3 Commits

Author SHA1 Message Date
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
1d02b13eb7 [LoopPredication] Enable predication when latchCheckIV is wider than rangeCheck
Summary:
This patch allows us to predicate range checks that have a type narrower than
the latch check type. We leverage SCEV analysis to identify a truncate for the
latchLimit and latchStart.
There is also safety checks in place which requires the start and limit to be
known at compile time. We require this to make sure that the SCEV truncate expr
for the IV corresponding to the latch does not cause us to lose information
about the IV range.
Added tests show the loop predication over range checks that are of various
types and are narrower than the latch type.
This enhancement has been in our downstream tree for a while.

Reviewers: apilipenko, sanjoy, mkazantsev

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D39500

llvm-svn: 317269
2017-11-02 21:21:02 +00:00