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Better code for > compares

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git-svn-id: svn://svn.cc65.org/cc65/trunk@823 b7a2c559-68d2-44c3-8de9-860c34a00d81
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cuz 2001-07-26 06:10:10 +00:00
parent d604ed5e3f
commit 58592116ac
1 changed files with 78 additions and 59 deletions
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31
src/cc65/codegen.c
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@ -3642,25 +3642,39 @@ void g_gt (unsigned flags, unsigned long val)
*/ */
if (flags & CF_CONST) { if (flags & CF_CONST) {
/* > is not very effective on the 6502, so try to convert
* it into >= if the value is in a valid range.
*/
/* Look at the type */ /* Look at the type */
switch (flags & CF_TYPE) { switch (flags & CF_TYPE) {
case CF_CHAR: case CF_CHAR:
if (flags & CF_FORCECHAR) { if (flags & CF_FORCECHAR) {
AddCodeLine ("cmp #$%02X", (unsigned char)val);
if (flags & CF_UNSIGNED) { if (flags & CF_UNSIGNED) {
/* If we have a compare > 0, we will replace it by /* If we have a compare > 0, we will replace it by
* != 0 here, since both are identical but the latter * != 0 here, since both are identical but the latter
* is easier to optimize. * is easier to optimize.
*/ */
if (val & 0xFF) { if (val == 0) {
AddCodeLine ("jsr boolugt"); AddCodeLine ("cmp #$%02X", (unsigned char)val);
} else {
AddCodeLine ("jsr boolne"); AddCodeLine ("jsr boolne");
} else if (val < 255) {
AddCodeLine ("cmp #$%02X", (unsigned char)val+1);
AddCodeLine ("jsr booluge");
} else {
AddCodeLine ("cmp #$%02X", (unsigned char)val);
AddCodeLine ("jsr boolugt");
} }
} else { } else {
if (val < 127) {
AddCodeLine ("cmp #$%02X", (unsigned char)val+1);
AddCodeLine ("jsr boolge");
} else {
AddCodeLine ("cmp #$%02X", (unsigned char)val);
AddCodeLine ("jsr boolgt"); AddCodeLine ("jsr boolgt");
} }
}
return; return;
} }
/* FALLTHROUGH */ /* FALLTHROUGH */
@ -3671,17 +3685,22 @@ void g_gt (unsigned flags, unsigned long val)
* != 0 here, since both are identical but the latter * != 0 here, since both are identical but the latter
* is easier to optimize. * is easier to optimize.
*/ */
if ((val & 0xFFFF) == 0) { if (val == 0) {
AddCodeLine ("stx tmp1"); AddCodeLine ("stx tmp1");
AddCodeLine ("ora tmp1"); AddCodeLine ("ora tmp1");
AddCodeLine ("jsr boolne"); AddCodeLine ("jsr boolne");
} else { } else {
unsigned L = GetLocalLabel(); unsigned L = GetLocalLabel();
const char* Name = "boolugt";
if (val < 65535) {
++val;
Name = "booluge";
}
AddCodeLine ("cpx #$%02X", (unsigned char)(val >> 8)); AddCodeLine ("cpx #$%02X", (unsigned char)(val >> 8));
AddCodeLine ("bne %s", LocalLabelName (L)); AddCodeLine ("bne %s", LocalLabelName (L));
AddCodeLine ("cmp #$%02X", (unsigned char)val); AddCodeLine ("cmp #$%02X", (unsigned char)val);
g_defcodelabel (L); g_defcodelabel (L);
AddCodeLine ("jsr boolugt"); AddCodeLine ("jsr %s", Name);
} }
return; return;
} }