| //===-- X86ShuffleDecode.cpp - X86 shuffle decode logic -------------------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // Define several functions to decode x86 specific shuffle semantics into a |
| // generic vector mask. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "X86ShuffleDecode.h" |
| #include "llvm/IR/Constants.h" |
| #include "llvm/CodeGen/MachineValueType.h" |
| |
| //===----------------------------------------------------------------------===// |
| // Vector Mask Decoding |
| //===----------------------------------------------------------------------===// |
| |
| namespace llvm { |
| |
| void DecodeINSERTPSMask(unsigned Imm, SmallVectorImpl<int> &ShuffleMask) { |
| // Defaults the copying the dest value. |
| ShuffleMask.push_back(0); |
| ShuffleMask.push_back(1); |
| ShuffleMask.push_back(2); |
| ShuffleMask.push_back(3); |
| |
| // Decode the immediate. |
| unsigned ZMask = Imm & 15; |
| unsigned CountD = (Imm >> 4) & 3; |
| unsigned CountS = (Imm >> 6) & 3; |
| |
| // CountS selects which input element to use. |
| unsigned InVal = 4+CountS; |
| // CountD specifies which element of destination to update. |
| ShuffleMask[CountD] = InVal; |
| // ZMask zaps values, potentially overriding the CountD elt. |
| if (ZMask & 1) ShuffleMask[0] = SM_SentinelZero; |
| if (ZMask & 2) ShuffleMask[1] = SM_SentinelZero; |
| if (ZMask & 4) ShuffleMask[2] = SM_SentinelZero; |
| if (ZMask & 8) ShuffleMask[3] = SM_SentinelZero; |
| } |
| |
| // <3,1> or <6,7,2,3> |
| void DecodeMOVHLPSMask(unsigned NElts, SmallVectorImpl<int> &ShuffleMask) { |
| for (unsigned i = NElts/2; i != NElts; ++i) |
| ShuffleMask.push_back(NElts+i); |
| |
| for (unsigned i = NElts/2; i != NElts; ++i) |
| ShuffleMask.push_back(i); |
| } |
| |
| // <0,2> or <0,1,4,5> |
| void DecodeMOVLHPSMask(unsigned NElts, SmallVectorImpl<int> &ShuffleMask) { |
| for (unsigned i = 0; i != NElts/2; ++i) |
| ShuffleMask.push_back(i); |
| |
| for (unsigned i = 0; i != NElts/2; ++i) |
| ShuffleMask.push_back(NElts+i); |
| } |
| |
| void DecodeMOVSLDUPMask(MVT VT, SmallVectorImpl<int> &ShuffleMask) { |
| unsigned NumElts = VT.getVectorNumElements(); |
| for (int i = 0, e = NumElts / 2; i < e; ++i) { |
| ShuffleMask.push_back(2 * i); |
| ShuffleMask.push_back(2 * i); |
| } |
| } |
| |
| void DecodeMOVSHDUPMask(MVT VT, SmallVectorImpl<int> &ShuffleMask) { |
| unsigned NumElts = VT.getVectorNumElements(); |
| for (int i = 0, e = NumElts / 2; i < e; ++i) { |
| ShuffleMask.push_back(2 * i + 1); |
| ShuffleMask.push_back(2 * i + 1); |
| } |
| } |
| |
| void DecodePSLLDQMask(MVT VT, unsigned Imm, SmallVectorImpl<int> &ShuffleMask) { |
| unsigned VectorSizeInBits = VT.getSizeInBits(); |
| unsigned NumElts = VectorSizeInBits / 8; |
| unsigned NumLanes = VectorSizeInBits / 128; |
| unsigned NumLaneElts = NumElts / NumLanes; |
| |
| for (unsigned l = 0; l < NumElts; l += NumLaneElts) |
| for (unsigned i = 0; i < NumLaneElts; ++i) { |
| int M = SM_SentinelZero; |
| if (i >= Imm) M = i - Imm + l; |
| ShuffleMask.push_back(M); |
| } |
| } |
| |
| void DecodePSRLDQMask(MVT VT, unsigned Imm, SmallVectorImpl<int> &ShuffleMask) { |
| unsigned VectorSizeInBits = VT.getSizeInBits(); |
| unsigned NumElts = VectorSizeInBits / 8; |
| unsigned NumLanes = VectorSizeInBits / 128; |
| unsigned NumLaneElts = NumElts / NumLanes; |
| |
| for (unsigned l = 0; l < NumElts; l += NumLaneElts) |
| for (unsigned i = 0; i < NumLaneElts; ++i) { |
| unsigned Base = i + Imm; |
| int M = Base + l; |
| if (Base >= NumLaneElts) M = SM_SentinelZero; |
