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llvm-project/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorOps.cpp

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//===- LegalizeVectorOps.cpp - Implement SelectionDAG::LegalizeVectors ----===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the SelectionDAG::LegalizeVectors method.
//
// The vector legalizer looks for vector operations which might need to be
// scalarized and legalizes them. This is a separate step from Legalize because
// scalarizing can introduce illegal types. For example, suppose we have an
// ISD::SDIV of type v2i64 on x86-32. The type is legal (for example, addition
// on a v2i64 is legal), but ISD::SDIV isn't legal, so we have to unroll the
// operation, which introduces nodes with the illegal type i64 which must be
// expanded. Similarly, suppose we have an ISD::SRA of type v16i8 on PowerPC;
// the operation must be unrolled, which introduces nodes with the illegal
// type i8 which must be promoted.
//
// This does not legalize vector manipulations like ISD::BUILD_VECTOR,
// or operations that happen to take a vector which are custom-lowered;
// the legalization for such operations never produces nodes
// with illegal types, so it's okay to put off legalizing them until
// SelectionDAG::Legalize runs.
//
//===----------------------------------------------------------------------===//
#include "llvm/ADT/APInt.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/CodeGen/ISDOpcodes.h"
#include "llvm/CodeGen/MachineMemOperand.h"
#include "llvm/CodeGen/MachineValueType.h"
#include "llvm/CodeGen/SelectionDAG.h"
#include "llvm/CodeGen/SelectionDAGNodes.h"
#include "llvm/CodeGen/TargetLowering.h"
#include "llvm/CodeGen/ValueTypes.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/MathExtras.h"
#include <cassert>
#include <cstdint>
#include <iterator>
#include <utility>
using namespace llvm;
#define DEBUG_TYPE "legalizevectorops"
namespace {
class VectorLegalizer {
SelectionDAG& DAG;
const TargetLowering &TLI;
bool Changed = false; // Keep track of whether anything changed
/// For nodes that are of legal width, and that have more than one use, this
/// map indicates what regularized operand to use. This allows us to avoid
/// legalizing the same thing more than once.
SmallDenseMap<SDValue, SDValue, 64> LegalizedNodes;
/// \brief Adds a node to the translation cache.
void AddLegalizedOperand(SDValue From, SDValue To) {
LegalizedNodes.insert(std::make_pair(From, To));
// If someone requests legalization of the new node, return itself.
if (From != To)
LegalizedNodes.insert(std::make_pair(To, To));
}
/// \brief Legalizes the given node.
SDValue LegalizeOp(SDValue Op);
/// \brief Assuming the node is legal, "legalize" the results.
SDValue TranslateLegalizeResults(SDValue Op, SDValue Result);
/// \brief Implements unrolling a VSETCC.
SDValue UnrollVSETCC(SDValue Op);
/// \brief Implement expand-based legalization of vector operations.
///
/// This is just a high-level routine to dispatch to specific code paths for
/// operations to legalize them.
SDValue Expand(SDValue Op);
/// \brief Implements expansion for FNEG; falls back to UnrollVectorOp if
/// FSUB isn't legal.
///
/// Implements expansion for UINT_TO_FLOAT; falls back to UnrollVectorOp if
/// SINT_TO_FLOAT and SHR on vectors isn't legal.
SDValue ExpandUINT_TO_FLOAT(SDValue Op);
/// \brief Implement expansion for SIGN_EXTEND_INREG using SRL and SRA.
SDValue ExpandSEXTINREG(SDValue Op);
/// \brief Implement expansion for ANY_EXTEND_VECTOR_INREG.
///
/// Shuffles the low lanes of the operand into place and bitcasts to the proper
/// type. The contents of the bits in the extended part of each element are
/// undef.
SDValue ExpandANY_EXTEND_VECTOR_INREG(SDValue Op);
/// \brief Implement expansion for SIGN_EXTEND_VECTOR_INREG.
///
/// Shuffles the low lanes of the operand into place, bitcasts to the proper
/// type, then shifts left and arithmetic shifts right to introduce a sign
/// extension.
SDValue ExpandSIGN_EXTEND_VECTOR_INREG(SDValue Op);
/// \brief Implement expansion for ZERO_EXTEND_VECTOR_INREG.
///
/// Shuffles the low lanes of the operand into place and blends zeros into
/// the remaining lanes, finally bitcasting to the proper type.
SDValue ExpandZERO_EXTEND_VECTOR_INREG(SDValue Op);
/// \brief Expand bswap of vectors into a shuffle if legal.
SDValue ExpandBSWAP(SDValue Op);
/// \brief Implement vselect in terms of XOR, AND, OR when blend is not
/// supported by the target.
SDValue ExpandVSELECT(SDValue Op);
SDValue ExpandSELECT(SDValue Op);
SDValue ExpandLoad(SDValue Op);
SDValue ExpandStore(SDValue Op);
SDValue ExpandFNEG(SDValue Op);
SDValue ExpandFSUB(SDValue Op);
SDValue ExpandBITREVERSE(SDValue Op);
SDValue ExpandCTLZ(SDValue Op);
SDValue ExpandCTTZ_ZERO_UNDEF(SDValue Op);
/// \brief Implements vector promotion.
///
/// This is essentially just bitcasting the operands to a different type and
/// bitcasting the result back to the original type.
SDValue Promote(SDValue Op);
/// \brief Implements [SU]INT_TO_FP vector promotion.
///
/// This is a [zs]ext of the input operand to a larger integer type.
SDValue PromoteINT_TO_FP(SDValue Op);
/// \brief Implements FP_TO_[SU]INT vector promotion of the result type.
///
/// It is promoted to a larger integer type. The result is then
/// truncated back to the original type.
