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swiftshader / SwiftShader / refs/heads/llvm10-clean / . / third_party / llvm-10.0 / llvm / lib / CodeGen / SelectionDAG / LegalizeVectorOps.cpp
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//===- LegalizeVectorOps.cpp - Implement SelectionDAG::LegalizeVectors ----===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// 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/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/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/MachineValueType.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;
/// 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));
}
/// Legalizes the given node.
SDValue LegalizeOp(SDValue Op);
/// Assuming the node is legal, "legalize" the results.
SDValue TranslateLegalizeResults(SDValue Op, SDNode *Result);
/// Make sure Results are legal and update the translation cache.
SDValue RecursivelyLegalizeResults(SDValue Op,
MutableArrayRef<SDValue> Results);
/// Wrapper to interface LowerOperation with a vector of Results.
/// Returns false if the target wants to use default expansion. Otherwise
/// returns true. If return is true and the Results are empty, then the
/// target wants to keep the input node as is.
bool LowerOperationWrapper(SDNode *N, SmallVectorImpl<SDValue> &Results);
/// Implements unrolling a VSETCC.
SDValue UnrollVSETCC(SDNode *Node);
/// 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.
void Expand(SDNode *Node, SmallVectorImpl<SDValue> &Results);
/// Implements expansion for FP_TO_UINT; falls back to UnrollVectorOp if
/// FP_TO_SINT isn't legal.
void ExpandFP_TO_UINT(SDNode *Node, SmallVectorImpl<SDValue> &Results);
/// Implements expansion for UINT_TO_FLOAT; falls back to UnrollVectorOp if
/// SINT_TO_FLOAT and SHR on vectors isn't legal.
void ExpandUINT_TO_FLOAT(SDNode *Node, SmallVectorImpl<SDValue> &Results);
/// Implement expansion for SIGN_EXTEND_INREG using SRL and SRA.
SDValue ExpandSEXTINREG(SDNode *Node);
/// 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(SDNode *Node);
/// 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(SDNode *Node);
/// 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(SDNode *Node);
/// Expand bswap of vectors into a shuffle if legal.
SDValue ExpandBSWAP(SDNode *Node);
/// Implement vselect in terms of XOR, AND, OR when blend is not
/// supported by the target.
SDValue ExpandVSELECT(SDNode *Node);
SDValue ExpandSELECT(SDNode *Node);
std::pair<SDValue, SDValue> ExpandLoad(SDNode *N);
SDValue ExpandStore(SDNode *N);
SDValue ExpandFNEG(SDNode *Node);
void ExpandFSUB(SDNode *Node, SmallVectorImpl<SDValue> &Results);
void ExpandBITREVERSE(SDNode *Node, SmallVectorImpl<SDValue> &Results);
void ExpandUADDSUBO(SDNode *Node, SmallVectorImpl<SDValue> &Results);
void ExpandSADDSUBO(SDNode *Node, SmallVectorImpl<SDValue> &Results);
void ExpandMULO(SDNode *Node, SmallVectorImpl<SDValue> &Results);
SDValue ExpandFixedPointDiv(SDNode *Node);
SDValue ExpandStrictFPOp(SDNode *Node);
void ExpandStrictFPOp(SDNode *Node, SmallVectorImpl<SDValue> &Results);
void UnrollStrictFPOp(SDNode *Node, SmallVectorImpl<SDValue> &Results);
/// Implements vector promotion.
///
/// This is essentially just bitcasting the operands to a different type and
/// bitcasting the result back to the original type.
void Promote(SDNode *Node, SmallVectorImpl<SDValue> &Results);
/// Implements [SU]INT_TO_FP vector promotion.
///
/// This is a [zs]ext of the input operand to a larger integer type.
void PromoteINT_TO_FP(SDNode *Node, SmallVectorImpl<SDValue> &Results);
/// 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.
void PromoteFP_TO_INT(SDNode *Node, SmallVectorImpl<SDValue> &Results);
public:
VectorLegalizer(SelectionDAG& dag) :
DAG(dag), TLI(dag.getTargetLoweringInfo()) {}
/// 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, SDNode *Result) {
assert(Op->getNumValues() == Result->getNumValues() &&
"Unexpected number of results");
// Generic legalization: just pass the operand through.
for (unsigned i = 0, e = Op->getNumValues(); i != e; ++i)
AddLegalizedOperand(Op.getValue(i), SDValue(Result, i));
return SDValue(Result, Op.getResNo());
}
SDValue
VectorLegalizer::RecursivelyLegalizeResults(SDValue Op,
MutableArrayRef<SDValue> Results) {
assert(Results.size() == Op->getNumValues() &&
"Unexpected number of results");
// Make sure that the generated code is itself legal.