| ShuffleMask.push_back(M); |
| } |
| } |
| |
| void DecodePALIGNRMask(MVT VT, unsigned Imm, |
| SmallVectorImpl<int> &ShuffleMask) { |
| unsigned NumElts = VT.getVectorNumElements(); |
| unsigned Offset = Imm * (VT.getVectorElementType().getSizeInBits() / 8); |
| |
| unsigned NumLanes = VT.getSizeInBits() / 128; |
| unsigned NumLaneElts = NumElts / NumLanes; |
| |
| for (unsigned l = 0; l != NumElts; l += NumLaneElts) { |
| for (unsigned i = 0; i != NumLaneElts; ++i) { |
| unsigned Base = i + Offset; |
| // if i+offset is out of this lane then we actually need the other source |
| if (Base >= NumLaneElts) Base += NumElts - NumLaneElts; |
| ShuffleMask.push_back(Base + l); |
| } |
| } |
| } |
| |
| /// DecodePSHUFMask - This decodes the shuffle masks for pshufd, and vpermilp*. |
| /// VT indicates the type of the vector allowing it to handle different |
| /// datatypes and vector widths. |
| void DecodePSHUFMask(MVT VT, unsigned Imm, SmallVectorImpl<int> &ShuffleMask) { |
| unsigned NumElts = VT.getVectorNumElements(); |
| |
| unsigned NumLanes = VT.getSizeInBits() / 128; |
| unsigned NumLaneElts = NumElts / NumLanes; |
| |
| unsigned NewImm = Imm; |
| for (unsigned l = 0; l != NumElts; l += NumLaneElts) { |
| for (unsigned i = 0; i != NumLaneElts; ++i) { |
| ShuffleMask.push_back(NewImm % NumLaneElts + l); |
| NewImm /= NumLaneElts; |
| } |
| if (NumLaneElts == 4) NewImm = Imm; // reload imm |
| } |
| } |
| |
| void DecodePSHUFHWMask(MVT VT, unsigned Imm, |
| SmallVectorImpl<int> &ShuffleMask) { |
| unsigned NumElts = VT.getVectorNumElements(); |
| |
| for (unsigned l = 0; l != NumElts; l += 8) { |
| unsigned NewImm = Imm; |
| for (unsigned i = 0, e = 4; i != e; ++i) { |
| ShuffleMask.push_back(l + i); |
| } |
| for (unsigned i = 4, e = 8; i != e; ++i) { |
| ShuffleMask.push_back(l + 4 + (NewImm & 3)); |
| NewImm >>= 2; |
| } |
| } |
| } |
| |
| void DecodePSHUFLWMask(MVT VT, unsigned Imm, |
| SmallVectorImpl<int> &ShuffleMask) { |
| unsigned NumElts = VT.getVectorNumElements(); |
| |
| for (unsigned l = 0; l != NumElts; l += 8) { |
| unsigned NewImm = Imm; |
| for (unsigned i = 0, e = 4; i != e; ++i) { |
| ShuffleMask.push_back(l + (NewImm & 3)); |
| NewImm >>= 2; |
| } |
| for (unsigned i = 4, e = 8; i != e; ++i) { |
| ShuffleMask.push_back(l + i); |
| } |
| } |
| } |
| |
| /// DecodeSHUFPMask - This decodes the shuffle masks for shufp*. VT indicates |
| /// the type of the vector allowing it to handle different datatypes and vector |
| /// widths. |
| void DecodeSHUFPMask(MVT VT, unsigned Imm, SmallVectorImpl<int> &ShuffleMask) { |
| unsigned NumElts = VT.getVectorNumElements(); |
| |
| unsigned NumLanes = VT.getSizeInBits() / 128; |
| unsigned NumLaneElts = NumElts / NumLanes; |
| |
| unsigned NewImm = Imm; |
| for (unsigned l = 0; l != NumElts; l += NumLaneElts) { |
| // each half of a lane comes from different source |
| for (unsigned s = 0; s != NumElts*2; s += NumElts) { |
| for (unsigned i = 0; i != NumLaneElts/2; ++i) { |
| ShuffleMask.push_back(NewImm % NumLaneElts + s + l); |
| NewImm /= NumLaneElts; |
| } |
| } |
| if (NumLaneElts == 4) NewImm = Imm; // reload imm |
| } |
| } |
| |
| /// DecodeUNPCKHMask - This decodes the shuffle masks for unpckhps/unpckhpd |
| /// and punpckh*. VT indicates the type of the vector allowing it to handle |
| /// different datatypes and vector widths. |
| void DecodeUNPCKHMask(MVT VT, SmallVectorImpl<int> &ShuffleMask) { |
| unsigned NumElts = VT.getVectorNumElements(); |
| |
