https://bugs.llvm.org/show_bug.cgi?id=42833
Bug ID: 42833
Summary: Incorrect result with -O3 -march=skx
Product: new-bugs
Version: trunk
Hardware: PC
OS: Windows NT
Status: NEW
Severity: enhancement
Priority: P
Component: new bugs
Assignee: [email protected]
Reporter: [email protected]
CC: [email protected], [email protected]
Clang produces incorrect result with -O3 -march=skx
Reproducer:
#include <stdio.h>
int b;
unsigned c[49];
int d[49];
void i() {
for (int g = 32; g <= 48; g++) {
d[g] -= c[g] + b;
c[g] += c[g] + b;
b -= b;
}
}
int main() {
for (int g = 0; g < 49; ++g)
c[g] = 3;
i();
printf("%d\n", d[36]);
}
Error:
>$ clang -O3 -march=skx small.c ; ./a.out
0
>$ clang -O0 -march=skx small.c ; ./a.out
-3
LLVM version:
clang version 10.0.0 (trunk 367162)
Target: x86_64-unknown-linux-gnu
Thread model: posix
--
You are receiving this mail because:
You are on the CC list for the bug._______________________________________________
llvm-bugs mailing list
[email protected]
https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-bugs
