Commit Graph

5 Commits

Author SHA1 Message Date
Nicolai Haehnle 74127fe8d7 AMDGPU: mark llvm.amdgcn.image.atomic.* as a source of divergence
Summary:
When multiple threads perform an atomic op with the same arguments, they
will usually see different return values.

Reviewers: arsenm, tstellarAMD

Subscribers: arsenm, llvm-commits

Differential Revision: http://reviews.llvm.org/D18101

llvm-svn: 263440
2016-03-14 15:37:18 +00:00
Matt Arsenault fe26def35c AMDGPU: Fix not handling new workitem intrinsics in DivergenceAnalysis
llvm-svn: 260491
2016-02-11 05:32:51 +00:00
Tom Stellard ffc1a5aef7 AMDGPU/SI: Fix implemenation of isSourceOfDivergence() for graphics shaders
Summary:
The analysis of shader inputs was completely wrong.  We were passing the
wrong index to AttributeSet::hasAttribute() and the logic for which
inputs where in SGPRs was wrong too.

Reviewers: arsenm

Subscribers: arsenm, llvm-commits

Differential Revision: http://reviews.llvm.org/D15608

llvm-svn: 256082
2015-12-19 02:54:15 +00:00
Jingyue Wu 3f422280f5 [DivergenceAnalysis] fix a bug in computing influence regions
Fixes PR25864

llvm-svn: 256036
2015-12-18 21:44:26 +00:00
Jingyue Wu 5da831cc31 Divergence analysis for GPU programs
Summary:
Some optimizations such as jump threading and loop unswitching can negatively
affect performance when applied to divergent branches. The divergence analysis
added in this patch conservatively estimates which branches in a GPU program
can diverge. This information can then help LLVM to run certain optimizations
selectively.

Test Plan: test/Analysis/DivergenceAnalysis/NVPTX/diverge.ll

Reviewers: resistor, hfinkel, eliben, meheff, jholewinski

Subscribers: broune, bjarke.roune, madhur13490, tstellarAMD, dberlin, echristo, jholewinski, llvm-commits

Differential Revision: http://reviews.llvm.org/D8576

llvm-svn: 234567
2015-04-10 05:03:50 +00:00