+
+
+
+unsigned OptPtrLoad18 (CodeSeg* S)
+/* Search for the sequence:
+**
+** ldx #$xx
+** lda #$yy
+** clc
+** adc xxx
+** bcc L
+** inx
+** L: ldy #$00
+** jsr ldauidx
+**
+** and replace it by:
+**
+** ldy xxx
+** ldx #$00
+** lda $xxyy,y
+**
+** This is similar to OptPtrLoad3 but works on a constant address
+** instead of a label. Also, the initial X and A loads are reversed.
+** Must be run before OptPtrLoad11.
+*/
+{
+ unsigned Changes = 0;
+
+ /* Walk over the entries */
+ unsigned I = 0;
+ while (I < CS_GetEntryCount (S)) {
+
+ CodeEntry* L[8];
+
+ /* Get next entry */
+ L[0] = CS_GetEntry (S, I);
+
+ /* Check for the sequence */
+ if (L[0]->OPC == OP65_LDX &&
+ L[0]->AM == AM65_IMM &&
+ CS_GetEntries (S, L+1, I+1, 7) &&
+ L[1]->OPC == OP65_LDA &&
+ L[1]->AM == AM65_IMM &&
+ L[2]->OPC == OP65_CLC &&
+ L[3]->OPC == OP65_ADC &&
+ (L[3]->AM == AM65_ABS || L[3]->AM == AM65_ZP) &&
+ (L[4]->OPC == OP65_BCC || L[4]->OPC == OP65_JCC) &&
+ L[4]->JumpTo != 0 &&
+ L[4]->JumpTo->Owner == L[6] &&
+ L[5]->OPC == OP65_INX &&
+ L[6]->OPC == OP65_LDY &&
+ CE_IsKnownImm (L[6], 0) &&
+ CE_IsCallTo (L[7], "ldauidx") &&
+ !CS_RangeHasLabel (S, I+1, 5) &&
+ !CE_HasLabel (L[7]) &&
+ strlen (L[0]->Arg) == 3 &&
+ L[0]->Arg[0] == '$' &&
+ strlen (L[1]->Arg) == 3 &&
+ L[1]->Arg[0] == '$' ) {
+
+ CodeEntry* X;
+ char* Label;
+
+ /* We will create all the new stuff behind the current one so
+ ** we keep the line references.
+ */
+ X = NewCodeEntry (OP65_LDY, L[3]->AM, L[3]->Arg, 0, L[0]->LI);
+ CS_InsertEntry (S, X, I+8);
+
+ X = NewCodeEntry (OP65_LDX, AM65_IMM, "$00", 0, L[0]->LI);
+ CS_InsertEntry (S, X, I+9);
+
+ Label = xmalloc(6);
+ sprintf(Label, "$%s%s", L[0]->Arg+1, L[1]->Arg+1);
+ X = NewCodeEntry (OP65_LDA, AM65_ABSY, Label, 0, L[0]->LI);
+ CS_InsertEntry (S, X, I+10);
+ xfree (Label);
+
+ /* Remove the old code */
+ CS_DelEntries (S, I, 8);
+
+ /* Remember, we had changes */
+ ++Changes;
+
+ }
+
+ /* Next entry */
+ ++I;
+
+ }
+
+ /* Return the number of changes made */
+ return Changes;
+}
+
+
+