gcc/genconfig.c

   1 /* Generate from machine description:
   2    - some #define configuration flags.
   3    Copyright (C) 1987, 1991, 1997, 1998 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 #ifdef __STDC__
  25 #include <stdarg.h>
  26 #else
  27 #include <varargs.h>
  28 #endif
  29 #include "system.h"
  30 #include "rtl.h"
  31 #include "obstack.h"
  32
  33 static struct obstack obstack;
  34 struct obstack *rtl_obstack = &obstack;
  35
  36 #define obstack_chunk_alloc xmalloc
  37 #define obstack_chunk_free free
  38
  39 /* Define this so we can link with print-rtl.o to get debug_rtx function.  */
  40 char **insn_name_ptr = 0;
  41
  42 /* flags to determine output of machine description dependent #define's.  */
  43 static int max_recog_operands;  /* Largest operand number seen.  */
  44 static int max_dup_operands;    /* Largest number of match_dup in any insn.  */
  45 static int max_clobbers_per_insn;
  46 static int register_constraint_flag;
  47 static int have_cc0_flag;
  48 static int have_cmove_flag;
  49 static int have_lo_sum_flag;
  50
  51 /* Maximum number of insns seen in a split.  */
  52 static int max_insns_per_split = 1;
  53
  54 static int clobbers_seen_this_insn;
  55 static int dup_operands_seen_this_insn;
  56
  57 char *xmalloc PROTO((unsigned));
  58 static void fatal PVPROTO ((char *, ...)) ATTRIBUTE_PRINTF_1;
  59 void fancy_abort PROTO((void));
  60
  61 static void walk_insn_part PROTO((rtx, int, int));
  62 static void gen_insn PROTO((rtx));
  63 static void gen_expand PROTO((rtx));
  64 static void gen_split PROTO((rtx));
  65 static void gen_peephole PROTO((rtx));
  66
  67 /* RECOG_P will be non-zero if this pattern was seen in a context where it will
  68    be used to recognize, rather than just generate an insn.
  69
  70    NON_PC_SET_SRC will be non-zero if this pattern was seen in a SET_SRC
  71    of a SET whose destination is not (pc).  */
  72
  73 static void
  74 walk_insn_part (part, recog_p, non_pc_set_src)
  75      rtx part;
  76      int recog_p;
  77      int non_pc_set_src;
  78 {
  79   register int i, j;
  80   register RTX_CODE code;
  81   register char *format_ptr;
  82
  83   if (part == 0)
  84     return;
  85
  86   code = GET_CODE (part);
  87   switch (code)
  88     {
  89     case CLOBBER:
  90       clobbers_seen_this_insn++;
  91       break;
  92
  93     case MATCH_OPERAND:
  94       if (XINT (part, 0) > max_recog_operands)
  95         max_recog_operands = XINT (part, 0);
  96       if (XSTR (part, 2) && *XSTR (part, 2))
  97         register_constraint_flag = 1;
  98       return;
  99
 100     case MATCH_OP_DUP:
 101     case MATCH_PAR_DUP:
 102       ++dup_operands_seen_this_insn;
 103     case MATCH_SCRATCH:
 104     case MATCH_PARALLEL:
 105     case MATCH_OPERATOR:
 106       if (XINT (part, 0) > max_recog_operands)
 107         max_recog_operands = XINT (part, 0);
 108       /* Now scan the rtl's in the vector inside the MATCH_OPERATOR or
 109          MATCH_PARALLEL.  */
 110       break;
 111
 112     case LABEL_REF:
 113       if (GET_CODE (XEXP (part, 0)) == MATCH_OPERAND)
 114         break;
 115       return;
 116
 117     case MATCH_DUP:
 118       ++dup_operands_seen_this_insn;
 119       if (XINT (part, 0) > max_recog_operands)
 120         max_recog_operands = XINT (part, 0);
 121       return;
 122
 123     case CC0:
 124       if (recog_p)
 125         have_cc0_flag = 1;
 126       return;
 127
 128     case LO_SUM:
 129       if (recog_p)
 130         have_lo_sum_flag = 1;
 131       return;
 132
 133     case SET:
 134       walk_insn_part (SET_DEST (part), 0, recog_p);
 135       walk_insn_part (SET_SRC (part), recog_p,
 136                       GET_CODE (SET_DEST (part)) != PC);
 137       return;
 138
 139     case IF_THEN_ELSE:
 140       /* Only consider this machine as having a conditional move if the
 141          two arms of the IF_THEN_ELSE are both MATCH_OPERAND.  Otherwise,
