http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58662
Bug ID: 58662 Summary: wrong code at -O2 and -O3 on x86_64-linux-gnu (in 64-bit mode) Product: gcc Version: 4.9.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: tree-optimization Assignee: unassigned at gcc dot gnu.org Reporter: su at cs dot ucdavis.edu The current gcc trunk miscompiles the attached testcase on x86_64-linux-gnu at -O2 and -O3 in 64-bit mode. It is a regression from 4.8.x. $ gcc-trunk -v Using built-in specs. COLLECT_GCC=gcc-trunk COLLECT_LTO_WRAPPER=/usr/local/gcc-trunk/libexec/gcc/x86_64-unknown-linux-gnu/4.9.0/lto-wrapper Target: x86_64-unknown-linux-gnu Configured with: ../gcc-trunk/configure --enable-languages=c,c++,objc,obj-c++,fortran,lto --disable-werror --enable-checking=release --with-gmp=/usr/local/gcc-trunk --with-mpfr=/usr/local/gcc-trunk --with-mpc=/usr/local/gcc-trunk --with-cloog=/usr/local/gcc-trunk --prefix=/usr/local/gcc-trunk Thread model: posix gcc version 4.9.0 20131007 (experimental) [trunk revision 203235] (GCC) $ $ gcc-trunk -Os small.c; a.out 0 $ gcc-trunk -O2 small.c; a.out -1008071096 $ gcc-trunk -O3 small.c; a.out 86090104 $ $ gcc-4.8 -O2 small.c; a.out 0 $ gcc-4.8 -O3 small.c; a.out 0 $ ------------------------------------- int printf (const char *, ...); int a, b, c, d; int foo (int p1, short p2) { return p1 / p2; } int main () { char e; d = foo (a == 0, (0, 35536)); e = d % 14; b = e && c; printf ("%d\n", b); return 0; }