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
  28 static struct obstack obstack;
  29 struct obstack *rtl_obstack = &obstack;
  30
  31 #define obstack_chunk_alloc xmalloc
  32 #define obstack_chunk_free free
  33
  34 /* Define this so we can link with print-rtl.o to get debug_rtx function.  */
  35 char **insn_name_ptr = 0;
  36
  37 /* flags to determine output of machine description dependent #define's.  */
  38 static int max_recog_operands;  /* Largest operand number seen.  */
  39 static int max_dup_operands;    /* Largest number of match_dup in any insn.  */
  40 static int max_clobbers_per_insn;
  41 static int register_constraint_flag;
  42 static int have_cc0_flag;
  43 static int have_cmove_flag;
  44 static int have_lo_sum_flag;
  45
  46 /* Maximum number of insns seen in a split.  */
  47 static int max_insns_per_split = 1;
  48
  49 static int clobbers_seen_this_insn;
  50 static int dup_operands_seen_this_insn;
  51
  52 void fatal PVPROTO ((const char *, ...))
  53   ATTRIBUTE_PRINTF_1 ATTRIBUTE_NORETURN;
  54
  55 static void walk_insn_part PROTO((rtx, int, int));
  56 static void gen_insn PROTO((rtx));
  57 static void gen_expand PROTO((rtx));
  58 static void gen_split PROTO((rtx));
  59 static void gen_peephole PROTO((rtx));
  60
  61 /* RECOG_P will be non-zero if this pattern was seen in a context where it will
  62    be used to recognize, rather than just generate an insn.
  63
  64    NON_PC_SET_SRC will be non-zero if this pattern was seen in a SET_SRC
  65    of a SET whose destination is not (pc).  */
  66
  67 static void
  68 walk_insn_part (part, recog_p, non_pc_set_src)
  69      rtx part;
  70      int recog_p;
  71      int non_pc_set_src;
  72 {
  73   register int i, j;
  74   register RTX_CODE code;
  75   register const char *format_ptr;
  76
  77   if (part == 0)
  78     return;
  79
  80   code = GET_CODE (part);
  81   switch (code)
  82     {
  83     case CLOBBER:
  84       clobbers_seen_this_insn++;
  85       break;
  86
  87     case MATCH_OPERAND:
  88       if (XINT (part, 0) > max_recog_operands)
  89         max_recog_operands = XINT (part, 0);
  90       if (XSTR (part, 2) && *XSTR (part, 2))
  91         register_constraint_flag = 1;
  92       return;
  93
  94     case MATCH_OP_DUP:
  95     case MATCH_PAR_DUP:
  96       ++dup_operands_seen_this_insn;
  97     case MATCH_SCRATCH:
  98     case MATCH_PARALLEL:
  99     case MATCH_OPERATOR:
 100       if (XINT (part, 0) > max_recog_operands)
 101         max_recog_operands = XINT (part, 0);
 102       /* Now scan the rtl's in the vector inside the MATCH_OPERATOR or
 103          MATCH_PARALLEL.  */
 104       break;
 105
 106     case LABEL_REF:
 107       if (GET_CODE (XEXP (part, 0)) == MATCH_OPERAND)
 108         break;
 109       return;
 110
 111     case MATCH_DUP:
 112       ++dup_operands_seen_this_insn;
 113       if (XINT (part, 0) > max_recog_operands)
 114         max_recog_operands = XINT (part, 0);
 115       return;
 116
 117     case CC0:
 118       if (recog_p)
 119         have_cc0_flag = 1;
 120       return;
 121
 122     case LO_SUM:
 123       if (recog_p)
 124         have_lo_sum_flag = 1;
 125       return;
 126
 127     case SET:
 128       walk_insn_part (SET_DEST (part), 0, recog_p);
 129       walk_insn_part (SET_SRC (part), recog_p,
 130                       GET_CODE (SET_DEST (part)) != PC);
 131       return;
 132
 133     case IF_THEN_ELSE:
 134       /* Only consider this machine as having a conditional move if the
 135          two arms of the IF_THEN_ELSE are both MATCH_OPERAND.  Otherwise,
 136          we have some specific IF_THEN_ELSE construct (like the doz
 137          instruction on the RS/6000) that can't be used in the general
 138          context we want it for.  */
 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       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 \f
 246 PTR
 247 xmalloc (size)
 248   size_t size;
 249 {
 250   register PTR val = (PTR) malloc (size);
 251
 252   if (val == 0)
 253     fatal ("virtual memory exhausted");
 254
 255   return val;
 256 }
 257
 258 PTR
 259 xrealloc (old, size)
 260   PTR old;
 261   size_t size;
 262 {
 263   register PTR ptr;
 264   if (old)
 265     ptr = (PTR) realloc (old, size);
 266   else
 267     ptr = (PTR) malloc (size);
 268   if (!ptr)
 269     fatal ("virtual memory exhausted");
 270   return ptr;
 271 }
 272
 273 void
 274 fatal VPROTO ((const char *format, ...))
