+unsigned X86TTIImpl::getShuffleCost(TTI::ShuffleKind Kind, Type *Tp, int Index,
+ Type *SubTp) {
+ // We only estimate the cost of reverse and alternate shuffles.
+ if (Kind != TTI::SK_Reverse && Kind != TTI::SK_Alternate)
+ return BaseT::getShuffleCost(Kind, Tp, Index, SubTp);
+
+ if (Kind == TTI::SK_Reverse) {
+ std::pair<unsigned, MVT> LT = TLI->getTypeLegalizationCost(DL, Tp);
+ unsigned Cost = 1;
+ if (LT.second.getSizeInBits() > 128)
+ Cost = 3; // Extract + insert + copy.
+
+ // Multiple by the number of parts.
+ return Cost * LT.first;
+ }
+
+ if (Kind == TTI::SK_Alternate) {
+ // 64-bit packed float vectors (v2f32) are widened to type v4f32.
+ // 64-bit packed integer vectors (v2i32) are promoted to type v2i64.
+ std::pair<unsigned, MVT> LT = TLI->getTypeLegalizationCost(DL, Tp);
+
+ // The backend knows how to generate a single VEX.256 version of
+ // instruction VPBLENDW if the target supports AVX2.
+ if (ST->hasAVX2() && LT.second == MVT::v16i16)
+ return LT.first;
+
+ static const CostTblEntry<MVT::SimpleValueType> AVXAltShuffleTbl[] = {
+ {ISD::VECTOR_SHUFFLE, MVT::v4i64, 1}, // vblendpd
+ {ISD::VECTOR_SHUFFLE, MVT::v4f64, 1}, // vblendpd
+
+ {ISD::VECTOR_SHUFFLE, MVT::v8i32, 1}, // vblendps
+ {ISD::VECTOR_SHUFFLE, MVT::v8f32, 1}, // vblendps
+
+ // This shuffle is custom lowered into a sequence of:
+ // 2x vextractf128 , 2x vpblendw , 1x vinsertf128
+ {ISD::VECTOR_SHUFFLE, MVT::v16i16, 5},
+
+ // This shuffle is custom lowered into a long sequence of:
+ // 2x vextractf128 , 4x vpshufb , 2x vpor , 1x vinsertf128
+ {ISD::VECTOR_SHUFFLE, MVT::v32i8, 9}
+ };
+
+ if (ST->hasAVX()) {
+ int Idx = CostTableLookup(AVXAltShuffleTbl, ISD::VECTOR_SHUFFLE, LT.second);
+ if (Idx != -1)
+ return LT.first * AVXAltShuffleTbl[Idx].Cost;
+ }
+
+ static const CostTblEntry<MVT::SimpleValueType> SSE41AltShuffleTbl[] = {
+ // These are lowered into movsd.
+ {ISD::VECTOR_SHUFFLE, MVT::v2i64, 1},
+ {ISD::VECTOR_SHUFFLE, MVT::v2f64, 1},
+
+ // packed float vectors with four elements are lowered into BLENDI dag
+ // nodes. A v4i32/v4f32 BLENDI generates a single 'blendps'/'blendpd'.
+ {ISD::VECTOR_SHUFFLE, MVT::v4i32, 1},
+ {ISD::VECTOR_SHUFFLE, MVT::v4f32, 1},
+
+ // This shuffle generates a single pshufw.
+ {ISD::VECTOR_SHUFFLE, MVT::v8i16, 1},
+
+ // There is no instruction that matches a v16i8 alternate shuffle.
+ // The backend will expand it into the sequence 'pshufb + pshufb + or'.
+ {ISD::VECTOR_SHUFFLE, MVT::v16i8, 3}
+ };
+
+ if (ST->hasSSE41()) {
+ int Idx = CostTableLookup(SSE41AltShuffleTbl, ISD::VECTOR_SHUFFLE, LT.second);
+ if (Idx != -1)
+ return LT.first * SSE41AltShuffleTbl[Idx].Cost;
+ }
+
+ static const CostTblEntry<MVT::SimpleValueType> SSSE3AltShuffleTbl[] = {
+ {ISD::VECTOR_SHUFFLE, MVT::v2i64, 1}, // movsd
+ {ISD::VECTOR_SHUFFLE, MVT::v2f64, 1}, // movsd
+
+ // SSE3 doesn't have 'blendps'. The following shuffles are expanded into
+ // the sequence 'shufps + pshufd'
+ {ISD::VECTOR_SHUFFLE, MVT::v4i32, 2},
+ {ISD::VECTOR_SHUFFLE, MVT::v4f32, 2},
+
+ {ISD::VECTOR_SHUFFLE, MVT::v8i16, 3}, // pshufb + pshufb + or
+ {ISD::VECTOR_SHUFFLE, MVT::v16i8, 3} // pshufb + pshufb + or
+ };
+
+ if (ST->hasSSSE3()) {
+ int Idx = CostTableLookup(SSSE3AltShuffleTbl, ISD::VECTOR_SHUFFLE, LT.second);
+ if (Idx != -1)
+ return LT.first * SSSE3AltShuffleTbl[Idx].Cost;
+ }
+
+ static const CostTblEntry<MVT::SimpleValueType> SSEAltShuffleTbl[] = {
+ {ISD::VECTOR_SHUFFLE, MVT::v2i64, 1}, // movsd
+ {ISD::VECTOR_SHUFFLE, MVT::v2f64, 1}, // movsd