SDValue PromoteFP_TO_INT(SDValue Op);
public:
VectorLegalizer(SelectionDAG& dag) :
DAG(dag), TLI(dag.getTargetLoweringInfo()) {}
/// \brief Begin legalizer the vector operations in the DAG.
bool Run();
};
} // end anonymous namespace
bool VectorLegalizer::Run() {
// Before we start legalizing vector nodes, check if there are any vectors.
bool HasVectors = false;
for (SelectionDAG::allnodes_iterator I = DAG.allnodes_begin(),
E = std::prev(DAG.allnodes_end()); I != std::next(E); ++I) {
// Check if the values of the nodes contain vectors. We don't need to check
// the operands because we are going to check their values at some point.
for (SDNode::value_iterator J = I->value_begin(), E = I->value_end();
J != E; ++J)
HasVectors |= J->isVector();
// If we found a vector node we can start the legalization.
if (HasVectors)
break;
}
// If this basic block has no vectors then no need to legalize vectors.
if (!HasVectors)
return false;
// The legalize process is inherently a bottom-up recursive process (users
// legalize their uses before themselves). Given infinite stack space, we
// could just start legalizing on the root and traverse the whole graph. In
// practice however, this causes us to run out of stack space on large basic
// blocks. To avoid this problem, compute an ordering of the nodes where each
// node is only legalized after all of its operands are legalized.
DAG.AssignTopologicalOrder();
for (SelectionDAG::allnodes_iterator I = DAG.allnodes_begin(),
E = std::prev(DAG.allnodes_end()); I != std::next(E); ++I)
LegalizeOp(SDValue(&*I, 0));
// Finally, it's possible the root changed. Get the new root.
SDValue OldRoot = DAG.getRoot();
assert(LegalizedNodes.count(OldRoot) && "Root didn't get legalized?");
DAG.setRoot(LegalizedNodes[OldRoot]);
LegalizedNodes.clear();
// Remove dead nodes now.
DAG.RemoveDeadNodes();
return Changed;
}
SDValue VectorLegalizer::TranslateLegalizeResults(SDValue Op, SDValue Result) {
// Generic legalization: just pass the operand through.
for (unsigned i = 0, e = Op.getNode()->getNumValues(); i != e; ++i)
AddLegalizedOperand(Op.getValue(i), Result.getValue(i));
return Result.getValue(Op.getResNo());
}
SDValue VectorLegalizer::LegalizeOp(SDValue Op) {
// Note that LegalizeOp may be reentered even from single-use nodes, which
// means that we always must cache transformed nodes.
DenseMap<SDValue, SDValue>::iterator I = LegalizedNodes.find(Op);
if (I != LegalizedNodes.end()) return I->second;
SDNode* Node = Op.getNode();
// Legalize the operands
SmallVector<SDValue, 8> Ops;
for (const SDValue &Op : Node->op_values())
Ops.push_back(LegalizeOp(Op));
SDValue Result = SDValue(DAG.UpdateNodeOperands(Op.getNode(), Ops), 0);
bool HasVectorValue = false;
if (Op.getOpcode() == ISD::LOAD) {
LoadSDNode *LD = cast<LoadSDNode>(Op.getNode());
ISD::LoadExtType ExtType = LD->getExtensionType();
if (LD->getMemoryVT().isVector() && ExtType != ISD::NON_EXTLOAD) {
DEBUG(dbgs() << "\nLegalizing extending vector load: "; Node->dump(&DAG));
switch (TLI.getLoadExtAction(LD->getExtensionType(), LD->getValueType(0),
LD->getMemoryVT())) {
default: llvm_unreachable("This action is not supported yet!");
case TargetLowering::Legal:
return TranslateLegalizeResults(Op, Result);
case TargetLowering::Custom:
if (SDValue Lowered = TLI.LowerOperation(Result, DAG)) {
if (Lowered == Result)
return TranslateLegalizeResults(Op, Lowered);
Changed = true;
if (Lowered->getNumValues() != Op->getNumValues()) {
// This expanded to something other than the load. Assume the
// lowering code took care of any chain values, and just handle the
// returned value.
assert(Result.getValue(1).use_empty() &&
"There are still live users of the old chain!");
return LegalizeOp(Lowered);
}
return TranslateLegalizeResults(Op, Lowered);
}
LLVM_FALLTHROUGH;
case TargetLowering::Expand:
Changed = true;
return LegalizeOp(ExpandLoad(Op));
}
}
} else if (Op.getOpcode() == ISD::STORE) {
StoreSDNode *ST = cast<StoreSDNode>(Op.getNode());
EVT StVT = ST->getMemoryVT();
MVT ValVT = ST->getValue().getSimpleValueType();
if (StVT.isVector() && ST->isTruncatingStore()) {
DEBUG(dbgs() << "\nLegalizing truncating vector store: ";
Node->dump(&DAG));
switch (TLI.getTruncStoreAction(ValVT, StVT)) {
default: llvm_unreachable("This action is not supported yet!");
case TargetLowering::Legal:
return TranslateLegalizeResults(Op, Result);
case TargetLowering::Custom: {
SDValue Lowered = TLI.LowerOperation(Result, DAG);
Changed = Lowered != Result;
return TranslateLegalizeResults(Op, Lowered);
}
case TargetLowering::Expand:
Changed = true;
return LegalizeOp(ExpandStore(Op));
}
}
} else if (Op.getOpcode() == ISD::MSCATTER || Op.getOpcode() == ISD::MSTORE)
HasVectorValue = true;
for (SDNode::value_iterator J = Node->value_begin(), E = Node->value_end();
J != E;
++J)
HasVectorValue |= J->isVector();
if (!HasVectorValue)
return TranslateLegalizeResults(Op, Result);
EVT QueryType;
