https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114386
Bug ID: 114386
Summary: [10/11/12 Regression] Miscompile at -O1
Product: gcc
Version: 12.3.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: patrick at rivosinc dot com
Target Milestone: ---
Testcase:
int printf(const char *, ...);
_Bool a, c = 1;
int b, d;
int main() {
_Bool g = c;
d = !a ? ({ c > a ? c : a; }) : 0;
printf("%x\n", d);
}
Commands:
> gcc -O0 red.c -o red.o
> ./red.o
0
> gcc -O1 red.c -o red.o
> ./red.o
1
> gcc -O2 red.c -o red.o
> ./red.o
0
> gcc -O3 red.c -o red.o
> ./red.o
1
Tested/discovered on x86 - gcc v11.4.0.
Issue is not present when targeting risc-v.
Godbolt shows it's a regression starting at 10.1 (with -O1) and resolved as of
13.1.
Godbolt: https://godbolt.org/z/q4P9xs5dx
