[Bug tree-optimization/45122] [4.6 Regression] -funsafe-loop-optimizations causes FAIL: gcc.c-torture/execute/pr27285.c execution

[aoliva at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45122

--- Comment #6 from Alexandre Oliva <aoliva at gcc dot gnu.org> 2011-01-16 08:13:44 UTC ---
Created attachment 22978
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=22978
Patch that fixes the problem by discarding too unsafe optimizations

When there's more than one exit from the loop, discarding the assumptions for
the trip count to apply might be regarded as a bit too unsafe, as in this
particular case.  This candidate patch disables the assumption entirely, and
disables the -Wunsafe-loop-optimizations warnings the loop exits would produce,
since -funsafe-loop-optimizations wouldn't affect them any longer.