unsigned OptPush2 (CodeSeg* S)
/* A sequence
*
* jsr ldaxidx
* jsr pushax
*
* may get replaced by
*
* jsr pushwidx
*
*/
{
unsigned I;
unsigned Changes = 0;
/* Generate register info */
CS_GenRegInfo (S);
/* Walk over the entries */
I = 0;
while (I < CS_GetEntryCount (S)) {
CodeEntry* L[2];
/* Get next entry */
L[0] = CS_GetEntry (S, I);
/* Check for the sequence */
if (CE_IsCallTo (L[0], "ldaxidx") &&
(L[1] = CS_GetNextEntry (S, I)) != 0 &&
!CE_HasLabel (L[1]) &&
CE_IsCallTo (L[1], "pushax")) {
/* Insert new code behind the pushax */
CodeEntry* X;
/* jsr pushwidx */
X = NewCodeEntry (OP65_JSR, AM65_ABS, "pushwidx", 0, L[1]->LI);
CS_InsertEntry (S, X, I+2);
/* Delete the old code */
CS_DelEntries (S, I, 2);
/* Remember, we had changes */
++Changes;
}
/* Next entry */
++I;
}
/* Free the register info */
CS_FreeRegInfo (S);
/* Return the number of changes made */
return Changes;
}
unsigned OptStore1 (CodeSeg* S)
/* Search for the sequence
**
** ldy #n
** jsr staxysp
** ldy #n+1
** jsr ldaxysp
**
** and remove the useless load.
*/
{
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_LDY &&
CE_IsConstImm (L[0]) &&
L[0]->Num < 0xFF &&
!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")) {
/* Register has already the correct value, remove the loads */
CS_DelEntries (S, I+2, 2);
/* Remember, we had changes */
++Changes;
}
/* Next entry */
++I;
}
/* Return the number of changes made */
return Changes;
}
unsigned OptBNegAX1 (CodeSeg* S)
/* On a call to bnegax, if X is zero, the result depends only on the value in
* A, so change the call to a call to bnega. This will get further optimized
* later if possible.
*/
{
unsigned Changes = 0;
unsigned I;
/* Walk over the entries */
I = 0;
while (I < CS_GetEntryCount (S)) {
/* Get next entry */
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_IsCallTo (E, "bnegax")) {
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;
}
/* Next entry */
++I;
}
/* Return the number of changes made */
return Changes;
}
unsigned OptBNegAX3 (CodeSeg* S)
/* Search for the sequence:
*
* lda xx
* ldx yy
* jsr bnegax
* jne/jeq ...
*
* and replace it by
*
* lda xx
* ora xx+1
* jeq/jne ...
*/
{
unsigned Changes = 0;
/* Walk over the entries */
unsigned I = 0;
while (I < CS_GetEntryCount (S)) {
CodeEntry* L[3];
/* Get next entry */
CodeEntry* E = CS_GetEntry (S, I);
/* Check for the sequence */
if (E->OPC == OP65_LDA &&
CS_GetEntries (S, L, I+1, 3) &&
L[0]->OPC == OP65_LDX &&
!CE_HasLabel (L[0]) &&
CE_IsCallTo (L[1], "bnegax") &&
!CE_HasLabel (L[1]) &&
(L[2]->Info & OF_ZBRA) != 0 &&
!CE_HasLabel (L[2])) {
/* ldx --> ora */
CE_ReplaceOPC (L[0], OP65_ORA);
/* Invert the branch */
CE_ReplaceOPC (L[2], GetInverseBranch (L[2]->OPC));
/* Delete the subroutine call */
CS_DelEntry (S, I+2);
/* Remember, we had changes */
++Changes;
}
/* Next entry */
++I;
}
/* Return the number of changes made */
return Changes;
}
unsigned OptBNegA2 (CodeSeg* S)
/* Check for
*
* lda ..
* jsr bnega
* jeq/jne ..
*
* Adjust the conditional branch and remove the call to the subroutine.