for (unsigned i = 0, e = Results.size(); i != e; ++i) {
Results[i] = LegalizeOp(Results[i]);
AddLegalizedOperand(Op.getValue(i), Results[i]);
}
return Results[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;
// Legalize the operands
SmallVector<SDValue, 8> Ops;
for (const SDValue &Oper : Op->op_values())
Ops.push_back(LegalizeOp(Oper));
SDNode *Node = DAG.UpdateNodeOperands(Op.getNode(), Ops);
if (Op.getOpcode() == ISD::LOAD) {
LoadSDNode *LD = cast<LoadSDNode>(Node);
ISD::LoadExtType ExtType = LD->getExtensionType();
if (LD->getMemoryVT().isVector() && ExtType != ISD::NON_EXTLOAD) {
LLVM_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, Node);
case TargetLowering::Custom: {
SmallVector<SDValue, 2> ResultVals;
if (LowerOperationWrapper(Node, ResultVals)) {
if (ResultVals.empty())
return TranslateLegalizeResults(Op, Node);
Changed = true;
return RecursivelyLegalizeResults(Op, ResultVals);
}
LLVM_FALLTHROUGH;
}
case TargetLowering::Expand: {
Changed = true;
std::pair<SDValue, SDValue> Tmp = ExpandLoad(Node);
AddLegalizedOperand(Op.getValue(0), Tmp.first);
AddLegalizedOperand(Op.getValue(1), Tmp.second);
return Op.getResNo() ? Tmp.first : Tmp.second;
}
}
}
} else if (Op.getOpcode() == ISD::STORE) {
StoreSDNode *ST = cast<StoreSDNode>(Node);
EVT StVT = ST->getMemoryVT();
MVT ValVT = ST->getValue().getSimpleValueType();
if (StVT.isVector() && ST->isTruncatingStore()) {
LLVM_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, Node);
case TargetLowering::Custom: {
SmallVector<SDValue, 1> ResultVals;
if (LowerOperationWrapper(Node, ResultVals)) {
if (ResultVals.empty())
return TranslateLegalizeResults(Op, Node);
Changed = true;
return RecursivelyLegalizeResults(Op, ResultVals);
}
LLVM_FALLTHROUGH;
}
case TargetLowering::Expand: {
Changed = true;
SDValue Chain = ExpandStore(Node);
AddLegalizedOperand(Op, Chain);
return Chain;
}
}
}
}
bool HasVectorValueOrOp = false;
for (auto J = Node->value_begin(), E = Node->value_end(); J != E; ++J)
HasVectorValueOrOp |= J->isVector();
for (const SDValue &Oper : Node->op_values())
HasVectorValueOrOp |= Oper.getValueType().isVector();
if (!HasVectorValueOrOp)
return TranslateLegalizeResults(Op, Node);
TargetLowering::LegalizeAction Action = TargetLowering::Legal;
EVT ValVT;
switch (Op.getOpcode()) {
default:
return TranslateLegalizeResults(Op, Node);
case ISD::MERGE_VALUES:
Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
// This operation lies about being legal: when it claims to be legal,
// it should actually be expanded.
if (Action == TargetLowering::Legal)
Action = TargetLowering::Expand;
break;
#define INSTRUCTION(NAME, NARG, ROUND_MODE, INTRINSIC, DAGN) \
case ISD::STRICT_##DAGN:
#include "llvm/IR/ConstrainedOps.def"
ValVT = Node->getValueType(0);
if (Op.getOpcode() == ISD::STRICT_SINT_TO_FP ||
Op.getOpcode() == ISD::STRICT_UINT_TO_FP)
ValVT = Node->getOperand(1).getValueType();
Action = TLI.getOperationAction(Node->getOpcode(), ValVT);
// If we're asked to expand a strict vector floating-point operation,
// by default we're going to simply unroll it. That is usually the
// best approach, except in the case where the resulting strict (scalar)
// operations would themselves use the fallback mutation to non-strict.
// In that specific case, just do the fallback on the vector op.