switch (Op.getOpcode()) {
default:
return TranslateLegalizeResults(Op, Result);
case ISD::ADD:
case ISD::SUB:
case ISD::MUL:
case ISD::SDIV:
case ISD::UDIV:
case ISD::SREM:
case ISD::UREM:
case ISD::SDIVREM:
case ISD::UDIVREM:
case ISD::FADD:
case ISD::FSUB:
case ISD::FMUL:
case ISD::FDIV:
case ISD::FREM:
case ISD::AND:
case ISD::OR:
case ISD::XOR:
case ISD::SHL:
case ISD::SRA:
case ISD::SRL:
case ISD::ROTL:
case ISD::ROTR:
case ISD::BSWAP:
case ISD::BITREVERSE:
case ISD::CTLZ:
case ISD::CTTZ:
case ISD::CTLZ_ZERO_UNDEF:
case ISD::CTTZ_ZERO_UNDEF:
case ISD::CTPOP:
case ISD::SELECT:
case ISD::VSELECT:
case ISD::SELECT_CC:
case ISD::SETCC:
case ISD::ZERO_EXTEND:
case ISD::ANY_EXTEND:
case ISD::TRUNCATE:
case ISD::SIGN_EXTEND:
case ISD::FP_TO_SINT:
case ISD::FP_TO_UINT:
case ISD::FNEG:
case ISD::FABS:
case ISD::FMINNUM:
case ISD::FMAXNUM:
case ISD::FMINNAN:
case ISD::FMAXNAN:
case ISD::FCOPYSIGN:
case ISD::FSQRT:
case ISD::FSIN:
case ISD::FCOS:
case ISD::FPOWI:
case ISD::FPOW:
case ISD::FLOG:
case ISD::FLOG2:
case ISD::FLOG10:
case ISD::FEXP:
case ISD::FEXP2:
case ISD::FCEIL:
case ISD::FTRUNC:
case ISD::FRINT:
case ISD::FNEARBYINT:
case ISD::FROUND:
case ISD::FFLOOR:
case ISD::FP_ROUND:
case ISD::FP_EXTEND:
case ISD::FMA:
case ISD::SIGN_EXTEND_INREG:
case ISD::ANY_EXTEND_VECTOR_INREG:
case ISD::SIGN_EXTEND_VECTOR_INREG:
case ISD::ZERO_EXTEND_VECTOR_INREG:
case ISD::SMIN:
case ISD::SMAX:
case ISD::UMIN:
case ISD::UMAX:
case ISD::SMUL_LOHI:
case ISD::UMUL_LOHI:
QueryType = Node->getValueType(0);
break;
case ISD::FP_ROUND_INREG:
QueryType = cast<VTSDNode>(Node->getOperand(1))->getVT();
break;
case ISD::SINT_TO_FP:
case ISD::UINT_TO_FP:
QueryType = Node->getOperand(0).getValueType();
break;
case ISD::MSCATTER:
QueryType = cast<MaskedScatterSDNode>(Node)->getValue().getValueType();
break;
case ISD::MSTORE:
QueryType = cast<MaskedStoreSDNode>(Node)->getValue().getValueType();
break;
}
DEBUG(dbgs() << "\nLegalizing vector op: "; Node->dump(&DAG));
switch (TLI.getOperationAction(Node->getOpcode(), QueryType)) {
default: llvm_unreachable("This action is not supported yet!");
case TargetLowering::Promote:
Result = Promote(Op);
Changed = true;
break;
case TargetLowering::Legal:
DEBUG(dbgs() << "Legal node: nothing to do\n");
break;
case TargetLowering::Custom: {
DEBUG(dbgs() << "Trying custom legalization\n");
if (SDValue Tmp1 = TLI.LowerOperation(Op, DAG)) {
DEBUG(dbgs() << "Successfully custom legalized node\n");
Result = Tmp1;
break;
}
DEBUG(dbgs() << "Could not custom legalize node\n");
LLVM_FALLTHROUGH;
}
case TargetLowering::Expand:
Result = Expand(Op);
}
// Make sure that the generated code is itself legal.
if (Result != Op) {
Result = LegalizeOp(Result);
Changed = true;
}
// Note that LegalizeOp may be reentered even from single-use nodes, which
// means that we always must cache transformed nodes.
AddLegalizedOperand(Op, Result);
return Result;
}
SDValue VectorLegalizer::Promote(SDValue Op) {
// For a few operations there is a specific concept for promotion based on
// the operand's type.
switch (Op.getOpcode()) {
case ISD::SINT_TO_FP:
case ISD::UINT_TO_FP:
// "Promote" the operation by extending the operand.
return PromoteINT_TO_FP(Op);
case ISD::FP_TO_UINT:
case ISD::FP_TO_SINT:
// Promote the operation by extending the operand.
return PromoteFP_TO_INT(Op);
}
// There are currently two cases of vector promotion:
// 1) Bitcasting a vector of integers to a different type to a vector of the
// same overall length. For example, x86 promotes ISD::AND v2i32 to v1i64.
// 2) Extending a vector of floats to a vector of the same number of larger
// floats. For example, AArch64 promotes ISD::FADD on v4f16 to v4f32.
MVT VT = Op.getSimpleValueType();
assert(Op.getNode()->getNumValues() == 1 &&
"Can't promote a vector with multiple results!");
MVT NVT = TLI.getTypeToPromoteTo(Op.getOpcode(), VT);
SDLoc dl(Op);
SmallVector<SDValue, 4> Operands(Op.getNumOperands());
for (unsigned j = 0; j != Op.getNumOperands(); ++j) {
if (Op.getOperand(j).getValueType().isVector())
if (Op.getOperand(j)
.getValueType()
.getVectorElementType()
.isFloatingPoint() &&
NVT.isVector() && NVT.getVectorElementType().isFloatingPoint())
Operands[j] = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Op.getOperand(j));
else
Operands[j] = DAG.getNode(ISD::BITCAST, dl, NVT, Op.getOperand(j));
else
Operands[j] = Op.getOperand(j);
}
Op = DAG.getNode(Op.getOpcode(), dl, NVT, Operands, Op.getNode()->getFlags());
if ((VT.isFloatingPoint() && NVT.isFloatingPoint()) ||
(VT.isVector() && VT.getVectorElementType().isFloatingPoint() &&
NVT.isVector() && NVT.getVectorElementType().isFloatingPoint()))
return DAG.getNode(ISD::FP_ROUND, dl, VT, Op, DAG.getIntPtrConstant(0, dl));
else
return DAG.getNode(ISD::BITCAST, dl, VT, Op);
}
SDValue VectorLegalizer::PromoteINT_TO_FP(SDValue Op) {
// INT_TO_FP operations may require the input operand be promoted even
// when the type is otherwise legal.
