Chris Lattner 42c66b7270 Split some code out to a helper function (FindReusablePredBB)
and add a doxygen comment.

Cache the phi entry to avoid doing tons of 
PHINode::getBasicBlockIndex calls in the common case.

On my insane testcase from re2c, this speeds up CGP from
617.4s to 7.9s (78x).

llvm-svn: 96083
2010-02-13 05:35:08 +00:00
..