1 /*****************************************************************************/
5 /* Optimize addition sequences */
9 /* (C) 2001-2002 Ullrich von Bassewitz */
11 /* D-70597 Stuttgart */
12 /* EMail: uz@cc65.org */
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. */
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: */
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 */
32 /*****************************************************************************/
43 /*****************************************************************************/
44 /* Optimize additions */
45 /*****************************************************************************/
49 unsigned OptAdd1 (CodeSeg* S)
50 /* Search for the sequence
77 /* Walk over the entries */
79 while (I < CS_GetEntryCount (S)) {
84 L[0] = CS_GetEntry (S, I);
86 /* Check for the sequence */
87 if (L[0]->OPC == OP65_LDY &&
89 !CS_RangeHasLabel (S, I+1, 5) &&
90 CS_GetEntries (S, L+1, I+1, 5) &&
91 CE_IsCallTo (L[1], "ldaxysp") &&
92 CE_IsCallTo (L[2], "pushax") &&
93 L[3]->OPC == OP65_LDY &&
95 CE_IsCallTo (L[4], "ldaxysp") &&
96 CE_IsCallTo (L[5], "tosaddax")) {
101 /* Correct the stack of the first Y register load */
102 CE_SetNumArg (L[0], L[0]->Num - 1);
105 X = NewCodeEntry (OP65_LDA, AM65_ZP_INDY, "sp", 0, L[1]->LI);
106 CS_InsertEntry (S, X, I+1);
109 X = NewCodeEntry (OP65_CLC, AM65_IMP, 0, 0, L[5]->LI);
110 CS_InsertEntry (S, X, I+2);
113 Arg = MakeHexArg (L[3]->Num - 3);
114 X = NewCodeEntry (OP65_LDY, AM65_IMM, Arg, 0, L[4]->LI);
115 CS_InsertEntry (S, X, I+3);
118 X = NewCodeEntry (OP65_ADC, AM65_ZP_INDY, "sp", 0, L[5]->LI);
119 CS_InsertEntry (S, X, I+4);
122 X = NewCodeEntry (OP65_PHA, AM65_IMP, 0, 0, L[5]->LI);
123 CS_InsertEntry (S, X, I+5);
125 /* ldy #xx (beware: L[0] has changed) */
126 Arg = MakeHexArg (L[0]->Num + 1);
127 X = NewCodeEntry (OP65_LDY, AM65_IMM, Arg, 0, L[1]->LI);
128 CS_InsertEntry (S, X, I+6);
131 X = NewCodeEntry (OP65_LDA, AM65_ZP_INDY, "sp", 0, L[1]->LI);
132 CS_InsertEntry (S, X, I+7);
135 Arg = MakeHexArg (L[3]->Num - 2);
136 X = NewCodeEntry (OP65_LDY, AM65_IMM, Arg, 0, L[4]->LI);
137 CS_InsertEntry (S, X, I+8);
140 X = NewCodeEntry (OP65_ADC, AM65_ZP_INDY, "sp", 0, L[5]->LI);
141 CS_InsertEntry (S, X, I+9);
144 X = NewCodeEntry (OP65_TAX, AM65_IMP, 0, 0, L[5]->LI);
145 CS_InsertEntry (S, X, I+10);
148 X = NewCodeEntry (OP65_PLA, AM65_IMP, 0, 0, L[5]->LI);
149 CS_InsertEntry (S, X, I+11);
151 /* Delete the old code */
152 CS_DelEntries (S, I+12, 5);
154 /* Remember, we had changes */
164 /* Return the number of changes made */
170 unsigned OptAdd2 (CodeSeg* S)
171 /* Search for the sequence
192 * provided that a/x is not used later.