MVT VT = Op.getOperand(0).getSimpleValueType();
MVT NVT = TLI.getTypeToPromoteTo(Op.getOpcode(), VT);
assert(NVT.getVectorNumElements() == VT.getVectorNumElements() &&
"Vectors have different number of elements!");
SDLoc dl(Op);
SmallVector<SDValue, 4> Operands(Op.getNumOperands());
unsigned Opc = Op.getOpcode() == ISD::UINT_TO_FP ? ISD::ZERO_EXTEND :
ISD::SIGN_EXTEND;
for (unsigned j = 0; j != Op.getNumOperands(); ++j) {
if (Op.getOperand(j).getValueType().isVector())
Operands[j] = DAG.getNode(Opc, dl, NVT, Op.getOperand(j));
else
Operands[j] = Op.getOperand(j);
}
return DAG.getNode(Op.getOpcode(), dl, Op.getValueType(), Operands);
}
// For FP_TO_INT we promote the result type to a vector type with wider
// elements and then truncate the result. This is different from the default
// PromoteVector which uses bitcast to promote thus assumning that the
// promoted vector type has the same overall size.
SDValue VectorLegalizer::PromoteFP_TO_INT(SDValue Op) {
MVT VT = Op.getSimpleValueType();
MVT NVT = TLI.getTypeToPromoteTo(Op.getOpcode(), VT);
assert(NVT.getVectorNumElements() == VT.getVectorNumElements() &&
"Vectors have different number of elements!");
unsigned NewOpc = Op->getOpcode();
// Change FP_TO_UINT to FP_TO_SINT if possible.
// TODO: Should we only do this if FP_TO_UINT itself isn't legal?
if (NewOpc == ISD::FP_TO_UINT &&
TLI.isOperationLegalOrCustom(ISD::FP_TO_SINT, NVT))
NewOpc = ISD::FP_TO_SINT;
SDLoc dl(Op);
SDValue Promoted = DAG.getNode(NewOpc, dl, NVT, Op.getOperand(0));
// Assert that the converted value fits in the original type. If it doesn't
// (eg: because the value being converted is too big), then the result of the
// original operation was undefined anyway, so the assert is still correct.
Promoted = DAG.getNode(Op->getOpcode() == ISD::FP_TO_UINT ? ISD::AssertZext
: ISD::AssertSext,
dl, NVT, Promoted,
DAG.getValueType(VT.getScalarType()));
return DAG.getNode(ISD::TRUNCATE, dl, VT, Promoted);
}
SDValue VectorLegalizer::ExpandLoad(SDValue Op) {
LoadSDNode *LD = cast<LoadSDNode>(Op.getNode());
EVT SrcVT = LD->getMemoryVT();
EVT SrcEltVT = SrcVT.getScalarType();
unsigned NumElem = SrcVT.getVectorNumElements();
SDValue NewChain;
SDValue Value;
if (SrcVT.getVectorNumElements() > 1 && !SrcEltVT.isByteSized()) {
SDLoc dl(Op);
SmallVector<SDValue, 8> Vals;
SmallVector<SDValue, 8> LoadChains;
EVT DstEltVT = LD->getValueType(0).getScalarType();
SDValue Chain = LD->getChain();
SDValue BasePTR = LD->getBasePtr();
ISD::LoadExtType ExtType = LD->getExtensionType();
// When elements in a vector is not byte-addressable, we cannot directly
// load each element by advancing pointer, which could only address bytes.
// Instead, we load all significant words, mask bits off, and concatenate
// them to form each element. Finally, they are extended to destination
// scalar type to build the destination vector.
EVT WideVT = TLI.getPointerTy(DAG.getDataLayout());
assert(WideVT.isRound() &&
"Could not handle the sophisticated case when the widest integer is"
" not power of 2.");
assert(WideVT.bitsGE(SrcEltVT) &&
"Type is not legalized?");
unsigned WideBytes = WideVT.getStoreSize();
unsigned Offset = 0;
unsigned RemainingBytes = SrcVT.getStoreSize();
SmallVector<SDValue, 8> LoadVals;
while (RemainingBytes > 0) {
SDValue ScalarLoad;
unsigned LoadBytes = WideBytes;
if (RemainingBytes >= LoadBytes) {
ScalarLoad =
DAG.getLoad(WideVT, dl, Chain, BasePTR,
LD->getPointerInfo().getWithOffset(Offset),
MinAlign(LD->getAlignment(), Offset),
LD->getMemOperand()->getFlags(), LD->getAAInfo());
} else {
EVT LoadVT = WideVT;
while (RemainingBytes < LoadBytes) {
LoadBytes >>= 1; // Reduce the load size by half.
LoadVT = EVT::getIntegerVT(*DAG.getContext(), LoadBytes << 3);
}
ScalarLoad =
DAG.getExtLoad(ISD::EXTLOAD, dl, WideVT, Chain, BasePTR,
LD->getPointerInfo().getWithOffset(Offset), LoadVT,
MinAlign(LD->getAlignment(), Offset),
LD->getMemOperand()->getFlags(), LD->getAAInfo());
}
RemainingBytes -= LoadBytes;
Offset += LoadBytes;
BasePTR = DAG.getObjectPtrOffset(dl, BasePTR, LoadBytes);
LoadVals.push_back(ScalarLoad.getValue(0));
LoadChains.push_back(ScalarLoad.getValue(1));
}
// Extract bits, pack and extend/trunc them into destination type.
