8 Commits

Author SHA1 Message Date
Kit Barton
de0b633999 [LoopFusion] Extend use of OptimizationRemarkEmitter
Summary:
This patch extends the use of the OptimizationRemarkEmitter to provide
information about loops that are not fused, and loops that are not eligible for
fusion. In particular, it uses the OptimizationRemarkAnalysis to identify loops
that are not eligible for fusion and the OptimizationRemarkMissed to identify
loops that cannot be fused.

It also reuses the statistics to provide the messages used in the
OptimizationRemarks. This provides common message strings between the
optimization remarks and the statistics.

I would like feedback on this approach, in general. If people are OK with this,
I will flesh out additional remarks in subsequent commits.

Subscribers: hiraditya, jsji, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D63844

llvm-svn: 367327
2019-07-30 15:58:43 +00:00
Kit Barton
8e64f0a649 Fix unused variable warning in LoopFusion pass.
Do not wrap the contents of printFusionCandidates in the LLVM_DEBUG macro. This
fixes an unused variable warning generated when compiling without asserts but
with -DENABLE_LLVM_DUMP.

Differential Revision: https://reviews.llvm.org/D61035

llvm-svn: 359161
2019-04-25 02:10:02 +00:00
Richard Trieu
7b6192025e Fix bad compare function over FusionCandidate.
Reverse the checking of the domiance order so that when a self compare happens,
it returns false.  This makes compare function have strict weak ordering.

llvm-svn: 358636
2019-04-18 01:39:45 +00:00
Kit Barton
3cdf87940f Add basic loop fusion pass.
This patch adds a basic loop fusion pass. It will fuse loops that conform to the
following 4 conditions:
  1. Adjacent (no code between them)
  2. Control flow equivalent (if one loop executes, the other loop executes)
  3. Identical bounds (both loops iterate the same number of iterations)
  4. No negative distance dependencies between the loop bodies.

The pass does not make any changes to the IR to create opportunities for fusion.
Instead, it checks if the necessary conditions are met and if so it fuses two
loops together.

The pass has not been added to the pass pipeline yet, and thus is not enabled by
default. It can be run stand alone using the -loop-fusion option.

Differential Revision: https://reviews.llvm.org/D55851

llvm-svn: 358607
2019-04-17 18:53:27 +00:00
Eric Christopher
e29874eaa0 Revert "Add basic loop fusion pass." Per request.
This reverts commit r358543/ab70da07286e618016e78247e4a24fcb84077fda.

llvm-svn: 358553
2019-04-17 04:55:24 +00:00
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
Kit Barton
ab70da0728 Add basic loop fusion pass.
This patch adds a basic loop fusion pass. It will fuse loops that conform to the
following 4 conditions:
  1. Adjacent (no code between them)
  2. Control flow equivalent (if one loop executes, the other loop executes)
  3. Identical bounds (both loops iterate the same number of iterations)
  4. No negative distance dependencies between the loop bodies.

The pass does not make any changes to the IR to create opportunities for fusion.
Instead, it checks if the necessary conditions are met and if so it fuses two
loops together.

The pass has not been added to the pass pipeline yet, and thus is not enabled by
default. It can be run stand alone using the -loop-fusion option.

Phabricator: https://reviews.llvm.org/D55851
llvm-svn: 358543
2019-04-17 01:37:00 +00:00