unsigned OptPtrLoad19 (CodeSeg* S)
/* Search for the sequence:
**
+** ldx #0
** and #mask (any value < 128)
** jsr aslax1/shlax1
** clc
**
** and replace it by:
**
+** ldx #0
** and #mask (remove if == 127)
** asl
** tay
I = 0;
while (I < CS_GetEntryCount (S)) {
- CodeEntry* L[11];
+ CodeEntry* L[12];
/* Get next entry */
L[0] = CS_GetEntry (S, I);
/* Check for the sequence */
- if (L[0]->OPC == OP65_AND &&
- L[0]->AM == AM65_IMM &&
- CE_HasNumArg (L[0]) && L[0]->Num <= 127 &&
- CS_GetEntries (S, L+1, I+1, 10) &&
- L[1]->OPC == OP65_JSR &&
- (strcmp (L[1]->Arg, "aslax1") == 0 ||
- strcmp (L[1]->Arg, "shlax1") == 0) &&
- L[2]->OPC == OP65_CLC &&
- L[3]->OPC == OP65_ADC &&
- L[4]->OPC == OP65_TAY &&
- L[5]->OPC == OP65_TXA &&
- L[6]->OPC == OP65_ADC &&
- L[7]->OPC == OP65_TAX &&
- L[8]->OPC == OP65_TYA &&
- L[9]->OPC == OP65_LDY &&
- CE_IsKnownImm(L[9], 1) &&
- strlen(L[3]->Arg) >= 3 &&
- L[3]->Arg[0] == '<' &&
- strlen(L[6]->Arg) >= 3 &&
- L[6]->Arg[0] == '>' &&
- !strcmp(L[3]->Arg+1, L[6]->Arg+1) &&
- CE_IsCallTo (L[10], "ldaxidx") &&
- !CS_RangeHasLabel (S, I+1, 10)) {
+ if (L[0]->OPC == OP65_LDX &&
+ CE_IsKnownImm(L[0], 0) &&
+ CS_GetEntries (S, L+1, I+1, 11) &&
+ L[1]->OPC == OP65_AND &&
+ L[1]->AM == AM65_IMM &&
+ CE_HasNumArg (L[1]) && L[1]->Num <= 127 &&
+ L[2]->OPC == OP65_JSR &&
+ (strcmp (L[2]->Arg, "aslax1") == 0 ||
+ strcmp (L[2]->Arg, "shlax1") == 0) &&
+ L[3]->OPC == OP65_CLC &&
+ L[4]->OPC == OP65_ADC &&
+ L[5]->OPC == OP65_TAY &&
+ L[6]->OPC == OP65_TXA &&
+ L[7]->OPC == OP65_ADC &&
+ L[8]->OPC == OP65_TAX &&
+ L[9]->OPC == OP65_TYA &&
+ L[10]->OPC == OP65_LDY &&
+ CE_IsKnownImm(L[10], 1) &&
+ strlen(L[4]->Arg) >= 3 &&
+ L[4]->Arg[0] == '<' &&
+ strlen(L[7]->Arg) >= 3 &&
+ L[7]->Arg[0] == '>' &&
+ !strcmp(L[4]->Arg+1, L[7]->Arg+1) &&
+ CE_IsCallTo (L[11], "ldaxidx") &&
+ !CS_RangeHasLabel (S, I+1, 11)) {
CodeEntry* X;
char* Label;
- int Len = strlen(L[3]->Arg);
+ int Len = strlen(L[4]->Arg);
/* Track the insertion point */
- unsigned IP = I + 11;
+ unsigned IP = I + 12;
/* asl a */
- X = NewCodeEntry (OP65_ASL, AM65_ACC, "a", 0, L[1]->LI);
+ X = NewCodeEntry (OP65_ASL, AM65_ACC, "a", 0, L[2]->LI);
CS_InsertEntry (S, X, IP++);
/* tay */
- X = NewCodeEntry (OP65_TAY, AM65_IMP, 0, 0, L[1]->LI);
+ X = NewCodeEntry (OP65_TAY, AM65_IMP, 0, 0, L[2]->LI);
CS_InsertEntry (S, X, IP++);
/* lda label,y */
- Label = memcpy (xmalloc (Len-2), L[3]->Arg+2, Len-3);
+ Label = memcpy (xmalloc (Len-2), L[4]->Arg+2, Len-3);
Label[Len-3] = '\0';
- X = NewCodeEntry (OP65_LDA, AM65_ABSY, Label, 0, L[9]->LI);
+ X = NewCodeEntry (OP65_LDA, AM65_ABSY, Label, 0, L[10]->LI);
CS_InsertEntry (S, X, IP++);
xfree (Label);
/* lda label+1,y */
- Label = memcpy (xmalloc (Len), L[3]->Arg+2, Len-3);
+ Label = memcpy (xmalloc (Len), L[4]->Arg+2, Len-3);
strcpy(&Label[Len-3], "+1");
- X = NewCodeEntry (OP65_LDX, AM65_ABSY, Label, 0, L[9]->LI);
+ X = NewCodeEntry (OP65_LDX, AM65_ABSY, Label, 0, L[10]->LI);
CS_InsertEntry (S, X, IP++);
xfree (Label);
/* Remove the old code */
/* Remove the AND only if it's == 127, since ASL erases high bit */
- if (L[0]->Num == 127)
- CS_DelEntries (S, I, 11);
+ if (L[1]->Num == 127)
+ CS_DelEntries (S, I+1, 11);
else
- CS_DelEntries (S, I+1, 10);
+ CS_DelEntries (S, I+2, 10);
+ /* Remove the ldx #0 */
+ CS_DelEntry(S, I);
/* Remember, we had changes */
++Changes;