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65C02 optimizations

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git-svn-id: svn://svn.cc65.org/cc65/trunk@548 b7a2c559-68d2-44c3-8de9-860c34a00d81
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cuz 2000-12-04 20:38:45 +00:00
parent d678c41294
commit e131b6e432
1 changed files with 20 additions and 3 deletions
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23
src/cc65/optimize.c
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@ -4106,10 +4106,18 @@ static Line* OptOneBlock (Line* L)
Delete = 1;
} else if (LineMatch (L, "\tlda\t(")) {
if (IsXAddrMode (L)) {
/* lda (zp,x) - if Y and X are both zero, replace by
* load indirect y and save one cycle in some cases.
/* lda (zp,x). */
/* If X is zero and we have a 65C02 cpu, replace it by
* an indirect load.
*/
if (X == 0 && Y == 0) {
if (X == 0 && CPU == CPU_65C02) {
unsigned Len = strlen (L->Line);
L->Line [Len-3] = ')';
L->Line [Len-2] = '\0';
/* If Y and X are both zero, replace by load indirect
* y and save one cycle in some cases.
*/
} else if (X == 0 && Y == 0) {
char Buf [256];
const char* S = L->Line + 6;
char* T = Buf + 6;
@ -4123,6 +4131,15 @@ static Line* OptOneBlock (Line* L)
*T = '\0';
L = ReplaceLine (L, Buf);
}
} else if (IsYAddrMode (L)) {
/* lda (zp),y. If Y is zero and we have a 65C02 CPU,
* replace it by an indirect load.
*/
if (Y == 0 && CPU == CPU_65C02) {
unsigned Len = strlen (L->Line);
L->Line [Len-3] = ')';
L->Line [Len-2] = '\0';
}
}
/* In any case invalidate A */
A = -1;