https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112996
Bug ID: 112996
Summary: Improperly evaluated value of the s390x conditional
expression
Product: gcc
Version: 11.4.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: 22s302h0659 at sonline20 dot sen.go.kr
Target Milestone: ---
# Environment
- Compiler: s390x-linux-gnu-gcc (64bit)
- Version: gcc version 11.4.0 (Ubuntu 11.4.0-1ubuntu1~22.04)
- Platform: Windows 11_5.15.90.1-microsoft-standard-WSL2
- Build Optimization Options: O0, O1, O2, O3
I installed the s390x-linux-gnu toolchain using the 'apt' package manager in
Ubuntu and utilized s390x-linux-gnu-gcc (version 11.4.0) from it.
# build script & excution script
```c
s390x-linux-gnu-gcc -o bug0 bug.c -O0 -fsanitize=undefined
s390x-linux-gnu-gcc -o bug1 bug.c -O1 -fsanitize=undefined
s390x-linux-gnu-gcc -o bug2 bug.c -O2 -fsanitize=undefined
s390x-linux-gnu-gcc -o bug3 bug.c -O3 -fsanitize=undefined
```
```c
qemu-s390x-static -L /usr/s390x-linux-gnu/ ./bug0
qemu-s390x-static -L /usr/s390x-linux-gnu/ ./bug1
qemu-s390x-static -L /usr/s390x-linux-gnu/ ./bug2
qemu-s390x-static -L /usr/s390x-linux-gnu/ ./bug3
```
This is the build script and the execution script.
# Source Code
```c
#include <stdio.h>
signed short v1 = 1;
signed int v2 = 2;
unsigned long long bug = 0;
int main ()
{
if ((v1 < v2))
{
bug = v2;
}
printf("bug = %llu\n", bug);
return 0;
}
```
The C code built with GCC on the s390x architecture returns incorrect values.
The evaluated value of the conditional expression in the 'if' statement should
be true, but with the O2 and O3 options, it returns false.
# output
```c
Expected output
O0: 2
O1: 2
O2: 2
O3: 2
Actual output
O0: 2
O1: 2
O2: 0
O3: 0
```
