https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120487
Bug ID: 120487
Summary: wrong code at -Os on x86_64-linux-gnu
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: zhendong.su at inf dot ethz.ch
Target Milestone: ---
Compiler Explorer: https://godbolt.org/z/a33Mb7vfW
It affects 15.1 and trunk, and is a regression from 14.*.
[514] % gcctk -v
Using built-in specs.
COLLECT_GCC=gcctk
COLLECT_LTO_WRAPPER=/local/home/suz/suz-local/software/local/gcc-trunk/bin/../libexec/gcc/x86_64-pc-linux-gnu/16.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ../gcc-trunk/configure --disable-bootstrap
--enable-checking=yes --prefix=/local/suz-local/software/local/gcc-trunk
--enable-sanitizers --enable-languages=c,c++ --disable-werror --enable-multilib
Thread model: posix
Supported LTO compression algorithms: zlib
gcc version 16.0.0 20250530 (experimental) (GCC)
[515] %
[515] % gcctk -Os small.c
[516] % ./a.out
Aborted
[517] %
[517] % cat small.c
int printf(const char *, ...);
int a, b, c, d, e;
static void f(int g, int h) {
int i;
b = -999 - 999 * g - 999 - 2147483647;
d = -999 * b - 2147483647;
j:
i = e - 999 * g - 2147483647;
c = -999 * g - 999 * e - 2147483647;
if (c <= -300)
return;
m:
g = h - 999 * g;
i = -d - 999 * i - 2147483647;
if (-999 * i - g - c - 1080117449 >= 0)
goto j;
while (1) {
a = i;
if (g + 36057402 * i)
goto m;
}
}
int main() {
f(-2149633, -2147483647);
if (a != 0)
__builtin_abort();
return 0;
}
