[NewPassManager] Add tuning option: SLPVectorization [clang-change]

Summary:
NewPassManager is not using CodeGenOpts values before this patch.
[to be coupled with D61616]

Reviewers: chandlerc

Subscribers: jlebar, cfe-commits, llvm-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D61617

llvm-svn: 361534
diff --git a/clang/lib/CodeGen/BackendUtil.cpp b/clang/lib/CodeGen/BackendUtil.cpp
index 32eb776..1dbeec1 100644
--- a/clang/lib/CodeGen/BackendUtil.cpp
+++ b/clang/lib/CodeGen/BackendUtil.cpp
@@ -1050,7 +1050,14 @@
                           CodeGenOpts.DebugInfoForProfiling);
   }
 
-  PassBuilder PB(TM.get(), PipelineTuningOptions(), PGOOpt);
+  PipelineTuningOptions PTO;
+  // For historical reasons, loop interleaving is set to mirror setting for loop
+  // unrolling.
+  PTO.LoopInterleaving = CodeGenOpts.UnrollLoops;
+  PTO.LoopVectorization = CodeGenOpts.VectorizeLoop;
+  PTO.SLPVectorization = CodeGenOpts.VectorizeSLP;
+
+  PassBuilder PB(TM.get(), PTO, PGOOpt);
 
   // Attempt to load pass plugins and register their callbacks with PB.
   for (auto &PluginFN : CodeGenOpts.PassPlugins) {