*/
{
unsigned Changes = 0;
/* Walk over the entries */
unsigned I = 0;
while (I < CS_GetEntryCount (S)) {
CodeEntry* L[2];
/* Get next entry */
CodeEntry* E = CS_GetEntry (S, I);
/* Check for the sequence */
if ((E->OPC == OP65_ADC ||
E->OPC == OP65_AND ||
E->OPC == OP65_DEA ||
E->OPC == OP65_EOR ||
E->OPC == OP65_INA ||
E->OPC == OP65_LDA ||
E->OPC == OP65_ORA ||
E->OPC == OP65_PLA ||
E->OPC == OP65_SBC ||
E->OPC == OP65_TXA ||
E->OPC == OP65_TYA) &&
CS_GetEntries (S, L, I+1, 2) &&
CE_IsCallTo (L[0], "bnega") &&
!CE_HasLabel (L[0]) &&
(L[1]->Info & OF_ZBRA) != 0 &&
!CE_HasLabel (L[1])) {
/* Invert the branch */
CE_ReplaceOPC (L[1], GetInverseBranch (L[1]->OPC));
/* Delete the subroutine call */
CS_DelEntry (S, I+1);
/* Remember, we had changes */
++Changes;
}
/* Next entry */
++I;
}
/* Return the number of changes made */
return Changes;
}
unsigned OptNegAX1 (CodeSeg* S)
/* Search for a call to negax and replace it by
*
* eor #$FF
* clc
* adc #$01
*
* if X isn't used later.
*/
{
unsigned Changes = 0;
unsigned I;
/* Walk over the entries */
I = 0;
while (I < CS_GetEntryCount (S)) {
/* Get next entry */
CodeEntry* E = CS_GetEntry (S, I);
/* Check if this is a call to negax, and if X isn't used later */
if (CE_IsCallTo (E, "negax") && !RegXUsed (S, I+1)) {
CodeEntry* X;
/* Add replacement code behind */
X = NewCodeEntry (OP65_EOR, AM65_IMM, "$FF", 0, E->LI);
CS_InsertEntry (S, X, I+1);
X = NewCodeEntry (OP65_CLC, AM65_IMP, 0, 0, E->LI);
CS_InsertEntry (S, X, I+2);
X = NewCodeEntry (OP65_ADC, AM65_IMM, "$01", 0, E->LI);
CS_InsertEntry (S, X, I+3);
/* Delete the call to negax */
CS_DelEntry (S, I);
/* Skip the generated code */
I += 2;
/* We had changes */
++Changes;
}
/* Next entry */
++I;
}
/* Return the number of changes made */
return Changes;
}
static unsigned OptLoad1 (CodeSeg* S)
/* Search for a call to ldaxysp where X is not used later and replace it by
** a load of just the A register.
*/
{
unsigned I;
unsigned Changes = 0;
/* Walk over the entries */
I = 0;
while (I < CS_GetEntryCount (S)) {
CodeEntry* E;
/* Get next entry */
E = CS_GetEntry (S, I);
/* Check for the sequence */
if (CE_IsCallTo (E, "ldaxysp") &&
RegValIsKnown (E->RI->In.RegY) &&
!RegXUsed (S, I+1)) {
CodeEntry* X;
/* Reload the Y register */
const char* Arg = MakeHexArg (E->RI->In.RegY - 1);
X = NewCodeEntry (OP65_LDY, AM65_IMM, Arg, 0, E->LI);
CS_InsertEntry (S, X, I+1);
/* Load from stack */
X = NewCodeEntry (OP65_LDA, AM65_ZP_INDY, "sp", 0, E->LI);
CS_InsertEntry (S, X, I+2);
/* Now remove the call to the subroutine */
CS_DelEntry (S, I);
/* Remember, we had changes */
++Changes;
}
/* Next entry */
++I;
}
/* Return the number of changes made */
return Changes;
}
unsigned OptBNegA1 (CodeSeg* S)
/* Check for
*
* ldx #$00
* lda ..
* jsr bnega
*
* Remove the ldx if the lda does not use it.