unsigned SrcEltBits = SrcEltVT.getSizeInBits();
SDValue SrcEltBitMask = DAG.getConstant((1U << SrcEltBits) - 1, dl, WideVT);
unsigned BitOffset = 0;
unsigned WideIdx = 0;
unsigned WideBits = WideVT.getSizeInBits();
for (unsigned Idx = 0; Idx != NumElem; ++Idx) {
SDValue Lo, Hi, ShAmt;
if (BitOffset < WideBits) {
ShAmt = DAG.getConstant(
BitOffset, dl, TLI.getShiftAmountTy(WideVT, DAG.getDataLayout()));
Lo = DAG.getNode(ISD::SRL, dl, WideVT, LoadVals[WideIdx], ShAmt);
Lo = DAG.getNode(ISD::AND, dl, WideVT, Lo, SrcEltBitMask);
}
BitOffset += SrcEltBits;
if (BitOffset >= WideBits) {
WideIdx++;
BitOffset -= WideBits;
if (BitOffset > 0) {
ShAmt = DAG.getConstant(
SrcEltBits - BitOffset, dl,
TLI.getShiftAmountTy(WideVT, DAG.getDataLayout()));
Hi = DAG.getNode(ISD::SHL, dl, WideVT, LoadVals[WideIdx], ShAmt);
Hi = DAG.getNode(ISD::AND, dl, WideVT, Hi, SrcEltBitMask);
}
}
if (Hi.getNode())
Lo = DAG.getNode(ISD::OR, dl, WideVT, Lo, Hi);
switch (ExtType) {
default: llvm_unreachable("Unknown extended-load op!");
case ISD::EXTLOAD:
Lo = DAG.getAnyExtOrTrunc(Lo, dl, DstEltVT);
break;
case ISD::ZEXTLOAD:
Lo = DAG.getZExtOrTrunc(Lo, dl, DstEltVT);
break;
case ISD::SEXTLOAD:
ShAmt =
DAG.getConstant(WideBits - SrcEltBits, dl,
TLI.getShiftAmountTy(WideVT, DAG.getDataLayout()));
Lo = DAG.getNode(ISD::SHL, dl, WideVT, Lo, ShAmt);
Lo = DAG.getNode(ISD::SRA, dl, WideVT, Lo, ShAmt);
Lo = DAG.getSExtOrTrunc(Lo, dl, DstEltVT);
break;
}
Vals.push_back(Lo);
}
NewChain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, LoadChains);
Value = DAG.getBuildVector(Op.getNode()->getValueType(0), dl, Vals);
} else {
SDValue Scalarized = TLI.scalarizeVectorLoad(LD, DAG);
NewChain = Scalarized.getValue(1);
Value = Scalarized.getValue(0);
}
AddLegalizedOperand(Op.getValue(0), Value);
AddLegalizedOperand(Op.getValue(1), NewChain);
return (Op.getResNo() ? NewChain : Value);
}
SDValue VectorLegalizer::ExpandStore(SDValue Op) {
StoreSDNode *ST = cast<StoreSDNode>(Op.getNode());
SDValue TF = TLI.scalarizeVectorStore(ST, DAG);
AddLegalizedOperand(Op, TF);
return TF;
}
SDValue VectorLegalizer::Expand(SDValue Op) {
switch (Op->getOpcode()) {
case ISD::SIGN_EXTEND_INREG:
return ExpandSEXTINREG(Op);
case ISD::ANY_EXTEND_VECTOR_INREG:
return ExpandANY_EXTEND_VECTOR_INREG(Op);
case ISD::SIGN_EXTEND_VECTOR_INREG:
return ExpandSIGN_EXTEND_VECTOR_INREG(Op);
case ISD::ZERO_EXTEND_VECTOR_INREG:
return ExpandZERO_EXTEND_VECTOR_INREG(Op);
case ISD::BSWAP:
return ExpandBSWAP(Op);
case ISD::VSELECT:
return ExpandVSELECT(Op);
case ISD::SELECT:
return ExpandSELECT(Op);
case ISD::UINT_TO_FP:
return ExpandUINT_TO_FLOAT(Op);
case ISD::FNEG:
return ExpandFNEG(Op);
case ISD::FSUB:
return ExpandFSUB(Op);
case ISD::SETCC:
return UnrollVSETCC(Op);
case ISD::BITREVERSE:
return ExpandBITREVERSE(Op);
case ISD::CTLZ:
case ISD::CTLZ_ZERO_UNDEF:
return ExpandCTLZ(Op);
case ISD::CTTZ_ZERO_UNDEF:
return ExpandCTTZ_ZERO_UNDEF(Op);
default:
return DAG.UnrollVectorOp(Op.getNode());
}
}
SDValue VectorLegalizer::ExpandSELECT(SDValue Op) {
// Lower a select instruction where the condition is a scalar and the
// operands are vectors. Lower this select to VSELECT and implement it
// using XOR AND OR. The selector bit is broadcasted.
EVT VT = Op.getValueType();
SDLoc DL(Op);
SDValue Mask = Op.getOperand(0);
SDValue Op1 = Op.getOperand(1);
SDValue Op2 = Op.getOperand(2);
assert(VT.isVector() && !Mask.getValueType().isVector()
&& Op1.getValueType() == Op2.getValueType() && "Invalid type");
// If we can't even use the basic vector operations of
// AND,OR,XOR, we will have to scalarize the op.
// Notice that the operation may be 'promoted' which means that it is
// 'bitcasted' to another type which is handled.
// Also, we need to be able to construct a splat vector using BUILD_VECTOR.
if (TLI.getOperationAction(ISD::AND, VT) == TargetLowering::Expand ||
TLI.getOperationAction(ISD::XOR, VT) == TargetLowering::Expand ||
TLI.getOperationAction(ISD::OR, VT) == TargetLowering::Expand ||
TLI.getOperationAction(ISD::BUILD_VECTOR, VT) == TargetLowering::Expand)
return DAG.UnrollVectorOp(Op.getNode());
// Generate a mask operand.
EVT MaskTy = VT.changeVectorElementTypeToInteger();
// What is the size of each element in the vector mask.
EVT BitTy = MaskTy.getScalarType();
Mask = DAG.getSelect(DL, BitTy, Mask,
DAG.getConstant(APInt::getAllOnesValue(BitTy.getSizeInBits()), DL,
BitTy),
DAG.getConstant(0, DL, BitTy));
// Broadcast the mask so that the entire vector is all-one or all zero.
Mask = DAG.getSplatBuildVector(MaskTy, DL, Mask);
// Bitcast the operands to be the same type as the mask.
// This is needed when we select between FP types because
// the mask is a vector of integers.
