gcc/genconfig.c

   1 /* Generate from machine description:
   2    - some #define configuration flags.
   3    Copyright (C) 1987-2013 Free Software Foundation, Inc.
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify it under
   8 the terms of the GNU General Public License as published by the Free
   9 Software Foundation; either version 3, or (at your option) any later
  10 version.
  11
  12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15 for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GCC; see the file COPYING3.  If not see
  19 <http://www.gnu.org/licenses/>.  */
  20
  21
  22 #include "bconfig.h"
  23 #include "system.h"
  24 #include "coretypes.h"
  25 #include "tm.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 (rtx, int, int);
  52 static void gen_insn (rtx);
  53 static void gen_expand (rtx);
  54 static void gen_split (rtx);
  55 static void gen_peephole (rtx);
  56 static void gen_peephole2 (rtx);
  57
  58 /* RECOG_P will be nonzero 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 nonzero 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 (rtx part, int recog_p, int non_pc_set_src)
  66 {
  67   int i, j;
  68   RTX_CODE code;
  69   const char *format_ptr;
  70
  71   if (part == 0)
  72     return;
  73
  74   code = GET_CODE (part);
  75   switch (code)
  76     {
  77     case CLOBBER:
  78       clobbers_seen_this_insn++;
  79       break;
  80
  81     case MATCH_OPERAND:
  82       if (XINT (part, 0) > max_recog_operands)
  83         max_recog_operands = XINT (part, 0);
  84       return;
  85
  86     case MATCH_OP_DUP:
  87     case MATCH_PAR_DUP:
  88       ++dup_operands_seen_this_insn;
  89     case MATCH_SCRATCH:
  90     case MATCH_PARALLEL:
  91     case MATCH_OPERATOR:
  92       if (XINT (part, 0) > max_recog_operands)
  93         max_recog_operands = XINT (part, 0);
  94       /* Now scan the rtl's in the vector inside the MATCH_OPERATOR or
  95          MATCH_PARALLEL.  */
  96       break;
  97
  98     case LABEL_REF:
  99       if (GET_CODE (XEXP (part, 0)) == MATCH_OPERAND
 100           || GET_CODE (XEXP (part, 0)) == MATCH_DUP)
 101         break;
 102       return;
 103
 104     case MATCH_DUP:
 105       ++dup_operands_seen_this_insn;
 106       if (XINT (part, 0) > max_recog_operands)
 107         max_recog_operands = XINT (part, 0);
 108       return;
 109
 110     case CC0:
 111       if (recog_p)
 112         have_cc0_flag = 1;
 113       return;
 114
 115     case LO_SUM:
 116       if (recog_p)
 117         have_lo_sum_flag = 1;
 118       return;
 119
 120     case SET:
 121       walk_insn_part (SET_DEST (part), 0, recog_p);
 122       walk_insn_part (SET_SRC (part), recog_p,
 123                       GET_CODE (SET_DEST (part)) != PC);
 124       return;
 125
 126     case IF_THEN_ELSE:
 127       /* Only consider this machine as having a conditional move if the
 128          two arms of the IF_THEN_ELSE are both MATCH_OPERAND.  Otherwise,
 129          we have some specific IF_THEN_ELSE construct (like the doz
 130          instruction on the RS/6000) that can't be used in the general
 131          context we want it for.  */
 132
 133       if (recog_p && non_pc_set_src
 134           && GET_CODE (XEXP (part, 1)) == MATCH_OPERAND
 135           && GET_CODE (XEXP (part, 2)) == MATCH_OPERAND)
 136         have_cmove_flag = 1;
 137       break;
 138
 139     case COND_EXEC:
 140       if (recog_p)
 141         have_cond_exec_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 (rtx insn)
 171 {
 172   int i;
 173
 174   /* Walk the insn pattern to gather the #define's status.  */
 175   clobbers_seen_this_insn = 0;
 176   dup_operands_seen_this_insn = 0;
 177   if (XVEC (insn, 1) != 0)
 178     for (i = 0; i < XVECLEN (insn, 1); i++)
 179       walk_insn_part (XVECEXP (insn, 1, i), 1, 0);
 180
 181   if (clobbers_seen_this_insn > max_clobbers_per_insn)
 182     max_clobbers_per_insn = clobbers_seen_this_insn;
 183   if (dup_operands_seen_this_insn > max_dup_operands)
 184     max_dup_operands = dup_operands_seen_this_insn;
 185 }
 186
 187 /* Similar but scan a define_expand.  */
 188
 189 static void
 190 gen_expand (rtx insn)
 191 {
 192   int i;
 193
 194   /* Walk the insn pattern to gather the #define's status.  */
 195
 196   /* Note that we don't bother recording the number of MATCH_DUPs
 197      that occur in a gen_expand, because only reload cares about that.  */
 198   if (XVEC (insn, 1) != 0)
 199     for (i = 0; i < XVECLEN (insn, 1); i++)
 200       {
 201         /* Compute the maximum SETs and CLOBBERS
 202            in any one of the sub-insns;
 203            don't sum across all of them.  */
 204         clobbers_seen_this_insn = 0;
 205
 206         walk_insn_part (XVECEXP (insn, 1, i), 0, 0);
 207
