[CostModel][X86] Fix AVX2 v16i16 shift 'splat' costs.
llvm-svn: 291366
diff --git a/llvm/lib/Target/X86/X86TargetTransformInfo.cpp b/llvm/lib/Target/X86/X86TargetTransformInfo.cpp
index 829b47b..30b2055 100644
--- a/llvm/lib/Target/X86/X86TargetTransformInfo.cpp
+++ b/llvm/lib/Target/X86/X86TargetTransformInfo.cpp
@@ -291,6 +291,20 @@
return LT.first * Entry->Cost;
}
+ static const CostTblEntry AVX2UniformCostTable[] = {
+ // Uniform splats are cheaper for the following instructions.
+ { ISD::SRL, MVT::v16i16, 1 }, // psrlw.
+ { ISD::SRA, MVT::v16i16, 1 }, // psraw.
+ };
+
+ if (ST->hasAVX2() &&
+ ((Op2Info == TargetTransformInfo::OK_UniformConstantValue) ||
+ (Op2Info == TargetTransformInfo::OK_UniformValue))) {
+ if (const auto *Entry =
+ CostTableLookup(AVX2UniformCostTable, ISD, LT.second))
+ return LT.first * Entry->Cost;
+ }
+
static const CostTblEntry XOPShiftCostTable[] = {
// 128bit shifts take 1cy, but right shifts require negation beforehand.
{ ISD::SHL, MVT::v16i8, 1 },
@@ -325,8 +339,7 @@
if (const auto *Entry = CostTableLookup(XOPShiftCostTable, ISD, LT.second))
return LT.first * Entry->Cost;
- static const CostTblEntry
- SSE2UniformCostTable[] = {
+ static const CostTblEntry SSE2UniformCostTable[] = {
// Uniform splats are cheaper for the following instructions.
{ ISD::SHL, MVT::v16i8, 1 }, // psllw.
{ ISD::SHL, MVT::v32i8, 2 }, // psllw.