File:  [gforth] / gforth / engine / peephole.c
Revision 1.5: download - view: text, annotated - select for diffs
Fri Jun 15 16:09:15 2001 UTC (20 years, 5 months ago) by ak042
Branches: MAIN
CVS tags: HEAD
revert all 2001/05/28 changes.

    1: /* Peephole optimization routines and tables
    2: 
    3:   Copyright (C) 2001 Free Software Foundation, Inc.
    4: 
    5:   This file is part of Gforth.
    6: 
    7:   Gforth is free software; you can redistribute it and/or
    8:   modify it under the terms of the GNU General Public License
    9:   as published by the Free Software Foundation; either version 2
   10:   of the License, or (at your option) any later version.
   11: 
   12:   This program 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 this program; if not, write to the Free Software
   19:   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
   20: */
   21: 
   22: #include "config.h"
   23: #include "forth.h"
   24: #include <stdlib.h>
   25: #include <string.h>
   26: #include <assert.h>
   27: 
   28: /* the numbers in this struct are primitive indices */
   29: typedef struct Combination {
   30:   int prefix;
   31:   int lastprim;
   32:   int combination_prim;
   33: } Combination;
   34: 
   35: Combination peephole_table[] = {
   36: #include "peephole.i"
   37: };
   38: 
   39: int use_super = 1;
   40: 
   41: typedef Xt Inst;
   42: 
   43: typedef struct Peeptable_entry {
   44:   struct Peeptable_entry *next;
   45:   Inst prefix;
   46:   Inst lastprim;
   47:   Inst combination_prim;
   48: } Peeptable_entry;
   49: 
   50: #define HASH_SIZE 1024
   51: #define hash(_i1,_i2) (((((Cell)(_i1))^((Cell)(_i2)))>>4)&(HASH_SIZE-1))
   52: 
   53: Cell peeptable;
   54: 
   55: Cell prepare_peephole_table(Inst insts[])
   56: {
   57:   Cell i;
   58:   Peeptable_entry **pt = (Peeptable_entry **)calloc(HASH_SIZE,sizeof(Peeptable_entry *));
   59: 
   60:   for (i=0; i<sizeof(peephole_table)/sizeof(peephole_table[0]); i++) {
   61:     Combination *c = &peephole_table[i];
   62:     Peeptable_entry *p = (Peeptable_entry *)malloc(sizeof(Peeptable_entry));
   63:     Cell h;
   64:     p->prefix =           insts[c->prefix];
   65:     p->lastprim =         insts[c->lastprim];
   66:     p->combination_prim = insts[c->combination_prim];
   67:     h = hash(p->prefix,p->lastprim);
   68:     p->next = pt[h];
   69:     pt[h] = p;
   70:   }
   71:   return (Cell)pt;
   72: }
   73: 
   74: Inst peephole_opt(Inst inst1, Inst inst2, Cell peeptable)
   75: {
   76:   Peeptable_entry **pt = (Peeptable_entry **)peeptable;
   77:   Peeptable_entry *p;
   78: 
   79:   if (use_super == 0)
   80:       return 0;
   81:   for (p = pt[hash(inst1,inst2)]; p != NULL; p = p->next)
   82:     if (inst1 == p->prefix && inst2 == p->lastprim)
   83:       return p->combination_prim;
   84:   return NULL;
   85: }

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