https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71398
Bug ID: 71398 Summary: ICE at -O3 in 32-bit and 64-bit mode on x86_64-linux-gnu (Segmentation fault, find_edge) Product: gcc Version: 7.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: tree-optimization Assignee: unassigned at gcc dot gnu.org Reporter: chengniansun at gmail dot com Target Milestone: --- $: gcc-trunk -v Using built-in specs. COLLECT_GCC=gcc-trunk COLLECT_LTO_WRAPPER=/usr/local/gcc-trunk/libexec/gcc/x86_64-pc-linux-gnu/7.0.0/lto-wrapper Target: x86_64-pc-linux-gnu Configured with: ../gcc-source-trunk/configure --enable-languages=c,c++,lto --prefix=/usr/local/gcc-trunk --disable-bootstrap Thread model: posix gcc version 7.0.0 20160602 (experimental) [trunk revision 237029] (GCC) $: $: gcc-trunk -O3 -m32 small.c small.c:1:16: warning: array ‘c’ assumed to have one element unsigned a, b, c[]; ^ small.c: In function ‘fn1’: small.c:3:6: internal compiler error: Segmentation fault void fn1() { ^~~ 0xbbceaf crash_signal ../../gcc-source-trunk/gcc/toplev.c:333 0x7886a4 find_edge(basic_block_def*, basic_block_def*) ../../gcc-source-trunk/gcc/cfganal.c:506 0xd05831 unloop_loops ../../gcc-source-trunk/gcc/tree-ssa-loop-ivcanon.c:633 0xd08ae2 tree_unroll_loops_completely(bool, bool) ../../gcc-source-trunk/gcc/tree-ssa-loop-ivcanon.c:1379 0xd08c93 execute ../../gcc-source-trunk/gcc/tree-ssa-loop-ivcanon.c:1587 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 small.c unsigned a, b, c[]; void __assert_fail() __attribute__((__noreturn__)); void fn1() { int d; unsigned e; for (;;) { d = 0; for (; d <= 6; d++) c[d] || a ? 0 : __assert_fail(); for (; e <= 5; e++) a = b; } } int main() {} $: