https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66856
Bug ID: 66856 Summary: [6 Regression] ICE in compute_live_loop_exits, at tree-ssa-loop-manip.c:234 Product: gcc Version: 6.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: tree-optimization Assignee: unassigned at gcc dot gnu.org Reporter: marxin at gcc dot gnu.org Target Milestone: --- Created attachment 35966 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=35966&action=edit vectorizer dump Firefox built with -flto and -O3 produces following ICE: /home/marxin/Programming/gecko-dev/gfx/cairo/libpixman/src/pixman-fast-path.c: In function ‘fast_write_back_r5g6b5’: /home/marxin/Programming/gecko-dev/gfx/cairo/libpixman/src/pixman-fast-path.c:2459:1: internal compiler error: in compute_live_loop_exits, at tree-ssa-loop-manip.c:234 fast_write_back_r5g6b5 (pixman_iter_t *iter) ^ 0xc8ed62 compute_live_loop_exits ../../gcc/tree-ssa-loop-manip.c:234 0xc8ed62 add_exit_phis_var ../../gcc/tree-ssa-loop-manip.c:321 0xc8ed62 add_exit_phis ../../gcc/tree-ssa-loop-manip.c:343 0xc8ed62 rewrite_into_loop_closed_ssa(bitmap_head*, unsigned int) ../../gcc/tree-ssa-loop-manip.c:538 0xd87283 vectorize_loops() ../../gcc/tree-vectorizer.c:586 Unfortunately, as it's a ltrans issue, it won't be hard to come up with a small reproducer. Thus, I attached vectorizer dump file, hope it will help. Thanks, Martin