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Merge pull request #2291 from colinleroy/fix-256-minus-1

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Fix bug introduced in #2260
This commit is contained in:
Bob Andrews 2023-12-09 22:11:33 +01:00 committed by GitHub
commit d805211002
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GPG Key ID: 4AEE18F83AFDEB23
2 changed files with 28 additions and 7 deletions
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8
src/cc65/codegen.c
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@ -3697,13 +3697,7 @@ void g_dec (unsigned flags, unsigned long val)
} else {
/* Inline the code */
if (val < 0x300) {
if ((CPUIsets[CPU] & CPU_ISET_65SC02) != 0 && val == 1) {
unsigned L = GetLocalLabel();
AddCodeLine ("bne %s", LocalLabelName (L));
AddCodeLine ("dex");
g_defcodelabel (L);
AddCodeLine ("dea");
} else if ((val & 0xFF) != 0) {
if ((val & 0xFF) != 0) {
unsigned L = GetLocalLabel();
AddCodeLine ("sec");
AddCodeLine ("sbc #$%02X", (unsigned char) val);

27
test/val/sub3.c
View File

@ -168,6 +168,31 @@ void post_dec_assign_test(void)
failures++;
}
void dex_tests(void) {
static unsigned int a, b;
a = 257;
b = a - 1;
if (b != 256) {
printf("fail 257 => 256\n");
failures++;
}
a = 256;
b = a - 1;
if (b != 255) {
printf("fail 256 => 255\n");
failures++;
}
a = 255;
b = a - 1;
if (b != 254) {
printf("fail 255 => 254\n");
failures++;
}
}
int main(void)
{
int0 = 5;
@ -186,6 +211,8 @@ int main(void)
int1 = 5;
post_dec_assign_test();
dex_tests();
printf("failures: %d\n",failures);
return failures;