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clang-p2996/llvm/lib/Target/X86/Utils/X86ShuffleDecode.cpp
Chandler Carruth 2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00

588 lines
20 KiB
C++

//===-- X86ShuffleDecode.cpp - X86 shuffle decode logic -------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// Define several functions to decode x86 specific shuffle semantics into a
// generic vector mask.
//
//===----------------------------------------------------------------------===//
#include "X86ShuffleDecode.h"
#include "llvm/ADT/ArrayRef.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;
}
void DecodeInsertElementMask(unsigned NumElts, unsigned Idx, unsigned Len,
SmallVectorImpl<int> &ShuffleMask) {
assert((Idx + Len) <= NumElts && "Insertion out of range");
for (unsigned i = 0; i != NumElts; ++i)
ShuffleMask.push_back(i);
for (unsigned i = 0; i != Len; ++i)
ShuffleMask[Idx + i] = NumElts + i;
}
// <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(unsigned NumElts, SmallVectorImpl<int> &ShuffleMask) {
for (int i = 0, e = NumElts / 2; i < e; ++i) {
ShuffleMask.push_back(2 * i);
ShuffleMask.push_back(2 * i);
}
}
void DecodeMOVSHDUPMask(unsigned NumElts, SmallVectorImpl<int> &ShuffleMask) {
for (int i = 0, e = NumElts / 2; i < e; ++i) {
ShuffleMask.push_back(2 * i + 1);
ShuffleMask.push_back(2 * i + 1);
}
}
void DecodeMOVDDUPMask(unsigned NumElts, SmallVectorImpl<int> &ShuffleMask) {
const unsigned NumLaneElts = 2;
for (unsigned l = 0; l < NumElts; l += NumLaneElts)
for (unsigned i = 0; i < NumLaneElts; ++i)
ShuffleMask.push_back(l);
}
void DecodePSLLDQMask(unsigned NumElts, unsigned Imm,
SmallVectorImpl<int> &ShuffleMask) {
const unsigned NumLaneElts = 16;
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(unsigned NumElts, unsigned Imm,
SmallVectorImpl<int> &ShuffleMask) {
const unsigned NumLaneElts = 16;
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(unsigned NumElts, unsigned Imm,
SmallVectorImpl<int> &ShuffleMask) {
const unsigned NumLaneElts = 16;
for (unsigned l = 0; l != NumElts; l += NumLaneElts) {
for (unsigned i = 0; i != NumLaneElts; ++i) {
unsigned Base = i + Imm;
// if i+imm is out of this lane then we actually need the other source
if (Base >= NumLaneElts) Base += NumElts - NumLaneElts;
ShuffleMask.push_back(Base + l);
}
}
}
void DecodeVALIGNMask(unsigned NumElts, unsigned Imm,
SmallVectorImpl<int> &ShuffleMask) {
// Not all bits of the immediate are used so mask it.
assert(isPowerOf2_32(NumElts) && "NumElts should be power of 2");
Imm = Imm & (NumElts - 1);
for (unsigned i = 0; i != NumElts; ++i)
ShuffleMask.push_back(i + Imm);
}
/// DecodePSHUFMask - This decodes the shuffle masks for pshufw, pshufd, and vpermilp*.
/// VT indicates the type of the vector allowing it to handle different
/// datatypes and vector widths.
void DecodePSHUFMask(unsigned NumElts, unsigned ScalarBits, unsigned Imm,
SmallVectorImpl<int> &ShuffleMask) {
unsigned Size = NumElts * ScalarBits;
unsigned NumLanes = Size / 128;
if (NumLanes == 0) NumLanes = 1; // Handle MMX
unsigned NumLaneElts = NumElts / NumLanes;
uint32_t SplatImm = (Imm & 0xff) * 0x01010101;
for (unsigned l = 0; l != NumElts; l += NumLaneElts) {
for (unsigned i = 0; i != NumLaneElts; ++i) {
ShuffleMask.push_back(SplatImm % NumLaneElts + l);
SplatImm /= NumLaneElts;
}
}
}
void DecodePSHUFHWMask(unsigned NumElts, unsigned Imm,
SmallVectorImpl<int> &ShuffleMask) {
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(unsigned NumElts, unsigned Imm,
SmallVectorImpl<int> &ShuffleMask) {
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);
}
}
}
void DecodePSWAPMask(unsigned NumElts, SmallVectorImpl<int> &ShuffleMask) {
unsigned NumHalfElts = NumElts / 2;
for (unsigned l = 0; l != NumHalfElts; ++l)
ShuffleMask.push_back(l + NumHalfElts);
for (unsigned h = 0; h != NumHalfElts; ++h)
ShuffleMask.push_back(h);
}
/// 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(unsigned NumElts, unsigned ScalarBits,
unsigned Imm, SmallVectorImpl<int> &ShuffleMask) {
unsigned NumLaneElts = 128 / ScalarBits;
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(unsigned NumElts, unsigned ScalarBits,
SmallVectorImpl<int> &ShuffleMask) {
// Handle 128 and 256-bit vector lengths. AVX defines UNPCK* to operate
// independently on 128-bit lanes.
