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llvm-project/llvm/lib/Target/X86/X86InterleavedAccess.cpp

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//===- X86InterleavedAccess.cpp -------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
/// \file
/// This file contains the X86 implementation of the interleaved accesses
/// optimization generating X86-specific instructions/intrinsics for
/// interleaved access groups.
//
//===----------------------------------------------------------------------===//
#include "X86ISelLowering.h"
#include "X86Subtarget.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/Analysis/VectorUtils.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/IRBuilder.h"
#include "llvm/IR/Instruction.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/Type.h"
#include "llvm/IR/Value.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/MachineValueType.h"
#include <algorithm>
#include <cassert>
#include <cmath>
#include <cstdint>
using namespace llvm;
namespace {
/// This class holds necessary information to represent an interleaved
/// access group and supports utilities to lower the group into
/// X86-specific instructions/intrinsics.
/// E.g. A group of interleaving access loads (Factor = 2; accessing every
/// other element)
/// %wide.vec = load <8 x i32>, <8 x i32>* %ptr
/// %v0 = shuffle <8 x i32> %wide.vec, <8 x i32> undef, <0, 2, 4, 6>
/// %v1 = shuffle <8 x i32> %wide.vec, <8 x i32> undef, <1, 3, 5, 7>
class X86InterleavedAccessGroup {
/// Reference to the wide-load instruction of an interleaved access
/// group.
Instruction *const Inst;
/// Reference to the shuffle(s), consumer(s) of the (load) 'Inst'.
ArrayRef<ShuffleVectorInst *> Shuffles;
/// Reference to the starting index of each user-shuffle.
ArrayRef<unsigned> Indices;
/// Reference to the interleaving stride in terms of elements.
const unsigned Factor;
/// Reference to the underlying target.
const X86Subtarget &Subtarget;
const DataLayout &DL;
IRBuilder<> &Builder;
/// Breaks down a vector \p 'Inst' of N elements into \p NumSubVectors
/// sub vectors of type \p T. Returns the sub-vectors in \p DecomposedVectors.
void decompose(Instruction *Inst, unsigned NumSubVectors, FixedVectorType *T,
SmallVectorImpl<Instruction *> &DecomposedVectors);
/// Performs matrix transposition on a 4x4 matrix \p InputVectors and
/// returns the transposed-vectors in \p TransposedVectors.
/// E.g.
/// InputVectors:
/// In-V0 = p1, p2, p3, p4
/// In-V1 = q1, q2, q3, q4
/// In-V2 = r1, r2, r3, r4
/// In-V3 = s1, s2, s3, s4
/// OutputVectors:
/// Out-V0 = p1, q1, r1, s1
/// Out-V1 = p2, q2, r2, s2
/// Out-V2 = p3, q3, r3, s3
/// Out-V3 = P4, q4, r4, s4
void transpose_4x4(ArrayRef<Instruction *> InputVectors,
SmallVectorImpl<Value *> &TransposedMatrix);
void interleave8bitStride4(ArrayRef<Instruction *> InputVectors,
SmallVectorImpl<Value *> &TransposedMatrix,
unsigned NumSubVecElems);
void interleave8bitStride4VF8(ArrayRef<Instruction *> InputVectors,
SmallVectorImpl<Value *> &TransposedMatrix);
void interleave8bitStride3(ArrayRef<Instruction *> InputVectors,
SmallVectorImpl<Value *> &TransposedMatrix,
unsigned NumSubVecElems);
void deinterleave8bitStride3(ArrayRef<Instruction *> InputVectors,
SmallVectorImpl<Value *> &TransposedMatrix,
unsigned NumSubVecElems);
public:
/// In order to form an interleaved access group X86InterleavedAccessGroup
/// requires a wide-load instruction \p 'I', a group of interleaved-vectors
/// \p Shuffs, reference to the first indices of each interleaved-vector
/// \p 'Ind' and the interleaving stride factor \p F. In order to generate
/// X86-specific instructions/intrinsics it also requires the underlying
/// target information \p STarget.
explicit X86InterleavedAccessGroup(Instruction *I,
ArrayRef<ShuffleVectorInst *> Shuffs,
ArrayRef<unsigned> Ind, const unsigned F,
const X86Subtarget &STarget,
IRBuilder<> &B)
: Inst(I), Shuffles(Shuffs), Indices(Ind), Factor(F), Subtarget(STarget),
DL(Inst->getModule()->getDataLayout()), Builder(B) {}
/// Returns true if this interleaved access group can be lowered into
/// x86-specific instructions/intrinsics, false otherwise.
bool isSupported() const;
/// Lowers this interleaved access group into X86-specific
/// instructions/intrinsics.
bool lowerIntoOptimizedSequence();
};
} // end anonymous namespace
bool X86InterleavedAccessGroup::isSupported() const {
VectorType *ShuffleVecTy = Shuffles[0]->getType();
Type *ShuffleEltTy = ShuffleVecTy->getElementType();
unsigned ShuffleElemSize = DL.getTypeSizeInBits(ShuffleEltTy);
unsigned WideInstSize;
// Currently, lowering is supported for the following vectors:
// Stride 4:
// 1. Store and load of 4-element vectors of 64 bits on AVX.