if (Action == TargetLowering::Expand && !TLI.isStrictFPEnabled() &&
TLI.getStrictFPOperationAction(Node->getOpcode(), ValVT) ==
TargetLowering::Legal) {
EVT EltVT = ValVT.getVectorElementType();
if (TLI.getOperationAction(Node->getOpcode(), EltVT)
== TargetLowering::Expand &&
TLI.getStrictFPOperationAction(Node->getOpcode(), EltVT)
== TargetLowering::Legal)
Action = TargetLowering::Legal;
}
break;
case ISD::ADD:
case ISD::SUB:
case ISD::MUL:
case ISD::MULHS:
case ISD::MULHU:
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::FSHL:
case ISD::FSHR:
case ISD::ROTL:
case ISD::ROTR:
case ISD::ABS:
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::FMINNUM_IEEE:
case ISD::FMAXNUM_IEEE:
case ISD::FMINIMUM:
case ISD::FMAXIMUM:
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:
case ISD::SADDO:
case ISD::UADDO:
case ISD::SSUBO:
case ISD::USUBO:
case ISD::SMULO:
case ISD::UMULO:
case ISD::FCANONICALIZE:
case ISD::SADDSAT:
case ISD::UADDSAT:
case ISD::SSUBSAT:
case ISD::USUBSAT:
Action = TLI.getOperationAction(Node->getOpcode(), Node->getValueType(0));
break;
case ISD::SMULFIX:
case ISD::SMULFIXSAT:
case ISD::UMULFIX:
case ISD::UMULFIXSAT:
case ISD::SDIVFIX:
case ISD::UDIVFIX: {
unsigned Scale = Node->getConstantOperandVal(2);
Action = TLI.getFixedPointOperationAction(Node->getOpcode(),
Node->getValueType(0), Scale);
break;
}
case ISD::SINT_TO_FP:
case ISD::UINT_TO_FP:
case ISD::VECREDUCE_ADD:
case ISD::VECREDUCE_MUL:
case ISD::VECREDUCE_AND:
case ISD::VECREDUCE_OR:
case ISD::VECREDUCE_XOR:
case ISD::VECREDUCE_SMAX:
case ISD::VECREDUCE_SMIN:
case ISD::VECREDUCE_UMAX:
case ISD::VECREDUCE_UMIN:
case ISD::VECREDUCE_FADD:
case ISD::VECREDUCE_FMUL:
case ISD::VECREDUCE_FMAX:
case ISD::VECREDUCE_FMIN:
Action = TLI.getOperationAction(Node->getOpcode(),
Node->getOperand(0).getValueType());
break;
}
LLVM_DEBUG(dbgs() << "\nLegalizing vector op: "; Node->dump(&DAG));
SmallVector<SDValue, 8> ResultVals;
switch (Action) {
default: llvm_unreachable("This action is not supported yet!");
case TargetLowering::Promote:
LLVM_DEBUG(dbgs() << "Promoting\n");
Promote(Node, ResultVals);
assert(!ResultVals.empty() && "No results for promotion?");
break;
case TargetLowering::Legal:
LLVM_DEBUG(dbgs() << "Legal node: nothing to do\n");
break;
case TargetLowering::Custom:
LLVM_DEBUG(dbgs() << "Trying custom legalization\n");
if (LowerOperationWrapper(Node, ResultVals))
break;
LLVM_DEBUG(dbgs() << "Could not custom legalize node\n");
LLVM_FALLTHROUGH;
case TargetLowering::Expand:
LLVM_DEBUG(dbgs() << "Expanding\n");
Expand(Node, ResultVals);
break;
}
if (ResultVals.empty())
return TranslateLegalizeResults(Op, Node);
Changed = true;
return RecursivelyLegalizeResults(Op, ResultVals);
}
// FIME: This is very similar to the X86 override of
// TargetLowering::LowerOperationWrapper. Can we merge them somehow?
bool VectorLegalizer::LowerOperationWrapper(SDNode *Node,
SmallVectorImpl<SDValue> &Results) {
SDValue Res = TLI.LowerOperation(SDValue(Node, 0), DAG);
if (!Res.getNode())
return false;
if (Res == SDValue(Node, 0))
return true;
// If the original node has one result, take the return value from
// LowerOperation as is. It might not be result number 0.
if (Node->getNumValues() == 1) {
Results.push_back(Res);
return true;
}
// If the original node has multiple results, then the return node should
// have the same number of results.
assert((Node->getNumValues() == Res->getNumValues()) &&
"Lowering returned the wrong number of results!");
// Places new result values base on N result number.
for (unsigned I = 0, E = Node->getNumValues(); I != E; ++I)
Results.push_back(Res.getValue(I));
return true;
}
void VectorLegalizer::Promote(SDNode *Node, SmallVectorImpl<SDValue> &Results) {
// For a few operations there is a specific concept for promotion based on
// the operand's type.
switch (Node->getOpcode()) {
case ISD::SINT_TO_FP:
case ISD::UINT_TO_FP:
case ISD::STRICT_SINT_TO_FP:
case ISD::STRICT_UINT_TO_FP:
// "Promote" the operation by extending the operand.
PromoteINT_TO_FP(Node, Results);
return;
case ISD::FP_TO_UINT:
case ISD::FP_TO_SINT:
case ISD::STRICT_FP_TO_UINT:
case ISD::STRICT_FP_TO_SINT:
// Promote the operation by extending the operand.
PromoteFP_TO_INT(Node, Results);
return;
case ISD::FP_ROUND:
case ISD::FP_EXTEND:
// These operations are used to do promotion so they can't be promoted
// themselves.
llvm_unreachable("Don't know how to promote this operation!");
}
// 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.