*/
{
unsigned Changes = 0;
/* Walk over the entries */
unsigned I = 0;
while (I < CS_GetEntryCount (S)) {
CodeEntry* L[2];
/* Get next entry */
CodeEntry* E = CS_GetEntry (S, I);
/* Check for a ldx */
if (E->OPC == OP65_LDX &&
E->AM == AM65_IMM &&
(E->Flags & CEF_NUMARG) != 0 &&
E->Num == 0 &&
CS_GetEntries (S, L, I+1, 2) &&
L[0]->OPC == OP65_LDA &&
(L[0]->Use & REG_X) == 0 &&
!CE_HasLabel (L[0]) &&
CE_IsCallTo (L[1], "bnega") &&
!CE_HasLabel (L[1])) {
/* Remove the ldx instruction */
CS_DelEntry (S, I);
/* Remember, we had changes */
++Changes;
}
/* Next entry */
++I;
}
/* Return the number of changes made */
return Changes;
}
unsigned OptAdd2 (CodeSeg* S)
/* Search for the sequence
*
* ldy #xx
* jsr ldaxysp
* ldy #yy
* jsr addeqysp
*
* and replace it by:
*
* ldy #xx-1
* lda (sp),y
* ldy #yy
* clc
* adc (sp),y
* sta (sp),y
* ldy #xx
* lda (sp),y
* ldy #yy+1
* adc (sp),y
* sta (sp),y
*
* provided that a/x is not used 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_LDY &&
CE_IsConstImm (L[0]) &&
!CS_RangeHasLabel (S, I+1, 3) &&
CS_GetEntries (S, L+1, I+1, 3) &&
CE_IsCallTo (L[1], "ldaxysp") &&
L[2]->OPC == OP65_LDY &&
CE_IsConstImm (L[2]) &&
CE_IsCallTo (L[3], "addeqysp") &&
(GetRegInfo (S, I+4, REG_AX) & REG_AX) == 0) {
/* Insert new code behind the addeqysp */
const char* Arg;
CodeEntry* X;
/* ldy #xx-1 */
Arg = MakeHexArg (L[0]->Num-1);
X = NewCodeEntry (OP65_LDY, AM65_IMM, Arg, 0, L[0]->LI);
CS_InsertEntry (S, X, I+4);
/* lda (sp),y */
X = NewCodeEntry (OP65_LDA, AM65_ZP_INDY, "sp", 0, L[1]->LI);
CS_InsertEntry (S, X, I+5);
/* ldy #yy */
X = NewCodeEntry (OP65_LDY, AM65_IMM, L[2]->Arg, 0, L[2]->LI);
CS_InsertEntry (S, X, I+6);
/* clc */
X = NewCodeEntry (OP65_CLC, AM65_IMP, 0, 0, L[3]->LI);
CS_InsertEntry (S, X, I+7);
/* adc (sp),y */
X = NewCodeEntry (OP65_ADC, AM65_ZP_INDY, "sp", 0, L[3]->LI);
CS_InsertEntry (S, X, I+8);
/* sta (sp),y */
X = NewCodeEntry (OP65_STA, AM65_ZP_INDY, "sp", 0, L[3]->LI);
CS_InsertEntry (S, X, I+9);
/* ldy #xx */
X = NewCodeEntry (OP65_LDY, AM65_IMM, L[0]->Arg, 0, L[0]->LI);
CS_InsertEntry (S, X, I+10);
/* lda (sp),y */
X = NewCodeEntry (OP65_LDA, AM65_ZP_INDY, "sp", 0, L[1]->LI);
CS_InsertEntry (S, X, I+11);
/* ldy #yy+1 */
Arg = MakeHexArg (L[2]->Num+1);
X = NewCodeEntry (OP65_LDY, AM65_IMM, Arg, 0, L[2]->LI);
CS_InsertEntry (S, X, I+12);
/* adc (sp),y */
X = NewCodeEntry (OP65_ADC, AM65_ZP_INDY, "sp", 0, L[3]->LI);
CS_InsertEntry (S, X, I+13);
/* sta (sp),y */
X = NewCodeEntry (OP65_STA, AM65_ZP_INDY, "sp", 0, L[3]->LI);
CS_InsertEntry (S, X, I+14);
/* Delete the old code */
CS_DelEntries (S, I, 4);
/* Remember, we had changes */
++Changes;
}
/* Next entry */
++I;
}
/* Return the number of changes made */
return Changes;
}
unsigned OptStore3 (CodeSeg* S)
/* Search for a call to steaxysp. If the eax register is not used later, and
** the value is constant, just use the A register and store directly into the
** stack.
*/
{
unsigned I;
unsigned Changes = 0;
/* Walk over the entries */
I = 0;
while (I < CS_GetEntryCount (S)) {
/* 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") &&
RegValIsKnown (RI->In.RegA) &&
RegValIsKnown (RI->In.RegX) &&
RegValIsKnown (RI->In.RegY) &&
RegValIsKnown (RI->In.SRegLo) &&
RegValIsKnown (RI->In.SRegHi) &&
!RegEAXUsed (S, I+1)) {
/* Get the register values */
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;
CodeEntry* N;