// 2. Store of 16/32-element vectors of 8 bits on AVX.
// Stride 3:
// 1. Load of 16/32-element vectors of 8 bits on AVX.
if (!Subtarget.hasAVX() || (Factor != 4 && Factor != 3))
return false;
if (isa<LoadInst>(Inst)) {
WideInstSize = DL.getTypeSizeInBits(Inst->getType());
if (cast<LoadInst>(Inst)->getPointerAddressSpace())
return false;
} else
WideInstSize = DL.getTypeSizeInBits(Shuffles[0]->getType());
// We support shuffle represents stride 4 for byte type with size of
// WideInstSize.
if (ShuffleElemSize == 64 && WideInstSize == 1024 && Factor == 4)
return true;
if (ShuffleElemSize == 8 && isa<StoreInst>(Inst) && Factor == 4 &&
(WideInstSize == 256 || WideInstSize == 512 || WideInstSize == 1024 ||
WideInstSize == 2048))
return true;
if (ShuffleElemSize == 8 && Factor == 3 &&
(WideInstSize == 384 || WideInstSize == 768 || WideInstSize == 1536))
return true;
return false;
}
void X86InterleavedAccessGroup::decompose(
Instruction *VecInst, unsigned NumSubVectors, FixedVectorType *SubVecTy,
SmallVectorImpl<Instruction *> &DecomposedVectors) {
assert((isa<LoadInst>(VecInst) || isa<ShuffleVectorInst>(VecInst)) &&
"Expected Load or Shuffle");
Type *VecWidth = VecInst->getType();
(void)VecWidth;
assert(VecWidth->isVectorTy() &&
DL.getTypeSizeInBits(VecWidth) >=
DL.getTypeSizeInBits(SubVecTy) * NumSubVectors &&
"Invalid Inst-size!!!");
if (auto *SVI = dyn_cast<ShuffleVectorInst>(VecInst)) {
Value *Op0 = SVI->getOperand(0);
Value *Op1 = SVI->getOperand(1);
// Generate N(= NumSubVectors) shuffles of T(= SubVecTy) type.
for (unsigned i = 0; i < NumSubVectors; ++i)
DecomposedVectors.push_back(
cast<ShuffleVectorInst>(Builder.CreateShuffleVector(
Op0, Op1,
createSequentialMask(Indices[i], SubVecTy->getNumElements(),
0))));
return;
}
// Decompose the load instruction.
LoadInst *LI = cast<LoadInst>(VecInst);
Type *VecBaseTy, *VecBasePtrTy;
Value *VecBasePtr;
unsigned int NumLoads = NumSubVectors;
// In the case of stride 3 with a vector of 32 elements load the information
// in the following way:
// [0,1...,VF/2-1,VF/2+VF,VF/2+VF+1,...,2VF-1]
unsigned VecLength = DL.getTypeSizeInBits(VecWidth);
if (VecLength == 768 || VecLength == 1536) {
VecBaseTy = FixedVectorType::get(Type::getInt8Ty(LI->getContext()), 16);
VecBasePtrTy = VecBaseTy->getPointerTo(LI->getPointerAddressSpace());
VecBasePtr = Builder.CreateBitCast(LI->getPointerOperand(), VecBasePtrTy);
NumLoads = NumSubVectors * (VecLength / 384);
} else {
VecBaseTy = SubVecTy;
VecBasePtrTy = VecBaseTy->getPointerTo(LI->getPointerAddressSpace());
VecBasePtr = Builder.CreateBitCast(LI->getPointerOperand(), VecBasePtrTy);
}
// Generate N loads of T type.
assert(VecBaseTy->getPrimitiveSizeInBits().isByteSized() &&
"VecBaseTy's size must be a multiple of 8");
const Align FirstAlignment = LI->getAlign();
const Align SubsequentAlignment = commonAlignment(
FirstAlignment, VecBaseTy->getPrimitiveSizeInBits().getFixedSize() / 8);
Align Alignment = FirstAlignment;
for (unsigned i = 0; i < NumLoads; i++) {
// TODO: Support inbounds GEP.
Value *NewBasePtr =
Builder.CreateGEP(VecBaseTy, VecBasePtr, Builder.getInt32(i));
Instruction *NewLoad =
Builder.CreateAlignedLoad(VecBaseTy, NewBasePtr, Alignment);
DecomposedVectors.push_back(NewLoad);
Alignment = SubsequentAlignment;
}
}
// Changing the scale of the vector type by reducing the number of elements and
// doubling the scalar size.
static MVT scaleVectorType(MVT VT) {
unsigned ScalarSize = VT.getVectorElementType().getScalarSizeInBits() * 2;
return MVT::getVectorVT(MVT::getIntegerVT(ScalarSize),
VT.getVectorNumElements() / 2);
}
static constexpr int Concat[] = {
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31,
32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47,
48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63};
// genShuffleBland - Creates shuffle according to two vectors.This function is
// only works on instructions with lane inside 256 registers. According to
// the mask 'Mask' creates a new Mask 'Out' by the offset of the mask. The
// offset amount depends on the two integer, 'LowOffset' and 'HighOffset'.
