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Merge pull request #2295 from colinleroy/fix-2262-too-eager-opt

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Fix #2262: Make sure there's no branching after the sequence
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Bob Andrews 2023-12-10 19:16:38 +01:00 committed by GitHub
commit 9634cc4d1e
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1 changed files with 51 additions and 28 deletions
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79
src/cc65/coptlong.c
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@ -49,24 +49,30 @@
/* Remove unused loads and stores */
/*****************************************************************************/
unsigned OptLongAssign (CodeSeg* S)
/* Simplify long assignments.
** Recognize
** lda ... 0
** lda #IMM 0
** sta sreg+1 1
** lda ... 2
** lda #IMM 2
** sta sreg 3
** lda ... 4
** ldx ... 5
** sta M0002 6
** stx M0002+1 7
** lda #IMM 4
** ldx #IMM 5
** sta YYY 6
** stx YYY+1 7
** ldy sreg 8
** sty M0002+2 9
** sty YYY+2 9
** ldy sreg+1 10
** sty M0002+3 11
** and simplify if not used right after.
** sty YYY+3 11
** and simplify, if not used right after and no branching occurs, to
** lda XXX+3
** sta YYY+3
** lda XXX+2
** sta YYY+2
** ldx XXX
** lda XXX+1
** sta YYY
** stx YYY+1
*/
{
unsigned Changes = 0;
@ -75,35 +81,43 @@ unsigned OptLongAssign (CodeSeg* S)
unsigned I = 0;
while (I < CS_GetEntryCount (S)) {
CodeEntry* L[12];
CodeEntry* L[13];
/* Get next entry */
L[0] = CS_GetEntry (S, I);
if (CS_GetEntries (S, L+1, I+1, 11)) {
if (L[0]->OPC == OP65_LDA &&
if (CS_GetEntries (S, L+1, I+1, 12)) {
if (/* Check the opcode sequence */
L[0]->OPC == OP65_LDA &&
L[1]->OPC == OP65_STA &&
!strcmp (L[1]->Arg, "sreg+1") &&
L[2]->OPC == OP65_LDA &&
L[3]->OPC == OP65_STA &&
!strcmp (L[3]->Arg, "sreg") &&
L[4]->OPC == OP65_LDA &&
L[5]->OPC == OP65_LDX &&
L[6]->OPC == OP65_STA &&
L[7]->OPC == OP65_STX &&
!strncmp(L[7]->Arg, L[6]->Arg, strlen(L[6]->Arg)) &&
!strcmp(L[7]->Arg + strlen(L[6]->Arg), "+1") &&
L[8]->OPC == OP65_LDY &&
!strcmp (L[8]->Arg, "sreg") &&
L[9]->OPC == OP65_STY &&
!strncmp(L[9]->Arg, L[6]->Arg, strlen(L[6]->Arg)) &&
!strcmp(L[9]->Arg + strlen(L[6]->Arg), "+2") &&
L[10]->OPC == OP65_LDY &&
!strcmp (L[10]->Arg, "sreg+1") &&
L[11]->OPC == OP65_STY &&
!strncmp(L[11]->Arg, L[6]->Arg, strlen(L[6]->Arg)) &&
/* Check the arguments match */
L[0]->AM == AM65_IMM &&
!strcmp (L[1]->Arg, "sreg+1") &&
L[2]->AM == AM65_IMM &&
!strcmp (L[3]->Arg, "sreg") &&
L[4]->AM == AM65_IMM &&
L[5]->AM == AM65_IMM &&
!strncmp(L[7]->Arg, L[6]->Arg, strlen(L[6]->Arg)) &&
!strcmp(L[7]->Arg + strlen(L[6]->Arg), "+1") &&
!strcmp (L[8]->Arg, "sreg") &&
!strncmp(L[9]->Arg, L[6]->Arg, strlen(L[6]->Arg)) &&
!strcmp(L[9]->Arg + strlen(L[6]->Arg), "+2") &&
!strcmp (L[10]->Arg, "sreg+1") &&
!strncmp(L[11]->Arg, L[6]->Arg, strlen(L[6]->Arg)) &&
!strcmp(L[11]->Arg + strlen(L[6]->Arg), "+3") &&
!RegXUsed (S, I+11)) {
/* Check there's nothing more */
!RegXUsed (S, I+12) &&
!CS_RangeHasLabel(S, I, 12)) {
L[1]->AM = L[11]->AM;
CE_SetArg(L[1], L[11]->Arg);
@ -142,7 +156,15 @@ unsigned OptLongCopy (CodeSeg* S)
** sty YYY+2 9
** ldy sreg+1 10
** sty YYY+3 11
** and simplify if not used right after.
** and simplify, if not used right after and no branching occurs, to
** lda XXX+3
** sta YYY+3
** lda XXX+2
** sta YYY+2
** ldx XXX
** lda XXX+1
** sta YYY
** stx YYY+1
*/
{
unsigned Changes = 0;
@ -151,12 +173,12 @@ unsigned OptLongCopy (CodeSeg* S)
unsigned I = 0;
while (I < CS_GetEntryCount (S)) {
CodeEntry* L[12];
CodeEntry* L[13];
/* Get next entry */
L[0] = CS_GetEntry (S, I);
if (CS_GetEntries (S, L+1, I+1, 11)) {
if (CS_GetEntries (S, L+1, I+1, 12)) {
if (L[0]->OPC == OP65_LDA &&
!strncmp(L[0]->Arg, L[5]->Arg, strlen(L[5]->Arg)) &&
!strcmp(L[0]->Arg + strlen(L[5]->Arg), "+3") &&
@ -185,7 +207,8 @@ unsigned OptLongCopy (CodeSeg* S)
L[11]->OPC == OP65_STY &&
!strncmp(L[11]->Arg, L[6]->Arg, strlen(L[6]->Arg)) &&
!strcmp(L[11]->Arg + strlen(L[6]->Arg), "+3") &&
!RegXUsed (S, I+11)) {
!RegXUsed (S, I+11) &&
!CS_RangeHasLabel(S, I, 12)) {
L[1]->AM = L[11]->AM;
CE_SetArg(L[1], L[11]->Arg);