Reapply fix PR23384 (part 3 of 3) r304824 (was reverted in r305720).

The root cause of reverting was fixed - PR33514.

Summary:
The patch makes instruction count the highest priority for
 LSR solution for X86 (previously registers had highest priority).

Reviewers: qcolombet

Differential Revision: http://reviews.llvm.org/D30562

From: Evgeny Stupachenko <evstupac@gmail.com>
                         <evgeny.v.stupachenko@intel.com>
llvm-svn: 310289

2 files changed, 13 insertions, 0 deletions

diff --git a/llvm/lib/Target/X86/X86TargetTransformInfo.cpp b/llvm/lib/Target/X86/X86TargetTransformInfo.cpp
index 17601b4ec37..82425189a0a 100644
--- a/llvm/lib/Target/X86/X86TargetTransformInfo.cpp
+++ b/llvm/lib/Target/X86/X86TargetTransformInfo.cpp
@@ -2183,6 +2183,17 @@ 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 dea4ab752d6..fc63eff049d 100644
--- a/llvm/lib/Target/X86/X86TargetTransformInfo.h
+++ b/llvm/lib/Target/X86/X86TargetTransformInfo.h
@@ -105,6 +105,8 @@ 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);