// Where the 'LowOffset' refers to the first vector and the highOffset refers to
// the second vector.
// |a0....a5,b0....b4,c0....c4|a16..a21,b16..b20,c16..c20|
// |c5...c10,a5....a9,b5....b9|c21..c26,a22..a26,b21..b25|
// |b10..b15,c11..c15,a10..a15|b26..b31,c27..c31,a27..a31|
// For the sequence to work as a mirror to the load.
// We must consider the elements order as above.
// In this function we are combining two types of shuffles.
// The first one is vpshufed and the second is a type of "blend" shuffle.
// By computing the shuffle on a sequence of 16 elements(one lane) and add the
// correct offset. We are creating a vpsuffed + blend sequence between two
// shuffles.
static void genShuffleBland(MVT VT, ArrayRef<int> Mask,
SmallVectorImpl<int> &Out, int LowOffset,
int HighOffset) {
assert(VT.getSizeInBits() >= 256 &&
"This function doesn't accept width smaller then 256");
unsigned NumOfElm = VT.getVectorNumElements();
for (unsigned i = 0; i < Mask.size(); i++)
Out.push_back(Mask[i] + LowOffset);
for (unsigned i = 0; i < Mask.size(); i++)
Out.push_back(Mask[i] + HighOffset + NumOfElm);
}
// reorderSubVector returns the data to is the original state. And de-facto is
// the opposite of the function concatSubVector.
// For VecElems = 16
// Invec[0] - |0| TransposedMatrix[0] - |0|
// Invec[1] - |1| => TransposedMatrix[1] - |1|
// Invec[2] - |2| TransposedMatrix[2] - |2|
// For VecElems = 32
// Invec[0] - |0|3| TransposedMatrix[0] - |0|1|
// Invec[1] - |1|4| => TransposedMatrix[1] - |2|3|
// Invec[2] - |2|5| TransposedMatrix[2] - |4|5|
// For VecElems = 64
// Invec[0] - |0|3|6|9 | TransposedMatrix[0] - |0|1|2 |3 |
// Invec[1] - |1|4|7|10| => TransposedMatrix[1] - |4|5|6 |7 |
// Invec[2] - |2|5|8|11| TransposedMatrix[2] - |8|9|10|11|
static void reorderSubVector(MVT VT, SmallVectorImpl<Value *> &TransposedMatrix,
ArrayRef<Value *> Vec, ArrayRef<int> VPShuf,
unsigned VecElems, unsigned Stride,
IRBuilder<> &Builder) {
if (VecElems == 16) {
for (unsigned i = 0; i < Stride; i++)
TransposedMatrix[i] = Builder.CreateShuffleVector(
Vec[i], UndefValue::get(Vec[i]->getType()), VPShuf);
return;
}
SmallVector<int, 32> OptimizeShuf;
Value *Temp[8];
for (unsigned i = 0; i < (VecElems / 16) * Stride; i += 2) {
genShuffleBland(VT, VPShuf, OptimizeShuf, (i / Stride) * 16,
(i + 1) / Stride * 16);
Temp[i / 2] = Builder.CreateShuffleVector(
Vec[i % Stride], Vec[(i + 1) % Stride], OptimizeShuf);
OptimizeShuf.clear();
}
if (VecElems == 32) {
std::copy(Temp, Temp + Stride, TransposedMatrix.begin());
return;
} else
for (unsigned i = 0; i < Stride; i++)
TransposedMatrix[i] =
Builder.CreateShuffleVector(Temp[2 * i], Temp[2 * i + 1], Concat);
}
void X86InterleavedAccessGroup::interleave8bitStride4VF8(
ArrayRef<Instruction *> Matrix,
SmallVectorImpl<Value *> &TransposedMatrix) {
// Assuming we start from the following vectors:
// Matrix[0]= c0 c1 c2 c3 c4 ... c7
// Matrix[1]= m0 m1 m2 m3 m4 ... m7
// Matrix[2]= y0 y1 y2 y3 y4 ... y7
// Matrix[3]= k0 k1 k2 k3 k4 ... k7
MVT VT = MVT::v8i16;
TransposedMatrix.resize(2);
SmallVector<int, 16> MaskLow;
SmallVector<int, 32> MaskLowTemp1, MaskLowWord;
SmallVector<int, 32> MaskHighTemp1, MaskHighWord;
for (unsigned i = 0; i < 8; ++i) {
MaskLow.push_back(i);
MaskLow.push_back(i + 8);
}
createUnpackShuffleMask(VT, MaskLowTemp1, true, false);
createUnpackShuffleMask(VT, MaskHighTemp1, false, false);
