https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70333
Bug ID: 70333 Summary: [5/6 Regression] Test miscompiled with -O0. Product: gcc Version: 6.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: target Assignee: unassigned at gcc dot gnu.org Reporter: vsevolod.livinskij at frtk dot ru Target Milestone: --- Created attachment 38042 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=38042&action=edit Reproducer. Test case produces incorrect result with -O0. It also fails with gcc version 5.3.1 20160318 (Revision=234347) and works fine with gcc version 4.9.4 20160318 (prerelease) (Revision=234347) GCC version: > g++ -v Using built-in specs. COLLECT_GCC=g++ COLLECT_LTO_WRAPPER=/export/users/vlivinsk/gcc-trunk/bin/libexec/gcc/x86_64-pc-linux-gnu/6.0.0/lto-wrapper Target: x86_64-pc-linux-gnu Configured with: /export/users/vlivinsk/gcc-trunk/gcc/configure --with-arch=corei7 --with-cpu=corei7 --enable-clocale=gnu --with-system-zlib --enable-shared --with-demangler-in-ld --enable-cloog-backend=isl --with-fpmath=sse --enable-checking=release --enable-languages=c,c++,lto --with-gmp=/export/users/vlivinsk/gcc-trunk/gmp-6.1.0/bin --with-mpfr=/export/users/vlivinsk/gcc-trunk/mpfr-3.1.3/bin --with-mpc=/export/users/vlivinsk/gcc-trunk/mpc-1.0.3/bin --prefix=/export/users/vlivinsk/gcc-trunk/bin Thread model: posix gcc version 6.0.0 20160319 (experimental) (Revision=234350) Test: #include <iostream> signed char a = -33; signed char b = -60; signed char c = 70; long int d = 8591990532774389055L; void foo () { signed char e = ((unsigned long int)a < (unsigned long int)8) == (a > c); d = ((2UL * b) * (e * 13)) * (32 << 24); } int main () { foo (); if (d != -837518622720) abort(); return 0; }