assert(Node->getNumValues() == 1 &&
"Can't promote a vector with multiple results!");
MVT VT = Node->getSimpleValueType(0);
MVT NVT = TLI.getTypeToPromoteTo(Node->getOpcode(), VT);
SDLoc dl(Node);
SmallVector<SDValue, 4> Operands(Node->getNumOperands());
for (unsigned j = 0; j != Node->getNumOperands(); ++j) {
if (Node->getOperand(j).getValueType().isVector())
if (Node->getOperand(j)
.getValueType()
.getVectorElementType()
.isFloatingPoint() &&
NVT.isVector() && NVT.getVectorElementType().isFloatingPoint())
Operands[j] = DAG.getNode(ISD::FP_EXTEND, dl, NVT, Node->getOperand(j));
else
Operands[j] = DAG.getNode(ISD::BITCAST, dl, NVT, Node->getOperand(j));
else
Operands[j] = Node->getOperand(j);
}
SDValue Res =
DAG.getNode(Node->getOpcode(), dl, NVT, Operands, Node->getFlags());
if ((VT.isFloatingPoint() && NVT.isFloatingPoint()) ||
(VT.isVector() && VT.getVectorElementType().isFloatingPoint() &&
NVT.isVector() && NVT.getVectorElementType().isFloatingPoint()))
Res = DAG.getNode(ISD::FP_ROUND, dl, VT, Res, DAG.getIntPtrConstant(0, dl));
else
Res = DAG.getNode(ISD::BITCAST, dl, VT, Res);
Results.push_back(Res);
}
void VectorLegalizer::PromoteINT_TO_FP(SDNode *Node,
SmallVectorImpl<SDValue> &Results) {
// INT_TO_FP operations may require the input operand be promoted even
// when the type is otherwise legal.
bool IsStrict = Node->isStrictFPOpcode();
MVT VT = Node->getOperand(IsStrict ? 1 : 0).getSimpleValueType();
MVT NVT = TLI.getTypeToPromoteTo(Node->getOpcode(), VT);
assert(NVT.getVectorNumElements() == VT.getVectorNumElements() &&
"Vectors have different number of elements!");
SDLoc dl(Node);
SmallVector<SDValue, 4> Operands(Node->getNumOperands());
unsigned Opc = (Node->getOpcode() == ISD::UINT_TO_FP ||
Node->getOpcode() == ISD::STRICT_UINT_TO_FP)
? ISD::ZERO_EXTEND
: ISD::SIGN_EXTEND;
for (unsigned j = 0; j != Node->getNumOperands(); ++j) {
if (Node->getOperand(j).getValueType().isVector())
Operands[j] = DAG.getNode(Opc, dl, NVT, Node->getOperand(j));
else
Operands[j] = Node->getOperand(j);
}
if (IsStrict) {
SDValue Res = DAG.getNode(Node->getOpcode(), dl,
{Node->getValueType(0), MVT::Other}, Operands);
Results.push_back(Res);
Results.push_back(Res.getValue(1));
return;
}
SDValue Res =
DAG.getNode(Node->getOpcode(), dl, Node->getValueType(0), Operands);
Results.push_back(Res);
}
// 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.
void VectorLegalizer::PromoteFP_TO_INT(SDNode *Node,
SmallVectorImpl<SDValue> &Results) {
MVT VT = Node->getSimpleValueType(0);
MVT NVT = TLI.getTypeToPromoteTo(Node->getOpcode(), VT);
bool IsStrict = Node->isStrictFPOpcode();
assert(NVT.getVectorNumElements() == VT.getVectorNumElements() &&
"Vectors have different number of elements!");
unsigned NewOpc = Node->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;
if (NewOpc == ISD::STRICT_FP_TO_UINT &&
TLI.isOperationLegalOrCustom(ISD::STRICT_FP_TO_SINT, NVT))
NewOpc = ISD::STRICT_FP_TO_SINT;
SDLoc dl(Node);
SDValue Promoted, Chain;
if (IsStrict) {
Promoted = DAG.getNode(NewOpc, dl, {NVT, MVT::Other},
{Node->getOperand(0), Node->getOperand(1)});
Chain = Promoted.getValue(1);
} else
Promoted = DAG.getNode(NewOpc, dl, NVT, Node->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.
if (Node->getOpcode() == ISD::FP_TO_UINT ||
Node->getOpcode() == ISD::STRICT_FP_TO_UINT)
NewOpc = ISD::AssertZext;
else
NewOpc = ISD::AssertSext;
Promoted = DAG.getNode(NewOpc, dl, NVT, Promoted,
DAG.getValueType(VT.getScalarType()));
Promoted = DAG.getNode(ISD::TRUNCATE, dl, VT, Promoted);
Results.push_back(Promoted);
if (IsStrict)
Results.push_back(Chain);
}
std::pair<SDValue, SDValue> VectorLegalizer::ExpandLoad(SDNode *N) {
LoadSDNode *LD = cast<LoadSDNode>(N);
EVT SrcVT = LD->getMemoryVT();
EVT SrcEltVT = SrcVT.getScalarType();
unsigned NumElem = SrcVT.getVectorNumElements();
SDValue NewChain;
SDValue Value;
if (SrcVT.getVectorNumElements() > 1 && !SrcEltVT.isByteSized()) {
SDLoc dl(N);
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));
}
unsigned BitOffset = 0;
unsigned WideIdx = 0;
unsigned WideBits = WideVT.getSizeInBits();
// Extract bits, pack and extend/trunc them into destination type.