unsigned IP = I + 1; /* Insertion point */
/* Replace the store. We will not remove the loads, since this is
** too complex and will be done by other optimizer steps.
*/
N = NewCodeEntry (OP65_LDA, AM65_IMM, MakeHexArg (A), 0, E->LI);
CS_InsertEntry (S, N, IP++);
InsertStore (S, &IP, E->LI);
Done |= 0x01;
/* Check if we can store one of the other bytes */
if (A == X && (Done & 0x02) == 0) {
N = NewCodeEntry (OP65_LDY, AM65_IMM, MakeHexArg (Y+1), 0, E->LI);
CS_InsertEntry (S, N, IP++);
InsertStore (S, &IP, E->LI);
Done |= 0x02;
}
if (A == L && (Done & 0x04) == 0) {
N = NewCodeEntry (OP65_LDY, AM65_IMM, MakeHexArg (Y+2), 0, E->LI);
CS_InsertEntry (S, N, IP++);
InsertStore (S, &IP, E->LI);
Done |= 0x04;
}
if (A == H && (Done & 0x08) == 0) {
N = NewCodeEntry (OP65_LDY, AM65_IMM, MakeHexArg (Y+3), 0, E->LI);
CS_InsertEntry (S, N, IP++);
InsertStore (S, &IP, E->LI);
Done |= 0x08;
}
/* Store the second byte */
if ((Done & 0x02) == 0) {
N = NewCodeEntry (OP65_LDA, AM65_IMM, MakeHexArg (X), 0, E->LI);
CS_InsertEntry (S, N, IP++);
N = NewCodeEntry (OP65_LDY, AM65_IMM, MakeHexArg (Y+1), 0, E->LI);
CS_InsertEntry (S, N, IP++);
InsertStore (S, &IP, E->LI);
Done |= 0x02;
}
/* Check if we can store one of the other bytes */
if (X == L && (Done & 0x04) == 0) {
N = NewCodeEntry (OP65_LDY, AM65_IMM, MakeHexArg (Y+2), 0, E->LI);
CS_InsertEntry (S, N, IP++);
InsertStore (S, &IP, E->LI);
Done |= 0x04;
}
if (X == H && (Done & 0x08) == 0) {
N = NewCodeEntry (OP65_LDY, AM65_IMM, MakeHexArg (Y+3), 0, E->LI);
CS_InsertEntry (S, N, IP++);
InsertStore (S, &IP, E->LI);
Done |= 0x08;
}
/* Store the third byte */
if ((Done & 0x04) == 0) {
N = NewCodeEntry (OP65_LDA, AM65_IMM, MakeHexArg (L), 0, E->LI);
CS_InsertEntry (S, N, IP++);
N = NewCodeEntry (OP65_LDY, AM65_IMM, MakeHexArg (Y+2), 0, E->LI);
CS_InsertEntry (S, N, IP++);
InsertStore (S, &IP, E->LI);
Done |= 0x04;
}
/* Check if we can store one of the other bytes */
if (L == H && (Done & 0x08) == 0) {
N = NewCodeEntry (OP65_LDY, AM65_IMM, MakeHexArg (Y+3), 0, E->LI);
CS_InsertEntry (S, N, IP++);
InsertStore (S, &IP, E->LI);
Done |= 0x08;
}
/* Store the fourth byte */
if ((Done & 0x08) == 0) {
N = NewCodeEntry (OP65_LDA, AM65_IMM, MakeHexArg (H), 0, E->LI);
CS_InsertEntry (S, N, IP++);
N = NewCodeEntry (OP65_LDY, AM65_IMM, MakeHexArg (Y+3), 0, E->LI);
CS_InsertEntry (S, N, IP++);
InsertStore (S, &IP, E->LI);
Done |= 0x08;
}
/* Remove the call */
CS_DelEntry (S, I);
/* Remember, we had changes */
++Changes;
}
/* Next entry */
++I;
}
/* Return the number of changes made */
return Changes;
}
static unsigned OptLoad2 (CodeSeg* S)
/* Replace calls to ldaxysp by inline code */
{
unsigned I;
unsigned Changes = 0;
/* Walk over the entries */
I = 0;
while (I < CS_GetEntryCount (S)) {
CodeEntry* L[3];
/* Get next entry */
L[0] = CS_GetEntry (S, I);
/* Check for the sequence */
if (CE_IsCallTo (L[0], "ldaxysp")) {
CodeEntry* X;
/* Followed by sta abs/stx abs? */
