https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114793
Bug ID: 114793
Summary: wrong code at -O1 with "-fschedule-insns2
-fselective-scheduling2" on x86_64-linux-gnu (the
generated code hangs)
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 seems to be a recent regression as it does not reproduce with 13.2 and
earlier.
Compiler Explorer: https://godbolt.org/z/b3cc1MqP9
[538] % gcctk -v
Using built-in specs.
COLLECT_GCC=gcctk
COLLECT_LTO_WRAPPER=/local/suz-local/software/local/gcc-trunk/libexec/gcc/x86_64-pc-linux-gnu/14.0.1/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 14.0.1 20240421 (experimental) (GCC)
[539] %
[539] % gcctk -O0 small.c
[540] % ./a.out
[541] %
[541] % gcctk -O1 -fschedule-insns2 -fselective-scheduling2 small.c
[542] % timeout -s 9 10 ./a.out
Killed
[543] %
[543] % cat small.c
int printf(const char *, ...);
volatile int a;
int b, c, d = 1, e, f;
int main() {
int g = 1;
for (; b; b -= d)
g = e;
for (; c < 2; c++) {
if (g) {
if (!d)
printf("%d", f);
continue;
}
a;
}
return 0;
}