narrowShuffleMaskElts(2, MaskHighTemp1, MaskHighWord);
narrowShuffleMaskElts(2, MaskLowTemp1, MaskLowWord);
// IntrVec1Low = c0 m0 c1 m1 c2 m2 c3 m3 c4 m4 c5 m5 c6 m6 c7 m7
// IntrVec2Low = y0 k0 y1 k1 y2 k2 y3 k3 y4 k4 y5 k5 y6 k6 y7 k7
Value *IntrVec1Low =
Builder.CreateShuffleVector(Matrix[0], Matrix[1], MaskLow);
Value *IntrVec2Low =
Builder.CreateShuffleVector(Matrix[2], Matrix[3], MaskLow);
// TransposedMatrix[0] = c0 m0 y0 k0 c1 m1 y1 k1 c2 m2 y2 k2 c3 m3 y3 k3
// TransposedMatrix[1] = c4 m4 y4 k4 c5 m5 y5 k5 c6 m6 y6 k6 c7 m7 y7 k7
TransposedMatrix[0] =
Builder.CreateShuffleVector(IntrVec1Low, IntrVec2Low, MaskLowWord);
TransposedMatrix[1] =
Builder.CreateShuffleVector(IntrVec1Low, IntrVec2Low, MaskHighWord);
}
void X86InterleavedAccessGroup::interleave8bitStride4(
ArrayRef<Instruction *> Matrix, SmallVectorImpl<Value *> &TransposedMatrix,
unsigned NumOfElm) {
// Example: Assuming we start from the following vectors:
// Matrix[0]= c0 c1 c2 c3 c4 ... c31
// Matrix[1]= m0 m1 m2 m3 m4 ... m31
// Matrix[2]= y0 y1 y2 y3 y4 ... y31
// Matrix[3]= k0 k1 k2 k3 k4 ... k31
MVT VT = MVT::getVectorVT(MVT::i8, NumOfElm);
MVT HalfVT = scaleVectorType(VT);
TransposedMatrix.resize(4);
SmallVector<int, 32> MaskHigh;
SmallVector<int, 32> MaskLow;
SmallVector<int, 32> LowHighMask[2];
SmallVector<int, 32> MaskHighTemp;
SmallVector<int, 32> MaskLowTemp;
// MaskHighTemp and MaskLowTemp built in the vpunpckhbw and vpunpcklbw X86
// shuffle pattern.
createUnpackShuffleMask(VT, MaskLow, true, false);
createUnpackShuffleMask(VT, MaskHigh, false, false);
// MaskHighTemp1 and MaskLowTemp1 built in the vpunpckhdw and vpunpckldw X86
// shuffle pattern.
createUnpackShuffleMask(HalfVT, MaskLowTemp, true, false);
createUnpackShuffleMask(HalfVT, MaskHighTemp, false, false);
narrowShuffleMaskElts(2, MaskLowTemp, LowHighMask[0]);
narrowShuffleMaskElts(2, MaskHighTemp, LowHighMask[1]);
// IntrVec1Low = c0 m0 c1 m1 ... c7 m7 | c16 m16 c17 m17 ... c23 m23
// IntrVec1High = c8 m8 c9 m9 ... c15 m15 | c24 m24 c25 m25 ... c31 m31
// IntrVec2Low = y0 k0 y1 k1 ... y7 k7 | y16 k16 y17 k17 ... y23 k23
// IntrVec2High = y8 k8 y9 k9 ... y15 k15 | y24 k24 y25 k25 ... y31 k31
Value *IntrVec[4];
IntrVec[0] = Builder.CreateShuffleVector(Matrix[0], Matrix[1], MaskLow);
IntrVec[1] = Builder.CreateShuffleVector(Matrix[0], Matrix[1], MaskHigh);
IntrVec[2] = Builder.CreateShuffleVector(Matrix[2], Matrix[3], MaskLow);
IntrVec[3] = Builder.CreateShuffleVector(Matrix[2], Matrix[3], MaskHigh);
// cmyk4 cmyk5 cmyk6 cmyk7 | cmyk20 cmyk21 cmyk22 cmyk23
// cmyk12 cmyk13 cmyk14 cmyk15 | cmyk28 cmyk29 cmyk30 cmyk31
// cmyk0 cmyk1 cmyk2 cmyk3 | cmyk16 cmyk17 cmyk18 cmyk19
// cmyk8 cmyk9 cmyk10 cmyk11 | cmyk24 cmyk25 cmyk26 cmyk27
Value *VecOut[4];
for (int i = 0; i < 4; i++)
VecOut[i] = Builder.CreateShuffleVector(IntrVec[i / 2], IntrVec[i / 2 + 2],
LowHighMask[i % 2]);
// cmyk0 cmyk1 cmyk2 cmyk3 | cmyk4 cmyk5 cmyk6 cmyk7
// cmyk8 cmyk9 cmyk10 cmyk11 | cmyk12 cmyk13 cmyk14 cmyk15
// cmyk16 cmyk17 cmyk18 cmyk19 | cmyk20 cmyk21 cmyk22 cmyk23
// cmyk24 cmyk25 cmyk26 cmyk27 | cmyk28 cmyk29 cmyk30 cmyk31
if (VT == MVT::v16i8) {
std::copy(VecOut, VecOut + 4, TransposedMatrix.begin());
return;
}
reorderSubVector(VT, TransposedMatrix, VecOut, makeArrayRef(Concat, 16),
NumOfElm, 4, Builder);
}
// createShuffleStride returns shuffle mask of size N.
