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 | |
52 | unsigned 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 | |
64 | unsigned 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 | |
70 | unsigned 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 | |
76 | unsigned 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 | |
88 | unsigned 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 | |