maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity

Add comments about why we put LoopSink pass at the very late stage. 

llvm-svn: 286480
This commit is contained in:
Dehao Chen 2016-11-10 17:42:18 +00:00
parent b92cfe6804
commit 5492f8646c
1 changed files with 4 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
llvm/lib/Transforms/IPO/PassManagerBuilder.cpp
View File

@ -647,6 +647,10 @@ void PassManagerBuilder::populateModulePassManager(
if (MergeFunctions) if (MergeFunctions)
MPM.add(createMergeFunctionsPass()); MPM.add(createMergeFunctionsPass());
// LoopSink pass sinks instructions hoisted by LICM, which serves as a
// canonicalization pass that enables other optimizations. As a result,
// LoopSink pass needs to be a very late IR pass to avoid undoing LICM
// result too early.
MPM.add(createLoopSinkPass()); MPM.add(createLoopSinkPass());
// Get rid of LCSSA nodes. // Get rid of LCSSA nodes.
MPM.add(createInstructionSimplifierPass()); MPM.add(createInstructionSimplifierPass());