unsigned NumLanes = (NumElts * ScalarBits) / 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(unsigned NumElts, unsigned ScalarBits,
SmallVectorImpl<int> &ShuffleMask) {
// Handle 128 and 256-bit vector lengths. AVX defines UNPCK* to operate
// independently on 128-bit lanes.
unsigned NumLanes = (NumElts * ScalarBits) / 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
}
}
}
/// Decodes a broadcast of the first element of a vector.
void DecodeVectorBroadcast(unsigned NumElts,
SmallVectorImpl<int> &ShuffleMask) {
ShuffleMask.append(NumElts, 0);
}
/// Decodes a broadcast of a subvector to a larger vector type.
void DecodeSubVectorBroadcast(unsigned DstNumElts, unsigned SrcNumElts,
SmallVectorImpl<int> &ShuffleMask) {
unsigned Scale = DstNumElts / SrcNumElts;
for (unsigned i = 0; i != Scale; ++i)
for (unsigned j = 0; j != SrcNumElts; ++j)
ShuffleMask.push_back(j);
}
/// Decode a shuffle packed values at 128-bit granularity
/// (SHUFF32x4/SHUFF64x2/SHUFI32x4/SHUFI64x2)
/// immediate mask into a shuffle mask.
void decodeVSHUF64x2FamilyMask(unsigned NumElts, unsigned ScalarSize,
unsigned Imm,
SmallVectorImpl<int> &ShuffleMask) {
unsigned NumElementsInLane = 128 / ScalarSize;
unsigned NumLanes = NumElts / NumElementsInLane;
for (unsigned l = 0; l != NumElts; l += NumElementsInLane) {
unsigned Index = (Imm % NumLanes) * NumElementsInLane;
Imm /= NumLanes; // Discard the bits we just used.
// We actually need the other source.
if (l >= (NumElts / 2))
Index += NumElts;
for (unsigned i = 0; i != NumElementsInLane; ++i)
ShuffleMask.push_back(Index + i);
}
}
void DecodeVPERM2X128Mask(unsigned NumElts, unsigned Imm,
SmallVectorImpl<int> &ShuffleMask) {
unsigned HalfSize = NumElts / 2;
for (unsigned l = 0; l != 2; ++l) {
unsigned HalfMask = Imm >> (l * 4);
unsigned HalfBegin = (HalfMask & 0x3) * HalfSize;
for (unsigned i = HalfBegin, e = HalfBegin + HalfSize; i != e; ++i)
ShuffleMask.push_back(HalfMask & 8 ? SM_SentinelZero : (int)i);
}
}
void DecodePSHUFBMask(ArrayRef<uint64_t> RawMask, const APInt &UndefElts,
SmallVectorImpl<int> &ShuffleMask) {
for (int i = 0, e = RawMask.size(); i < e; ++i) {
uint64_t M = RawMask[i];
if (UndefElts[i]) {
ShuffleMask.push_back(SM_SentinelUndef);
continue;
}
// For 256/512-bit vectors the base of the shuffle is the 128-bit
// subvector we're inside.
int Base = (i / 16) * 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(unsigned NumElts, unsigned Imm,
SmallVectorImpl<int> &ShuffleMask) {
for (unsigned i = 0; i < NumElts; ++i) {
// If there are more than 8 elements in the vector, then any immediate blend
// mask wraps around.
unsigned Bit = i % 8;
ShuffleMask.push_back(((Imm >> Bit) & 1) ? NumElts + i : i);
}
}
void DecodeVPPERMMask(ArrayRef<uint64_t> RawMask, const APInt &UndefElts,
SmallVectorImpl<int> &ShuffleMask) {
assert(RawMask.size() == 16 && "Illegal VPPERM shuffle mask size");
// VPPERM Operation
// Bits[4:0] - Byte Index (0 - 31)
// Bits[7:5] - Permute Operation
//
// Permute Operation:
// 0 - Source byte (no logical operation).
// 1 - Invert source byte.
// 2 - Bit reverse of source byte.
// 3 - Bit reverse of inverted source byte.
// 4 - 00h (zero - fill).
