1 files changed, 15 insertions, 6 deletions
diff --git a/lib/Transforms/IPO/PassManagerBuilder.cpp b/lib/Transforms/IPO/PassManagerBuilder.cpp
index 8408437..43b4ab5 100644
--- a/lib/Transforms/IPO/PassManagerBuilder.cpp
+++ b/lib/Transforms/IPO/PassManagerBuilder.cpp
@@ -35,6 +35,11 @@ using namespace llvm;
 static cl::opt<bool>
 RunVectorization("vectorize", cl::desc("Run vectorization passes"));
 
+static cl::opt<bool>
+UseGVNAfterVectorization("use-gvn-after-vectorization",
+  cl::init(false), cl::Hidden,
+  cl::desc("Run GVN instead of Early CSE after vectorization passes"));
+
 PassManagerBuilder::PassManagerBuilder() {
     OptLevel = 2;
     SizeLevel = 0;
@@ -182,8 +187,10 @@ void PassManagerBuilder::populateModulePassManager(PassManagerBase &MPM) {
   if (Vectorize) {
     MPM.add(createBBVectorizePass());
     MPM.add(createInstructionCombiningPass());
-    if (OptLevel > 1)
-      MPM.add(createGVNPass());                 // Remove redundancies
+    if (OptLevel > 1 && UseGVNAfterVectorization)
+      MPM.add(createGVNPass());                   // Remove redundancies
+    else
+      MPM.add(createEarlyCSEPass());              // Catch trivial redundancies
   }
 
   MPM.add(createAggressiveDCEPass());         // Delete dead instructions
@@ -202,11 +209,13 @@ void PassManagerBuilder::populateModulePassManager(PassManagerBase &MPM) {
     if (OptLevel > 1)
       MPM.add(createConstantMergePass());     // Merge dup global constants
   }
+  addExtensionsToPM(EP_OptimizerLast, MPM);
 }
 
 void PassManagerBuilder::populateLTOPassManager(PassManagerBase &PM,
                                                 bool Internalize,
-                                                bool RunInliner) {
+                                                bool RunInliner,
+                                                bool DisableGVNLoadPRE) {
   // Provide AliasAnalysis services for optimizations.
   addInitialAliasAnalysisPasses(PM);
 
@@ -262,9 +271,9 @@ void PassManagerBuilder::populateLTOPassManager(PassManagerBase &PM,
   PM.add(createFunctionAttrsPass()); // Add nocapture.
   PM.add(createGlobalsModRefPass()); // IP alias analysis.
 
-  PM.add(createLICMPass());      // Hoist loop invariants.
-  PM.add(createGVNPass());       // Remove redundancies.
-  PM.add(createMemCpyOptPass()); // Remove dead memcpys.
+  PM.add(createLICMPass());                 // Hoist loop invariants.
+  PM.add(createGVNPass(DisableGVNLoadPRE)); // Remove redundancies.
+  PM.add(createMemCpyOptPass());            // Remove dead memcpys.
   // Nuke dead stores.
   PM.add(createDeadStoreEliminationPass());