Add a basic-block autovectorization pass.

This is the initial checkin of the basic-block autovectorization pass along with some supporting vectorization infrastructure.
Special thanks to everyone who helped review this code over the last several months (especially Tobias Grosser).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149468 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/IPO/PassManagerBuilder.cpp b/lib/Transforms/IPO/PassManagerBuilder.cpp
index afd25dc..8408437 100644
--- a/lib/Transforms/IPO/PassManagerBuilder.cpp
+++ b/lib/Transforms/IPO/PassManagerBuilder.cpp
@@ -21,14 +21,20 @@
 #include "llvm/DefaultPasses.h"
 #include "llvm/PassManager.h"
 #include "llvm/Analysis/Passes.h"
+#include "llvm/Analysis/Verifier.h"
+#include "llvm/Support/CommandLine.h"
 #include "llvm/Target/TargetLibraryInfo.h"
 #include "llvm/Transforms/Scalar.h"
+#include "llvm/Transforms/Vectorize.h"
 #include "llvm/Transforms/IPO.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/Support/ManagedStatic.h"
 
 using namespace llvm;
 
+static cl::opt<bool>
+RunVectorization("vectorize", cl::desc("Run vectorization passes"));
+
 PassManagerBuilder::PassManagerBuilder() {
     OptLevel = 2;
     SizeLevel = 0;
@@ -37,6 +43,7 @@
     DisableSimplifyLibCalls = false;
     DisableUnitAtATime = false;
     DisableUnrollLoops = false;
+    Vectorize = RunVectorization;
 }
 
 PassManagerBuilder::~PassManagerBuilder() {
@@ -172,6 +179,13 @@
 
   addExtensionsToPM(EP_ScalarOptimizerLate, MPM);
 
+  if (Vectorize) {
+    MPM.add(createBBVectorizePass());
+    MPM.add(createInstructionCombiningPass());
+    if (OptLevel > 1)
+      MPM.add(createGVNPass());                 // Remove redundancies
+  }
+
   MPM.add(createAggressiveDCEPass());         // Delete dead instructions
   MPM.add(createCFGSimplificationPass());     // Merge & remove BBs
   MPM.add(createInstructionCombiningPass());  // Clean up after everything.