// 5 - FFh (ones - fill).
// 6 - Most significant bit of source byte replicated in all bit positions.
// 7 - Invert most significant bit of source byte and replicate in all bit positions.
for (int i = 0, e = RawMask.size(); i < e; ++i) {
if (UndefElts[i]) {
ShuffleMask.push_back(SM_SentinelUndef);
continue;
}
uint64_t M = RawMask[i];
uint64_t PermuteOp = (M >> 5) & 0x7;
if (PermuteOp == 4) {
ShuffleMask.push_back(SM_SentinelZero);
continue;
}
if (PermuteOp != 0) {
ShuffleMask.clear();
return;
}
uint64_t Index = M & 0x1F;
ShuffleMask.push_back((int)Index);
}
}
/// DecodeVPERMMask - this decodes the shuffle masks for VPERMQ/VPERMPD.
void DecodeVPERMMask(unsigned NumElts, unsigned Imm,
SmallVectorImpl<int> &ShuffleMask) {
for (unsigned l = 0; l != NumElts; l += 4)
for (unsigned i = 0; i != 4; ++i)
ShuffleMask.push_back(l + ((Imm >> (2 * i)) & 3));
}
void DecodeZeroExtendMask(unsigned SrcScalarBits, unsigned DstScalarBits,
unsigned NumDstElts, SmallVectorImpl<int> &Mask) {
unsigned Scale = DstScalarBits / SrcScalarBits;
assert(SrcScalarBits < DstScalarBits &&
"Expected zero extension mask to increase scalar size");
for (unsigned i = 0; i != NumDstElts; i++) {
Mask.push_back(i);
for (unsigned j = 1; j != Scale; j++)
Mask.push_back(SM_SentinelZero);
}
}
void DecodeZeroMoveLowMask(unsigned NumElts,
SmallVectorImpl<int> &ShuffleMask) {
ShuffleMask.push_back(0);
for (unsigned i = 1; i < NumElts; i++)
ShuffleMask.push_back(SM_SentinelZero);
}
void DecodeScalarMoveMask(unsigned NumElts, bool IsLoad,
SmallVectorImpl<int> &Mask) {
// First element comes from the first element of second source.
// Remaining elements: Load zero extends / Move copies from first source.
Mask.push_back(NumElts);
for (unsigned i = 1; i < NumElts; i++)
Mask.push_back(IsLoad ? static_cast<int>(SM_SentinelZero) : i);
}
void DecodeEXTRQIMask(unsigned NumElts, unsigned EltSize, int Len, int Idx,
SmallVectorImpl<int> &ShuffleMask) {
unsigned HalfElts = NumElts / 2;
// Only the bottom 6 bits are valid for each immediate.
Len &= 0x3F;
Idx &= 0x3F;
// We can only decode this bit extraction instruction as a shuffle if both the
// length and index work with whole elements.
if (0 != (Len % EltSize) || 0 != (Idx % EltSize))
return;
// A length of zero is equivalent to a bit length of 64.
if (Len == 0)
Len = 64;
// If the length + index exceeds the bottom 64 bits the result is undefined.
if ((Len + Idx) > 64) {
ShuffleMask.append(NumElts, SM_SentinelUndef);
return;
}
// Convert index and index to work with elements.
Len /= EltSize;
Idx /= EltSize;
// EXTRQ: Extract Len elements starting from Idx. Zero pad the remaining
// elements of the lower 64-bits. The upper 64-bits are undefined.
for (int i = 0; i != Len; ++i)
ShuffleMask.push_back(i + Idx);
for (int i = Len; i != (int)HalfElts; ++i)
ShuffleMask.push_back(SM_SentinelZero);
for (int i = HalfElts; i != (int)NumElts; ++i)
ShuffleMask.push_back(SM_SentinelUndef);
}
void DecodeINSERTQIMask(unsigned NumElts, unsigned EltSize, int Len, int Idx,
SmallVectorImpl<int> &ShuffleMask) {
unsigned HalfElts = NumElts / 2;
// Only the bottom 6 bits are valid for each immediate.
Len &= 0x3F;
Idx &= 0x3F;
// We can only decode this bit insertion instruction as a shuffle if both the
// length and index work with whole elements.
if (0 != (Len % EltSize) || 0 != (Idx % EltSize))
return;
// A length of zero is equivalent to a bit length of 64.
if (Len == 0)
Len = 64;
// If the length + index exceeds the bottom 64 bits the result is undefined.
if ((Len + Idx) > 64) {
ShuffleMask.append(NumElts, SM_SentinelUndef);
return;
}
// Convert index and index to work with elements.
