https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110509
Bug ID: 110509
Summary: wrong code at -O3 on x86_64-linux-gnu
(nondeterministic hang)
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: ---
This appears to be a recent regression.
Compiler Explorer: https://godbolt.org/z/xMnq1jYeW
[521] % 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 20230701 (experimental) (GCC)
[522] %
[522] % gcctk -O3 small.c
[523] % for i in $(seq 1 10); do
> echo $i
> timeout -s 9 5 ./a.out
> done
1
2
3
4
Killed
5
6
7
Killed
8
Killed
9
Killed
10
Killed
[524] %
[524] % cat small.c
int printf (const char *, ...);
int a, d = 10, b = 8, c, e, i, r, f, j;
int g (short l) {
if (d)
return l;
}
int main () {
int m[] = {987, 1, 47}, p, o = 2;
L1:
p = g (m[2] >= 8);
while (1) {
while (p > 1)
while (r) {
int h = m[a];
while (1)
;
}
while (i < 9) {
if (c && f) {
if (o) {
p = 7 ^ j;
b = o = 0;
if (p <= 4) {
printf ("%d", j);
goto L2;
}
}
if (j)
goto L1;
L2:
b > 1;
}
if (b)
return e;
}
}
return 0;
}
