https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117420
Bug ID: 117420
Summary: wrong code at -O1 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: ---
It appears to be a recent regression as it doesn't reproduce with 14.2 and
earlier.
Compiler Explorer: https://godbolt.org/z/7nKzWzohb
[674] % 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/15.0.0/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 15.0.0 20241102 (experimental) (GCC)
[675] %
[675] % gcctk -O1 small.c
[676] % ./a.out
Aborted
[677] % cat small.c
int a, b;
int main() {
b = -(1 | -(a < 1));
a = (~b & 2) / 2;
if (b != 1)
__builtin_abort();
return 0;
}