 275 {
 276 #ifndef ANSI_PROTOTYPES
 277   const char *format;
 278 #endif
 279   va_list ap;
 280
 281   VA_START (ap, format);
 282
 283 #ifndef ANSI_PROTOTYPES
 284   format = va_arg (ap, const char *);
 285 #endif
 286
 287   fprintf (stderr, "genconfig: ");
 288   vfprintf (stderr, format, ap);
 289   va_end (ap);
 290   fprintf (stderr, "\n");
 291   exit (FATAL_EXIT_CODE);
 292 }
 293
 294 int
 295 main (argc, argv)
 296      int argc;
 297      char **argv;
 298 {
 299   rtx desc;
 300   FILE *infile;
 301   register int c;
 302
 303   obstack_init (rtl_obstack);
 304
 305   if (argc <= 1)
 306     fatal ("No input file name.");
 307
 308   infile = fopen (argv[1], "r");
 309   if (infile == 0)
 310     {
 311       perror (argv[1]);
 312       exit (FATAL_EXIT_CODE);
 313     }
 314
 315   init_rtl ();
 316
 317   printf ("/* Generated automatically by the program `genconfig'\n\
 318 from the machine description file `md'.  */\n\n");
 319
 320   /* Allow at least 10 operands for the sake of asm constructs.  */
 321   max_recog_operands = 9;  /* We will add 1 later.  */
 322   max_dup_operands = 1;
 323
 324   /* Read the machine description.  */
 325
 326   while (1)
 327     {
 328       c = read_skip_spaces (infile);
 329       if (c == EOF)
 330         break;
 331       ungetc (c, infile);
 332
 333       desc = read_rtx (infile);
 334       if (GET_CODE (desc) == DEFINE_INSN)
 335         gen_insn (desc);
 336       if (GET_CODE (desc) == DEFINE_EXPAND)
 337         gen_expand (desc);
 338       if (GET_CODE (desc) == DEFINE_SPLIT)
 339         gen_split (desc);
 340       if (GET_CODE (desc) == DEFINE_PEEPHOLE)
 341         gen_peephole (desc);
 342     }
 343
 344   printf ("\n#define MAX_RECOG_OPERANDS %d\n", max_recog_operands + 1);
 345
 346   printf ("\n#define MAX_DUP_OPERANDS %d\n", max_dup_operands);
 347
 348   /* This is conditionally defined, in case the user writes code which emits
 349      more splits than we can readily see (and knows s/he does it).  */
 350   printf ("#ifndef MAX_INSNS_PER_SPLIT\n#define MAX_INSNS_PER_SPLIT %d\n#endif\n",
 351           max_insns_per_split);
 352
 353   if (register_constraint_flag)
 354     printf ("#define REGISTER_CONSTRAINTS\n");
 355
 356   if (have_cc0_flag)
 357     printf ("#define HAVE_cc0\n");
 358
 359   if (have_cmove_flag)
 360     printf ("#define HAVE_conditional_move\n");
 361
 362   if (have_lo_sum_flag)
 363     printf ("#define HAVE_lo_sum\n");
 364
 365   fflush (stdout);
 366   exit (ferror (stdout) != 0 ? FATAL_EXIT_CODE : SUCCESS_EXIT_CODE);
 367   /* NOTREACHED */
 368   return 0;
 369 }