From 6623d050c6f4351293bc1849e49bc0e37ec04596 Mon Sep 17 00:00:00 2001
From: Benjamin Kramer <benny.kra@googlemail.com>
Date: Wed, 2 Oct 2013 19:06:06 +0000
Subject: [PATCH] SLPVectorizer: Make store chain finding more aggressive with
 GetUnderlyingObject.

This recursively strips all GEPs like the existing code. It also handles bitcasts and
other operations that do not change the pointer value.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191847 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Transforms/Vectorize/SLPVectorizer.cpp    | 13 ++++--------
 test/Transforms/SLPVectorizer/X86/simplebb.ll | 21 +++++++++++++++++++
 2 files changed, 25 insertions(+), 9 deletions(-)

diff --git a/lib/Transforms/Vectorize/SLPVectorizer.cpp b/lib/Transforms/Vectorize/SLPVectorizer.cpp
index c2c53c7c577..4bee2cbf89c 100644
--- a/lib/Transforms/Vectorize/SLPVectorizer.cpp
+++ b/lib/Transforms/Vectorize/SLPVectorizer.cpp
@@ -25,8 +25,8 @@
 #include "llvm/Analysis/AliasAnalysis.h"
 #include "llvm/Analysis/ScalarEvolution.h"
 #include "llvm/Analysis/ScalarEvolutionExpressions.h"
-#include "llvm/Analysis/AliasAnalysis.h"
 #include "llvm/Analysis/TargetTransformInfo.h"
+#include "llvm/Analysis/ValueTracking.h"
 #include "llvm/Analysis/Verifier.h"
 #include "llvm/Analysis/LoopInfo.h"
 #include "llvm/IR/DataLayout.h"
@@ -318,10 +318,7 @@ private:
     /// \returns true if the scalars in VL are equal to this entry.
     bool isSame(ArrayRef<Value *> VL) const {
       assert(VL.size() == Scalars.size() && "Invalid size");
-      for (int i = 0, e = VL.size(); i != e; ++i)
-        if (VL[i] != Scalars[i])
-          return false;
-      return true;
+      return std::equal(VL.begin(), VL.end(), Scalars.begin());
     }
 
     /// A vector of scalars.
@@ -1783,10 +1780,8 @@ unsigned SLPVectorizer::collectStores(BasicBlock *BB, BoUpSLP &R) {
     if (Ty->isAggregateType() || Ty->isVectorTy())
       return 0;
 
-    // Find the base of the GEP.
-    Value *Ptr = SI->getPointerOperand();
-    if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(Ptr))
-      Ptr = GEP->getPointerOperand();
+    // Find the base pointer.
+    Value *Ptr = GetUnderlyingObject(SI->getPointerOperand(), DL);
 
     // Save the store locations.
     StoreRefs[Ptr].push_back(SI);
diff --git a/test/Transforms/SLPVectorizer/X86/simplebb.ll b/test/Transforms/SLPVectorizer/X86/simplebb.ll
index cd0b99e6467..0b76bec07bd 100644
--- a/test/Transforms/SLPVectorizer/X86/simplebb.ll
+++ b/test/Transforms/SLPVectorizer/X86/simplebb.ll
@@ -23,3 +23,24 @@ entry:
   ret void
 }
 
+; Simple 3-pair chain with loads and stores, obfuscated with bitcasts
+; CHECK: test2
+; CHECK: store <2 x double>
+; CHECK: ret
+define void @test2(double* %a, double* %b, i8* %e) {
+entry:
+  %i0 = load double* %a, align 8
+  %i1 = load double* %b, align 8
+  %mul = fmul double %i0, %i1
+  %arrayidx3 = getelementptr inbounds double* %a, i64 1
+  %i3 = load double* %arrayidx3, align 8
+  %arrayidx4 = getelementptr inbounds double* %b, i64 1
+  %i4 = load double* %arrayidx4, align 8
+  %mul5 = fmul double %i3, %i4
+  %c = bitcast i8* %e to double*
+  store double %mul, double* %c, align 8
+  %carrayidx5 = getelementptr inbounds i8* %e, i64 8
+  %arrayidx5 = bitcast i8* %carrayidx5 to double*
+  store double %mul5, double* %arrayidx5, align 8
+  ret void
+}