195 unsigned Changes = 0;
197 /* Walk over the entries */
199 while (I < CS_GetEntryCount (S)) {
204 L[0] = CS_GetEntry (S, I);
206 /* Check for the sequence */
207 if (L[0]->OPC == OP65_LDY &&
208 CE_KnownImm (L[0]) &&
209 !CS_RangeHasLabel (S, I+1, 3) &&
210 CS_GetEntries (S, L+1, I+1, 3) &&
211 CE_IsCallTo (L[1], "ldaxysp") &&
212 L[2]->OPC == OP65_LDY &&
213 CE_KnownImm (L[2]) &&
214 CE_IsCallTo (L[3], "addeqysp") &&
215 (GetRegInfo (S, I+4, REG_AX) & REG_AX) == 0) {
217 /* Insert new code behind the addeqysp */
222 Arg = MakeHexArg (L[0]->Num-1);
223 X = NewCodeEntry (OP65_LDY, AM65_IMM, Arg, 0, L[0]->LI);
224 CS_InsertEntry (S, X, I+4);
227 X = NewCodeEntry (OP65_LDA, AM65_ZP_INDY, "sp", 0, L[1]->LI);
228 CS_InsertEntry (S, X, I+5);
231 X = NewCodeEntry (OP65_LDY, AM65_IMM, L[2]->Arg, 0, L[2]->LI);
232 CS_InsertEntry (S, X, I+6);
235 X = NewCodeEntry (OP65_CLC, AM65_IMP, 0, 0, L[3]->LI);
236 CS_InsertEntry (S, X, I+7);
239 X = NewCodeEntry (OP65_ADC, AM65_ZP_INDY, "sp", 0, L[3]->LI);
240 CS_InsertEntry (S, X, I+8);
243 X = NewCodeEntry (OP65_STA, AM65_ZP_INDY, "sp", 0, L[3]->LI);
244 CS_InsertEntry (S, X, I+9);
247 X = NewCodeEntry (OP65_LDY, AM65_IMM, L[0]->Arg, 0, L[0]->LI);
248 CS_InsertEntry (S, X, I+10);
251 X = NewCodeEntry (OP65_LDA, AM65_ZP_INDY, "sp", 0, L[1]->LI);
252 CS_InsertEntry (S, X, I+11);
255 Arg = MakeHexArg (L[2]->Num+1);
256 X = NewCodeEntry (OP65_LDY, AM65_IMM, Arg, 0, L[2]->LI);
257 CS_InsertEntry (S, X, I+12);
260 X = NewCodeEntry (OP65_ADC, AM65_ZP_INDY, "sp", 0, L[3]->LI);
261 CS_InsertEntry (S, X, I+13);
264 X = NewCodeEntry (OP65_STA, AM65_ZP_INDY, "sp", 0, L[3]->LI);
265 CS_InsertEntry (S, X, I+14);
267 /* Delete the old code */
268 CS_DelEntries (S, I, 4);
270 /* Remember, we had changes */
280 /* Return the number of changes made */
286 unsigned OptAdd3 (CodeSeg* S)
287 /* Search for the sequence
305 unsigned Changes = 0;
307 /* Walk over the entries */
309 while (I < CS_GetEntryCount (S)) {
314 L[0] = CS_GetEntry (S, I);
316 /* Check for the sequence */
317 if (CE_IsCallTo (L[0], "pushax") &&
318 CS_GetEntries (S, L+1, I+1, 3) &&
319 !CS_RangeHasLabel (S, I+1, 3) &&
320 L[1]->OPC == OP65_LDA &&
321 (L[1]->AM == AM65_ABS || L[1]->AM == AM65_ZP) &&
322 L[2]->OPC == OP65_LDX &&
323 (L[2]->AM == AM65_ABS || L[2]->AM == AM65_ZP) &&
324 CE_IsCallTo (L[3], "tosaddax")) {
328 /* Insert new code behind the sequence */
329 X = NewCodeEntry (OP65_CLC, AM65_IMP, 0, 0, L[3]->LI);
330 CS_InsertEntry (S, X, I+4);
333 X = NewCodeEntry (OP65_ADC, L[1]->AM, L[1]->Arg, 0, L[3]->LI);
334 CS_InsertEntry (S, X, I+5);
337 X = NewCodeEntry (OP65_PHA, AM65_IMP, 0, 0, L[3]->LI);
338 CS_InsertEntry (S, X, I+6);
341 X = NewCodeEntry (OP65_TXA, AM65_IMP, 0, 0, L[3]->LI);
342 CS_InsertEntry (S, X, I+7);
345 X = NewCodeEntry (OP65_ADC, L[2]->AM, L[2]->Arg, 0, L[3]->LI);
346 CS_InsertEntry (S, X, I+8);
349 X = NewCodeEntry (OP65_TAX, AM65_IMP, 0, 0, L[3]->LI);
350 CS_InsertEntry (S, X, I+9);
353 X = NewCodeEntry (OP65_PLA, AM65_IMP, 0, 0, L[3]->LI);
354 CS_InsertEntry (S, X, I+10);
356 /* Delete the old code */
357 CS_DelEntries (S, I, 4);
359 /* Remember, we had changes */
369 /* Return the number of changes made */
375 unsigned OptAdd4 (CodeSeg* S)
376 /* Search for the sequence
383 * and remove the handling of the high byte if X is not used later.
386 unsigned Changes = 0;
388 /* Walk over the entries */
390 while (I < CS_GetEntryCount (S)) {
395 CodeEntry* E = CS_GetEntry (S, I);
397 /* Check for the sequence */
398 if (E->OPC == OP65_ADC &&
399 CS_GetEntries (S, L, I+1, 3) &&
400 (L[0]->OPC == OP65_BCC || L[0]->OPC == OP65_JCC) &&
402 !CE_HasLabel (L[0]) &&
403 L[1]->OPC == OP65_INX &&
404 !CE_HasLabel (L[1]) &&
405 L[0]->JumpTo->Owner == L[2] &&
406 !RegXUsed (S, I+3)) {
408 /* Remove the bcs/dex */
409 CS_DelEntries (S, I+1, 2);
411 /* Remember, we had changes */
421 /* Return the number of changes made */