Op1 = DAG.getNode(ISD::BITCAST, DL, MaskTy, Op1);
Op2 = DAG.getNode(ISD::BITCAST, DL, MaskTy, Op2);
SDValue AllOnes = DAG.getConstant(
APInt::getAllOnesValue(BitTy.getSizeInBits()), DL, MaskTy);
SDValue NotMask = DAG.getNode(ISD::XOR, DL, MaskTy, Mask, AllOnes);
Op1 = DAG.getNode(ISD::AND, DL, MaskTy, Op1, Mask);
Op2 = DAG.getNode(ISD::AND, DL, MaskTy, Op2, NotMask);
SDValue Val = DAG.getNode(ISD::OR, DL, MaskTy, Op1, Op2);
return DAG.getNode(ISD::BITCAST, DL, Op.getValueType(), Val);
}
SDValue VectorLegalizer::ExpandSEXTINREG(SDValue Op) {
EVT VT = Op.getValueType();
// Make sure that the SRA and SHL instructions are available.
if (TLI.getOperationAction(ISD::SRA, VT) == TargetLowering::Expand ||
TLI.getOperationAction(ISD::SHL, VT) == TargetLowering::Expand)
return DAG.UnrollVectorOp(Op.getNode());
SDLoc DL(Op);
EVT OrigTy = cast<VTSDNode>(Op->getOperand(1))->getVT();
unsigned BW = VT.getScalarSizeInBits();
unsigned OrigBW = OrigTy.getScalarSizeInBits();
SDValue ShiftSz = DAG.getConstant(BW - OrigBW, DL, VT);
Op = Op.getOperand(0);
Op = DAG.getNode(ISD::SHL, DL, VT, Op, ShiftSz);
return DAG.getNode(ISD::SRA, DL, VT, Op, ShiftSz);
}
// Generically expand a vector anyext in register to a shuffle of the relevant
// lanes into the appropriate locations, with other lanes left undef.
SDValue VectorLegalizer::ExpandANY_EXTEND_VECTOR_INREG(SDValue Op) {
SDLoc DL(Op);
EVT VT = Op.getValueType();
int NumElements = VT.getVectorNumElements();
SDValue Src = Op.getOperand(0);
EVT SrcVT = Src.getValueType();
int NumSrcElements = SrcVT.getVectorNumElements();
// Build a base mask of undef shuffles.
SmallVector<int, 16> ShuffleMask;
ShuffleMask.resize(NumSrcElements, -1);
// Place the extended lanes into the correct locations.
int ExtLaneScale = NumSrcElements / NumElements;
int EndianOffset = DAG.getDataLayout().isBigEndian() ? ExtLaneScale - 1 : 0;
for (int i = 0; i < NumElements; ++i)
ShuffleMask[i * ExtLaneScale + EndianOffset] = i;
return DAG.getNode(
ISD::BITCAST, DL, VT,
DAG.getVectorShuffle(SrcVT, DL, Src, DAG.getUNDEF(SrcVT), ShuffleMask));
}
SDValue VectorLegalizer::ExpandSIGN_EXTEND_VECTOR_INREG(SDValue Op) {
SDLoc DL(Op);
EVT VT = Op.getValueType();
SDValue Src = Op.getOperand(0);
EVT SrcVT = Src.getValueType();
// First build an any-extend node which can be legalized above when we
// recurse through it.
Op = DAG.getAnyExtendVectorInReg(Src, DL, VT);
// Now we need sign extend. Do this by shifting the elements. Even if these
// aren't legal operations, they have a better chance of being legalized
// without full scalarization than the sign extension does.
unsigned EltWidth = VT.getScalarSizeInBits();
unsigned SrcEltWidth = SrcVT.getScalarSizeInBits();
SDValue ShiftAmount = DAG.getConstant(EltWidth - SrcEltWidth, DL, VT);
return DAG.getNode(ISD::SRA, DL, VT,
DAG.getNode(ISD::SHL, DL, VT, Op, ShiftAmount),
ShiftAmount);
}
// Generically expand a vector zext in register to a shuffle of the relevant
// lanes into the appropriate locations, a blend of zero into the high bits,
// and a bitcast to the wider element type.
SDValue VectorLegalizer::ExpandZERO_EXTEND_VECTOR_INREG(SDValue Op) {
SDLoc DL(Op);
EVT VT = Op.getValueType();
int NumElements = VT.getVectorNumElements();
SDValue Src = Op.getOperand(0);
EVT SrcVT = Src.getValueType();
int NumSrcElements = SrcVT.getVectorNumElements();
// Build up a zero vector to blend into this one.
SDValue Zero = DAG.getConstant(0, DL, SrcVT);
// Shuffle the incoming lanes into the correct position, and pull all other
// lanes from the zero vector.
SmallVector<int, 16> ShuffleMask;
ShuffleMask.reserve(NumSrcElements);
for (int i = 0; i < NumSrcElements; ++i)
ShuffleMask.push_back(i);
int ExtLaneScale = NumSrcElements / NumElements;
int EndianOffset = DAG.getDataLayout().isBigEndian() ? ExtLaneScale - 1 : 0;
for (int i = 0; i < NumElements; ++i)
ShuffleMask[i * ExtLaneScale + EndianOffset] = NumSrcElements + i;
return DAG.getNode(ISD::BITCAST, DL, VT,
DAG.getVectorShuffle(SrcVT, DL, Zero, Src, ShuffleMask));
}
static void createBSWAPShuffleMask(EVT VT, SmallVectorImpl<int> &ShuffleMask) {
int ScalarSizeInBytes = VT.getScalarSizeInBits() / 8;
for (int I = 0, E = VT.getVectorNumElements(); I != E; ++I)
for (int J = ScalarSizeInBytes - 1; J >= 0; --J)
ShuffleMask.push_back((I * ScalarSizeInBytes) + J);
}
SDValue VectorLegalizer::ExpandBSWAP(SDValue Op) {
EVT VT = Op.getValueType();
// Generate a byte wise shuffle mask for the BSWAP.
