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)
