Revert "In visitSTORE, always use FindBetterChain, rather than only when UseAA is enabled."

This reverts commit r293893 which is miscompiling lua on ARM and
bootstrapping for x86-windows.

llvm-svn: 293915

3 files changed, 11 insertions, 6 deletions

diff --git a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
index 5929daa2629..8fb9c5c4a38 100644
--- a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
+++ b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
@@ -9254,7 +9254,7 @@ static SDValue performSTORECombine(SDNode *N,
   return SDValue();
 }
 
-/// This function handles the log2-shuffle pattern produced by the
+  /// This function handles the log2-shuffle pattern produced by the
 /// LoopVectorizer for the across vector reduction. It consists of
 /// log2(NumVectorElements) steps and, in each step, 2^(s) elements
 /// are reduced, where s is an induction variable from 0 to
diff --git a/llvm/lib/Target/AMDGPU/AMDGPUISelLowering.cpp b/llvm/lib/Target/AMDGPU/AMDGPUISelLowering.cpp
index d48eac4b0fe..3350654daad 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUISelLowering.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUISelLowering.cpp
@@ -451,6 +451,16 @@ AMDGPUTargetLowering::AMDGPUTargetLowering(const TargetMachine &TM,
 
   PredictableSelectIsExpensive = false;
 
+  // We want to find all load dependencies for long chains of stores to enable
+  // merging into very wide vectors. The problem is with vectors with > 4
+  // elements. MergeConsecutiveStores will attempt to merge these because x8/x16
+  // vectors are a legal type, even though we have to split the loads
+  // usually. When we can more precisely specify load legality per address
+  // space, we should be able to make FindBetterChain/MergeConsecutiveStores
+  // smarter so that they can figure out what to do in 2 iterations without all
+  // N > 4 stores on the same chain.
+  GatherAllAliasesMaxDepth = 16;
+
   // FIXME: Need to really handle these.
   MaxStoresPerMemcpy  = 4096;
   MaxStoresPerMemmove = 4096;
diff --git a/llvm/lib/Target/ARM/ARMISelLowering.h b/llvm/lib/Target/ARM/ARMISelLowering.h
index 2b4cdf92ea9..84c6eb845bb 100644
--- a/llvm/lib/Target/ARM/ARMISelLowering.h
+++ b/llvm/lib/Target/ARM/ARMISelLowering.h
@@ -500,11 +500,6 @@ class InstrItineraryData;
     bool canCombineStoreAndExtract(Type *VectorTy, Value *Idx,
                                    unsigned &Cost) const override;
 
-    bool canMergeStoresTo(EVT MemVT) const override {
-      // Do not merge to larger than i32.
-      return (MemVT.getSizeInBits() <= 32);
-    }
-
     bool isCheapToSpeculateCttz() const override;
     bool isCheapToSpeculateCtlz() const override;