     case PC:
 146       return;
 147
 148     default:
 149       break;
 150     }
 151
 152   format_ptr = GET_RTX_FORMAT (GET_CODE (part));
 153
 154   for (i = 0; i < GET_RTX_LENGTH (GET_CODE (part)); i++)
 155     switch (*format_ptr++)
 156       {
 157       case 'e':
 158       case 'u':
 159         walk_insn_part (XEXP (part, i), recog_p, non_pc_set_src);
 160         break;
 161       case 'E':
 162         if (XVEC (part, i) != NULL)
 163           for (j = 0; j < XVECLEN (part, i); j++)
 164             walk_insn_part (XVECEXP (part, i, j), recog_p, non_pc_set_src);
 165         break;
 166       }
 167 }
 168
 169 static void
 170 gen_insn (insn)
 171      rtx insn;
 172 {
 173   int i;
 174
 175   /* Walk the insn pattern to gather the #define's status.  */
 176   clobbers_seen_this_insn = 0;
 177   dup_operands_seen_this_insn = 0;
 178   if (XVEC (insn, 1) != 0)
 179     for (i = 0; i < XVECLEN (insn, 1); i++)
 180       walk_insn_part (XVECEXP (insn, 1, i), 1, 0);
 181
 182   if (clobbers_seen_this_insn > max_clobbers_per_insn)
 183     max_clobbers_per_insn = clobbers_seen_this_insn;
 184   if (dup_operands_seen_this_insn > max_dup_operands)
 185     max_dup_operands = dup_operands_seen_this_insn;
 186 }
 187
 188 /* Similar but scan a define_expand.  */
 189
 190 static void
 191 gen_expand (insn)
 192      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 (split)
 219      rtx split;
 220 {
 221   int i;
 222
 223   /* Look through the patterns that are matched
 224      to compute the maximum operand number.  */
 225   for (i = 0; i < XVECLEN (split, 0); i++)
 226     walk_insn_part (XVECEXP (split, 0, i), 1, 0);
 227   /* Look at the number of insns this insn could split into.  */
 228   if (XVECLEN (split, 2) > max_insns_per_split)
 229     max_insns_per_split = XVECLEN (split, 2);
 230 }
 231
 232 static void
 233 gen_peephole (peep)
 234      rtx peep;
 235 {
 236   int i;
 237
 238   /* Look through the patterns that are matched
 239      to compute the maximum operand number.  */
 240   for (i = 0; i < XVECLEN (peep, 0); i++)
 241     walk_insn_part (XVECEXP (peep, 0, i), 1, 0);
 242 }
 243 \f
 244 PTR
 245 xmalloc (size)
 246   size_t size;
 247 {
 248   register PTR val = (PTR) malloc (size);
 249
 250   if (val == 0)
 251     fatal ("virtual memory exhausted");
 252
 253   return val;
 254 }
 255
 256 PTR
 257 xrealloc (old, size)
 258   PTR old;
 259   size_t size;
 260 {
 261   register PTR ptr;
 262   if (old)
 263     ptr = (PTR) realloc (old, size);
 264   else
 265     ptr = (PTR) malloc (size);
 266   if (!ptr)
 267     fatal ("virtual memory exhausted");
 268   return ptr;
 269 }
 270
 271 int
 272 main (argc, argv)
 273      int argc;
 274      char **argv;
 275 {
 276   rtx desc;
 277   FILE *infile;
 278   register int c;
 279
 280   progname = "genconfig";
 281   obstack_init (rtl_obstack);
 282
 283   if (argc <= 1)
 284     fatal ("No input file name.");
 285
 286   infile = fopen (argv[1], "r");
 287   if (infile == 0)
 288     {
 289       perror (argv[1]);
 290       exit (FATAL_EXIT_CODE);
 291     }
 292
 293   init_rtl ();
 294
 295   printf ("/* Generated automatically by the program `genconfig'\n\
 296 from the machine description file `md'.  */\n\n");
 297
 298   /* Allow at least 10 operands for the sake of asm constructs.  */
 299   max_recog_operands = 9;  /* We will add 1 later.  */
 300   max_dup_operands = 1;
 301
 302   /* Read the machine description.  */
 303
 304   while (1)
 305     {
 306       c = read_skip_spaces (infile);
 307       if (c == EOF)
 308         break;
 309       ungetc (c, infile);
 310
 311       desc = read_rtx (infile);
 312       if (GET_CODE (desc) == DEFINE_INSN)
 313         gen_insn (desc);
 314       if (GET_CODE (desc) == DEFINE_EXPAND)
 315         gen_expand (desc);
 316       if (GET_CODE (desc) == DEFINE_SPLIT)
 317         gen_split (desc);
 318       if (GET_CODE (desc) == DEFINE_PEEPHOLE)
 319         gen_peephole (desc);
 320     }
 321
 322   printf ("\n#define MAX_RECOG_OPERANDS %d\n", max_recog_operands + 1);
 323
 324   printf ("\n#define MAX_DUP_OPERANDS %d\n", max_dup_operands);
 325
 326   /* This is conditionally defined, in case the user writes code which emits
 327      more splits than we can readily see (and knows s/he does it).  */
 328   printf ("#ifndef MAX_INSNS_PER_SPLIT\n#define MAX_INSNS_PER_SPLIT %d\n#endif\n",
 329           max_insns_per_split);
 330
 331   if (register_constraint_flag)
 332     printf ("#define REGISTER_CONSTRAINTS\n");
 333
 334   if (have_cc0_flag)
 335     printf ("#define HAVE_cc0\n");
 336
 337   if (have_cmove_flag)
 338     printf ("#define HAVE_conditional_move\n");
 339
 340   if (have_lo_sum_flag)
 341     printf ("#define HAVE_lo_sum\n");
 342
 343   fflush (stdout);
 344   exit (ferror (stdout) != 0 ? FATAL_EXIT_CODE : SUCCESS_EXIT_CODE);
 345   /* NOTREACHED */
 346   return 0;
 347 }