if (CS_GetEntries (S, L+1, I+1, 2) &&
L[1]->OPC == OP65_STA &&
L[2]->OPC == OP65_STX &&
(L[1]->Arg == 0 ||
L[2]->Arg == 0 ||
strcmp (L[1]->Arg, L[2]->Arg) != 0) &&
!CS_RangeHasLabel (S, I+1, 2) &&
!RegXUsed (S, I+3)) {
/* A/X are stored into memory somewhere and X is not used
** later
*/
/* lda (sp),y */
X = NewCodeEntry (OP65_LDA, AM65_ZP_INDY, "sp", 0, L[0]->LI);
CS_InsertEntry (S, X, I+3);
/* sta abs */
X = NewCodeEntry (OP65_STA, L[2]->AM, L[2]->Arg, 0, L[2]->LI);
CS_InsertEntry (S, X, I+4);
/* dey */
X = NewCodeEntry (OP65_DEY, AM65_IMP, 0, 0, L[0]->LI);
CS_InsertEntry (S, X, I+5);
/* lda (sp),y */
X = NewCodeEntry (OP65_LDA, AM65_ZP_INDY, "sp", 0, L[0]->LI);
CS_InsertEntry (S, X, I+6);
/* sta abs */
X = NewCodeEntry (OP65_STA, L[1]->AM, L[1]->Arg, 0, L[1]->LI);
CS_InsertEntry (S, X, I+7);
/* Now remove the call to the subroutine and the sta/stx */
CS_DelEntries (S, I, 3);
} else {
/* Standard replacement */
/* lda (sp),y */
X = NewCodeEntry (OP65_LDA, AM65_ZP_INDY, "sp", 0, L[0]->LI);
CS_InsertEntry (S, X, I+1);
/* tax */
X = NewCodeEntry (OP65_TAX, AM65_IMP, 0, 0, L[0]->LI);
CS_InsertEntry (S, X, I+2);
/* dey */
X = NewCodeEntry (OP65_DEY, AM65_IMP, 0, 0, L[0]->LI);
CS_InsertEntry (S, X, I+3);
/* lda (sp),y */
X = NewCodeEntry (OP65_LDA, AM65_ZP_INDY, "sp", 0, L[0]->LI);
CS_InsertEntry (S, X, I+4);
/* Now remove the call to the subroutine */
CS_DelEntry (S, I);
}
/* Remember, we had changes */
++Changes;
}
/* Next entry */
++I;
}
/* Return the number of changes made */
return Changes;
}
unsigned OptCmp5 (CodeSeg* S)
/* Optimize compares of local variables:
*
* ldy #o
* jsr ldaxysp
* cpx #a
* bne L1
* cmp #b
* jne/jeq L2
*/
{
unsigned Changes = 0;
/* Walk over the entries */
unsigned I = 0;
while (I < CS_GetEntryCount (S)) {
CodeEntry* L[6];
/* Get the next entry */
L[0] = CS_GetEntry (S, I);
/* Check for the sequence */
if (L[0]->OPC == OP65_LDY &&
CE_IsConstImm (L[0]) &&
CS_GetEntries (S, L+1, I+1, 5) &&
!CE_HasLabel (L[1]) &&
CE_IsCallTo (L[1], "ldaxysp") &&
IsImmCmp16 (L+2)) {
if ((L[5]->Info & OF_FBRA) != 0 && L[2]->Num == 0 && L[4]->Num == 0) {
CodeEntry* X;
char Buf[20];
/* The value is zero, we may use the simple code version:
* ldy #o-1
* lda (sp),y
* ldy #o
* ora (sp),y
* jne/jeq ...
*/
sprintf (Buf, "$%02X", (int)(L[0]->Num-1));
X = NewCodeEntry (OP65_LDY, AM65_IMM, Buf, 0, L[0]->LI);
CS_InsertEntry (S, X, I+1);
X = NewCodeEntry (OP65_LDA, AM65_ZP_INDY, "sp", 0, L[1]->LI);
CS_InsertEntry (S, X, I+2);
X = NewCodeEntry (OP65_LDY, AM65_IMM, L[0]->Arg, 0, L[0]->LI);
CS_InsertEntry (S, X, I+3);
X = NewCodeEntry (OP65_ORA, AM65_ZP_INDY, "sp", 0, L[1]->LI);
CS_InsertEntry (S, X, I+4);
CS_DelEntries (S, I+5, 3); /* cpx/bne/cmp */
CS_DelEntry (S, I); /* ldy */
} else {
CodeEntry* X;
char Buf[20];
/* Change the code to just use the A register. Move the load
* of the low byte after the first branch if possible:
*
* ldy #o
* lda (sp),y
* cmp #a
* bne L1
* ldy #o-1
* lda (sp),y
* cmp #b
* jne/jeq ...
