Commit Graph

4 Commits

Author SHA1 Message Date
Florian Hahn 6feb637124 [LoopInterchange] Preserve LCSSA.
This patch extends LoopInterchange to move LCSSA to the right place
after interchanging. This is required for LoopInterchange to become a
function pass.

An alternative to the manual moving of the PHIs, we could also re-form
the LCSSA phis for a set of interchanged loops, but that's more
expensive.

Reviewers: efriedma, mcrosier, davide

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D52154

llvm-svn: 343132
2018-09-26 19:34:25 +00:00
Florian Hahn 3afb974aa5 [LoopInterchange] Preserve ScalarEvolution, by forgetting about interchanged loops.
As preparation for LoopInterchange becoming a loop pass, it needs to
preserve ScalarEvolution. Even though interchanging should not change
the trip count of the loop, it modifies loop entry, latch and exit
blocks.

I added -verify-scev to some loop interchange tests, but the verification does
not catch problems caused by missing invalidation of SE in loop interchange, as
the trip counts themselves do not change. So there might be potential to
make the SE verification covering more stuff in the future.

Reviewers: mkazantsev, efriedma, karthikthecool

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D52026

llvm-svn: 342209
2018-09-14 07:50:20 +00:00
Florian Hahn 831a757728 [LoopInterchange] Preserve LoopInfo after interchanging.
LoopInterchange relies on LoopInfo being up-to-date, so we should
preserve it after interchanging. This patch updates restructureLoops to
move the BBs of the interchanged loops to the right place.

Reviewers: davide, efriedma, karthikthecool, mcrosier

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D45278

llvm-svn: 329264
2018-04-05 09:48:45 +00:00
Florian Hahn b79217077d [LoopInterchange] Update tests so DA can handle access after D35430.
I have taken the opportunity to simplify some tests slightly and move
parts around.

It also brings back a few IR checks for interchangable loops.

Reviewers: karthikthecool, sebpop, grosser

Reviewed By: sebpop

Differential Revision: https://reviews.llvm.org/D45207

llvm-svn: 329081
2018-04-03 16:37:58 +00:00