unsigned SrcEltBits = SrcEltVT.getSizeInBits();
SDValue SrcEltBitMask = DAG.getConstant(
APInt::getLowBitsSet(WideBits, SrcEltBits), dl, WideVT);
for (unsigned Idx = 0; Idx != NumElem; ++Idx) {
assert(BitOffset < WideBits && "Unexpected offset!");
SDValue ShAmt = DAG.getConstant(
BitOffset, dl, TLI.getShiftAmountTy(WideVT, DAG.getDataLayout()));
SDValue Lo = DAG.getNode(ISD::SRL, dl, WideVT, LoadVals[WideIdx], ShAmt);
BitOffset += SrcEltBits;
if (BitOffset >= WideBits) {
WideIdx++;
BitOffset -= WideBits;
if (BitOffset > 0) {
ShAmt = DAG.getConstant(
SrcEltBits - BitOffset, dl,
TLI.getShiftAmountTy(WideVT, DAG.getDataLayout()));
SDValue Hi =
DAG.getNode(ISD::SHL, dl, WideVT, LoadVals[WideIdx], ShAmt);
Lo = DAG.getNode(ISD::OR, dl, WideVT, Lo, Hi);
}
}
Lo = DAG.getNode(ISD::AND, dl, WideVT, Lo, SrcEltBitMask);
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(N->getValueType(0), dl, Vals);
} else {
std::tie(Value, NewChain) = TLI.scalarizeVectorLoad(LD, DAG);
}
return std::make_pair(Value, NewChain);
}
SDValue VectorLegalizer::ExpandStore(SDNode *N) {
StoreSDNode *ST = cast<StoreSDNode>(N);
SDValue TF = TLI.scalarizeVectorStore(ST, DAG);
return TF;
}
void VectorLegalizer::Expand(SDNode *Node, SmallVectorImpl<SDValue> &Results) {
SDValue Tmp;
switch (Node->getOpcode()) {
case ISD::MERGE_VALUES:
for (unsigned i = 0, e = Node->getNumValues(); i != e; ++i)
Results.push_back(Node->getOperand(i));
return;
case ISD::SIGN_EXTEND_INREG:
Results.push_back(ExpandSEXTINREG(Node));
return;
case ISD::ANY_EXTEND_VECTOR_INREG:
Results.push_back(ExpandANY_EXTEND_VECTOR_INREG(Node));
return;
case ISD::SIGN_EXTEND_VECTOR_INREG:
Results.push_back(ExpandSIGN_EXTEND_VECTOR_INREG(Node));
return;
case ISD::ZERO_EXTEND_VECTOR_INREG:
Results.push_back(ExpandZERO_EXTEND_VECTOR_INREG(Node));
return;
case ISD::BSWAP:
Results.push_back(ExpandBSWAP(Node));
return;
case ISD::VSELECT:
Results.push_back(ExpandVSELECT(Node));
return;
case ISD::SELECT:
Results.push_back(ExpandSELECT(Node));
return;
case ISD::FP_TO_UINT:
ExpandFP_TO_UINT(Node, Results);
return;
case ISD::UINT_TO_FP:
ExpandUINT_TO_FLOAT(Node, Results);
return;
case ISD::FNEG:
Results.push_back(ExpandFNEG(Node));
return;
case ISD::FSUB:
ExpandFSUB(Node, Results);
return;
case ISD::SETCC:
Results.push_back(UnrollVSETCC(Node));
return;
case ISD::ABS:
if (TLI.expandABS(Node, Tmp, DAG)) {
Results.push_back(Tmp);
return;
}
break;
case ISD::BITREVERSE:
ExpandBITREVERSE(Node, Results);
return;
case ISD::CTPOP:
if (TLI.expandCTPOP(Node, Tmp, DAG)) {
Results.push_back(Tmp);
return;
}
break;
case ISD::CTLZ:
case ISD::CTLZ_ZERO_UNDEF:
if (TLI.expandCTLZ(Node, Tmp, DAG)) {
Results.push_back(Tmp);
return;
}
break;
case ISD::CTTZ:
case ISD::CTTZ_ZERO_UNDEF:
if (TLI.expandCTTZ(Node, Tmp, DAG)) {
Results.push_back(Tmp);
return;
}
break;
case ISD::FSHL:
case ISD::FSHR:
if (TLI.expandFunnelShift(Node, Tmp, DAG)) {
Results.push_back(Tmp);
return;
}
break;
case ISD::ROTL:
case ISD::ROTR:
if (TLI.expandROT(Node, Tmp, DAG)) {
Results.push_back(Tmp);
return;
}
break;
case ISD::FMINNUM:
case ISD::FMAXNUM:
if (SDValue Expanded = TLI.expandFMINNUM_FMAXNUM(Node, DAG)) {
Results.push_back(Expanded);
return;
}
break;
case ISD::UADDO:
case ISD::USUBO:
ExpandUADDSUBO(Node, Results);
return;
case ISD::SADDO:
case ISD::SSUBO:
ExpandSADDSUBO(Node, Results);
return;
case ISD::UMULO:
case ISD::SMULO:
ExpandMULO(Node, Results);
return;
case ISD::USUBSAT:
case ISD::SSUBSAT:
case ISD::UADDSAT:
case ISD::SADDSAT:
if (SDValue Expanded = TLI.expandAddSubSat(Node, DAG)) {
Results.push_back(Expanded);
return;
}
break;
case ISD::SMULFIX:
case ISD::UMULFIX:
if (SDValue Expanded = TLI.expandFixedPointMul(Node, DAG)) {
Results.push_back(Expanded);
return;
}
break;
case ISD::SMULFIXSAT:
case ISD::UMULFIXSAT:
// FIXME: We do not expand SMULFIXSAT/UMULFIXSAT here yet, not sure exactly
// why. Maybe it results in worse codegen compared to the unroll for some
// targets? This should probably be investigated. And if we still prefer to
// unroll an explanation could be helpful.
