Improved implementation of OptPushPop

[cc65] / src / cc65 / coptneg.c

diff --git a/src/cc65/coptneg.c b/src/cc65/coptneg.c
index 6aed9ccc2fbd9e54cb1e81d4c45856cce5881aaf..7ca08249ea7cc9dd905f1faa167e7460c77d058b 100644 (file)
--- a/src/cc65/coptneg.c
+++ b/src/cc65/coptneg.c
@@ -185,12 +185,11 @@ unsigned OptNegAX1 (CodeSeg* S)
                CodeEntry* E = CS_GetEntry (S, I);
 
        /* Check if this is a call to bnegax, and if X is known and zero */
-       if (E->RI->In.RegX == 0             &&
-                   CE_IsCall (E, "bnegax")) {
+       if (E->RI->In.RegX == 0 && CE_IsCall (E, "bnegax")) {
 
-           /* We're cheating somewhat here ... */
-           E->Arg[5] = '\0';
-           E->Use &= ~REG_X;
+           CodeEntry* X = NewCodeEntry (OP65_JSR, AM65_ABS, "bnega", 0, E->LI);
+           CS_InsertEntry (S, X, I+1);
+           CS_DelEntry (S, I);
 
            /* We had changes */
            ++Changes;
@@ -213,18 +212,17 @@ unsigned OptNegAX1 (CodeSeg* S)
 unsigned OptNegAX2 (CodeSeg* S)
 /* Search for the sequence:
  *
- *     lda     (xx),y
- *     tax
- *     dey
- *     lda     (xx),y
+ *      ldy     #xx
+ *      jsr     ldaxysp
  *     jsr     bnegax
  *     jne/jeq ...
  *
  * and replace it by
  *
- *     lda     (xx),y
+ *      ldy     #xx
+ *     lda     (sp),y
  *     dey
- *     ora     (xx),y
+ *     ora     (sp),y
  *     jeq/jne ...
  */
 {
@@ -234,37 +232,39 @@ unsigned OptNegAX2 (CodeSeg* S)
     unsigned I = 0;
     while (I < CS_GetEntryCount (S)) {
 
-       CodeEntry* L[5];
+       CodeEntry* L[4];
 
        /* Get next entry */
-               CodeEntry* E = CS_GetEntry (S, I);
+               L[0] = CS_GetEntry (S, I);
 
        /* Check for the sequence */
-               if (E->OPC == OP65_LDA                  &&
-           E->AM == AM65_ZP_INDY               &&
-           CS_GetEntries (S, L, I+1, 5)        &&
-           L[0]->OPC == OP65_TAX               &&
-           L[1]->OPC == OP65_DEY               &&
-           L[2]->OPC == OP65_LDA               &&
-           L[2]->AM == AM65_ZP_INDY            &&
-           strcmp (L[2]->Arg, E->Arg) == 0     &&
-           !CE_HasLabel (L[2])                 &&
-                   CE_IsCall (L[3], "bnegax")          &&
-           !CE_HasLabel (L[3])                 &&
-                   (L[4]->Info & OF_ZBRA) != 0         &&
-           !CE_HasLabel (L[4])) {
-
-           /* lda --> ora */
-           CE_ReplaceOPC (L[2], OP65_ORA);
+       if (L[0]->OPC == OP65_LDY               &&
+           CE_KnownImm (L[0])                  &&
+           !CS_RangeHasLabel (S, I+1, 3)       &&
+                   CS_GetEntries (S, L+1, I+1, 3)      &&
+           CE_IsCall (L[1], "ldaxysp")         &&
+                   CE_IsCall (L[2], "bnegax")          &&
+                   (L[3]->Info & OF_ZBRA) != 0) {
+
+           CodeEntry* X;
+
+           /* lda (sp),y */
+           X = NewCodeEntry (OP65_LDA, AM65_ZP_INDY, "sp", 0, L[1]->LI);
+           CS_InsertEntry (S, X, I+1);
+
+           /* dey */
+           X = NewCodeEntry (OP65_DEY, AM65_IMP, 0, 0, L[1]->LI);
+           CS_InsertEntry (S, X, I+2);
+
+           /* ora (sp),y */
+           X = NewCodeEntry (OP65_ORA, AM65_ZP_INDY, "sp", 0, L[1]->LI);
+           CS_InsertEntry (S, X, I+3);
 
            /* Invert the branch */
-           CE_ReplaceOPC (L[4], GetInverseBranch (L[4]->OPC));
+                   CE_ReplaceOPC (L[3], GetInverseBranch (L[3]->OPC));
 
-           /* Delete the entries no longer needed. Beware: Deleting entries
-            * will change the indices.
-            */
-                   CS_DelEntry (S, I+4);               /* jsr bnegax */
-           CS_DelEntry (S, I+1);               /* tax */
+           /* Delete the entries no longer needed. */
+                   CS_DelEntries (S, I+4, 2);
 
            /* Remember, we had changes */
            ++Changes;