*/
X = NewCodeEntry (OP65_LDY, AM65_IMM, L[0]->Arg, 0, L[0]->LI);
CS_InsertEntry (S, X, I+3);
X = NewCodeEntry (OP65_LDA, AM65_ZP_INDY, "sp", 0, L[1]->LI);
CS_InsertEntry (S, X, I+4);
X = NewCodeEntry (OP65_CMP, L[2]->AM, L[2]->Arg, 0, L[2]->LI);
CS_InsertEntry (S, X, I+5);
sprintf (Buf, "$%02X", (int)(L[0]->Num-1));
X = NewCodeEntry (OP65_LDY, AM65_IMM, Buf, 0, L[0]->LI);
CS_InsertEntry (S, X, I+7);
X = NewCodeEntry (OP65_LDA, AM65_ZP_INDY, "sp", 0, L[1]->LI);
CS_InsertEntry (S, X, I+8);
CS_DelEntries (S, I, 3); /* ldy/jsr/cpx */
}
++Changes;
}
/* Next entry */
++I;
}
/* Return the number of changes made */
return Changes;
}
unsigned OptPush1 (CodeSeg* S)
/* Given a sequence
*
* jsr ldaxysp
* jsr pushax
*
* If a/x are not used later, and Y is known, replace that by
*
* ldy #xx+2
* jsr pushwysp
*
* saving 3 bytes and several cycles.
*/
{
unsigned I;
unsigned Changes = 0;
/* Walk over the entries */
I = 0;
while (I < CS_GetEntryCount (S)) {
CodeEntry* L[2];
/* Get next entry */
L[0] = CS_GetEntry (S, I);
/* Check for the sequence */
if (CE_IsCallTo (L[0], "ldaxysp") &&
RegValIsKnown (L[0]->RI->In.RegY) &&
L[0]->RI->In.RegY < 0xFE &&
(L[1] = CS_GetNextEntry (S, I)) != 0 &&
!CE_HasLabel (L[1]) &&
CE_IsCallTo (L[1], "pushax") &&
!RegAXUsed (S, I+2)) {
/* Insert new code behind the pushax */
const char* Arg;
CodeEntry* X;
/* ldy #xx+1 */
Arg = MakeHexArg (L[0]->RI->In.RegY+2);
X = NewCodeEntry (OP65_LDY, AM65_IMM, Arg, 0, L[0]->LI);
CS_InsertEntry (S, X, I+2);
/* jsr pushwysp */
X = NewCodeEntry (OP65_JSR, AM65_ABS, "pushwysp", 0, L[1]->LI);
CS_InsertEntry (S, X, I+3);
/* Delete the old code */
CS_DelEntries (S, I, 2);
/* Remember, we had changes */
++Changes;
}
/* Next entry */
++I;
}
/* Return the number of changes made */
return Changes;
}
unsigned OptNegAX2 (CodeSeg* S)
/* Search for a call to negax and replace it by
*
* ldx #$FF
* eor #$FF
* clc
* adc #$01
* bne L1
* inx
* L1:
*
* if X is known and zero on entry.
*/
{
unsigned Changes = 0;
unsigned I;
/* Walk over the entries */
I = 0;
while (I < CS_GetEntryCount (S)) {
CodeEntry* P;
/* Get next entry */
CodeEntry* E = CS_GetEntry (S, I);
/* Check if this is a call to negax, and if X is known and zero */
if (E->RI->In.RegX == 0 &&
CE_IsCallTo (E, "negax") &&
(P = CS_GetNextEntry (S, I)) != 0) {
CodeEntry* X;
CodeLabel* L;
/* Add replacement code behind */
/* ldx #$FF */
X = NewCodeEntry (OP65_LDX, AM65_IMM, "$FF", 0, E->LI);
CS_InsertEntry (S, X, I+1);
/* eor #$FF */
X = NewCodeEntry (OP65_EOR, AM65_IMM, "$FF", 0, E->LI);
CS_InsertEntry (S, X, I+2);
/* clc */
X = NewCodeEntry (OP65_CLC, AM65_IMP, 0, 0, E->LI);
CS_InsertEntry (S, X, I+3);
/* adc #$01 */
X = NewCodeEntry (OP65_ADC, AM65_IMM, "$01", 0, E->LI);
CS_InsertEntry (S, X, I+4);
/* Get the label attached to the insn following the call */
L = CS_GenLabel (S, P);
/* bne L */
X = NewCodeEntry (OP65_BNE, AM65_BRA, L->Name, L, E->LI);
CS_InsertEntry (S, X, I+5);
/* inx */
X = NewCodeEntry (OP65_INX, AM65_IMP, 0, 0, E->LI);
CS_InsertEntry (S, X, I+6);
