[llvm] r266399 - [PM] Add a SpeculativeExecution pass for targets with divergent branches.

[Justin Lebar via llvm-commits]

Author: jlebar
Date: Thu Apr 14 19:32:12 2016
New Revision: 266399

URL: http://llvm.org/viewvc/llvm-project?rev=266399&view=rev
Log:
[PM] Add a SpeculativeExecution pass for targets with divergent branches.

Summary:
This IR pass is helpful for GPUs, and other targets with divergent
branches.  It's a nop on targets without divergent branches.

Reviewers: chandlerc

Subscribers: llvm-commits, jingyue, rnk, joker.eph, tra

Differential Revision: http://reviews.llvm.org/D18626

Modified:
    llvm/trunk/lib/Transforms/IPO/PassManagerBuilder.cpp

Modified: llvm/trunk/lib/Transforms/IPO/PassManagerBuilder.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/IPO/PassManagerBuilder.cpp?rev=266399&r1=266398&r2=266399&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/IPO/PassManagerBuilder.cpp (original)
+++ llvm/trunk/lib/Transforms/IPO/PassManagerBuilder.cpp Thu Apr 14 19:32:12 2016
@@ -234,6 +234,8 @@ void PassManagerBuilder::addFunctionSimp
   else
     MPM.add(createScalarReplAggregatesPass(-1, false));
   MPM.add(createEarlyCSEPass());              // Catch trivial redundancies
+  // Speculative execution if the target has divergent branches; otherwise nop.
+  MPM.add(createSpeculativeExecutionIfHasBranchDivergencePass());
   MPM.add(createJumpThreadingPass());         // Thread jumps.
   MPM.add(createCorrelatedValuePropagationPass()); // Propagate conditionals
   MPM.add(createCFGSimplificationPass());     // Merge & remove BBs