// The shuffle pattern is as following :
// {0, Stride%(VF/Lane), (2*Stride%(VF/Lane))...(VF*Stride/Lane)%(VF/Lane),
// (VF/ Lane) ,(VF / Lane)+Stride%(VF/Lane),...,
// (VF / Lane)+(VF*Stride/Lane)%(VF/Lane)}
// Where Lane is the # of lanes in a register:
// VectorSize = 128 => Lane = 1
// VectorSize = 256 => Lane = 2
// For example shuffle pattern for VF 16 register size 256 -> lanes = 2
// {<[0|3|6|1|4|7|2|5]-[8|11|14|9|12|15|10|13]>}
static void createShuffleStride(MVT VT, int Stride,
SmallVectorImpl<int> &Mask) {
int VectorSize = VT.getSizeInBits();
int VF = VT.getVectorNumElements();
int LaneCount = std::max(VectorSize / 128, 1);
for (int Lane = 0; Lane < LaneCount; Lane++)
for (int i = 0, LaneSize = VF / LaneCount; i != LaneSize; ++i)
Mask.push_back((i * Stride) % LaneSize + LaneSize * Lane);
}
// setGroupSize sets 'SizeInfo' to the size(number of elements) of group
// inside mask a shuffleMask. A mask contains exactly 3 groups, where
// each group is a monotonically increasing sequence with stride 3.
// For example shuffleMask {0,3,6,1,4,7,2,5} => {3,3,2}
static void setGroupSize(MVT VT, SmallVectorImpl<int> &SizeInfo) {
int VectorSize = VT.getSizeInBits();
int VF = VT.getVectorNumElements() / std::max(VectorSize / 128, 1);
for (int i = 0, FirstGroupElement = 0; i < 3; i++) {
int GroupSize = std::ceil((VF - FirstGroupElement) / 3.0);
SizeInfo.push_back(GroupSize);
FirstGroupElement = ((GroupSize)*3 + FirstGroupElement) % VF;
}
}
// DecodePALIGNRMask returns the shuffle mask of vpalign instruction.
// vpalign works according to lanes
// Where Lane is the # of lanes in a register:
// VectorWide = 128 => Lane = 1
// VectorWide = 256 => Lane = 2
// For Lane = 1 shuffle pattern is: {DiffToJump,...,DiffToJump+VF-1}.
// For Lane = 2 shuffle pattern is:
// {DiffToJump,...,VF/2-1,VF,...,DiffToJump+VF-1}.
// Imm variable sets the offset amount. The result of the
// function is stored inside ShuffleMask vector and it built as described in
// the begin of the description. AlignDirection is a boolean that indicates the
// direction of the alignment. (false - align to the "right" side while true -
// align to the "left" side)
static void DecodePALIGNRMask(MVT VT, unsigned Imm,
SmallVectorImpl<int> &ShuffleMask,
bool AlignDirection = true, bool Unary = false) {
unsigned NumElts = VT.getVectorNumElements();
unsigned NumLanes = std::max((int)VT.getSizeInBits() / 128, 1);
unsigned NumLaneElts = NumElts / NumLanes;
Imm = AlignDirection ? Imm : (NumLaneElts - Imm);
unsigned Offset = Imm * (VT.getScalarSizeInBits() / 8);
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 Unary the other source is the first source.
if (Base >= NumLaneElts)
Base = Unary ? Base % NumLaneElts : Base + NumElts - NumLaneElts;
ShuffleMask.push_back(Base + l);
}
}
}
// concatSubVector - The function rebuilds the data to a correct expected
// order. An assumption(The shape of the matrix) was taken for the
// deinterleaved to work with lane's instructions like 'vpalign' or 'vphuf'.
// This function ensures that the data is built in correct way for the lane
// instructions. Each lane inside the vector is a 128-bit length.
//
// The 'InVec' argument contains the data in increasing order. In InVec[0] You
// can find the first 128 bit data. The number of different lanes inside a
// vector depends on the 'VecElems'.In general, the formula is
// VecElems * type / 128. The size of the array 'InVec' depends and equal to
// 'VecElems'.