SmallVector<int, 16> ShuffleMask;
createBSWAPShuffleMask(VT, ShuffleMask);
EVT ByteVT = EVT::getVectorVT(*DAG.getContext(), MVT::i8, ShuffleMask.size());
// Only emit a shuffle if the mask is legal.
if (!TLI.isShuffleMaskLegal(ShuffleMask, ByteVT))
return DAG.UnrollVectorOp(Op.getNode());
SDLoc DL(Op);
Op = DAG.getNode(ISD::BITCAST, DL, ByteVT, Op.getOperand(0));
Op = DAG.getVectorShuffle(ByteVT, DL, Op, DAG.getUNDEF(ByteVT), ShuffleMask);
return DAG.getNode(ISD::BITCAST, DL, VT, Op);
}
SDValue VectorLegalizer::ExpandBITREVERSE(SDValue Op) {
EVT VT = Op.getValueType();
// If we have the scalar operation, it's probably cheaper to unroll it.
if (TLI.isOperationLegalOrCustom(ISD::BITREVERSE, VT.getScalarType()))
return DAG.UnrollVectorOp(Op.getNode());
// If the vector element width is a whole number of bytes, test if its legal
// to BSWAP shuffle the bytes and then perform the BITREVERSE on the byte
// vector. This greatly reduces the number of bit shifts necessary.
unsigned ScalarSizeInBits = VT.getScalarSizeInBits();
if (ScalarSizeInBits > 8 && (ScalarSizeInBits % 8) == 0) {
SmallVector<int, 16> BSWAPMask;
createBSWAPShuffleMask(VT, BSWAPMask);
EVT ByteVT = EVT::getVectorVT(*DAG.getContext(), MVT::i8, BSWAPMask.size());
if (TLI.isShuffleMaskLegal(BSWAPMask, ByteVT) &&
(TLI.isOperationLegalOrCustom(ISD::BITREVERSE, ByteVT) ||
(TLI.isOperationLegalOrCustom(ISD::SHL, ByteVT) &&
TLI.isOperationLegalOrCustom(ISD::SRL, ByteVT) &&
TLI.isOperationLegalOrCustomOrPromote(ISD::AND, ByteVT) &&
TLI.isOperationLegalOrCustomOrPromote(ISD::OR, ByteVT)))) {
SDLoc DL(Op);
Op = DAG.getNode(ISD::BITCAST, DL, ByteVT, Op.getOperand(0));
Op = DAG.getVectorShuffle(ByteVT, DL, Op, DAG.getUNDEF(ByteVT),
BSWAPMask);
Op = DAG.getNode(ISD::BITREVERSE, DL, ByteVT, Op);
return DAG.getNode(ISD::BITCAST, DL, VT, Op);
}
}
// If we have the appropriate vector bit operations, it is better to use them
// than unrolling and expanding each component.
if (!TLI.isOperationLegalOrCustom(ISD::SHL, VT) ||
!TLI.isOperationLegalOrCustom(ISD::SRL, VT) ||
!TLI.isOperationLegalOrCustomOrPromote(ISD::AND, VT) ||
!TLI.isOperationLegalOrCustomOrPromote(ISD::OR, VT))
return DAG.UnrollVectorOp(Op.getNode());
// Let LegalizeDAG handle this later.
return Op;
}
SDValue VectorLegalizer::ExpandVSELECT(SDValue Op) {
// Implement VSELECT in terms of XOR, AND, OR
// on platforms which do not support blend natively.
SDLoc DL(Op);
SDValue Mask = Op.getOperand(0);
SDValue Op1 = Op.getOperand(1);
SDValue Op2 = Op.getOperand(2);
EVT VT = Mask.getValueType();
// If we can't even use the basic vector operations of
// AND,OR,XOR, we will have to scalarize the op.
// Notice that the operation may be 'promoted' which means that it is
// 'bitcasted' to another type which is handled.
// This operation also isn't safe with AND, OR, XOR when the boolean
// type is 0/1 as we need an all ones vector constant to mask with.
// FIXME: Sign extend 1 to all ones if thats legal on the target.
if (TLI.getOperationAction(ISD::AND, VT) == TargetLowering::Expand ||
TLI.getOperationAction(ISD::XOR, VT) == TargetLowering::Expand ||
TLI.getOperationAction(ISD::OR, VT) == TargetLowering::Expand ||
TLI.getBooleanContents(Op1.getValueType()) !=
TargetLowering::ZeroOrNegativeOneBooleanContent)
return DAG.UnrollVectorOp(Op.getNode());
// If the mask and the type are different sizes, unroll the vector op. This
// can occur when getSetCCResultType returns something that is different in
// size from the operand types. For example, v4i8 = select v4i32, v4i8, v4i8.
if (VT.getSizeInBits() != Op1.getValueSizeInBits())
return DAG.UnrollVectorOp(Op.getNode());
// Bitcast the operands to be the same type as the mask.
// This is needed when we select between FP types because
// the mask is a vector of integers.
Op1 = DAG.getNode(ISD::BITCAST, DL, VT, Op1);
Op2 = DAG.getNode(ISD::BITCAST, DL, VT, Op2);
SDValue AllOnes = DAG.getConstant(
APInt::getAllOnesValue(VT.getScalarSizeInBits()), DL, VT);
SDValue NotMask = DAG.getNode(ISD::XOR, DL, VT, Mask, AllOnes);
Op1 = DAG.getNode(ISD::AND, DL, VT, Op1, Mask);
Op2 = DAG.getNode(ISD::AND, DL, VT, Op2, NotMask);
SDValue Val = DAG.getNode(ISD::OR, DL, VT, Op1, Op2);
return DAG.getNode(ISD::BITCAST, DL, Op.getValueType(), Val);
}
SDValue VectorLegalizer::ExpandUINT_TO_FLOAT(SDValue Op) {
EVT VT = Op.getOperand(0).getValueType();
SDLoc DL(Op);
// Make sure that the SINT_TO_FP and SRL instructions are available.
if (TLI.getOperationAction(ISD::SINT_TO_FP, VT) == TargetLowering::Expand ||
TLI.getOperationAction(ISD::SRL, VT) == TargetLowering::Expand)
return DAG.UnrollVectorOp(Op.getNode());
unsigned BW = VT.getScalarSizeInBits();
assert((BW == 64 || BW == 32) &&
"Elements in vector-UINT_TO_FP must be 32 or 64 bits wide");
SDValue HalfWord = DAG.getConstant(BW / 2, DL, VT);
// Constants to clear the upper part of the word.
// Notice that we can also use SHL+SHR, but using a constant is slightly
// faster on x86.
uint64_t HWMask = (BW == 64) ? 0x00000000FFFFFFFF : 0x0000FFFF;
SDValue HalfWordMask = DAG.getConstant(HWMask, DL, VT);
// Two to the power of half-word-size.