| // Handle 128 and 256-bit vector lengths. AVX defines UNPCK* to operate |
| // independently on 128-bit lanes. |
| unsigned NumLanes = VT.getSizeInBits() / 128; |
| if (NumLanes == 0 ) NumLanes = 1; // Handle MMX |
| unsigned NumLaneElts = NumElts / NumLanes; |
| |
| for (unsigned l = 0; l != NumElts; l += NumLaneElts) { |
| for (unsigned i = l + NumLaneElts/2, e = l + NumLaneElts; i != e; ++i) { |
| ShuffleMask.push_back(i); // Reads from dest/src1 |
| ShuffleMask.push_back(i+NumElts); // Reads from src/src2 |
| } |
| } |
| } |
| |
| /// DecodeUNPCKLMask - This decodes the shuffle masks for unpcklps/unpcklpd |
| /// and punpckl*. VT indicates the type of the vector allowing it to handle |
| /// different datatypes and vector widths. |
| void DecodeUNPCKLMask(MVT VT, SmallVectorImpl<int> &ShuffleMask) { |
| unsigned NumElts = VT.getVectorNumElements(); |
| |
| // Handle 128 and 256-bit vector lengths. AVX defines UNPCK* to operate |
| // independently on 128-bit lanes. |
| unsigned NumLanes = VT.getSizeInBits() / 128; |
| if (NumLanes == 0 ) NumLanes = 1; // Handle MMX |
| unsigned NumLaneElts = NumElts / NumLanes; |
| |
| for (unsigned l = 0; l != NumElts; l += NumLaneElts) { |
| for (unsigned i = l, e = l + NumLaneElts/2; i != e; ++i) { |
| ShuffleMask.push_back(i); // Reads from dest/src1 |
| ShuffleMask.push_back(i+NumElts); // Reads from src/src2 |
| } |
| } |
| } |
| |
| void DecodeVPERM2X128Mask(MVT VT, unsigned Imm, |
| SmallVectorImpl<int> &ShuffleMask) { |
| if (Imm & 0x88) |
| return; // Not a shuffle |
| |
| unsigned HalfSize = VT.getVectorNumElements()/2; |
| |
| for (unsigned l = 0; l != 2; ++l) { |
| unsigned HalfBegin = ((Imm >> (l*4)) & 0x3) * HalfSize; |
| for (unsigned i = HalfBegin, e = HalfBegin+HalfSize; i != e; ++i) |
| ShuffleMask.push_back(i); |
| } |
| } |
| |
| void DecodePSHUFBMask(const Constant *C, SmallVectorImpl<int> &ShuffleMask) { |
| Type *MaskTy = C->getType(); |
| // It is not an error for the PSHUFB mask to not be a vector of i8 because the |
| // constant pool uniques constants by their bit representation. |
| // e.g. the following take up the same space in the constant pool: |
| // i128 -170141183420855150465331762880109871104 |
| // |
| // <2 x i64> <i64 -9223372034707292160, i64 -9223372034707292160> |
| // |
| // <4 x i32> <i32 -2147483648, i32 -2147483648, |
| // i32 -2147483648, i32 -2147483648> |
| |
| unsigned MaskTySize = MaskTy->getPrimitiveSizeInBits(); |
| |
| if (MaskTySize != 128 && MaskTySize != 256) // FIXME: Add support for AVX-512. |
| return; |
| |
| // This is a straightforward byte vector. |
| if (MaskTy->isVectorTy() && MaskTy->getVectorElementType()->isIntegerTy(8)) { |
| int NumElements = MaskTy->getVectorNumElements(); |
| ShuffleMask.reserve(NumElements); |
| |
| for (int i = 0; i < NumElements; ++i) { |
| // For AVX vectors with 32 bytes the base of the shuffle is the 16-byte |
| // lane of the vector we're inside. |
| int Base = i < 16 ? 0 : 16; |
| Constant *COp = C->getAggregateElement(i); |
| if (!COp) { |
| ShuffleMask.clear(); |
| return; |
| } else if (isa<UndefValue>(COp)) { |
| ShuffleMask.push_back(SM_SentinelUndef); |
| continue; |
| } |
| uint64_t Element = cast<ConstantInt>(COp)->getZExtValue(); |
| // If the high bit (7) of the byte is set, the element is zeroed. |
| if (Element & (1 << 7)) |
| ShuffleMask.push_back(SM_SentinelZero); |
| else { |
| // Only the least significant 4 bits of the byte are used. |
| int Index = Base + (Element & 0xf); |
| ShuffleMask.push_back(Index); |