// For VecElems = 16
// Invec[0] - |0| Vec[0] - |0|
// Invec[1] - |1| => Vec[1] - |1|
// Invec[2] - |2| Vec[2] - |2|
// For VecElems = 32
// Invec[0] - |0|1| Vec[0] - |0|3|
// Invec[1] - |2|3| => Vec[1] - |1|4|
// Invec[2] - |4|5| Vec[2] - |2|5|
// For VecElems = 64
// Invec[0] - |0|1|2 |3 | Vec[0] - |0|3|6|9 |
// Invec[1] - |4|5|6 |7 | => Vec[1] - |1|4|7|10|
// Invec[2] - |8|9|10|11| Vec[2] - |2|5|8|11|
static void concatSubVector(Value **Vec, ArrayRef<Instruction *> InVec,
unsigned VecElems, IRBuilder<> &Builder) {
if (VecElems == 16) {
for (int i = 0; i < 3; i++)
Vec[i] = InVec[i];
return;
}
for (unsigned j = 0; j < VecElems / 32; j++)
for (int i = 0; i < 3; i++)
Vec[i + j * 3] = Builder.CreateShuffleVector(
InVec[j * 6 + i], InVec[j * 6 + i + 3], makeArrayRef(Concat, 32));
if (VecElems == 32)
return;
for (int i = 0; i < 3; i++)
Vec[i] = Builder.CreateShuffleVector(Vec[i], Vec[i + 3], Concat);
}
void X86InterleavedAccessGroup::deinterleave8bitStride3(
ArrayRef<Instruction *> InVec, SmallVectorImpl<Value *> &TransposedMatrix,
unsigned VecElems) {
// Example: Assuming we start from the following vectors:
// Matrix[0]= a0 b0 c0 a1 b1 c1 a2 b2
// Matrix[1]= c2 a3 b3 c3 a4 b4 c4 a5
// Matrix[2]= b5 c5 a6 b6 c6 a7 b7 c7
TransposedMatrix.resize(3);
SmallVector<int, 32> VPShuf;
SmallVector<int, 32> VPAlign[2];
SmallVector<int, 32> VPAlign2;
SmallVector<int, 32> VPAlign3;
SmallVector<int, 3> GroupSize;
Value *Vec[6], *TempVector[3];
MVT VT = MVT::getVT(Shuffles[0]->getType());
createShuffleStride(VT, 3, VPShuf);
setGroupSize(VT, GroupSize);
for (int i = 0; i < 2; i++)
DecodePALIGNRMask(VT, GroupSize[2 - i], VPAlign[i], false);
DecodePALIGNRMask(VT, GroupSize[2] + GroupSize[1], VPAlign2, true, true);
DecodePALIGNRMask(VT, GroupSize[1], VPAlign3, true, true);
concatSubVector(Vec, InVec, VecElems, Builder);
// Vec[0]= a0 a1 a2 b0 b1 b2 c0 c1
// Vec[1]= c2 c3 c4 a3 a4 a5 b3 b4
// Vec[2]= b5 b6 b7 c5 c6 c7 a6 a7
for (int i = 0; i < 3; i++)
Vec[i] = Builder.CreateShuffleVector(
Vec[i], UndefValue::get(Vec[0]->getType()), VPShuf);
// TempVector[0]= a6 a7 a0 a1 a2 b0 b1 b2
// TempVector[1]= c0 c1 c2 c3 c4 a3 a4 a5
// TempVector[2]= b3 b4 b5 b6 b7 c5 c6 c7
for (int i = 0; i < 3; i++)
TempVector[i] =
Builder.CreateShuffleVector(Vec[(i + 2) % 3], Vec[i], VPAlign[0]);
// Vec[0]= a3 a4 a5 a6 a7 a0 a1 a2
// Vec[1]= c5 c6 c7 c0 c1 c2 c3 c4
// Vec[2]= b0 b1 b2 b3 b4 b5 b6 b7
for (int i = 0; i < 3; i++)
Vec[i] = Builder.CreateShuffleVector(TempVector[(i + 1) % 3], TempVector[i],
VPAlign[1]);
// TransposedMatrix[0]= a0 a1 a2 a3 a4 a5 a6 a7
// TransposedMatrix[1]= b0 b1 b2 b3 b4 b5 b6 b7
// TransposedMatrix[2]= c0 c1 c2 c3 c4 c5 c6 c7
Value *TempVec = Builder.CreateShuffleVector(
Vec[1], UndefValue::get(Vec[1]->getType()), VPAlign3);
TransposedMatrix[0] = Builder.CreateShuffleVector(
Vec[0], UndefValue::get(Vec[1]->getType()), VPAlign2);
TransposedMatrix[1] = VecElems == 8 ? Vec[2] : TempVec;
TransposedMatrix[2] = VecElems == 8 ? TempVec : Vec[2];
}
// group2Shuffle reorder the shuffle stride back into continuous order.
// For example For VF16 with Mask1 = {0,3,6,9,12,15,2,5,8,11,14,1,4,7,10,13} =>
// MaskResult = {0,11,6,1,12,7,2,13,8,3,14,9,4,15,10,5}.
static void group2Shuffle(MVT VT, SmallVectorImpl<int> &Mask,
SmallVectorImpl<int> &Output) {
int IndexGroup[3] = {0, 0, 0};
int Index = 0;
int VectorWidth = VT.getSizeInBits();
int VF = VT.getVectorNumElements();
// Find the index of the different groups.
int Lane = (VectorWidth / 128 > 0) ? VectorWidth / 128 : 1;
for (int i = 0; i < 3; i++) {
IndexGroup[(Index * 3) % (VF / Lane)] = Index;
Index += Mask[i];
}
// According to the index compute the convert mask.
