1/*****************************************************************************/
2/* */
3/* coptc02.h */
4/* */
5/* 65C02 specific optimizations */
6/* */
7/* */
8/* */
9/* (C) 2001-2012, Ullrich von Bassewitz */
10/* Roeerstrasse 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#include <string.h>
37
38/* cc65 */
39#include "codeent.h"
40#include "codeinfo.h"
41#include "error.h"
42#include "coptc02.h"
43
44
45
46/*****************************************************************************/
47/* Data */
48/*****************************************************************************/
49
50
51
52/*****************************************************************************/
53/* Helper functions */
54/*****************************************************************************/
55
56
57
58/*****************************************************************************/
59/* Code */
60/*****************************************************************************/
61
62
63
64unsigned Opt65C02Ind (CodeSeg* S)
65/* Try to use the indirect addressing mode where possible */
66{
67 unsigned Changes = 0;
68 unsigned I;
69
70 /* Walk over the entries */
71 I = 0;
72 while (I < CS_GetEntryCount (S)) {
73
74 /* Get next entry */
75 CodeEntry* E = CS_GetEntry (S, I);
76
77 /* Check for addressing mode indirect indexed Y where Y is zero.
78 ** Note: All opcodes that are available as (zp),y are also available
79 ** as (zp), so we can ignore the actual opcode here.
80 */
81 if (E->AM == AM65_ZP_INDY && E->RI->In.RegY == 0) {
82
83 /* Replace it by indirect addressing mode */
84 CodeEntry* X = NewCodeEntry (E->OPC, AM65_ZP_IND, E->Arg, 0, E->LI);
85 CS_InsertEntry (S, X, I+1);
86 CS_DelEntry (S, I);
87
88 /* We had changes */
89 ++Changes;
90
91 }
92
93 /* Next entry */
94 ++I;
95
96 }
97
98 /* Return the number of changes made */
99 return Changes;
100}
101
102
103
104unsigned Opt65C02BitOps (CodeSeg* S)
105/* Use special bit op instructions of the C02 */
106{
107 unsigned Changes = 0;
108 unsigned I;
109
110 /* Walk over the entries */
111 I = 0;
112 while (I < CS_GetEntryCount (S)) {
113
114 CodeEntry* L[3];
115
116 /* Get next entry */
117 L[0] = CS_GetEntry (S, I);
118
119 /* Check for the sequence */
120 if (L[0]->OPC == OP65_LDA &&
121 (L[0]->AM == AM65_ZP || L[0]->AM == AM65_ABS) &&
122 !CS_RangeHasLabel (S, I+1, 2) &&
123 CS_GetEntries (S, L+1, I+1, 2) &&
124 (L[1]->OPC == OP65_AND || L[1]->OPC == OP65_ORA) &&
125 CE_IsConstImm (L[1]) &&
126 L[2]->OPC == OP65_STA &&
127 L[2]->AM == L[0]->AM &&
128 strcmp (L[2]->Arg, L[0]->Arg) == 0 &&
129 !RegAUsed (S, I+3)) {
130
131 char Buf[32];
132 CodeEntry* X;
133
134 /* Use TRB for AND and TSB for ORA */
135 if (L[1]->OPC == OP65_AND) {
136
137 /* LDA #XX */
138 sprintf (Buf, "$%02X", (int) ((~L[1]->Num) & 0xFF));
139 X = NewCodeEntry (OP65_LDA, AM65_IMM, Buf, 0, L[1]->LI);
140 CS_InsertEntry (S, X, I+3);
141
142 /* TRB */
143 X = NewCodeEntry (OP65_TRB, L[0]->AM, L[0]->Arg, 0, L[0]->LI);
144 CS_InsertEntry (S, X, I+4);
145
146 } else {
147
148 /* LDA #XX */
149 sprintf (Buf, "$%02X", (int) L[1]->Num);
150 X = NewCodeEntry (OP65_LDA, AM65_IMM, Buf, 0, L[1]->LI);
151 CS_InsertEntry (S, X, I+3);
152
153 /* TSB */
154 X = NewCodeEntry (OP65_TSB, L[0]->AM, L[0]->Arg, 0, L[0]->LI);
155 CS_InsertEntry (S, X, I+4);
156 }
157
158 /* Delete the old stuff */
159 CS_DelEntries (S, I, 3);
160
161 /* We had changes */
162 ++Changes;
163 }
164
165 /* Next entry */
166 ++I;
167
168 }
169
170 /* Return the number of changes made */
171 return Changes;
172}
173
174
175
176unsigned Opt65C02Stores (CodeSeg* S)
177/* Use STZ where possible */
178{
179 unsigned Changes = 0;
180 unsigned I;
181
182 /* Walk over the entries */
183 I = 0;
184 while (I < CS_GetEntryCount (S)) {
185
186 /* Get next entry */
187 CodeEntry* E = CS_GetEntry (S, I);
188
189 /* Check for a store with a register value of zero and an addressing
190 ** mode available with STZ.
191 */
192 if (((E->OPC == OP65_STA && E->RI->In.RegA == 0) ||
193 (E->OPC == OP65_STX && E->RI->In.RegX == 0) ||
194 (E->OPC == OP65_STY && E->RI->In.RegY == 0)) &&
195 (E->AM == AM65_ZP || E->AM == AM65_ABS ||
196 E->AM == AM65_ZPX || E->AM == AM65_ABSX)) {
197
198 /* Replace by STZ */
199 CodeEntry* X = NewCodeEntry (OP65_STZ, E->AM, E->Arg, 0, E->LI);
200 CS_InsertEntry (S, X, I+1);
201
202 /* Delete the old stuff */
203 CS_DelEntry (S, I);
204
205 /* We had changes */
206 ++Changes;
207 }
208
209 /* Next entry */
210 ++I;
211
212 }
213
214 /* Return the number of changes made */
215 return Changes;
216}
217