[Bug tree-optimization/56501] gcc 4.6 ICE on noreturn function at -Os and above

[mikpe at it dot uu.se]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56501

Mikael Pettersson <mikpe at it dot uu.se> changed:

           What    |Removed                     |Added
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                 CC|                            |mikpe at it dot uu.se

--- Comment #1 from Mikael Pettersson <mikpe at it dot uu.se> 2013-03-03 11:06:24 UTC ---
The original ICE stopped occurring for 4.7 in r171450, which added an FRE pass
after early SRA.  From that point on it reproduces with -Os -fno-tree-free.  It
then stopped again for 4.8 in r186901, Steven Bosscher's "Simplify
tree-switch-conversion.c a bit - prep work for gimple switch lowering" patch.

The ICE in 4.7 occurs because tree-switch-conversion.c:check_process_case calls
single_succ on a bb that has NULL succs, leading to a SEGV in
VEC_edge_base_index.

The patch in r186901 doesn't apply at all to 4.7, and I don't see any obvious
bug fix in it that could be cherry-picked and applied to 4.7.