3 files changed, 14 insertions, 1 deletions
diff --git a/llvm/lib/Target/X86/X86TargetTransformInfo.cpp b/llvm/lib/Target/X86/X86TargetTransformInfo.cpp
index 1d58cccc308..11ba7025e1b 100644
--- a/llvm/lib/Target/X86/X86TargetTransformInfo.cpp
+++ b/llvm/lib/Target/X86/X86TargetTransformInfo.cpp
@@ -2178,6 +2178,17 @@ int X86TTIImpl::getGatherScatterOpCost(unsigned Opcode, Type *SrcVTy,
   return getGSVectorCost(Opcode, SrcVTy, Ptr, Alignment, AddressSpace);
 }
 
+bool X86TTIImpl::isLSRCostLess(TargetTransformInfo::LSRCost &C1,
+                               TargetTransformInfo::LSRCost &C2) {
+    // X86 specific here are "instruction number 1st priority".
+    return std::tie(C1.Insns, C1.NumRegs, C1.AddRecCost,
+                    C1.NumIVMuls, C1.NumBaseAdds,
+                    C1.ScaleCost, C1.ImmCost, C1.SetupCost) <
+           std::tie(C2.Insns, C2.NumRegs, C2.AddRecCost,
+                    C2.NumIVMuls, C2.NumBaseAdds,
+                    C2.ScaleCost, C2.ImmCost, C2.SetupCost);
+}
+
 bool X86TTIImpl::isLegalMaskedLoad(Type *DataTy) {
   Type *ScalarTy = DataTy->getScalarType();
   int DataWidth = isa<PointerType>(ScalarTy) ?
diff --git a/llvm/lib/Target/X86/X86TargetTransformInfo.h b/llvm/lib/Target/X86/X86TargetTransformInfo.h
index b907b7556a1..09ce2c90498 100644
--- a/llvm/lib/Target/X86/X86TargetTransformInfo.h
+++ b/llvm/lib/Target/X86/X86TargetTransformInfo.h
@@ -101,6 +101,8 @@ public:
   int getIntImmCost(unsigned Opcode, unsigned Idx, const APInt &Imm, Type *Ty);
   int getIntImmCost(Intrinsic::ID IID, unsigned Idx, const APInt &Imm,
                     Type *Ty);
+  bool isLSRCostLess(TargetTransformInfo::LSRCost &C1,
+                     TargetTransformInfo::LSRCost &C2);
   bool isLegalMaskedLoad(Type *DataType);
   bool isLegalMaskedStore(Type *DataType);
   bool isLegalMaskedGather(Type *DataType);
diff --git a/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp b/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
index 73436f13c94..b027278b24f 100644
--- a/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
@@ -131,7 +131,7 @@ static cl::opt<bool> EnablePhiElim(
 
 // The flag adds instruction count to solutions cost comparision.
 static cl::opt<bool> InsnsCost(
-  "lsr-insns-cost", cl::Hidden, cl::init(false),
+  "lsr-insns-cost", cl::Hidden, cl::init(true),
   cl::desc("Add instruction count to a LSR cost model"));
 
 // Flag to choose how to narrow complex lsr solution