https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95118
Bug ID: 95118 Summary: gcc-10 and master -O3 -fopt-info-vec causes gcc to hang Product: gcc Version: 10.1.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: tree-optimization Assignee: unassigned at gcc dot gnu.org Reporter: slyfox at inbox dot ru Target Milestone: --- The bug originally reported by Adrien Dessemond as https://bugs.gentoo.org/722774 where gzip-1.10's ./configure CFLAGS="-O3 -pipe -march=native -fomit-frame-pointer -fopt-info-vec -mindirect-branch=thunk -mindirect-branch-register" makes gcc hang. Minimal reproducer against gcc-10.1.0 anf gcc-master is: // $ cat bug.c void a(); void b() { union { int c[4]; long double d; } e = {{0, 0, 4}}; a(e.d); } $ /usr/bin/x86_64-pc-linux-gnu-gcc-10.1.0 -o conftest -O3 -fopt-info-vec -c bug.c <hung> Reproducible on the following gcc config against master: Reading specs from /home/slyfox/dev/git/gcc-native-quick/gcc/specs COLLECT_GCC=/home/slyfox/dev/git/gcc-native-quick/gcc/xgcc COLLECT_LTO_WRAPPER=/home/slyfox/dev/git/gcc-native-quick/gcc/lto-wrapper Target: x86_64-pc-linux-gnu Configured with: ../gcc/configure --enable-languages=c,c++ --disable-bootstrap --with-multilib-list=m64 --prefix=/home/slyfox/dev/git/gcc-native-quick/../gcc-native-quick-installed --disable-nls --without-isl --disable-libsanitizer --disable-libvtv --disable-libgomp --disable-libstdcxx-pch --disable-libunwind-exceptions CFLAGS='-O1 ' CXXFLAGS='-O1 ' --with-sysroot=/usr/x86_64-HEAD-linux-gnu Thread model: posix Supported LTO compression algorithms: zlib zstd gcc version 11.0.0 20200513 (experimental) (GCC)