Commit Graph

5 Commits

Author SHA1 Message Date
Eric Christopher cee313d288 Revert "Temporarily Revert "Add basic loop fusion pass.""
The reversion apparently deleted the test/Transforms directory.

Will be re-reverting again.

llvm-svn: 358552
2019-04-17 04:52:47 +00:00
Eric Christopher a863435128 Temporarily Revert "Add basic loop fusion pass."
As it's causing some bot failures (and per request from kbarton).

This reverts commit r358543/ab70da07286e618016e78247e4a24fcb84077fda.

llvm-svn: 358546
2019-04-17 02:12:23 +00:00
Philip Reames d109e2a7c3 [LoopPred] Delete the old condition expressions if unused
LoopPredication was replacing the original condition, but leaving the instructions to compute the old conditions around.  This would get cleaned up by other passes of course, but we might as well do it eagerly.  That also makes the test output less confusing.  

llvm-svn: 357406
2019-04-01 16:05:15 +00:00
Philip Reames 7eee62b5d4 [Tests] Autogen all the LoopPredication tests
I'm about to make some changes to the pass which cause widespread - but uninteresting - test diffs.  Prepare the tests for easy updating.

llvm-svn: 357404
2019-04-01 15:35:30 +00:00
Anna Thomas 9b1176b0ef [LoopPredication] Add profitability check based on BPI
Summary:
LoopPredication is not profitable when the loop is known to always exit
through some block other than the latch block.
A coarse grained latch check can cause loop predication to predicate the
loop, and unconditionally deoptimize.

However, without predicating the loop, the guard may never fail within the
loop during the dynamic execution because the non-latch loop termination
condition exits the loop before the latch condition causes the loop to
exit.
We teach LP about this using BranchProfileInfo pass.

Reviewers: apilipenko, skatkov, mkazantsev, reames

Reviewed by: skatkov

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D44667

llvm-svn: 328210
2018-03-22 16:03:59 +00:00