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:
26: /* the numbers in this struct are primitive indices */
27: typedef struct Combination {
28: int prefix;
29: int lastprim;
30: int combination_prim;
31: } Combination;
32:
33: Combination peephole_table[] = {
34: #include "peephole.i"
35: };
36:
37: int use_super = 1;
38:
39: typedef Xt Inst;
40:
41: typedef struct Peeptable_entry {
42: struct Peeptable_entry *next;
43: Inst prefix;
44: Inst lastprim;
45: Inst combination_prim;
46: } Peeptable_entry;
47:
48: #define HASH_SIZE 1024
49: #define hash(_i1,_i2) (((((Cell)(_i1))^((Cell)(_i2)))>>4)&(HASH_SIZE-1))
50:
51: Cell peeptable;
52:
53: Cell prepare_peephole_table(Inst insts[])
54: {
55: Cell i;
56: Peeptable_entry **pt = (Peeptable_entry **)calloc(HASH_SIZE,sizeof(Peeptable_entry *));
57:
58: for (i=0; i<sizeof(peephole_table)/sizeof(peephole_table[0]); i++) {
59: Combination *c = &peephole_table[i];
60: Peeptable_entry *p = (Peeptable_entry *)malloc(sizeof(Peeptable_entry));
61: Cell h;
62: p->prefix = insts[c->prefix];
63: p->lastprim = insts[c->lastprim];
64: p->combination_prim = insts[c->combination_prim];
65: h = hash(p->prefix,p->lastprim);
66: p->next = pt[h];
67: pt[h] = p;
68: }
69: return (Cell)pt;
70: }
71:
72: Inst peephole_opt(Inst inst1, Inst inst2, Cell peeptable)
73: {
74: Peeptable_entry **pt = (Peeptable_entry **)peeptable;
75: Peeptable_entry *p;
76:
77: if (use_super == 0)
78: return 0;
79: for (p = pt[hash(inst1,inst2)]; p != NULL; p = p->next)
80: if (inst1 == p->prefix && inst2 == p->lastprim)
81: return p->combination_prim;
82: return NULL;
83: }
FreeBSD-CVSweb <freebsd-cvsweb@FreeBSD.org>