Added another optimization step

git-svn-id: svn://svn.cc65.org/cc65/trunk@3732 b7a2c559-68d2-44c3-8de9-860c34a00d81

diff --git a/src/cc65/codeopt.c b/src/cc65/codeopt.c
index fa6ab9bfe3d00f1f57218eb924d92cddfcb395f7..730c8db41e3fe0bb2162c3bbae6d41e3ef5cef80 100644 (file)
--- a/src/cc65/codeopt.c
+++ b/src/cc65/codeopt.c
@@ -1395,6 +1395,86 @@ static unsigned OptPtrLoad7 (CodeSeg* S)
 
 
 static unsigned OptPtrLoad8 (CodeSeg* S)
+/* Search for the sequence:
+ *
+ *      lda     zp
+ *      ldx     zp+1
+ *      (anything that doesn't change a/x)
+ *      ldy     xx
+ *      jsr     ldauidx
+ *
+ * and replace it by:
+ *
+ *      lda     zp
+ *      ldx     zp+1
+ *      (anything that doesn't change a/x)
+ *      ldy     xx
+ *      ldx     #$00
+ *      lda     (zp),y
+ *
+ * Must execute before OptPtrLoad10!
+ */
+{
+    unsigned Changes = 0;
+
+    /* Generate register info */
+    CS_GenRegInfo (S);
+
+    /* Walk over the entries */
+    unsigned I = 0;
+    while (I < CS_GetEntryCount (S)) {
+
+       CodeEntry* L[5];
+       unsigned Len;
+
+       /* Get next entry */
+               L[0] = CS_GetEntry (S, I);
+
+       /* Check for the sequence */
+               if (L[0]->OPC == OP65_LDA && L[0]->AM == AM65_ZP        &&
+                   CS_GetEntries (S, L+1, I+1, 4)                      &&
+            !CS_RangeHasLabel (S, I+1, 4)                       &&
+                   L[1]->OPC == OP65_LDX && L[1]->AM == AM65_ZP        &&
+            (Len = strlen (L[0]->Arg)) > 0                      &&
+            strncmp (L[0]->Arg, L[1]->Arg, Len) == 0            &&
+            strcmp (L[1]->Arg + Len, "+1") == 0                 &&
+            (L[2]->Chg & REG_AX) == 0                           &&
+                   L[3]->OPC == OP65_LDY                               &&
+                   CE_IsCallTo (L[4], "ldauidx")) {
+
+           CodeEntry* X;
+
+           /* ldx #$00 */
+           X = NewCodeEntry (OP65_LDX, AM65_IMM, "$00", 0, L[3]->LI);
+           CS_InsertEntry (S, X, I+5);
+
+           /* lda (zp),y */
+           X = NewCodeEntry (OP65_LDA, AM65_ZP_INDY, L[0]->Arg, 0, L[3]->LI);
+           CS_InsertEntry (S, X, I+6);
+
+           /* Remove the old code */
+           CS_DelEntry (S, I+4);
+
+           /* Remember, we had changes */
+           ++Changes;
+
+       }
+
+       /* Next entry */
+       ++I;
+
+    }
+
+    /* Free the register info */
+    CS_FreeRegInfo (S);
+
+    /* Return the number of changes made */
+    return Changes;
+}
+
+
+
+static unsigned OptPtrLoad9 (CodeSeg* S)
 /* Search for the sequence:
  *
  *      lda     zp
@@ -1472,7 +1552,7 @@ static unsigned OptPtrLoad8 (CodeSeg* S)
 
 
 
-static unsigned OptPtrLoad9 (CodeSeg* S)
+static unsigned OptPtrLoad10 (CodeSeg* S)
 /* Search for the sequence
  *
  *      ldy     ...
@@ -1848,8 +1928,9 @@ static OptFunc DOptPtrLoad4       = { OptPtrLoad4,     "OptPtrLoad4",     100, 0,
 static OptFunc DOptPtrLoad5            = { OptPtrLoad5,     "OptPtrLoad5",      92, 0, 0, 0, 0, 0 };
 static OptFunc DOptPtrLoad6            = { OptPtrLoad6,     "OptPtrLoad6",      50, 0, 0, 0, 0, 0 };
 static OptFunc DOptPtrLoad7            = { OptPtrLoad7,     "OptPtrLoad7",      65, 0, 0, 0, 0, 0 };
-static OptFunc DOptPtrLoad8            = { OptPtrLoad8,     "OptPtrLoad8",      86, 0, 0, 0, 0, 0 };
-static OptFunc DOptPtrLoad9            = { OptPtrLoad9,     "OptPtrLoad9",     100, 0, 0, 0, 0, 0 };
+static OptFunc DOptPtrLoad8            = { OptPtrLoad8,     "OptPtrLoad8",     108, 0, 0, 0, 0, 0 };
+static OptFunc DOptPtrLoad9            = { OptPtrLoad9,     "OptPtrLoad9",      86, 0, 0, 0, 0, 0 };
+static OptFunc DOptPtrLoad10           = { OptPtrLoad10,    "OptPtrLoad10",    100, 0, 0, 0, 0, 0 };
 static OptFunc DOptPtrStore1           = { OptPtrStore1,    "OptPtrStore1",    100, 0, 0, 0, 0, 0 };
 static OptFunc DOptPtrStore2           = { OptPtrStore2,    "OptPtrStore2",     40, 0, 0, 0, 0, 0 };
 static OptFunc DOptPush1               = { OptPush1,        "OptPush1",         65, 0, 0, 0, 0, 0 };
@@ -1914,6 +1995,7 @@ static OptFunc* OptFuncs[] = {
     &DOptNegAX4,
     &DOptPrecalc,
     &DOptPtrLoad1,
+    &DOptPtrLoad10,
     &DOptPtrLoad2,
     &DOptPtrLoad3,
     &DOptPtrLoad4,
@@ -2194,6 +2276,7 @@ static unsigned RunOptGroup1 (CodeSeg* S)
     Changes += RunOptFunc (S, &DOptPtrLoad6, 1);
     Changes += RunOptFunc (S, &DOptPtrLoad7, 1);
     Changes += RunOptFunc (S, &DOptPtrLoad8, 1);
+    Changes += RunOptFunc (S, &DOptPtrLoad9, 1);
     Changes += RunOptFunc (S, &DOptNegAX1, 1);
     Changes += RunOptFunc (S, &DOptNegAX2, 1);
     Changes += RunOptFunc (S, &DOptNegAX3, 1);
@@ -2245,7 +2328,7 @@ static unsigned RunOptGroup3 (CodeSeg* S)
     do {
                C = 0;
 
-               C += RunOptFunc (S, &DOptPtrLoad9, 1);
+               C += RunOptFunc (S, &DOptPtrLoad10, 1);
                C += RunOptFunc (S, &DOptNegA1, 1);
                C += RunOptFunc (S, &DOptNegA2, 1);
                C += RunOptFunc (S, &DOptSub1, 1);
@@ -2320,7 +2403,7 @@ static unsigned RunOptGroup5 (CodeSeg* S)
 /* Run another round of pattern replacements. These are done late, since there
  * may be better replacements before.
  */
-{                                      
+{
     unsigned Changes = 0;
 
     Changes += RunOptFunc (S, &DOptPush1, 1);