 142          we have some specific IF_THEN_ELSE construct (like the doz
 143          instruction on the RS/6000) that can't be used in the general
 144          context we want it for.  */
 145
 146       if (recog_p && non_pc_set_src
 147           && GET_CODE (XEXP (part, 1)) == MATCH_OPERAND
 148           && GET_CODE (XEXP (part, 2)) == MATCH_OPERAND)
 149         have_cmove_flag = 1;
 150       break;
 151
 152     case REG: case CONST_INT: case SYMBOL_REF:
 153     case PC:
 154       return;
 155
 156     default:
 157       break;
 158     }
 159
 160   format_ptr = GET_RTX_FORMAT (GET_CODE (part));
 161
 162   for (i = 0; i < GET_RTX_LENGTH (GET_CODE (part)); i++)
 163     switch (*format_ptr++)
 164       {
 165       case 'e':
 166       case 'u':
 167         walk_insn_part (XEXP (part, i), recog_p, non_pc_set_src);
 168         break;
 169       case 'E':
 170         if (XVEC (part, i) != NULL)
 171           for (j = 0; j < XVECLEN (part, i); j++)
 172             walk_insn_part (XVECEXP (part, i, j), recog_p, non_pc_set_src);
 173         break;
 174       }
 175 }
 176
 177 static void
 178 gen_insn (insn)
 179      rtx insn;
 180 {
 181   int i;
 182
 183   /* Walk the insn pattern to gather the #define's status.  */
 184   clobbers_seen_this_insn = 0;
 185   dup_operands_seen_this_insn = 0;
 186   if (XVEC (insn, 1) != 0)
 187     for (i = 0; i < XVECLEN (insn, 1); i++)
 188       walk_insn_part (XVECEXP (insn, 1, i), 1, 0);
 189
 190   if (clobbers_seen_this_insn > max_clobbers_per_insn)
 191     max_clobbers_per_insn = clobbers_seen_this_insn;
 192   if (dup_operands_seen_this_insn > max_dup_operands)
 193     max_dup_operands = dup_operands_seen_this_insn;
 194 }
 195
 196 /* Similar but scan a define_expand.  */
 197
 198 static void
 199 gen_expand (insn)
 200      rtx insn;
 201 {
 202   int i;
 203
 204   /* Walk the insn pattern to gather the #define's status.  */
 205
 206   /* Note that we don't bother recording the number of MATCH_DUPs
 207      that occur in a gen_expand, because only reload cares about that.  */
 208   if (XVEC (insn, 1) != 0)
 209     for (i = 0; i < XVECLEN (insn, 1); i++)
 210       {
 211         /* Compute the maximum SETs and CLOBBERS
 212            in any one of the sub-insns;
 213            don't sum across all of them.  */
 214         clobbers_seen_this_insn = 0;
 215
 216         walk_insn_part (XVECEXP (insn, 1, i), 0, 0);
 217
 218         if (clobbers_seen_this_insn > max_clobbers_per_insn)
 219           max_clobbers_per_insn = clobbers_seen_this_insn;
 220       }
 221 }
 222
 223 /* Similar but scan a define_split.  */
 224
 225 static void
 226 gen_split (split)
 227      rtx split;
 228 {
 229   int i;
 230
 231   /* Look through the patterns that are matched
 232      to compute the maximum operand number.  */
 233   for (i = 0; i < XVECLEN (split, 0); i++)
 234     walk_insn_part (XVECEXP (split, 0, i), 1, 0);
 235   /* Look at the number of insns this insn could split into.  */
 236   if (XVECLEN (split, 2) > max_insns_per_split)
 237     max_insns_per_split = XVECLEN (split, 2);
 238 }
 239
 240 static void
 241 gen_peephole (peep)
 242      rtx peep;
 243 {
 244   int i;
 245
 246   /* Look through the patterns that are matched
 247      to compute the maximum operand number.  */
 248   for (i = 0; i < XVECLEN (peep, 0); i++)
 249     walk_insn_part (XVECEXP (peep, 0, i), 1, 0);
 250 }
 251 \f
 252 char *
 253 xmalloc (size)
 254      unsigned size;
 255 {
 256   register char *val = (char *) malloc (size);
 257
 258   if (val == 0)
 259     fatal ("virtual memory exhausted");
 260
 261   return val;
 262 }
 263
 264 char *
 265 xrealloc (ptr, size)
 266      char *ptr;
 267      unsigned size;
 268 {
 269   char *result = (char *) realloc (ptr, size);
 270   if (!result)
 271     fatal ("virtual memory exhausted");
 272   return result;
 273 }
 274
 275 static void
 276 fatal VPROTO ((char *format, ...))
