From 61bdc51339875e7674723191b3822784bcbf79b5 Mon Sep 17 00:00:00 2001
From: Silviu Baranga <silviu.baranga@arm.com>
Date: Mon, 10 Aug 2015 14:50:54 +0000
Subject: [PATCH] [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
---
 llvm/include/llvm/Analysis/TargetTransformInfo.h     |  7 +++++++
 llvm/include/llvm/Analysis/TargetTransformInfoImpl.h |  2 ++
 llvm/lib/Analysis/TargetTransformInfo.cpp            |  4 ++++
 llvm/lib/Transforms/Vectorize/LoopVectorize.cpp      | 10 ++++++++--
 4 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/llvm/include/llvm/Analysis/TargetTransformInfo.h b/llvm/include/llvm/Analysis/TargetTransformInfo.h
index 31036f71f7e4..7bfc3356c268 100644
--- a/llvm/include/llvm/Analysis/TargetTransformInfo.h
+++ b/llvm/include/llvm/Analysis/TargetTransformInfo.h
@@ -357,6 +357,9 @@ public:
   /// \brief Don't restrict interleaved unrolling to small loops.
   bool enableAggressiveInterleaving(bool LoopHasReductions) const;
 
+  /// \brief Enable matching of interleaved access groups.
+  bool enableInterleavedAccessVectorization() const;
+
   /// \brief Return hardware support for population count.
   PopcntSupportKind getPopcntSupport(unsigned IntTyWidthInBit) const;
 
@@ -578,6 +581,7 @@ public:
   virtual unsigned getJumpBufSize() = 0;
   virtual bool shouldBuildLookupTables() = 0;
   virtual bool enableAggressiveInterleaving(bool LoopHasReductions) = 0;
+  virtual bool enableInterleavedAccessVectorization() = 0;
   virtual PopcntSupportKind getPopcntSupport(unsigned IntTyWidthInBit) = 0;
   virtual bool haveFastSqrt(Type *Ty) = 0;
   virtual int getFPOpCost(Type *Ty) = 0;
@@ -719,6 +723,9 @@ public:
   bool enableAggressiveInterleaving(bool LoopHasReductions) override {
     return Impl.enableAggressiveInterleaving(LoopHasReductions);
   }
+  bool enableInterleavedAccessVectorization() override {
+    return Impl.enableInterleavedAccessVectorization();
+  }
   PopcntSupportKind getPopcntSupport(unsigned IntTyWidthInBit) override {
     return Impl.getPopcntSupport(IntTyWidthInBit);
   }
diff --git a/llvm/include/llvm/Analysis/TargetTransformInfoImpl.h b/llvm/include/llvm/Analysis/TargetTransformInfoImpl.h
index 9805f6bc663a..e903679259fc 100644
--- a/llvm/include/llvm/Analysis/TargetTransformInfoImpl.h
+++ b/llvm/include/llvm/Analysis/TargetTransformInfoImpl.h
@@ -230,6 +230,8 @@ public:
 
   bool enableAggressiveInterleaving(bool LoopHasReductions) { return false; }
 
+  bool enableInterleavedAccessVectorization() { return false; }
+
   TTI::PopcntSupportKind getPopcntSupport(unsigned IntTyWidthInBit) {
     return TTI::PSK_Software;
   }
diff --git a/llvm/lib/Analysis/TargetTransformInfo.cpp b/llvm/lib/Analysis/TargetTransformInfo.cpp
index 91413687eb36..f2984ef1ae26 100644
--- a/llvm/lib/Analysis/TargetTransformInfo.cpp
+++ b/llvm/lib/Analysis/TargetTransformInfo.cpp
@@ -166,6 +166,10 @@ bool TargetTransformInfo::enableAggressiveInterleaving(bool LoopHasReductions) c
   return TTIImpl->enableAggressiveInterleaving(LoopHasReductions);
 }
 
+bool TargetTransformInfo::enableInterleavedAccessVectorization() const {
+  return TTIImpl->enableInterleavedAccessVectorization();
+}
+
 TargetTransformInfo::PopcntSupportKind
 TargetTransformInfo::getPopcntSupport(unsigned IntTyWidthInBit) const {
   return TTIImpl->getPopcntSupport(IntTyWidthInBit);
diff --git a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
index 139b7fd96324..53074b0f9d65 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