https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63380
Bug ID: 63380 Summary: Wrong constant folding Product: gcc Version: 5.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: tree-optimization Assignee: unassigned at gcc dot gnu.org Reporter: ishiura-compiler at ml dot kwansei.ac.jp GCC 5.0.0 for x86_64 miscompiles the following code. $ cat test.c int a = 0, b = 1, c = 0, d = 1, e, f, g, h; int main () { e = 1 >> d; f = ((31 / (1 > e)) || c) / 2; g = b || a; h = 31 / g; if (!h) __builtin_abort(); return 0; } $ x86_64-unknown-linux-gnu-gcc-5.0.0 test.c -O2 $ ./a.out Floating point exception (core dumped) $ x86_64-unknown-linux-gnu-gcc-5.0.0 -v Using built-in specs. COLLECT_GCC=x86_64-unknown-linux-gnu-gcc-5.0.0 COLLECT_LTO_WRAPPER=/usr/local/x86_64-tools/gcc- 5.0.0/libexec/gcc/x86_64-unknown-linux-gnu/5.0.0/lto-wrapper Target: x86_64-unknown-linux-gnu Configured with: /home/orange3/gcc-master/configure -- prefix=/usr/local/x86_64-tools/gcc-5.0.0/ --with-gmp=/usr/local/gmp- 5.1.1/ --with-mpfr=/usr/local/mpfr-3.1.2/ --with-mpc=/usr/local/mpc- 1.0.1/ --disable-multilib --disable-nls --enable-languages=c Thread model: posix gcc version 5.0.0 20140922 (experimental) (GCC)