CostModel: initial checkin for code that estimates the cost of special shuffles.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171180 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index e5122ab..5d495a6 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -18237,3 +18237,19 @@
return VectorTargetTransformImpl::getCastInstrCost(Opcode, Dst, Src);
}
+
+unsigned X86VectorTargetTransformInfo::getShuffleCost(ShuffleKind Kind, Type *Tp,
+ int Index) const {
+ // We only estimate the cost of reverse shuffles.
+ if (Kind != Reverse)
+ return VectorTargetTransformImpl::getShuffleCost(Kind, Tp, Index);
+
+ std::pair<unsigned, MVT> LT = getTypeLegalizationCost(Tp);
+ unsigned Cost = 1;
+ if (LT.second.getSizeInBits() > 128)
+ Cost = 3; // Extract + insert + copy.
+
+ // Multiple by the number of parts.
+ return Cost * LT.first;
+}
+