 277 {
 278 #ifndef __STDC__
 279   char *format;
 280 #endif
 281   va_list ap;
 282
 283   VA_START (ap, format);
 284
 285 #ifndef __STDC__
 286   format = va_arg (ap, char *);
 287 #endif
 288
 289   fprintf (stderr, "genconfig: ");
 290   vfprintf (stderr, format, ap);
 291   va_end (ap);
 292   fprintf (stderr, "\n");
 293   exit (FATAL_EXIT_CODE);
 294 }
 295
 296 /* More 'friendly' abort that prints the line and file.
 297    config.h can #define abort fancy_abort if you like that sort of thing.  */
 298
 299 void
 300 fancy_abort ()
 301 {
 302   fatal ("Internal gcc abort.");
 303 }
 304 \f
 305 int
 306 main (argc, argv)
 307      int argc;
 308      char **argv;
 309 {
 310   rtx desc;
 311   FILE *infile;
 312   register int c;
 313
 314   obstack_init (rtl_obstack);
 315
 316   if (argc <= 1)
 317     fatal ("No input file name.");
 318
 319   infile = fopen (argv[1], "r");
 320   if (infile == 0)
 321     {
 322       perror (argv[1]);
 323       exit (FATAL_EXIT_CODE);
 324     }
 325
 326   init_rtl ();
 327
 328   printf ("/* Generated automatically by the program `genconfig'\n\
 329 from the machine description file `md'.  */\n\n");
 330
 331   /* Allow at least 10 operands for the sake of asm constructs.  */
 332   max_recog_operands = 9;  /* We will add 1 later.  */
 333   max_dup_operands = 1;
 334
 335   /* Read the machine description.  */
 336
 337   while (1)
 338     {
 339       c = read_skip_spaces (infile);
 340       if (c == EOF)
 341         break;
 342       ungetc (c, infile);
 343
 344       desc = read_rtx (infile);
 345       if (GET_CODE (desc) == DEFINE_INSN)
 346         gen_insn (desc);
 347       if (GET_CODE (desc) == DEFINE_EXPAND)
 348         gen_expand (desc);
 349       if (GET_CODE (desc) == DEFINE_SPLIT)
 350         gen_split (desc);
 351       if (GET_CODE (desc) == DEFINE_PEEPHOLE)
 352         gen_peephole (desc);
 353     }
 354
 355   printf ("\n#define MAX_RECOG_OPERANDS %d\n", max_recog_operands + 1);
 356
 357   printf ("\n#define MAX_DUP_OPERANDS %d\n", max_dup_operands);
 358
 359   /* This is conditionally defined, in case the user writes code which emits
 360      more splits than we can readily see (and knows s/he does it).  */
 361   printf ("#ifndef MAX_INSNS_PER_SPLIT\n#define MAX_INSNS_PER_SPLIT %d\n#endif\n",
 362           max_insns_per_split);
 363
 364   if (register_constraint_flag)
 365     printf ("#define REGISTER_CONSTRAINTS\n");
 366
 367   if (have_cc0_flag)
 368     printf ("#define HAVE_cc0\n");
 369
 370   if (have_cmove_flag)
 371     printf ("#define HAVE_conditional_move\n");
 372
 373   if (have_lo_sum_flag)
 374     printf ("#define HAVE_lo_sum\n");
 375
 376   fflush (stdout);
 377   exit (ferror (stdout) != 0 ? FATAL_EXIT_CODE : SUCCESS_EXIT_CODE);
 378   /* NOTREACHED */
 379   return 0;
 380 }