/* Delete the call to negax */
CS_DelEntry (S, I);
/* Skip the generated code */
I += 5;
/* We had changes */
++Changes;
}
/* Next entry */
++I;
}
/* Return the number of changes made */
return Changes;
}
unsigned OptAdd3 (CodeSeg* S)
/* Search for the sequence
*
* jsr pushax
* ldx #$00
* lda xxx
* jsr tosaddax
*
* and replace it by
*
* clc
* adc xxx
* bcc L1
* inx
* L1:
*/
{
unsigned Changes = 0;
/* Walk over the entries */
unsigned I = 0;
while (I < CS_GetEntryCount (S)) {
CodeEntry* L[5];
/* Get next entry */
L[0] = CS_GetEntry (S, I);
/* Check for the sequence */
if (CE_IsCallTo (L[0], "pushax") &&
CS_GetEntries (S, L+1, I+1, 4) &&
!CS_RangeHasLabel (S, I+1, 3) &&
L[1]->OPC == OP65_LDX &&
CE_IsKnownImm (L[1], 0) &&
L[2]->OPC == OP65_LDA &&
CE_IsCallTo (L[3], "tosaddax")) {
CodeEntry* X;
CodeLabel* Label;
/* Insert new code behind the sequence */
X = NewCodeEntry (OP65_CLC, AM65_IMP, 0, 0, L[3]->LI);
CS_InsertEntry (S, X, I+4);
/* adc xxx */
X = NewCodeEntry (OP65_ADC, L[2]->AM, L[2]->Arg, 0, L[3]->LI);
CS_InsertEntry (S, X, I+5);
/* bcc L1 */
Label = CS_GenLabel (S, L[4]);
X = NewCodeEntry (OP65_BCC, AM65_BRA, Label->Name, Label, L[3]->LI);
CS_InsertEntry (S, X, I+6);
/* inx */
X = NewCodeEntry (OP65_INX, AM65_IMP, 0, 0, L[3]->LI);
CS_InsertEntry (S, X, I+7);
/* Delete the old code */
CS_DelEntries (S, I, 4);
/* Remember, we had changes */
++Changes;
}
/* Next entry */
++I;
}
/* Return the number of changes made */
return Changes;
}
unsigned OptAdd4 (CodeSeg* S)
/* Search for the sequence
*
* jsr pushax
* lda xxx
* ldx yyy
* jsr tosaddax
*
* and replace it by
*
* clc
* adc xxx
* pha
* txa
* adc yyy
* tax
* pla
*/
{
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 (CE_IsCallTo (L[0], "pushax") &&
CS_GetEntries (S, L+1, I+1, 3) &&
!CS_RangeHasLabel (S, I+1, 3) &&
L[1]->OPC == OP65_LDA &&
(L[1]->AM == AM65_ABS || L[1]->AM == AM65_ZP) &&
L[2]->OPC == OP65_LDX &&
(L[2]->AM == AM65_ABS || L[2]->AM == AM65_ZP) &&
CE_IsCallTo (L[3], "tosaddax")) {
CodeEntry* X;
/* Insert new code behind the sequence */
X = NewCodeEntry (OP65_CLC, AM65_IMP, 0, 0, L[3]->LI);
CS_InsertEntry (S, X, I+4);
/* adc xxx */
X = NewCodeEntry (OP65_ADC, L[1]->AM, L[1]->Arg, 0, L[3]->LI);
CS_InsertEntry (S, X, I+5);
/* pha */
X = NewCodeEntry (OP65_PHA, AM65_IMP, 0, 0, L[3]->LI);
CS_InsertEntry (S, X, I+6);
/* txa */
X = NewCodeEntry (OP65_TXA, AM65_IMP, 0, 0, L[3]->LI);
CS_InsertEntry (S, X, I+7);
/* adc yyy */
X = NewCodeEntry (OP65_ADC, L[2]->AM, L[2]->Arg, 0, L[3]->LI);
CS_InsertEntry (S, X, I+8);
/* tax */
X = NewCodeEntry (OP65_TAX, AM65_IMP, 0, 0, L[3]->LI);
CS_InsertEntry (S, X, I+9);
/* pla */
X = NewCodeEntry (OP65_PLA, AM65_IMP, 0, 0, L[3]->LI);
CS_InsertEntry (S, X, I+10);
/* Delete the old code */
CS_DelEntries (S, I, 4);
/* Remember, we had changes */
++Changes;
}
/* Next entry */
++I;
}
/* Return the number of changes made */
return Changes;
}
unsigned OptBNegAX2 (CodeSeg* S)
/* Search for the sequence:
*
* ldy #xx
* jsr ldaxysp
* jsr bnegax
* jne/jeq ...
