Backport r210254 from trunk for Google b/
14380607.
2014-05-08 Jeff Law <law@redhat.com>
PR tree-optimization/61009
* tree-ssa-threadedge.c (thread_through_normal_block): Return a
tri-state rather than a boolean. When a block is too big to
thread through, inform caller via negative return value.
(thread_across_edge): If a block was too big for normal threading,
then it's too big for a joiner too, so remove temporary equivalences
and return immediately.
PR tree-optimization/61009
* g++.dg/tree-ssa/pr61009.C: New test.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/google@210279 138bc75d-0d04-0410-961f-82ee72b054a4