[Bug tree-optimization/100934] New: wrong code at -O3 on x86_64-linux-gnu
zhendong.su at inf dot ethz.ch
gcc-bugzilla@gcc.gnu.org
Sun Jun 6 20:49:44 GMT 2021
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100934
Bug ID: 100934
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 seems to affect all versions since GCC 8.4 (but not GCC 8.3).
[583] % 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/12.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ../gcc-trunk/configure --disable-bootstrap
--prefix=/local/suz-local/software/local/gcc-trunk --enable-languages=c,c++
--disable-werror --enable-multilib --with-system-zlib
Thread model: posix
Supported LTO compression algorithms: zlib
gcc version 12.0.0 20210606 (experimental) [master revision
28c62475050:a6bc26893ec:a589877a0036fc2f66b7a957859940c53efdc7c9] (GCC)
[584] %
[584] % gcctk -O2 small.c; ./a.out
[585] %
[585] % gcctk -O3 small.c
[586] % ./a.out
Segmentation fault
[587] %
[587] % cat small.c
int a, b, c, d, e;
int main() {
int f = 0, g = 0;
for (; f < 2; f++) {
int h, i;
for (h = 0; h < 2; h++) {
b = e = g ? a % g : 0;
c = d;
for (i = 0; i < 1; i++)
g = 0;
for (; g < 2; g++)
;
}
}
return 0;
}
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