Commit Graph

4 Commits

Author SHA1 Message Date
Teresa Johnson
99dd11f7e8 [PM] Split LoopUnrollPass and make partial unroller a function pass
Summary:
This is largely NFC*, in preparation for utilizing ProfileSummaryInfo
and BranchFrequencyInfo analyses. In this patch I am only doing the
splitting for the New PM, but I can do the same for the legacy PM as
a follow-on if this looks good.

*Not NFC since for partial unrolling we lose the updates done to the
loop traversal (adding new sibling and child loops) - according to
Chandler this is not very useful for partial unrolling, but it also
means that the debugging flag -unroll-revisit-child-loops no longer
works for partial unrolling.

Reviewers: chandlerc

Subscribers: mehdi_amini, mzolotukhin, eraman, llvm-commits

Differential Revision: https://reviews.llvm.org/D36157

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@309886 91177308-0d34-0410-b5e6-96231b3b80d8
2017-08-02 20:35:29 +00:00
Evgeny Stupachenko
c40a2f9b2a The patch turns on epilogue unroll for loops with constant recurency start.
Summary:

Set unroll remainder to epilog if a loop contains a phi with constant parameter:

  loop:
  pn = phi [Const, PreHeader], [pn.next, Latch]
  ...

Reviewer: hfinkel

Differential Revision: http://reviews.llvm.org/D27004

From: Evgeny Stupachenko <evstupac@gmail.com>


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@296770 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-02 17:38:46 +00:00
Michael Kuperstein
3ef6c7c651 [LoopUnroll] Properly update loopinfo for runtime unrolling by 2
Even when we don't create a remainder loop (that is, when we unroll by 2), we
may duplicate nested loops into the remainder. This is complicated by the fact
the remainder may itself be either inserted into an outer loop, or at the top
level. In the latter case, we may need to create new top-level loops.

Differential Revision: https://reviews.llvm.org/D29156


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@293124 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-26 01:04:11 +00:00
Chandler Carruth
f541c74552 [PM] Teach LoopUnroll to update the LPM infrastructure as it unrolls
loops.

We do this by reconstructing the newly added loops after the unroll
completes to avoid threading pass manager details through all the mess
of the unrolling infrastructure.

I've enabled some extra assertions in the LPM to try and catch issues
here and enabled a bunch of unroller tests to try and make sure this is
sane.

Currently, I'm manually running loop-simplify when needed. That should
go away once it is folded into the LPM infrastructure.

Differential Revision: https://reviews.llvm.org/D28848

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@293011 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-25 02:49:01 +00:00