 208         if (clobbers_seen_this_insn > max_clobbers_per_insn)
 209           max_clobbers_per_insn = clobbers_seen_this_insn;
 210       }
 211 }
 212
 213 /* Similar but scan a define_split.  */
 214
 215 static void
 216 gen_split (rtx split)
 217 {
 218   int i;
 219
 220   /* Look through the patterns that are matched
 221      to compute the maximum operand number.  */
 222   for (i = 0; i < XVECLEN (split, 0); i++)
 223     walk_insn_part (XVECEXP (split, 0, i), 1, 0);
 224   /* Look at the number of insns this insn could split into.  */
 225   if (XVECLEN (split, 2) > max_insns_per_split)
 226     max_insns_per_split = XVECLEN (split, 2);
 227 }
 228
 229 static void
 230 gen_peephole (rtx peep)
 231 {
 232   int i;
 233
 234   /* Look through the patterns that are matched
 235      to compute the maximum operand number.  */
 236   for (i = 0; i < XVECLEN (peep, 0); i++)
 237     walk_insn_part (XVECEXP (peep, 0, i), 1, 0);
 238 }
 239
 240 static void
 241 gen_peephole2 (rtx peep)
 242 {
 243   int i, n;
 244
 245   /* Look through the patterns that are matched
 246      to compute the maximum operand number.  */
 247   for (i = XVECLEN (peep, 0) - 1; i >= 0; --i)
 248     walk_insn_part (XVECEXP (peep, 0, i), 1, 0);
 249
 250   /* Look at the number of insns this insn can be matched from.  */
 251   for (i = XVECLEN (peep, 0) - 1, n = 0; i >= 0; --i)
 252     if (GET_CODE (XVECEXP (peep, 0, i)) != MATCH_DUP
 253         && GET_CODE (XVECEXP (peep, 0, i)) != MATCH_SCRATCH)
 254       n++;
 255   if (n > max_insns_per_peep2)
 256     max_insns_per_peep2 = n;
 257 }
 258
 259 int
 260 main (int argc, char **argv)
 261 {
 262   rtx desc;
 263
 264   progname = "genconfig";
 265
 266   if (!init_rtx_reader_args (argc, argv))
 267     return (FATAL_EXIT_CODE);
 268
 269   puts ("/* Generated automatically by the program `genconfig'");
 270   puts ("   from the machine description file `md'.  */\n");
 271   puts ("#ifndef GCC_INSN_CONFIG_H");
 272   puts ("#define GCC_INSN_CONFIG_H\n");
 273
 274   /* Allow at least 30 operands for the sake of asm constructs.  */
 275   /* ??? We *really* ought to reorganize things such that there
 276      is no fixed upper bound.  */
 277   max_recog_operands = 29;  /* We will add 1 later.  */
 278   max_dup_operands = 1;
 279
 280   /* Read the machine description.  */
 281
 282   while (1)
 283     {
 284       int line_no, insn_code_number = 0;
 285
 286       desc = read_md_rtx (&line_no, &insn_code_number);
 287       if (desc == NULL)
 288         break;
 289
 290       switch (GET_CODE (desc))
 291         {
 292           case DEFINE_INSN:
 293             gen_insn (desc);
 294             break;
 295
 296           case DEFINE_EXPAND:
 297             gen_expand (desc);
 298             break;
 299
 300           case DEFINE_SPLIT:
 301             gen_split (desc);
 302             break;
 303
 304           case DEFINE_PEEPHOLE2:
 305             have_peephole2_flag = 1;
 306             gen_peephole2 (desc);
 307             break;
 308
 309           case DEFINE_PEEPHOLE:
 310             have_peephole_flag = 1;
 311             gen_peephole (desc);
 312             break;
 313
 314           default:
 315             break;
 316         }
 317     }
 318
 319   printf ("#define MAX_RECOG_OPERANDS %d\n", max_recog_operands + 1);
 320   printf ("#define MAX_DUP_OPERANDS %d\n", max_dup_operands);
 321
 322   /* This is conditionally defined, in case the user writes code which emits
 323      more splits than we can readily see (and knows s/he does it).  */
 324   printf ("#ifndef MAX_INSNS_PER_SPLIT\n");
 325   printf ("#define MAX_INSNS_PER_SPLIT %d\n", max_insns_per_split);
 326   printf ("#endif\n");
 327
 328   if (have_cc0_flag)
 329     {
 330       printf ("#define HAVE_cc0 1\n");
 331       printf ("#define CC0_P(X) ((X) == cc0_rtx)\n");
 332     }
 333   else
 334     {
 335       /* We output CC0_P this way to make sure that X is declared
 336          somewhere.  */
 337       printf ("#define CC0_P(X) ((X) ? 0 : 0)\n");
 338     }
 339
 340   if (have_cmove_flag)
 341     printf ("#define HAVE_conditional_move 1\n");
 342
 343   if (have_cond_exec_flag)
 344     printf ("#define HAVE_conditional_execution 1\n");
 345
 346   if (have_lo_sum_flag)
 347     printf ("#define HAVE_lo_sum 1\n");
 348
 349   if (have_peephole_flag)
 350     printf ("#define HAVE_peephole 1\n");
 351
 352   if (have_peephole2_flag)
 353     {
 354       printf ("#define HAVE_peephole2 1\n");
 355       printf ("#define MAX_INSNS_PER_PEEP2 %d\n", max_insns_per_peep2);
 356     }
 357
 358   puts ("\n#endif /* GCC_INSN_CONFIG_H */");
 359
 360   if (ferror (stdout) || fflush (stdout) || fclose (stdout))
 361     return FATAL_EXIT_CODE;
 362
 363   return SUCCESS_EXIT_CODE;
 364 }