https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118953
Bug ID: 118953
Summary: Miscompile at -O3
Product: gcc
Version: 15.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: yunboni at smail dot nju.edu.cn
Target Milestone: ---
This code prints 45 at -O3 and 0 at -O0/1/2/s:
int printf(const char *, ...);
int a, d;
long b, c;
int e(int f, int g, unsigned long h, long j) {
unsigned long i = 0;
if (g)
switch (f) {
case 8:
i = b;
break;
case 6:
i = c;
}
else
switch (f) {
case 8:
i = h;
break;
case 24:
case 32:
i = j;
}
return i;
}
int main() {
int k = a * (409628 - 28);
d = e(k - 1048524, 0, k - 1048487, (unsigned long)k - 1048531);
printf("%d\n", d);
}
Compiler Explorer: https://godbolt.org/z/YTWjbWe3s
Bisected to
https://github.com/gcc-mirror/gcc/commit/602e824eec30a7c6792b8b27d61c40f1c1a2714c
