[NVPTX] run SeparateConstOffsetFromGEP before SLSR

[oota-llvm.git] / lib / Target / NVPTX / NVPTXTargetMachine.cpp

diff --git a/lib/Target/NVPTX/NVPTXTargetMachine.cpp b/lib/Target/NVPTX/NVPTXTargetMachine.cpp
index f9545cc1d414b6b0c861bf303f5207a9c59df4cf..dc8e8a2952826db9bc39849a6faaa0e6285d547f 100644 (file)
--- a/lib/Target/NVPTX/NVPTXTargetMachine.cpp
+++ b/lib/Target/NVPTX/NVPTXTargetMachine.cpp
@@ -168,11 +168,13 @@ void NVPTXPassConfig::addIRPasses() {
   // them unused. We could remove dead code in an ad-hoc manner, but that
   // requires manual work and might be error-prone.
   addPass(createDeadCodeEliminationPass());
-  addPass(createStraightLineStrengthReducePass());
   addPass(createSeparateConstOffsetFromGEPPass());
-  // The SeparateConstOffsetFromGEP pass creates variadic bases that can be used
-  // by multiple GEPs. Run GVN or EarlyCSE to really reuse them. GVN generates
-  // significantly better code than EarlyCSE for some of our benchmarks.
+  // ReassociateGEPs exposes more opportunites for SLSR. See
+  // the example in reassociate-geps-and-slsr.ll.
+  addPass(createStraightLineStrengthReducePass());
+  // SeparateConstOffsetFromGEP and SLSR creates common expressions which GVN or
+  // EarlyCSE can reuse. GVN generates significantly better code than EarlyCSE
+  // for some of our benchmarks.
   if (getOptLevel() == CodeGenOpt::Aggressive)
     addPass(createGVNPass());
   else