for (int i = 0; i < VF / Lane; i++) {
Output.push_back(IndexGroup[i % 3]);
IndexGroup[i % 3]++;
}
}
void X86InterleavedAccessGroup::interleave8bitStride3(
ArrayRef<Instruction *> InVec, SmallVectorImpl<Value *> &TransposedMatrix,
unsigned VecElems) {
// Example: Assuming we start from the following vectors:
// Matrix[0]= a0 a1 a2 a3 a4 a5 a6 a7
// Matrix[1]= b0 b1 b2 b3 b4 b5 b6 b7
// Matrix[2]= c0 c1 c2 c3 c3 a7 b7 c7
TransposedMatrix.resize(3);
SmallVector<int, 3> GroupSize;
SmallVector<int, 32> VPShuf;
SmallVector<int, 32> VPAlign[3];
SmallVector<int, 32> VPAlign2;
SmallVector<int, 32> VPAlign3;
Value *Vec[3], *TempVector[3];
MVT VT = MVT::getVectorVT(MVT::i8, VecElems);
setGroupSize(VT, GroupSize);
for (int i = 0; i < 3; i++)
DecodePALIGNRMask(VT, GroupSize[i], VPAlign[i]);
DecodePALIGNRMask(VT, GroupSize[1] + GroupSize[2], VPAlign2, false, true);
DecodePALIGNRMask(VT, GroupSize[1], VPAlign3, false, true);
// Vec[0]= a3 a4 a5 a6 a7 a0 a1 a2
// Vec[1]= c5 c6 c7 c0 c1 c2 c3 c4
// Vec[2]= b0 b1 b2 b3 b4 b5 b6 b7
Vec[0] = Builder.CreateShuffleVector(
InVec[0], UndefValue::get(InVec[0]->getType()), VPAlign2);
Vec[1] = Builder.CreateShuffleVector(
InVec[1], UndefValue::get(InVec[1]->getType()), VPAlign3);
Vec[2] = InVec[2];
// Vec[0]= a6 a7 a0 a1 a2 b0 b1 b2
// Vec[1]= c0 c1 c2 c3 c4 a3 a4 a5
// Vec[2]= b3 b4 b5 b6 b7 c5 c6 c7
for (int i = 0; i < 3; i++)
TempVector[i] =
Builder.CreateShuffleVector(Vec[i], Vec[(i + 2) % 3], VPAlign[1]);
// Vec[0]= a0 a1 a2 b0 b1 b2 c0 c1
// Vec[1]= c2 c3 c4 a3 a4 a5 b3 b4
// Vec[2]= b5 b6 b7 c5 c6 c7 a6 a7
for (int i = 0; i < 3; i++)
Vec[i] = Builder.CreateShuffleVector(TempVector[i], TempVector[(i + 1) % 3],
VPAlign[2]);
// TransposedMatrix[0] = a0 b0 c0 a1 b1 c1 a2 b2
// TransposedMatrix[1] = c2 a3 b3 c3 a4 b4 c4 a5
// TransposedMatrix[2] = b5 c5 a6 b6 c6 a7 b7 c7
unsigned NumOfElm = VT.getVectorNumElements();
group2Shuffle(VT, GroupSize, VPShuf);
reorderSubVector(VT, TransposedMatrix, Vec, VPShuf, NumOfElm, 3, Builder);
}
void X86InterleavedAccessGroup::transpose_4x4(
ArrayRef<Instruction *> Matrix,
SmallVectorImpl<Value *> &TransposedMatrix) {
assert(Matrix.size() == 4 && "Invalid matrix size");
TransposedMatrix.resize(4);
// dst = src1[0,1],src2[0,1]
static constexpr int IntMask1[] = {0, 1, 4, 5};
ArrayRef<int> Mask = makeArrayRef(IntMask1, 4);
Value *IntrVec1 = Builder.CreateShuffleVector(Matrix[0], Matrix[2], Mask);
Value *IntrVec2 = Builder.CreateShuffleVector(Matrix[1], Matrix[3], Mask);
// dst = src1[2,3],src2[2,3]
static constexpr int IntMask2[] = {2, 3, 6, 7};
Mask = makeArrayRef(IntMask2, 4);
Value *IntrVec3 = Builder.CreateShuffleVector(Matrix[0], Matrix[2], Mask);
Value *IntrVec4 = Builder.CreateShuffleVector(Matrix[1], Matrix[3], Mask);
// dst = src1[0],src2[0],src1[2],src2[2]
static constexpr int IntMask3[] = {0, 4, 2, 6};
Mask = makeArrayRef(IntMask3, 4);
TransposedMatrix[0] = Builder.CreateShuffleVector(IntrVec1, IntrVec2, Mask);
TransposedMatrix[2] = Builder.CreateShuffleVector(IntrVec3, IntrVec4, Mask);
// dst = src1[1],src2[1],src1[3],src2[3]
static constexpr int IntMask4[] = {1, 5, 3, 7};
Mask = makeArrayRef(IntMask4, 4);
TransposedMatrix[1] = Builder.CreateShuffleVector(IntrVec1, IntrVec2, Mask);
TransposedMatrix[3] = Builder.CreateShuffleVector(IntrVec3, IntrVec4, Mask);
}
// Lowers this interleaved access group into X86-specific
// instructions/intrinsics.
