Annotation of gforth/engine/peephole.c, revision 1.6
1.1 anton 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"
1.2 anton 24: #include <stdlib.h>
1.4 ak042 25: #include <string.h>
26: #include <assert.h>
1.1 anton 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:
1.6 ! anton 39: #ifdef PRINT_SUPER_LENGTHS
! 40: char *prim_names[] = {
! 41: #include "prim_names.i"
! 42: };
! 43:
! 44: Combination *find_super(Cell prim)
! 45: {
! 46: Cell i;
! 47:
! 48: for (i=0; i<sizeof(peephole_table)/sizeof(peephole_table[0]); i++) {
! 49: if (peephole_table[i].combination_prim == prim)
! 50: return &peephole_table[i];
! 51: }
! 52: return NULL;
! 53: }
! 54:
! 55: Cell sum_length(Cell prim)
! 56: {
! 57: Combination *super=find_super(prim);
! 58:
! 59: if (super)
! 60: return sum_length(super->prefix)+prim_length(super->lastprim);
! 61: else
! 62: return prim_length(prim);
! 63: }
! 64:
! 65: void print_prim(Cell prim)
! 66: {
! 67: fprintf(stderr, "%s", prim_names[prim]);
! 68: }
! 69:
! 70: void print_super(Cell prim)
! 71: {
! 72: Combination *super=find_super(prim);
! 73:
! 74: if (super) {
! 75: print_super(super->prefix);
! 76: fprintf(stderr, " ");
! 77: print_prim(super->lastprim);
! 78: } else {
! 79: print_prim(prim);
! 80: }
! 81: }
! 82:
! 83: void print_super_lengths()
! 84: {
! 85: Cell i;
! 86:
! 87: for (i=0; i<sizeof(peephole_table)/sizeof(peephole_table[0]); i++) {
! 88: Cell super_length = prim_length(peephole_table[i].combination_prim);
! 89: Cell sum_super_length = sum_length(peephole_table[i].combination_prim);
! 90:
! 91: fprintf(stderr, "%6.4f %3d %3d ", ((double)super_length)/sum_super_length,
! 92: super_length, sum_super_length);
! 93: print_super(peephole_table[i].combination_prim);
! 94: fprintf(stderr,"\n");
! 95: }
! 96: }
! 97: #endif
! 98:
1.3 anton 99: int use_super = 1;
100:
101: typedef Xt Inst;
1.1 anton 102:
1.3 anton 103: typedef struct Peeptable_entry {
104: struct Peeptable_entry *next;
105: Inst prefix;
106: Inst lastprim;
107: Inst combination_prim;
108: } Peeptable_entry;
1.1 anton 109:
1.3 anton 110: #define HASH_SIZE 1024
111: #define hash(_i1,_i2) (((((Cell)(_i1))^((Cell)(_i2)))>>4)&(HASH_SIZE-1))
1.1 anton 112:
1.3 anton 113: Cell peeptable;
1.1 anton 114:
1.3 anton 115: Cell prepare_peephole_table(Inst insts[])
1.1 anton 116: {
117: Cell i;
1.3 anton 118: Peeptable_entry **pt = (Peeptable_entry **)calloc(HASH_SIZE,sizeof(Peeptable_entry *));
1.1 anton 119:
1.3 anton 120: for (i=0; i<sizeof(peephole_table)/sizeof(peephole_table[0]); i++) {
1.1 anton 121: Combination *c = &peephole_table[i];
1.3 anton 122: Peeptable_entry *p = (Peeptable_entry *)malloc(sizeof(Peeptable_entry));
123: Cell h;
124: p->prefix = insts[c->prefix];
125: p->lastprim = insts[c->lastprim];
126: p->combination_prim = insts[c->combination_prim];
127: h = hash(p->prefix,p->lastprim);
128: p->next = pt[h];
129: pt[h] = p;
1.1 anton 130: }
1.3 anton 131: return (Cell)pt;
132: }
133:
134: Inst peephole_opt(Inst inst1, Inst inst2, Cell peeptable)
135: {
136: Peeptable_entry **pt = (Peeptable_entry **)peeptable;
137: Peeptable_entry *p;
138:
139: if (use_super == 0)
140: return 0;
141: for (p = pt[hash(inst1,inst2)]; p != NULL; p = p->next)
142: if (inst1 == p->prefix && inst2 == p->lastprim)
143: return p->combination_prim;
144: return NULL;
1.1 anton 145: }
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