/* */
/* */
/* */
-/* (C) 2002-2005, Ullrich von Bassewitz */
-/* Römerstrasse 52 */
+/* (C) 2002-2012, Ullrich von Bassewitz */
+/* Roemerstrasse 52 */
/* D-70794 Filderstadt */
/* EMail: uz@cc65.org */
/* */
/*****************************************************************************/
-/* Code */
+/* Code */
/*****************************************************************************/
* ldy #n+1
* jsr ldaxysp
*
- * and remove the useless load, provided that the next insn doesn't use flags
- * from the load.
+ * and remove the useless load.
*/
{
unsigned Changes = 0;
unsigned I = 0;
while (I < CS_GetEntryCount (S)) {
- CodeEntry* L[5];
+ CodeEntry* L[4];
- /* Get next entry */
- L[0] = CS_GetEntry (S, I);
+ /* Get next entry */
+ L[0] = CS_GetEntry (S, I);
/* Check for the sequence */
if (L[0]->OPC == OP65_LDY &&
- CE_IsConstImm (L[0]) &&
+ CE_IsConstImm (L[0]) &&
L[0]->Num < 0xFF &&
- !CS_RangeHasLabel (S, I+1, 3) &&
- CS_GetEntries (S, L+1, I+1, 4) &&
+ !CS_RangeHasLabel (S, I+1, 3) &&
+ CS_GetEntries (S, L+1, I+1, 3) &&
CE_IsCallTo (L[1], "staxysp") &&
L[2]->OPC == OP65_LDY &&
CE_IsKnownImm (L[2], L[0]->Num + 1) &&
- CE_IsCallTo (L[3], "ldaxysp") &&
- !CE_UseLoadFlags (L[4])) {
+ CE_IsCallTo (L[3], "ldaxysp")) {
- /* Register has already the correct value, remove the loads */
- CS_DelEntries (S, I+2, 2);
+ /* Register has already the correct value, remove the loads */
+ CS_DelEntries (S, I+2, 2);
- /* Remember, we had changes */
- ++Changes;
+ /* Remember, we had changes */
+ ++Changes;
- }
+ }
- /* Next entry */
- ++I;
+ /* Next entry */
+ ++I;
}
unsigned I;
unsigned Changes = 0;
- /* Generate register info */
- CS_GenRegInfo (S);
-
/* Walk over the entries */
I = 0;
while (I < CS_GetEntryCount (S)) {
- /* Get next entry */
- CodeEntry* E = CS_GetEntry (S, I);
+ /* Get next entry */
+ CodeEntry* E = CS_GetEntry (S, I);
/* Get the input registers */
const RegInfo* RI = E->RI;
- /* Check for the call */
- if (CE_IsCallTo (E, "staxysp") &&
+ /* Check for the call */
+ if (CE_IsCallTo (E, "staxysp") &&
RegValIsKnown (RI->In.RegA) &&
RegValIsKnown (RI->In.RegX) &&
RegValIsKnown (RI->In.RegY) &&
!RegAXUsed (S, I+1)) {
/* Get the register values */
- unsigned char A = RI->In.RegA;
- unsigned char X = RI->In.RegX;
- unsigned char Y = RI->In.RegY;
+ unsigned char A = (unsigned char) RI->In.RegA;
+ unsigned char X = (unsigned char) RI->In.RegX;
+ unsigned char Y = (unsigned char) RI->In.RegY;
/* Setup other variables */
CodeEntry* N;
/* Remove the call */
CS_DelEntry (S, I);
- /* Remember, we had changes */
- ++Changes;
+ /* Remember, we had changes */
+ ++Changes;
- }
+ }
- /* Next entry */
- ++I;
+ /* Next entry */
+ ++I;
}
- /* Free the register info */
- CS_FreeRegInfo (S);
-
/* Return the number of changes made */
return Changes;
}
unsigned I;
unsigned Changes = 0;
- /* Generate register info */
- CS_GenRegInfo (S);
-
/* Walk over the entries */
I = 0;
while (I < CS_GetEntryCount (S)) {
- /* Get next entry */
- CodeEntry* E = CS_GetEntry (S, I);
+ /* Get next entry */
+ CodeEntry* E = CS_GetEntry (S, I);
/* Get the input registers */
const RegInfo* RI = E->RI;
- /* Check for the call */
- if (CE_IsCallTo (E, "steaxysp") &&
+ /* Check for the call */
