gcc/gensupport.c

   1 /* Read machine descriptions, return top level rtx for use by the
   2    various generation passes.
   3
   4    Copyright (C) 2000 Free Software Foundation, Inc.
   5
   6    This file is part of GNU CC.
   7
   8    GNU CC is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 2, or (at your option)
  11    any later version.
  12
  13    GNU CC is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with GNU CC; see the file COPYING.  If not, write to
  20    the Free Software Foundation, 59 Temple Place - Suite 330,
  21    Boston, MA 02111-1307, USA.  */
  22
  23 #include "hconfig.h"
  24 #include "system.h"
  25 #include "rtl.h"
  26 #include "errors.h"
  27 #include "gensupport.h"
  28
  29 static FILE *input_file;
  30
  31 static int sequence_num;
  32
  33 struct queue_elem {
  34     rtx data;
  35     struct queue_elem *next;
  36 };
  37
  38 static struct queue_elem *rtx_ready_queue;
  39
  40 /* Recursively remove constraints from an rtx.  */
  41
  42 static void
  43 remove_constraints (part)
  44      rtx part;
  45 {
  46   register int i, j;
  47   register const char *format_ptr;
  48
  49   if (part == 0)
  50     return;
  51
  52   if (GET_CODE (part) == MATCH_OPERAND)
  53     XSTR (part, 2) = "";
  54   else if (GET_CODE (part) == MATCH_SCRATCH)
  55     XSTR (part, 1) = "";
  56
  57   format_ptr = GET_RTX_FORMAT (GET_CODE (part));
  58
  59   for (i = 0; i < GET_RTX_LENGTH (GET_CODE (part)); i++)
  60     switch (*format_ptr++)
  61       {
  62       case 'e':
  63       case 'u':
  64         remove_constraints (XEXP (part, i));
  65         break;
  66       case 'E':
  67         if (XVEC (part, i) != NULL)
  68           for (j = 0; j < XVECLEN (part, i); j++)
  69             remove_constraints (XVECEXP (part, i, j));
  70         break;
  71       }
  72 }
  73
  74 /* Handle any synthetic top level rtx, i.e. anything except:
  75        DEFINE_INSN
  76        DEFINE_EXPAND
  77        DEFINE_SPLIT
  78        DEFINE_PEEPHOLE
  79        DEFINE_PEEPHOLE2
  80        DEFINE_ATTRIBUTE
  81        DEFINE_FUNCTION_UNIT
  82        DEFINE_ASM_ATTRIBUTES */
  83
  84 static void
  85 process_rtx (desc)
  86     rtx* desc;
  87 {
  88   if (GET_CODE (*desc) == DEFINE_INSN_AND_SPLIT)
  89     {
  90       struct queue_elem* elem = xmalloc (sizeof (struct queue_elem));
  91       const char *split_cond;
  92
  93       /* Create a split with values from the insn_and_split. */
  94       rtx split = rtx_alloc (DEFINE_SPLIT);
  95       XVEC (split, 0) = copy_rtx (XVEC (*desc, 1));
  96       remove_constraints (XVEC (split, 0));
  97       split_cond = XSTR (split, 1) = XSTR (*desc, 4);
  98
  99       /* If the split condition starts with "&&", append it to the
 100          insn condition to create the new split condition.  */
 101       if (split_cond[0] == '&' && split_cond[1] == '&')
 102         {
 103         const char *insn_cond = XSTR (*desc, 2);
 104         char *combined =
 105             xmalloc (strlen (insn_cond) + strlen (split_cond) + 1);
 106         strcpy (combined, insn_cond);
 107         strcat (combined, split_cond);
 108         XSTR (split, 1) = combined;
 109         }
 110
 111       XVEC (split, 2) = XVEC (*desc, 5);
 112       XSTR (split, 3) = XSTR (*desc, 6);
 113
 114       /* Fix up the DEFINE_INSN.  */
 115       PUT_CODE (*desc, DEFINE_INSN);
 116       XVEC (*desc, 4) = XSTR (*desc, 7);
 117
 118       /* Return the DEFINE_INSN part, and put the DEFINE_SPLIT
 119          in the queue.  */
 120       elem->next = rtx_ready_queue;
 121       elem->data = split;
 122       rtx_ready_queue = elem;
 123     }
 124 }
 125
 126 /* The entry point for initializing the reader.  */
 127
 128 int
 129 init_md_reader (filename)
 130     const char *filename;
 131 {
 132
 133   input_file = fopen (filename, "r");
 134
 135   if (input_file == 0)
 136     {
 137       perror (filename);
 138       return FATAL_EXIT_CODE;
 139     }
 140
 141   read_rtx_filename = filename;
 142   sequence_num = 0;
 143   rtx_ready_queue = NULL;
 144
 145   return SUCCESS_EXIT_CODE;
 146 }
 147
 148
 149 /* The entry point for reading a single rtx from an md file.  */
 150
 151 rtx
 152 read_md_rtx (lineno, seqnr)
 153     int *lineno;
 154     int *seqnr;
 155 {
 156   rtx desc;
 157
 158   if (rtx_ready_queue != NULL)
 159     {
 160       desc = rtx_ready_queue->data;
 161       rtx_ready_queue = rtx_ready_queue->next;
 162     }
 163   else
 164     {
 165       int c;
 166       c = read_skip_spaces (input_file);
 167       if (c == EOF)
 168         return NULL;
 169
 170       ungetc (c, input_file);
 171       desc = read_rtx (input_file);
 172       process_rtx (&desc);
 173     }
 174   *lineno = read_rtx_lineno;
 175   *seqnr = sequence_num;
 176   switch (GET_CODE (desc))
 177     {
 178       case DEFINE_INSN:
 179       case DEFINE_EXPAND:
 180       case DEFINE_SPLIT:
 181       case DEFINE_PEEPHOLE:
 182       case DEFINE_PEEPHOLE2:
 183         sequence_num++;
 184         break;
 185
 186       default:
 187         break;
 188     }
 189
 190   return desc;
 191 }