https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71477
Bug ID: 71477 Summary: gcc ICE at -O3 on valid code on x86_64-linux-gnu with “seg fault” Product: gcc Version: 7.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: tree-optimization Assignee: unassigned at gcc dot gnu.org Reporter: helloqirun at gmail dot com Target Milestone: --- The following valid code causes an ICE when compiled with the current gcc trunk at only -O3 on x86_64-linux-gnu in 64-bit mode. 32-bit mode works fine. It appears to be a 7 regression. $ gcc-trunk -v Using built-in specs. COLLECT_GCC=gcc-trunk COLLECT_LTO_WRAPPER=/home/absozero/trunk/root-gcc/libexec/gcc/x86_64-pc-linux-gnu/7.0.0/lto-wrapper Target: x86_64-pc-linux-gnu Configured with: ../gcc/configure --prefix=/home/absozero/trunk/root-gcc --enable-languages=c,c++ --disable-werror --enable-multilib Thread model: posix gcc version 7.0.0 20160608 (experimental) [trunk revision 237212] (GCC) $ gcc-trunk -O3 abc.c abc.c: In function ‘fn1’: abc.c:3:6: internal compiler error: Segmentation fault void fn1() { ^~~ 0xb635cf crash_signal ../../gcc/gcc/toplev.c:335 0xe5a184 top_bit_of ../../gcc/gcc/wide-int.cc:424 0xe5a184 wi::add_large(long*, long const*, unsigned int, long const*, unsigned int, unsigned int, signop, bool*) ../../gcc/gcc/wide-int.cc:1143 0xdad921 wi::binary_traits<generic_wide_int<fixed_wide_int_storage<192> >, int, wi::int_traits<generic_wide_int<fixed_wide_int_storage<192> > >::precision_type, wi::int_traits<int>::precision_type>::result_type wi::add<generic_wide_int<fixed_wide_int_storage<192> >, int>(generic_wide_int<fixed_wide_int_storage<192> > const&, int const&) ../../gcc/gcc/wide-int.h:2330 0xdad921 wi::binary_traits<generic_wide_int<fixed_wide_int_storage<192> >, int, (wi::precision_type)2, wi::int_traits<int>::precision_type>::result_type generic_wide_int<fixed_wide_int_storage<192> >::operator+<int>(int const&) const ../../gcc/gcc/wide-int.h:711 0xdad921 vect_transform_loop(_loop_vec_info*) ../../gcc/gcc/tree-vect-loop.c:6935 0xdc9bc5 vectorize_loops() ../../gcc/gcc/tree-vectorizer.c:554 Please submit a full bug report, with preprocessed source if appropriate. Please include the complete backtrace with any bug report. See <http://gcc.gnu.org/bugs.html> for instructions. $ cat abc.c #define N 6 int a; void fn1() { int k = 0; for (; k < N;) for (a = 0; a < N; k++) a = k + N; }