break;
case ISD::SDIVFIX:
case ISD::UDIVFIX:
Results.push_back(ExpandFixedPointDiv(Node));
return;
#define INSTRUCTION(NAME, NARG, ROUND_MODE, INTRINSIC, DAGN) \
case ISD::STRICT_##DAGN:
#include "llvm/IR/ConstrainedOps.def"
ExpandStrictFPOp(Node, Results);
return;
case ISD::VECREDUCE_ADD:
case ISD::VECREDUCE_MUL:
case ISD::VECREDUCE_AND:
case ISD::VECREDUCE_OR:
case ISD::VECREDUCE_XOR:
case ISD::VECREDUCE_SMAX:
case ISD::VECREDUCE_SMIN:
case ISD::VECREDUCE_UMAX:
case ISD::VECREDUCE_UMIN:
case ISD::VECREDUCE_FADD:
case ISD::VECREDUCE_FMUL:
case ISD::VECREDUCE_FMAX:
case ISD::VECREDUCE_FMIN:
Results.push_back(TLI.expandVecReduce(Node, DAG));
return;
}
Results.push_back(DAG.UnrollVectorOp(Node));
}
SDValue VectorLegalizer::ExpandSELECT(SDNode *Node) {
// 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 = Node->getValueType(0);
SDLoc DL(Node);
SDValue Mask = Node->getOperand(0);
SDValue Op1 = Node->getOperand(1);
SDValue Op2 = Node->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(Node);
// 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, Node->getValueType(0), Val);
}
SDValue VectorLegalizer::ExpandSEXTINREG(SDNode *Node) {
EVT VT = Node->getValueType(0);
// 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(Node);
SDLoc DL(Node);
EVT OrigTy = cast<VTSDNode>(Node->getOperand(1))->getVT();
unsigned BW = VT.getScalarSizeInBits();
unsigned OrigBW = OrigTy.getScalarSizeInBits();
SDValue ShiftSz = DAG.getConstant(BW - OrigBW, DL, VT);
SDValue Op = DAG.getNode(ISD::SHL, DL, VT, Node->getOperand(0), 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(SDNode *Node) {
SDLoc DL(Node);
EVT VT = Node->getValueType(0);
int NumElements = VT.getVectorNumElements();
SDValue Src = Node->getOperand(0);
EVT SrcVT = Src.getValueType();
int NumSrcElements = SrcVT.getVectorNumElements();
// *_EXTEND_VECTOR_INREG SrcVT can be smaller than VT - so insert the vector
// into a larger vector type.
if (SrcVT.bitsLE(VT)) {
assert((VT.getSizeInBits() % SrcVT.getScalarSizeInBits()) == 0 &&
"ANY_EXTEND_VECTOR_INREG vector size mismatch");
NumSrcElements = VT.getSizeInBits() / SrcVT.getScalarSizeInBits();
SrcVT = EVT::getVectorVT(*DAG.getContext(), SrcVT.getScalarType(),
NumSrcElements);
Src = DAG.getNode(
ISD::INSERT_SUBVECTOR, DL, SrcVT, DAG.getUNDEF(SrcVT), Src,
DAG.getConstant(0, DL, TLI.getVectorIdxTy(DAG.getDataLayout())));
}
// 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(SDNode *Node) {
SDLoc DL(Node);
EVT VT = Node->getValueType(0);
SDValue Src = Node->getOperand(0);
EVT SrcVT = Src.getValueType();
// First build an any-extend node which can be legalized above when we
// recurse through it.
SDValue Op = DAG.getNode(ISD::ANY_EXTEND_VECTOR_INREG, DL, VT, Src);
// 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(SDNode *Node) {
SDLoc DL(Node);
EVT VT = Node->getValueType(0);
int NumElements = VT.getVectorNumElements();
SDValue Src = Node->getOperand(0);
EVT SrcVT = Src.getValueType();
int NumSrcElements = SrcVT.getVectorNumElements();
// *_EXTEND_VECTOR_INREG SrcVT can be smaller than VT - so insert the vector
// into a larger vector type.