| } |
| } |
| } |
| // TODO: Handle funny-looking vectors too. |
| } |
| |
| void DecodePSHUFBMask(ArrayRef<uint64_t> RawMask, |
| SmallVectorImpl<int> &ShuffleMask) { |
| for (int i = 0, e = RawMask.size(); i < e; ++i) { |
| uint64_t M = RawMask[i]; |
| if (M == (uint64_t)SM_SentinelUndef) { |
| ShuffleMask.push_back(M); |
| continue; |
| } |
| // For AVX vectors with 32 bytes the base of the shuffle is the half of |
| // the vector we're inside. |
| int Base = i < 16 ? 0 : 16; |
| // If the high bit (7) of the byte is set, the element is zeroed. |
| if (M & (1 << 7)) |
| ShuffleMask.push_back(SM_SentinelZero); |
| else { |
| // Only the least significant 4 bits of the byte are used. |
| int Index = Base + (M & 0xf); |
| ShuffleMask.push_back(Index); |
| } |
| } |
| } |
| |
| void DecodeBLENDMask(MVT VT, unsigned Imm, SmallVectorImpl<int> &ShuffleMask) { |
| int ElementBits = VT.getScalarSizeInBits(); |
| int NumElements = VT.getVectorNumElements(); |
| for (int i = 0; i < NumElements; ++i) { |
| // If there are more than 8 elements in the vector, then any immediate blend |
| // mask applies to each 128-bit lane. There can never be more than |
| // 8 elements in a 128-bit lane with an immediate blend. |
| int Bit = NumElements > 8 ? i % (128 / ElementBits) : i; |
| assert(Bit < 8 && |
| "Immediate blends only operate over 8 elements at a time!"); |
| ShuffleMask.push_back(((Imm >> Bit) & 1) ? NumElements + i : i); |
| } |
| } |
| |
| /// DecodeVPERMMask - this decodes the shuffle masks for VPERMQ/VPERMPD. |
| /// No VT provided since it only works on 256-bit, 4 element vectors. |
| void DecodeVPERMMask(unsigned Imm, SmallVectorImpl<int> &ShuffleMask) { |
| for (unsigned i = 0; i != 4; ++i) { |
| ShuffleMask.push_back((Imm >> (2*i)) & 3); |
| } |
| } |
| |
| void DecodeVPERMILPMask(const Constant *C, SmallVectorImpl<int> &ShuffleMask) { |
| Type *MaskTy = C->getType(); |
| assert(MaskTy->isVectorTy() && "Expected a vector constant mask!"); |
| assert(MaskTy->getVectorElementType()->isIntegerTy() && |
| "Expected integer constant mask elements!"); |
| int ElementBits = MaskTy->getScalarSizeInBits(); |
| int NumElements = MaskTy->getVectorNumElements(); |
| assert((NumElements == 2 || NumElements == 4 || NumElements == 8) && |
| "Unexpected number of vector elements."); |
| ShuffleMask.reserve(NumElements); |
| if (auto *CDS = dyn_cast<ConstantDataSequential>(C)) { |
| assert((unsigned)NumElements == CDS->getNumElements() && |
| "Constant mask has a different number of elements!"); |
| |
| for (int i = 0; i < NumElements; ++i) { |
| int Base = (i * ElementBits / 128) * (128 / ElementBits); |
| uint64_t Element = CDS->getElementAsInteger(i); |
| // Only the least significant 2 bits of the integer are used. |
| int Index = Base + (Element & 0x3); |
| ShuffleMask.push_back(Index); |
| } |
| } else if (auto *CV = dyn_cast<ConstantVector>(C)) { |
| assert((unsigned)NumElements == C->getNumOperands() && |
| "Constant mask has a different number of elements!"); |
| |
| for (int i = 0; i < NumElements; ++i) { |
| int Base = (i * ElementBits / 128) * (128 / ElementBits); |
| Constant *COp = CV->getOperand(i); |
| if (isa<UndefValue>(COp)) { |
| ShuffleMask.push_back(SM_SentinelUndef); |
| continue; |
| } |
| uint64_t Element = cast<ConstantInt>(COp)->getZExtValue(); |
| // Only the least significant 2 bits of the integer are used. |
| int Index = Base + (Element & 0x3); |
| ShuffleMask.push_back(Index); |
| } |
| } |
| } |
| |
| } // llvm namespace |