https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110369
Bug ID: 110369
Summary: wrong code 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. I'm unsure how interesting the test is as
it uses a few non-default flags, but here it is.
Compiler Explorer: https://godbolt.org/z/rvsrfzb1K
[813] % 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/14.0.0/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
--disable-multilib
Thread model: posix
Supported LTO compression algorithms: zlib
gcc version 14.0.0 20230622 (experimental) [master r14-924-gd709841ae0f] (GCC)
[814] %
[814] % gcctk -O3 -fno-thread-jumps -fsel-sched-pipelining
-fsel-sched-pipelining-outer-loops -fno-split-loops -fno-tree-loop-ivcanon
-fselective-scheduling2 -w small.c
[815] % timeout -s 9 5 ./a.out
Killed
[816] %
[816] % gcctk -O3 -w small.c; ./a.out
[817] %
[817] % cat small.c
int printf(const char *, ...);
int a, b[2] = {0, 0}, c;
void d() {
int e, f;
for (f = 0; f < 2; f++)
if (a) {
for (e = 0; e < 5; e++) {
printf("%d", b[e]);
if (c)
printf("\n");
}
}
}
int main() { d(); }
