1/*****************************************************************************/
2/* */
3/* coptstore.h */
4/* */
5/* Optimize stores */
6/* */
7/* */
8/* */
9/* (C) 2002-2006, Ullrich von Bassewitz */
10/* Roemerstrasse 52 */
11/* D-70794 Filderstadt */
12/* EMail: uz@cc65.org */
13/* */
14/* */
15/* This software is provided 'as-is', without any expressed or implied */
16/* warranty. In no event will the authors be held liable for any damages */
17/* arising from the use of this software. */
18/* */
19/* Permission is granted to anyone to use this software for any purpose, */
20/* including commercial applications, and to alter it and redistribute it */
21/* freely, subject to the following restrictions: */
22/* */
23/* 1. The origin of this software must not be misrepresented; you must not */
24/* claim that you wrote the original software. If you use this software */
25/* in a product, an acknowledgment in the product documentation would be */
26/* appreciated but is not required. */
27/* 2. Altered source versions must be plainly marked as such, and must not */
28/* be misrepresented as being the original software. */
29/* 3. This notice may not be removed or altered from any source */
30/* distribution. */
31/* */
32/*****************************************************************************/
33
34
35
36#ifndef COPTSTORE_H
37#define COPTSTORE_H
38
39
40
41/* cc65 */
42#include "codeseg.h"
43
44
45
46/*****************************************************************************/
47/* Code */
48/*****************************************************************************/
49
50
51
52unsigned OptStore1 (CodeSeg* S);
53/* Search for the sequence
54**
55** ldy #n
56** jsr staxysp
57** ldy #n+1
58** jsr ldaxysp
59**
60** and remove the useless load, provided that the next insn doesn't use flags
61** from the load.
62*/
63
64unsigned OptStore2 (CodeSeg* S);
65/* Search for a call to staxysp. If the ax register is not used later, and
66** the value is constant, just use the A register and store directly into the
67** stack.
68*/
69
70unsigned OptStore3 (CodeSeg* S);
71/* Search for a call to steaxysp. If the eax register is not used later, and
72** the value is constant, just use the A register and store directly into the
73** stack.
74*/
75
76unsigned OptStore4 (CodeSeg* S);
77/* Search for the sequence
78**
79** sta xx
80** stx yy
81** lda xx
82** ldx yy
83**
84** and remove the useless load, provided that the next insn doesn't use flags
85** from the load.
86*/
87
88unsigned OptStore5 (CodeSeg* S);
89/* Search for the sequence
90**
91** lda foo
92** ldx bar
93** sta something
94** stx something-else
95**
96** and replace it by
97**
98** lda foo
99** sta something
100** lda bar
101** sta something-else
102**
103** if X is not used later. This replacement doesn't save any cycles or bytes,
104** but it keeps the value of X, which may be reused later.
105*/
106
107
108
109/* End of coptstore.h */
110
111#endif
112