Detect an additional sequence that is used with pointers in register

variables.

git-svn-id: svn://svn.cc65.org/cc65/trunk@5688 b7a2c559-68d2-44c3-8de9-860c34a00d81

diff --git a/src/cc65/coptptrload.c b/src/cc65/coptptrload.c
index 3a496a1def99eb87c376622ecde9afad7191c0d1..1e4b152d5e5d0cd7e1baca829b2467c4e9d388f6 100644 (file)
--- a/src/cc65/coptptrload.c
+++ b/src/cc65/coptptrload.c
@@ -1227,11 +1227,15 @@ unsigned OptPtrLoad15 (CodeSeg* S)
  *
  *      lda     zp
  *      ldx     zp+1
+ *      jsr     pushax          <- optional
  *      ldy     xx
  *      jsr     ldaxidx
  *
  * and replace it by:
  *
+ *      lda     zp              <- only if
+ *      ldx     zp+1            <- call to
+ *      jsr     pushax          <- pushax present
  *      ldy     xx
  *      lda     (zp),y
  *      tax
@@ -1243,50 +1247,58 @@ unsigned OptPtrLoad15 (CodeSeg* S)
 
     /* Walk over the entries */
     unsigned I = 0;
-    while (I < CS_GetEntryCount (S)) {
+    while (I < CS_GetEntryCount (S) - 3) {
 
-       CodeEntry* L[4];
+       CodeEntry* L[5];
        unsigned Len;
 
-       /* Get next entry */
-               L[0] = CS_GetEntry (S, I);
+       /* Get next 3 entries */
+               CS_GetEntries (S, L, I, 3);
 
-       /* Check for the sequence */
+       /* Check for the start of the sequence */
                if (L[0]->OPC == OP65_LDA && L[0]->AM == AM65_ZP        &&
-                   CS_GetEntries (S, L+1, I+1, 3)                      &&
-            !CS_RangeHasLabel (S, I+1, 3)                       &&
                    L[1]->OPC == OP65_LDX && L[1]->AM == AM65_ZP        &&
+            !CS_RangeHasLabel (S, I+1, 2)                       &&
             (Len = strlen (L[0]->Arg)) > 0                      &&
             strncmp (L[0]->Arg, L[1]->Arg, Len) == 0            &&
-            strcmp (L[1]->Arg + Len, "+1") == 0                 &&
-           L[2]->OPC == OP65_LDY                               &&
-                   CE_IsCallTo (L[3], "ldaxidx")) {
+            strcmp (L[1]->Arg + Len, "+1") == 0) {
 
-           CodeEntry* X;
+            unsigned PushAX = CE_IsCallTo (L[2], "pushax");
 
-                   /* lda (zp),y */
-           X = NewCodeEntry (OP65_LDA, AM65_ZP_INDY, L[0]->Arg, 0, L[3]->LI);
-           CS_InsertEntry (S, X, I+4);
+            /* Check for the remainder of the sequence */
+            if (CS_GetEntries (S, L+3, I+3, 1 + PushAX)         &&
+                !CS_RangeHasLabel (S, I+3, 1 + PushAX)          &&
+                L[2+PushAX]->OPC == OP65_LDY                    &&
+                CE_IsCallTo (L[3+PushAX], "ldaxidx")) {
 
-           /* tax */
-            X = NewCodeEntry (OP65_TAX, AM65_IMP, 0, 0, L[3]->LI);
-            CS_InsertEntry (S, X, I+5);
+                CodeEntry* X;
 
-           /* dey */
-            X = NewCodeEntry (OP65_DEY, AM65_IMP, 0, 0, L[3]->LI);
-            CS_InsertEntry (S, X, I+6);
+                /* lda (zp),y */
+                X = NewCodeEntry (OP65_LDA, AM65_ZP_INDY, L[0]->Arg, 0, L[3]->LI);
+                CS_InsertEntry (S, X, I+PushAX+4);
 
-                   /* lda (zp),y */
-           X = NewCodeEntry (OP65_LDA, AM65_ZP_INDY, L[0]->Arg, 0, L[3]->LI);
-           CS_InsertEntry (S, X, I+7);
+                /* tax */
+                X = NewCodeEntry (OP65_TAX, AM65_IMP, 0, 0, L[3]->LI);
+                CS_InsertEntry (S, X, I+PushAX+5);
 
-           /* Remove the old code */
-           CS_DelEntry (S, I+3);
-           CS_DelEntries (S, I, 2);
+                /* dey */
+                X = NewCodeEntry (OP65_DEY, AM65_IMP, 0, 0, L[3]->LI);
+                CS_InsertEntry (S, X, I+PushAX+6);
 
-           /* Remember, we had changes */
-           ++Changes;
+                /* lda (zp),y */
+                X = NewCodeEntry (OP65_LDA, AM65_ZP_INDY, L[0]->Arg, 0, L[3]->LI);
+                CS_InsertEntry (S, X, I+PushAX+7);
 
+                /* Remove the old code */
+                CS_DelEntry (S, I+PushAX+3);
+                if (!PushAX) {
+                    CS_DelEntries (S, I, 2);
+                }
+
+                /* Remember, we had changes */
+                ++Changes;
+
+            }
        }
 
        /* Next entry */