bool X86InterleavedAccessGroup::lowerIntoOptimizedSequence() {
SmallVector<Instruction *, 4> DecomposedVectors;
SmallVector<Value *, 4> TransposedVectors;
auto *ShuffleTy = cast<FixedVectorType>(Shuffles[0]->getType());
if (isa<LoadInst>(Inst)) {
// Try to generate target-sized register(/instruction).
decompose(Inst, Factor, ShuffleTy, DecomposedVectors);
auto *ShuffleEltTy = cast<FixedVectorType>(Inst->getType());
unsigned NumSubVecElems = ShuffleEltTy->getNumElements() / Factor;
// Perform matrix-transposition in order to compute interleaved
// results by generating some sort of (optimized) target-specific
// instructions.
switch (NumSubVecElems) {
default:
return false;
case 4:
transpose_4x4(DecomposedVectors, TransposedVectors);
break;
case 8:
case 16:
case 32:
case 64:
deinterleave8bitStride3(DecomposedVectors, TransposedVectors,
NumSubVecElems);
break;
}
// Now replace the unoptimized-interleaved-vectors with the
// transposed-interleaved vectors.
for (unsigned i = 0, e = Shuffles.size(); i < e; ++i)
Shuffles[i]->replaceAllUsesWith(TransposedVectors[Indices[i]]);
return true;
}
Type *ShuffleEltTy = ShuffleTy->getElementType();
unsigned NumSubVecElems = ShuffleTy->getNumElements() / Factor;
// Lower the interleaved stores:
// 1. Decompose the interleaved wide shuffle into individual shuffle
// vectors.
decompose(Shuffles[0], Factor,
FixedVectorType::get(ShuffleEltTy, NumSubVecElems),
DecomposedVectors);
// 2. Transpose the interleaved-vectors into vectors of contiguous
// elements.
switch (NumSubVecElems) {
case 4:
transpose_4x4(DecomposedVectors, TransposedVectors);
break;
case 8:
interleave8bitStride4VF8(DecomposedVectors, TransposedVectors);
break;
case 16:
case 32:
case 64:
if (Factor == 4)
interleave8bitStride4(DecomposedVectors, TransposedVectors,
NumSubVecElems);
if (Factor == 3)
interleave8bitStride3(DecomposedVectors, TransposedVectors,
NumSubVecElems);
break;
default:
return false;
}
// 3. Concatenate the contiguous-vectors back into a wide vector.
Value *WideVec = concatenateVectors(Builder, TransposedVectors);
// 4. Generate a store instruction for wide-vec.
StoreInst *SI = cast<StoreInst>(Inst);
Builder.CreateAlignedStore(WideVec, SI->getPointerOperand(), SI->getAlign());
return true;
}
// Lower interleaved load(s) into target specific instructions/
// intrinsics. Lowering sequence varies depending on the vector-types, factor,
// number of shuffles and ISA.
// Currently, lowering is supported for 4x64 bits with Factor = 4 on AVX.
bool X86TargetLowering::lowerInterleavedLoad(
LoadInst *LI, ArrayRef<ShuffleVectorInst *> Shuffles,
ArrayRef<unsigned> Indices, unsigned Factor) const {
assert(Factor >= 2 && Factor <= getMaxSupportedInterleaveFactor() &&
"Invalid interleave factor");
assert(!Shuffles.empty() && "Empty shufflevector input");
assert(Shuffles.size() == Indices.size() &&
"Unmatched number of shufflevectors and indices");
// Create an interleaved access group.
IRBuilder<> Builder(LI);
X86InterleavedAccessGroup Grp(LI, Shuffles, Indices, Factor, Subtarget,
Builder);
return Grp.isSupported() && Grp.lowerIntoOptimizedSequence();
}
bool X86TargetLowering::lowerInterleavedStore(StoreInst *SI,
ShuffleVectorInst *SVI,
unsigned Factor) const {
assert(Factor >= 2 && Factor <= getMaxSupportedInterleaveFactor() &&
"Invalid interleave factor");
assert(cast<FixedVectorType>(SVI->getType())->getNumElements() % Factor ==
0 &&
"Invalid interleaved store");
// Holds the indices of SVI that correspond to the starting index of each
// interleaved shuffle.
SmallVector<unsigned, 4> Indices;
auto Mask = SVI->getShuffleMask();
for (unsigned i = 0; i < Factor; i++)
Indices.push_back(Mask[i]);
ArrayRef<ShuffleVectorInst *> Shuffles = makeArrayRef(SVI);
// Create an interleaved access group.
IRBuilder<> Builder(SI);
X86InterleavedAccessGroup Grp(SI, Shuffles, Indices, Factor, Subtarget,
Builder);
return Grp.isSupported() && Grp.lowerIntoOptimizedSequence();
}
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