+ if (CE_IsCallTo (E, "steaxysp") &&
RegValIsKnown (RI->In.RegA) &&
RegValIsKnown (RI->In.RegX) &&
RegValIsKnown (RI->In.RegY) &&
!RegEAXUsed (S, I+1)) {
/* Get the register values */
- unsigned char A = RI->In.RegA;
- unsigned char X = RI->In.RegX;
- unsigned char Y = RI->In.RegY;
- unsigned char L = RI->In.SRegLo;
- unsigned char H = RI->In.SRegHi;
+ unsigned char A = (unsigned char) RI->In.RegA;
+ unsigned char X = (unsigned char) RI->In.RegX;
+ unsigned char Y = (unsigned char) RI->In.RegY;
+ unsigned char L = (unsigned char) RI->In.SRegLo;
+ unsigned char H = (unsigned char) RI->In.SRegHi;
/* Setup other variables */
unsigned Done = 0;
/* Remove the call */
CS_DelEntry (S, I);
- /* Remember, we had changes */
- ++Changes;
+ /* Remember, we had changes */
+ ++Changes;
- }
+ }
- /* Next entry */
- ++I;
+ /* Next entry */
+ ++I;
}
- /* Free the register info */
- CS_FreeRegInfo (S);
-
/* Return the number of changes made */
return Changes;
}
unsigned I = 0;
while (I < CS_GetEntryCount (S)) {
- CodeEntry* L[5];
+ CodeEntry* L[5];
- /* Get next entry */
- L[0] = CS_GetEntry (S, I);
+ /* Get next entry */
+ L[0] = CS_GetEntry (S, I);
/* Check for the sequence */
if (L[0]->OPC == OP65_STA &&
(L[0]->AM == AM65_ABS || L[0]->AM == AM65_ZP) &&
- !CS_RangeHasLabel (S, I+1, 3) &&
- CS_GetEntries (S, L+1, I+1, 4) &&
+ !CS_RangeHasLabel (S, I+1, 3) &&
+ CS_GetEntries (S, L+1, I+1, 4) &&
L[1]->OPC == OP65_STX &&
L[1]->AM == L[0]->AM &&
L[2]->OPC == OP65_LDA &&
strcmp (L[1]->Arg, L[3]->Arg) == 0 &&
!CE_UseLoadFlags (L[4])) {
- /* Register has already the correct value, remove the loads */
- CS_DelEntries (S, I+2, 2);
+ /* Register has already the correct value, remove the loads */
+ CS_DelEntries (S, I+2, 2);
- /* Remember, we had changes */
- ++Changes;
+ /* Remember, we had changes */
+ ++Changes;
- }
+ }
- /* Next entry */
- ++I;
+ /* Next entry */
+ ++I;
}
+unsigned OptStore5 (CodeSeg* S)
+/* Search for the sequence
+ *
+ * lda foo
+ * ldx bar
+ * sta something
+ * stx something-else
+ *
+ * and replace it by
+ *
+ * lda foo
+ * sta something
+ * lda bar
+ * sta something-else
+ *
+ * if X is not used later. This replacement doesn't save any cycles or bytes,
+ * but it keeps the value of X, which may be reused later.
+ */
+{
+ unsigned Changes = 0;
+
+ /* Walk over the entries */
+ unsigned I = 0;
+ while (I < CS_GetEntryCount (S)) {
+
+ CodeEntry* L[4];
+
+ /* Get next entry */
+ L[0] = CS_GetEntry (S, I);
+
+ /* Check for the sequence */
+ if (L[0]->OPC == OP65_LDA &&
+ !CS_RangeHasLabel (S, I+1, 3) &&
+ CS_GetEntries (S, L+1, I+1, 3) &&
+ L[1]->OPC == OP65_LDX &&
+ L[2]->OPC == OP65_STA &&
+ L[3]->OPC == OP65_STX &&
+ !RegXUsed (S, I+4)) {
+
+ CodeEntry* X;
+
+ /* Insert the code after the sequence */
+ X = NewCodeEntry (OP65_LDA, L[1]->AM, L[1]->Arg, 0, L[1]->LI);
+ CS_InsertEntry (S, X, I+4);
+ X = NewCodeEntry (OP65_STA, L[3]->AM, L[3]->Arg, 0, L[3]->LI);
+ CS_InsertEntry (S, X, I+5);
+
+ /* Delete the old code */
+ CS_DelEntry (S, I+3);
+ CS_DelEntry (S, I+1);
+
+ /* Remember, we had changes */
+ ++Changes;
+ }
+
+ /* Next entry */
+ ++I;
+
+ }
+
+ /* Return the number of changes made */
+ return Changes;
+}
projects / cc65 / blobdiff