[TTI] Add a hook for specifying per-target defaults for Interleaved Accesses

Summary:
This adds a hook to TTI which enables us to selectively turn on by default
interleaved access vectorization for targets on which we have have performed
the required benchmarking.

Reviewers: rengolin

Subscribers: rengolin, llvm-commits

Differential Revision: http://reviews.llvm.org/D11901

llvm-svn: 244449

1 files changed, 8 insertions, 2 deletions

diff --git a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
index 139b7fd9632..53074b0f9d6 100644
--- a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -3880,9 +3880,15 @@ bool LoopVectorizationLegality::canVectorize() {
                        : "")
                << "!\n");
 
+  bool UseInterleaved = TTI->enableInterleavedAccessVectorization();
+
+  // If an override option has been passed in for interleaved accesses, use it.
+  if (EnableInterleavedMemAccesses.getNumOccurrences() > 0)
+    UseInterleaved = EnableInterleavedMemAccesses;
+
   // Analyze interleaved memory accesses.
-  if (EnableInterleavedMemAccesses)
-    InterleaveInfo.analyzeInterleaving(Strides);
+  if (UseInterleaved)
+     InterleaveInfo.analyzeInterleaving(Strides);
 
   // Okay! We can vectorize. At this point we don't have any other mem analysis
   // which may limit our maximum vectorization factor, so just return true with