Len /= EltSize;
Idx /= EltSize;
// INSERTQ: Extract lowest Len elements from lower half of second source and
// insert over first source starting at Idx element. The upper 64-bits are
// undefined.
for (int i = 0; i != Idx; ++i)
ShuffleMask.push_back(i);
for (int i = 0; i != Len; ++i)
ShuffleMask.push_back(i + NumElts);
for (int i = Idx + Len; i != (int)HalfElts; ++i)
ShuffleMask.push_back(i);
for (int i = HalfElts; i != (int)NumElts; ++i)
ShuffleMask.push_back(SM_SentinelUndef);
}
void DecodeVPERMILPMask(unsigned NumElts, unsigned ScalarBits,
ArrayRef<uint64_t> RawMask, const APInt &UndefElts,
SmallVectorImpl<int> &ShuffleMask) {
unsigned VecSize = NumElts * ScalarBits;
unsigned NumLanes = VecSize / 128;
unsigned NumEltsPerLane = NumElts / NumLanes;
assert((VecSize == 128 || VecSize == 256 || VecSize == 512) &&
"Unexpected vector size");
assert((ScalarBits == 32 || ScalarBits == 64) && "Unexpected element size");
for (unsigned i = 0, e = RawMask.size(); i < e; ++i) {
if (UndefElts[i]) {
ShuffleMask.push_back(SM_SentinelUndef);
continue;
}
uint64_t M = RawMask[i];
M = (ScalarBits == 64 ? ((M >> 1) & 0x1) : (M & 0x3));
unsigned LaneOffset = i & ~(NumEltsPerLane - 1);
ShuffleMask.push_back((int)(LaneOffset + M));
}
}
void DecodeVPERMIL2PMask(unsigned NumElts, unsigned ScalarBits, unsigned M2Z,
ArrayRef<uint64_t> RawMask, const APInt &UndefElts,
SmallVectorImpl<int> &ShuffleMask) {
unsigned VecSize = NumElts * ScalarBits;
unsigned NumLanes = VecSize / 128;
unsigned NumEltsPerLane = NumElts / NumLanes;
assert((VecSize == 128 || VecSize == 256) && "Unexpected vector size");
assert((ScalarBits == 32 || ScalarBits == 64) && "Unexpected element size");
assert((NumElts == RawMask.size()) && "Unexpected mask size");
for (unsigned i = 0, e = RawMask.size(); i < e; ++i) {
if (UndefElts[i]) {
ShuffleMask.push_back(SM_SentinelUndef);
continue;
}
// VPERMIL2 Operation.
// Bits[3] - Match Bit.
// Bits[2:1] - (Per Lane) PD Shuffle Mask.
// Bits[2:0] - (Per Lane) PS Shuffle Mask.
uint64_t Selector = RawMask[i];
unsigned MatchBit = (Selector >> 3) & 0x1;
// M2Z[0:1] MatchBit
// 0Xb X Source selected by Selector index.
// 10b 0 Source selected by Selector index.
// 10b 1 Zero.
// 11b 0 Zero.
// 11b 1 Source selected by Selector index.
if ((M2Z & 0x2) != 0 && MatchBit != (M2Z & 0x1)) {
ShuffleMask.push_back(SM_SentinelZero);
continue;
}
int Index = i & ~(NumEltsPerLane - 1);
if (ScalarBits == 64)
Index += (Selector >> 1) & 0x1;
else
Index += Selector & 0x3;
int Src = (Selector >> 2) & 0x1;
Index += Src * NumElts;
ShuffleMask.push_back(Index);
}
}
void DecodeVPERMVMask(ArrayRef<uint64_t> RawMask, const APInt &UndefElts,
SmallVectorImpl<int> &ShuffleMask) {
uint64_t EltMaskSize = RawMask.size() - 1;
for (int i = 0, e = RawMask.size(); i != e; ++i) {
if (UndefElts[i]) {
ShuffleMask.push_back(SM_SentinelUndef);
continue;
}
uint64_t M = RawMask[i];
M &= EltMaskSize;
ShuffleMask.push_back((int)M);
}
}
void DecodeVPERMV3Mask(ArrayRef<uint64_t> RawMask, const APInt &UndefElts,
SmallVectorImpl<int> &ShuffleMask) {
uint64_t EltMaskSize = (RawMask.size() * 2) - 1;
for (int i = 0, e = RawMask.size(); i != e; ++i) {
if (UndefElts[i]) {
ShuffleMask.push_back(SM_SentinelUndef);
continue;
}
uint64_t M = RawMask[i];
M &= EltMaskSize;
ShuffleMask.push_back((int)M);
}
}
} // llvm namespace