[Bug rtl-optimization/50764] [4.7 Regression] ICE: in maybe_record_trace_start, at dwarf2cfi.c:2243 with -O2 -fsched2-use-superblocks -ftree-tail-merge

[matz at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50764

Michael Matz <matz at gcc dot gnu.org> changed:

           What    |Removed                     |Added
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                 CC|                            |matz at gcc dot gnu.org

--- Comment #11 from Michael Matz <matz at gcc dot gnu.org> 2011-11-21 16:23:00 UTC ---
That sched2 moves frame related instructions into paths that didn't have
them before seems dubious.  The assert is correct in sofar as triggering
implies generating wrong unwind info:  Depending on if bb5 (the abort) would
be placed after or before bb 3, it would have wrong unwind info for the
path 2->5 (CFA would be r10, but it wouldn't be set up) or 3->5 (CFA would
be r6, but due to the push at the wrong offset).

I think the dead-label moving just exposes the bug in sched2.