if (SrcVT.bitsLE(VT)) {
assert((VT.getSizeInBits() % SrcVT.getScalarSizeInBits()) == 0 &&
"ZERO_EXTEND_VECTOR_INREG vector size mismatch");
NumSrcElements = VT.getSizeInBits() / SrcVT.getScalarSizeInBits();
SrcVT = EVT::getVectorVT(*DAG.getContext(), SrcVT.getScalarType(),
NumSrcElements);
Src = DAG.getNode(
ISD::INSERT_SUBVECTOR, DL, SrcVT, DAG.getUNDEF(SrcVT), Src,
DAG.getConstant(0, DL, TLI.getVectorIdxTy(DAG.getDataLayout())));
}
// 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(SDNode *Node) {
EVT VT = Node->getValueType(0);
// 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(Node);
SDLoc DL(Node);
SDValue Op = DAG.getNode(ISD::BITCAST, DL, ByteVT, Node->getOperand(0));
Op = DAG.getVectorShuffle(ByteVT, DL, Op, DAG.getUNDEF(ByteVT), ShuffleMask);
return DAG.getNode(ISD::BITCAST, DL, VT, Op);
}
void VectorLegalizer::ExpandBITREVERSE(SDNode *Node,
SmallVectorImpl<SDValue> &Results) {
EVT VT = Node->getValueType(0);
// If we have the scalar operation, it's probably cheaper to unroll it.
if (TLI.isOperationLegalOrCustom(ISD::BITREVERSE, VT.getScalarType())) {
SDValue Tmp = DAG.UnrollVectorOp(Node);
Results.push_back(Tmp);
return;
}
// 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(Node);
SDValue Op = DAG.getNode(ISD::BITCAST, DL, ByteVT, Node->getOperand(0));
Op = DAG.getVectorShuffle(ByteVT, DL, Op, DAG.getUNDEF(ByteVT),
BSWAPMask);
Op = DAG.getNode(ISD::BITREVERSE, DL, ByteVT, Op);
Op = DAG.getNode(ISD::BITCAST, DL, VT, Op);
Results.push_back(Op);
return;
}
}
// 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))
// Let LegalizeDAG handle this later.
return;
// Otherwise unroll.
SDValue Tmp = DAG.UnrollVectorOp(Node);
Results.push_back(Tmp);
}
SDValue VectorLegalizer::ExpandVSELECT(SDNode *Node) {
// Implement VSELECT in terms of XOR, AND, OR
// on platforms which do not support blend natively.
SDLoc DL(Node);
SDValue Mask = Node->getOperand(0);
SDValue Op1 = Node->getOperand(1);
SDValue Op2 = Node->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(Node);
// 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(Node);
// 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, Node->getValueType(0), Val);
}
void VectorLegalizer::ExpandFP_TO_UINT(SDNode *Node,
SmallVectorImpl<SDValue> &Results) {
// Attempt to expand using TargetLowering.
SDValue Result, Chain;
if (TLI.expandFP_TO_UINT(Node, Result, Chain, DAG)) {
Results.push_back(Result);
if (Node->isStrictFPOpcode())
Results.push_back(Chain);
return;
}
// Otherwise go ahead and unroll.
if (Node->isStrictFPOpcode()) {
UnrollStrictFPOp(Node, Results);
return;
}
Results.push_back(DAG.UnrollVectorOp(Node));
}
void VectorLegalizer::ExpandUINT_TO_FLOAT(SDNode *Node,
SmallVectorImpl<SDValue> &Results) {
bool IsStrict = Node->isStrictFPOpcode();
unsigned OpNo = IsStrict ? 1 : 0;
SDValue Src = Node->getOperand(OpNo);
EVT VT = Src.getValueType();
SDLoc DL(Node);
// Attempt to expand using TargetLowering.
SDValue Result;
SDValue Chain;
if (TLI.expandUINT_TO_FP(Node, Result, Chain, DAG)) {
Results.push_back(Result);
if (IsStrict)
Results.push_back(Chain);
return;
}
// Make sure that the SINT_TO_FP and SRL instructions are available.
if (((!IsStrict && TLI.getOperationAction(ISD::SINT_TO_FP, VT) ==
TargetLowering::Expand) ||
(IsStrict && TLI.getOperationAction(ISD::STRICT_SINT_TO_FP, VT) ==
TargetLowering::Expand)) ||
TLI.getOperationAction(ISD::SRL, VT) == TargetLowering::Expand) {
if (IsStrict) {
UnrollStrictFPOp(Node, Results);
return;
}
Results.push_back(DAG.UnrollVectorOp(Node));
return;
}
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(1ULL << (BW / 2), DL, Node->getValueType(0));
// Clear upper part of LO, lower HI
SDValue HI = DAG.getNode(ISD::SRL, DL, VT, Src, HalfWord);
SDValue LO = DAG.getNode(ISD::AND, DL, VT, Src, HalfWordMask);
if (IsStrict) {
// 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::STRICT_SINT_TO_FP, DL,
{Node->getValueType(0), MVT::Other},
{Node->getOperand(0), HI});
fHI = DAG.getNode(ISD::STRICT_FMUL, DL, {Node->getValueType(0), MVT::Other},
{fHI.getValue(1), fHI, TWOHW});
SDValue fLO = DAG.getNode(ISD::STRICT_SINT_TO_FP, DL,
{Node->getValueType(0), MVT::Other},
{Node->getOperand(0), LO});
SDValue TF = DAG.getNode(ISD::TokenFactor, DL, MVT::Other, fHI.getValue(1),
fLO.getValue(1));
// Add the two halves
SDValue Result =
DAG.getNode(ISD::STRICT_FADD, DL, {Node->getValueType(0), MVT::Other},
{TF, fHI, fLO});
Results.push_back(Result);
Results.push_back(Result.getValue(1));
return;
}
// 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, Node->getValueType(0), HI);
fHI = DAG.getNode(ISD::FMUL, DL, Node->getValueType(0), fHI, TWOHW);
SDValue fLO = DAG.getNode(ISD::SINT_TO_FP, DL, Node->getValueType(0), LO);
// Add the two halves
Results.push_back(
DAG.getNode(ISD::FADD, DL, Node->getValueType(0), fHI, fLO));
}
SDValue VectorLegalizer::ExpandFNEG(SDNode *Node) {
if (TLI.isOperationLegalOrCustom(ISD::FSUB, Node->getValueType(0))) {
SDLoc DL(Node);
SDValue Zero = DAG.getConstantFP(-0.0, DL, Node->getValueType(0));
// TODO: If FNEG had fast-math-flags, they'd get propagated to this FSUB.