*
* and replace it by
*
* ldy #xx
* lda (sp),y
* dey
* ora (sp),y
* jeq/jne ...
*/
{
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_LDY &&
CE_IsConstImm (L[0]) &&
!CS_RangeHasLabel (S, I+1, 3) &&
CS_GetEntries (S, L+1, I+1, 3) &&
CE_IsCallTo (L[1], "ldaxysp") &&
CE_IsCallTo (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[3], GetInverseBranch (L[3]->OPC));
/* Delete the entries no longer needed. */
CS_DelEntries (S, I+4, 2);
/* Remember, we had changes */
++Changes;
}
/* Next entry */
++I;
}
/* Return the number of changes made */
return Changes;
}
unsigned OptAdd1 (CodeSeg* S)
/* Search for the sequence
*
* ldy #xx
* jsr ldaxysp
* jsr pushax
* ldy #yy
* jsr ldaxysp
* jsr tosaddax
*
* and replace it by:
*
* ldy #xx-1
* lda (sp),y
* ldy #yy-3
* clc
* adc (sp),y
* pha
* ldy #xx
* lda (sp),y
* ldy #yy-2
* adc (sp),y
* tax
* pla
*/
{
unsigned Changes = 0;
/* Walk over the entries */
unsigned I = 0;
while (I < CS_GetEntryCount (S)) {
CodeEntry* L[6];
/* Get next entry */
L[0] = CS_GetEntry (S, I);
/* Check for the sequence */
if (L[0]->OPC == OP65_LDY &&
CE_IsConstImm (L[0]) &&
!CS_RangeHasLabel (S, I+1, 5) &&
CS_GetEntries (S, L+1, I+1, 5) &&
CE_IsCallTo (L[1], "ldaxysp") &&
CE_IsCallTo (L[2], "pushax") &&
L[3]->OPC == OP65_LDY &&
CE_IsConstImm (L[3]) &&
CE_IsCallTo (L[4], "ldaxysp") &&
CE_IsCallTo (L[5], "tosaddax")) {
CodeEntry* X;
const char* Arg;
/* Correct the stack of the first Y register load */
CE_SetNumArg (L[0], L[0]->Num - 1);
/* lda (sp),y */
X = NewCodeEntry (OP65_LDA, AM65_ZP_INDY, "sp", 0, L[1]->LI);
CS_InsertEntry (S, X, I+1);
/* ldy #yy-3 */
Arg = MakeHexArg (L[3]->Num - 3);
X = NewCodeEntry (OP65_LDY, AM65_IMM, Arg, 0, L[4]->LI);
CS_InsertEntry (S, X, I+2);
/* clc */
X = NewCodeEntry (OP65_CLC, AM65_IMP, 0, 0, L[5]->LI);
CS_InsertEntry (S, X, I+3);
/* adc (sp),y */
X = NewCodeEntry (OP65_ADC, AM65_ZP_INDY, "sp", 0, L[5]->LI);
CS_InsertEntry (S, X, I+4);
/* pha */
X = NewCodeEntry (OP65_PHA, AM65_IMP, 0, 0, L[5]->LI);
CS_InsertEntry (S, X, I+5);
/* ldy #xx (beware: L[0] has changed) */
Arg = MakeHexArg (L[0]->Num + 1);
X = NewCodeEntry (OP65_LDY, AM65_IMM, Arg, 0, L[1]->LI);
CS_InsertEntry (S, X, I+6);
/* lda (sp),y */
X = NewCodeEntry (OP65_LDA, AM65_ZP_INDY, "sp", 0, L[1]->LI);
CS_InsertEntry (S, X, I+7);
/* ldy #yy-2 */
Arg = MakeHexArg (L[3]->Num - 2);
X = NewCodeEntry (OP65_LDY, AM65_IMM, Arg, 0, L[4]->LI);
CS_InsertEntry (S, X, I+8);
/* adc (sp),y */
X = NewCodeEntry (OP65_ADC, AM65_ZP_INDY, "sp", 0, L[5]->LI);
CS_InsertEntry (S, X, I+9);
/* tax */
X = NewCodeEntry (OP65_TAX, AM65_IMP, 0, 0, L[5]->LI);
CS_InsertEntry (S, X, I+10);
/* pla */
X = NewCodeEntry (OP65_PLA, AM65_IMP, 0, 0, L[5]->LI);
CS_InsertEntry (S, X, I+11);
/* Delete the old code */
CS_DelEntries (S, I+12, 5);
/* Remember, we had changes */
++Changes;
}
/* Next entry */
++I;
}
/* Return the number of changes made */
return Changes;
}