SDValue TWOHW = DAG.getConstantFP(1 << (BW / 2), DL, Op.getValueType());
// Clear upper part of LO, lower HI
SDValue HI = DAG.getNode(ISD::SRL, DL, VT, Op.getOperand(0), HalfWord);
SDValue LO = DAG.getNode(ISD::AND, DL, VT, Op.getOperand(0), HalfWordMask);
// Convert hi and lo to floats
// Convert the hi part back to the upper values
// TODO: Can any fast-math-flags be set on these nodes?
SDValue fHI = DAG.getNode(ISD::SINT_TO_FP, DL, Op.getValueType(), HI);
fHI = DAG.getNode(ISD::FMUL, DL, Op.getValueType(), fHI, TWOHW);
SDValue fLO = DAG.getNode(ISD::SINT_TO_FP, DL, Op.getValueType(), LO);
// Add the two halves
return DAG.getNode(ISD::FADD, DL, Op.getValueType(), fHI, fLO);
}
SDValue VectorLegalizer::ExpandFNEG(SDValue Op) {
if (TLI.isOperationLegalOrCustom(ISD::FSUB, Op.getValueType())) {
SDLoc DL(Op);
SDValue Zero = DAG.getConstantFP(-0.0, DL, Op.getValueType());
// TODO: If FNEG had fast-math-flags, they'd get propagated to this FSUB.
return DAG.getNode(ISD::FSUB, DL, Op.getValueType(),
Zero, Op.getOperand(0));
}
return DAG.UnrollVectorOp(Op.getNode());
}
SDValue VectorLegalizer::ExpandFSUB(SDValue Op) {
// For floating-point values, (a-b) is the same as a+(-b). If FNEG is legal,
// we can defer this to operation legalization where it will be lowered as
// a+(-b).
EVT VT = Op.getValueType();
if (TLI.isOperationLegalOrCustom(ISD::FNEG, VT) &&
TLI.isOperationLegalOrCustom(ISD::FADD, VT))
return Op; // Defer to LegalizeDAG
return DAG.UnrollVectorOp(Op.getNode());
}
SDValue VectorLegalizer::ExpandCTLZ(SDValue Op) {
EVT VT = Op.getValueType();
unsigned NumBitsPerElt = VT.getScalarSizeInBits();
// If the non-ZERO_UNDEF version is supported we can use that instead.
if (Op.getOpcode() == ISD::CTLZ_ZERO_UNDEF &&
TLI.isOperationLegalOrCustom(ISD::CTLZ, VT)) {
SDLoc DL(Op);
return DAG.getNode(ISD::CTLZ, DL, Op.getValueType(), Op.getOperand(0));
}
// If CTPOP is available we can lower with a CTPOP based method:
// u16 ctlz(u16 x) {
// x |= (x >> 1);
// x |= (x >> 2);
// x |= (x >> 4);
// x |= (x >> 8);
// return ctpop(~x);
// }
// Ref: "Hacker's Delight" by Henry Warren
if (isPowerOf2_32(NumBitsPerElt) &&
TLI.isOperationLegalOrCustom(ISD::CTPOP, VT) &&
TLI.isOperationLegalOrCustom(ISD::SRL, VT) &&
TLI.isOperationLegalOrCustomOrPromote(ISD::OR, VT) &&
TLI.isOperationLegalOrCustomOrPromote(ISD::XOR, VT)) {
SDLoc DL(Op);
SDValue Res = Op.getOperand(0);
EVT ShiftTy = TLI.getShiftAmountTy(VT, DAG.getDataLayout());
for (unsigned i = 1; i != NumBitsPerElt; i *= 2)
Res = DAG.getNode(
ISD::OR, DL, VT, Res,
DAG.getNode(ISD::SRL, DL, VT, Res, DAG.getConstant(i, DL, ShiftTy)));
Res = DAG.getNOT(DL, Res, VT);
return DAG.getNode(ISD::CTPOP, DL, VT, Res);
}
// Otherwise go ahead and unroll.
return DAG.UnrollVectorOp(Op.getNode());
}
SDValue VectorLegalizer::ExpandCTTZ_ZERO_UNDEF(SDValue Op) {
// If the non-ZERO_UNDEF version is supported we can use that instead.
if (TLI.isOperationLegalOrCustom(ISD::CTTZ, Op.getValueType())) {
SDLoc DL(Op);
return DAG.getNode(ISD::CTTZ, DL, Op.getValueType(), Op.getOperand(0));
}
// Otherwise go ahead and unroll.
return DAG.UnrollVectorOp(Op.getNode());
}
SDValue VectorLegalizer::UnrollVSETCC(SDValue Op) {
EVT VT = Op.getValueType();
unsigned NumElems = VT.getVectorNumElements();
EVT EltVT = VT.getVectorElementType();
SDValue LHS = Op.getOperand(0), RHS = Op.getOperand(1), CC = Op.getOperand(2);
EVT TmpEltVT = LHS.getValueType().getVectorElementType();
SDLoc dl(Op);
SmallVector<SDValue, 8> Ops(NumElems);
for (unsigned i = 0; i < NumElems; ++i) {
SDValue LHSElem = DAG.getNode(
ISD::EXTRACT_VECTOR_ELT, dl, TmpEltVT, LHS,
DAG.getConstant(i, dl, TLI.getVectorIdxTy(DAG.getDataLayout())));
SDValue RHSElem = DAG.getNode(
ISD::EXTRACT_VECTOR_ELT, dl, TmpEltVT, RHS,
DAG.getConstant(i, dl, TLI.getVectorIdxTy(DAG.getDataLayout())));
Ops[i] = DAG.getNode(ISD::SETCC, dl,
TLI.getSetCCResultType(DAG.getDataLayout(),
*DAG.getContext(), TmpEltVT),
LHSElem, RHSElem, CC);
Ops[i] = DAG.getSelect(dl, EltVT, Ops[i],
DAG.getConstant(APInt::getAllOnesValue
(EltVT.getSizeInBits()), dl, EltVT),
DAG.getConstant(0, dl, EltVT));
}
return DAG.getBuildVector(VT, dl, Ops);
}
bool SelectionDAG::LegalizeVectors() {
return VectorLegalizer(*this).Run();
}
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