https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111792
Bug ID: 111792
Summary: wrong code at -O3 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.
compiler Explorer: https://godbolt.org/z/7vfzPYTrn
[537] % 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/14.0.0/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 14.0.0 20231013 (experimental) (GCC)
[538] %
[538] % gcctk -O2 small.c; ./a.out
[539] %
[539] % gcctk -O3 small.c
[540] % ./a.out
Aborted
[541] % cat small.c
int c, d, h, i, j, l, *n = &h;
short e, f, g, *k, m;
long o;
short p(short p1, int q) { return q >= 32 || p1 > 5 >> q ? 1 : p1 << q; }
long u(unsigned p1) {
int r = 50, s, *t = &c;
L:
m && (*k = 0);
for (d = 1; d; d--)
for (s = 0; s < 3; s++) {
*n = i ^ p1;
*t = p1 > (unsigned)p((unsigned)(o = 4073709551615) >= p1 && 5, r);
if (f)
goto L;
}
for (; e < 1;)
return j;
int *b[2] = {&s, &r};
for (; l; l--) {
long a[1];
for (r = 0; r < 1; r++) {
h = a[0];
if (g)
goto L;
}
}
return 0;
}
int main() {
u(6);
if (c != 1)
__builtin_abort();
return 0;
}