https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112305
Bug ID: 112305
Summary: [13/14 Regression] Wrong code at -O1/2/3/s on
x86_64-pc-linux-gnu
Product: gcc
Version: 14.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: middle-end
Assignee: unassigned at gcc dot gnu.org
Reporter: jwzeng at nuaa dot edu.cn
Target Milestone: ---
I compiled the following code with gcc at -O1/2/3/s, and it produces the wrong
code. The correct output result should be -1560359471, but -486617677 was
output under -O1/2/3/s.
I found this bug was introduced starting from gcc-13.1
Compiler explorer: https://godbolt.org/z/s7K9z5166
```c
$ cat test.c
int printf(const char *, ...);
int a;
void b() {
long c = 3;
unsigned int d = 50253292;
int e = 2147483648;
for (; a < 5; a++)
do {
e += 4;
d -= c;
} while (e < 20);
printf("%d\n", d);
}
int main() { b(); }
$
$ gcc-tk test.c -O0; ./test.c
-1560359471
$ gcc-tk test.c -O1; ./test.c
-486617677
$ gcc-tk test.c -O2; ./test.c
-486617677
$ gcc-tk test.c -O3; ./test.c
-486617677
$ gcc-tk test.c -Os; ./test.c
-486617677
$ ccomp test.c -O1; ./a.out
-1560359471
$
$ gcc-tk --version
gcc (GCC) 14.0.0 20231028 (experimental) [master r14-4987-g7f974c5fd4]
Copyright (C) 2023 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
$
$ ccomp --version
The CompCert C verified compiler, version 3.12
```
