https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98381
Bug ID: 98381
Summary: Wrong code with -O3 -march=skylake-avx512
Product: gcc
Version: 11.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: vsevolod.livinskij at frtk dot ru
Target Milestone: ---
Reproducer:
//func.cpp
extern bool var_22;
void test(long long a, unsigned b, unsigned long long c) {
for (long i = 0; i < 16; i += 1ULL)
if (a)
var_22 = 5023804122334ULL >= (char)c;
}
//driver.cpp
#include <stdio.h>
long long int a = -2161098602020439353LL;
unsigned int b = 1621447385U;
unsigned long long int c = 16505450185101189749ULL;
bool var_22 = (bool)0;
void test(long long int a, unsigned int b, unsigned long long int c);
int main() {
test(a, b, c);
printf("%d\n", (int)var_22);
}
Error:
>$ g++ -O3 -march=skylake-avx512 func.cpp driver.cpp && sde -skx -- ./a.out
0
>$ g++ -O0 func.cpp driver.cpp && sde -skx -- ./a.out
1
gcc version 11.0.0 20201217 (6f8486523f61bf0aa476dfa4197d1e3b71a0a8f3) (GCC)
