From 01abb2c35536d13f660d90ebffc8d2e536f0cb87 Mon Sep 17 00:00:00 2001
From: Adam Nemet <anemet@apple.com>
Date: Wed, 18 Feb 2015 03:43:19 +0000
Subject: [PATCH] [LoopAccesses] Make blockNeedsPredication static

blockNeedsPredication is in LoopAccess in order to share it with the
vectorizer.  It's a utility needed by LoopAccess not strictly provided
by it but it's a good place to share it.  This makes the function static
so that it no longer required to create an LoopAccessInfo instance in
order to access it from LV.

This was actually causing problems because it would have required
creating LAI much earlier that LV::canVectorizeMemory().

This is part of the patchset that converts LoopAccessAnalysis into an
actual analysis pass.

llvm-svn: 229625
---
 llvm/include/llvm/Analysis/LoopAccessAnalysis.h | 3 ++-
 llvm/lib/Analysis/LoopAccessAnalysis.cpp        | 7 ++++---
 llvm/lib/Transforms/Vectorize/LoopVectorize.cpp | 6 ++++--
 3 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/llvm/include/llvm/Analysis/LoopAccessAnalysis.h b/llvm/include/llvm/Analysis/LoopAccessAnalysis.h
index 0cdde4c25647..3fbdb8bb8512 100644
--- a/llvm/include/llvm/Analysis/LoopAccessAnalysis.h
+++ b/llvm/include/llvm/Analysis/LoopAccessAnalysis.h
@@ -147,7 +147,8 @@ public:
 
   /// Return true if the block BB needs to be predicated in order for the loop
   /// to be vectorized.
-  bool blockNeedsPredication(BasicBlock *BB);
+  static bool blockNeedsPredication(BasicBlock *BB, Loop *TheLoop,
+                                    DominatorTree *DT);
 
   /// Returns true if the value V is uniform within the loop.
   bool isUniform(Value *V);
diff --git a/llvm/lib/Analysis/LoopAccessAnalysis.cpp b/llvm/lib/Analysis/LoopAccessAnalysis.cpp
index 6ebb0eff812e..ca6e7a83e573 100644
--- a/llvm/lib/Analysis/LoopAccessAnalysis.cpp
+++ b/llvm/lib/Analysis/LoopAccessAnalysis.cpp
@@ -931,7 +931,7 @@ void LoopAccessInfo::analyzeLoop(ValueToValueMap &Strides) {
       // The TBAA metadata could have a control dependency on the predication
       // condition, so we cannot rely on it when determining whether or not we
       // need runtime pointer checks.
-      if (blockNeedsPredication(ST->getParent()))
+      if (blockNeedsPredication(ST->getParent(), TheLoop, DT))
         Loc.AATags.TBAA = nullptr;
 
       Accesses.addStore(Loc);
@@ -968,7 +968,7 @@ void LoopAccessInfo::analyzeLoop(ValueToValueMap &Strides) {
     // The TBAA metadata could have a control dependency on the predication
     // condition, so we cannot rely on it when determining whether or not we
     // need runtime pointer checks.
-    if (blockNeedsPredication(LD->getParent()))
+    if (blockNeedsPredication(LD->getParent(), TheLoop, DT))
       Loc.AATags.TBAA = nullptr;
 
     Accesses.addLoad(Loc, IsReadOnlyPtr);
@@ -1075,7 +1075,8 @@ void LoopAccessInfo::analyzeLoop(ValueToValueMap &Strides) {
         " need a runtime memory check.\n");
 }
 
-bool LoopAccessInfo::blockNeedsPredication(BasicBlock *BB)  {
+bool LoopAccessInfo::blockNeedsPredication(BasicBlock *BB, Loop *TheLoop,
+                                           DominatorTree *DT)  {
   assert(TheLoop->contains(BB) && "Unknown block used");
 
   // Blocks that do not dominate the latch need predication.
diff --git a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
index 1def103d9700..1dc4041a3005 100644
--- a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -554,7 +554,7 @@ public:
                             AliasAnalysis *AA, Function *F,
                             const TargetTransformInfo *TTI)
       : NumPredStores(0), TheLoop(L), SE(SE), DL(DL),
-        TLI(TLI), TheFunction(F), TTI(TTI), Induction(nullptr),
+        TLI(TLI), TheFunction(F), TTI(TTI), DT(DT), Induction(nullptr),
         WidestIndTy(nullptr),
         LAI(L, SE, DL, TLI, AA, DT),
         HasFunNoNaNAttr(false) {}
@@ -855,6 +855,8 @@ private:
   Function *TheFunction;
   /// Target Transform Info
   const TargetTransformInfo *TTI;
+  /// Dominator Tree.
+  DominatorTree *DT;
 
   //  ---  vectorization state --- //
 
@@ -4173,7 +4175,7 @@ bool LoopVectorizationLegality::isInductionVariable(const Value *V) {
 }
 
 bool LoopVectorizationLegality::blockNeedsPredication(BasicBlock *BB)  {
-  return LAI.blockNeedsPredication(BB);
+  return LoopAccessInfo::blockNeedsPredication(BB, TheLoop, DT);
 }
 
 bool LoopVectorizationLegality::blockCanBePredicated(BasicBlock *BB,