Commit Graph

2 Commits

Author SHA1 Message Date
Dan Gohman
6d31268a7d Revert the main portion of r31856. It was causing BranchFolding
to break up CFG diamonds by banishing one of the blocks to the end of
the function, which is bad for code density and branch size.

This does pessimize MultiSource/Benchmarks/Ptrdist/yacr2, the
benchmark cited as the reason for the change, however I've examined
the code and it looks more like a case of gaming a particular
branch than of being generally applicable.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@84803 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-22 00:03:58 +00:00
Dan Gohman
07adb85cb7 Re-apply r84295, with fixes to how the loop "top" and "bottom" blocks are
tracked. Instead of trying to manually keep track of these locations
while doing complex modifications, just recompute them when they're needed.
This fixes a bug in which the TopMBB and BotMBB were not correctly updated,
leading to invalid transformations.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@84598 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-20 04:50:37 +00:00