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More optimizations

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git-svn-id: svn://svn.cc65.org/cc65/trunk@836 b7a2c559-68d2-44c3-8de9-860c34a00d81
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cuz 2001-08-03 06:45:38 +00:00
parent 254948fcfe
commit 7cf676d40c
1 changed files with 138 additions and 2 deletions
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140
src/cc65/codeopt.c
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@ -1431,7 +1431,142 @@ static unsigned OptNegAX4 (CodeSeg* S)
static unsigned OptPtrStore1Sub (CodeSeg* S, unsigned I, CodeEntry** const L)
/* Check if this is one of the allowed suboperation for OptPtrStore1 */
{
/* Check for a label attached to the entry */
if (CE_HasLabel (L[0])) {
return 0;
}
/* Check for single insn sub ops */
if (L[0]->OPC == OP65_AND ||
L[0]->OPC == OP65_EOR ||
L[0]->OPC == OP65_ORA ||
(L[0]->OPC == OP65_JSR && strncmp (L[0]->Arg, "shlax", 5) == 0) ||
(L[0]->OPC == OP65_JSR && strncmp (L[0]->Arg, "shrax", 5) == 0)) {
/* One insn */
return 1;
} else if (L[0]->OPC == OP65_CLC &&
(L[1] = CS_GetNextEntry (S, I)) != 0 &&
L[1]->OPC == OP65_ADC &&
!CE_HasLabel (L[1])) {
return 2;
} else if (L[0]->OPC == OP65_SEC &&
(L[1] = CS_GetNextEntry (S, I)) != 0 &&
L[1]->OPC == OP65_SBC &&
!CE_HasLabel (L[1])) {
return 2;
}
/* Not found */
return 0;
}
static unsigned OptPtrStore1 (CodeSeg* S)
/* Search for the sequence:
*
* jsr pushax
* ldy xxx
* jsr ldauidx
* subop
* ldy yyy
* jsr staspidx
*
* and replace it by:
*
* sta ptr1
* stx ptr1+1
* ldy xxx
* ldx #$00
* lda (ptr1),y
* subop
* ldy yyy
* sta (ptr1),y
*/
{
unsigned Changes = 0;
/* Walk over the entries */
unsigned I = 0;
while (I < CS_GetEntryCount (S)) {
unsigned K;
CodeEntry* L[10];
/* Get next entry */
L[0] = CS_GetEntry (S, I);
/* Check for the sequence */
if (L[0]->OPC == OP65_JSR &&
strcmp (L[0]->Arg, "pushax") == 0 &&
CS_GetEntries (S, L+1, I+1, 3) &&
L[1]->OPC == OP65_LDY &&
CE_KnownImm (L[1]) &&
!CE_HasLabel (L[1]) &&
L[2]->OPC == OP65_JSR &&
strcmp (L[2]->Arg, "ldauidx") == 0 &&
!CE_HasLabel (L[2]) &&
(K = OptPtrStore1Sub (S, I+3, L+3)) > 0 &&
CS_GetEntries (S, L+3+K, I+3+K, 2) &&
L[3+K]->OPC == OP65_LDY &&
CE_KnownImm (L[3+K]) &&
!CE_HasLabel (L[3+K]) &&
L[4+K]->OPC == OP65_JSR &&
strcmp (L[4+K]->Arg, "staspidx") == 0 &&
!CE_HasLabel (L[4+K])) {
CodeEntry* X;
/* Create and insert the stores */
X = NewCodeEntry (OP65_STA, AM65_ZP, "ptr1", 0, L[0]->LI);
CS_InsertEntry (S, X, I+1);
X = NewCodeEntry (OP65_STX, AM65_ZP, "ptr1+1", 0, L[0]->LI);
CS_InsertEntry (S, X, I+2);
/* Delete the call to pushax */
CS_DelEntry (S, I);
/* Delete the call to ldauidx */
CS_DelEntry (S, I+3);
/* Insert the load from ptr1 */
X = NewCodeEntry (OP65_LDX, AM65_IMM, "$00", 0, L[3]->LI);
CS_InsertEntry (S, X, I+3);
X = NewCodeEntry (OP65_LDA, AM65_ZP_INDY, "ptr1", 0, L[2]->LI);
CS_InsertEntry (S, X, I+4);
/* Insert the store through ptr1 */
X = NewCodeEntry (OP65_STA, AM65_ZP_INDY, "ptr1", 0, L[3]->LI);
CS_InsertEntry (S, X, I+6+K);
/* Delete the call to staspidx */
CS_DelEntry (S, I+7+K);
/* Remember, we had changes */
++Changes;
}
/* Next entry */
++I;
}
/* Return the number of changes made */
return Changes;
}
static unsigned OptPtrStore2 (CodeSeg* S)
/* Search for the sequence:
*
* jsr pushax
@ -1693,12 +1828,13 @@ struct OptFunc {
static OptFunc OptFuncs [] = {
/* Optimizes stores through pointers */
OptEntry (OptPtrStore1, optPre),
OptEntry (OptPtrStore2, optPre),
/* Optimize loads through pointers */
OptEntry (OptPtrLoad1, optMain),
OptEntry (OptPtrLoad2, optMain),
/* Optimize calls to nega */
OptEntry (OptNegA1, optPre),
OptEntry (OptNegA2, optPre),
OptEntry (OptNegA1, optMain),
OptEntry (OptNegA2, optMain),
/* Optimize calls to negax */
OptEntry (OptNegAX1, optPre),
OptEntry (OptNegAX2, optPre),