return DAG.getNode(ISD::FSUB, DL, Node->getValueType(0), Zero,
Node->getOperand(0));
}
return DAG.UnrollVectorOp(Node);
}
void VectorLegalizer::ExpandFSUB(SDNode *Node,
SmallVectorImpl<SDValue> &Results) {
// 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 = Node->getValueType(0);
if (TLI.isOperationLegalOrCustom(ISD::FNEG, VT) &&
TLI.isOperationLegalOrCustom(ISD::FADD, VT))
return; // Defer to LegalizeDAG
SDValue Tmp = DAG.UnrollVectorOp(Node);
Results.push_back(Tmp);
}
void VectorLegalizer::ExpandUADDSUBO(SDNode *Node,
SmallVectorImpl<SDValue> &Results) {
SDValue Result, Overflow;
TLI.expandUADDSUBO(Node, Result, Overflow, DAG);
Results.push_back(Result);
Results.push_back(Overflow);
}
void VectorLegalizer::ExpandSADDSUBO(SDNode *Node,
SmallVectorImpl<SDValue> &Results) {
SDValue Result, Overflow;
TLI.expandSADDSUBO(Node, Result, Overflow, DAG);
Results.push_back(Result);
Results.push_back(Overflow);
}
void VectorLegalizer::ExpandMULO(SDNode *Node,
SmallVectorImpl<SDValue> &Results) {
SDValue Result, Overflow;
if (!TLI.expandMULO(Node, Result, Overflow, DAG))
std::tie(Result, Overflow) = DAG.UnrollVectorOverflowOp(Node);
Results.push_back(Result);
Results.push_back(Overflow);
}
SDValue VectorLegalizer::ExpandFixedPointDiv(SDNode *Node) {
SDNode *N = Node;
if (SDValue Expanded = TLI.expandFixedPointDiv(N->getOpcode(), SDLoc(N),
N->getOperand(0), N->getOperand(1), N->getConstantOperandVal(2), DAG))
return Expanded;
return DAG.UnrollVectorOp(N);
}
void VectorLegalizer::ExpandStrictFPOp(SDNode *Node,
SmallVectorImpl<SDValue> &Results) {
if (Node->getOpcode() == ISD::STRICT_UINT_TO_FP) {
ExpandUINT_TO_FLOAT(Node, Results);
return;
}
if (Node->getOpcode() == ISD::STRICT_FP_TO_UINT) {
ExpandFP_TO_UINT(Node, Results);
return;
}
UnrollStrictFPOp(Node, Results);
}
void VectorLegalizer::UnrollStrictFPOp(SDNode *Node,
SmallVectorImpl<SDValue> &Results) {
EVT VT = Node->getValueType(0);
EVT EltVT = VT.getVectorElementType();
unsigned NumElems = VT.getVectorNumElements();
unsigned NumOpers = Node->getNumOperands();
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
EVT TmpEltVT = EltVT;
if (Node->getOpcode() == ISD::STRICT_FSETCC ||
Node->getOpcode() == ISD::STRICT_FSETCCS)
TmpEltVT = TLI.getSetCCResultType(DAG.getDataLayout(),
*DAG.getContext(), TmpEltVT);
EVT ValueVTs[] = {TmpEltVT, MVT::Other};
SDValue Chain = Node->getOperand(0);
SDLoc dl(Node);
SmallVector<SDValue, 32> OpValues;
SmallVector<SDValue, 32> OpChains;
for (unsigned i = 0; i < NumElems; ++i) {
SmallVector<SDValue, 4> Opers;
SDValue Idx = DAG.getConstant(i, dl,
TLI.getVectorIdxTy(DAG.getDataLayout()));
// The Chain is the first operand.
Opers.push_back(Chain);
// Now process the remaining operands.
for (unsigned j = 1; j < NumOpers; ++j) {
SDValue Oper = Node->getOperand(j);
EVT OperVT = Oper.getValueType();
if (OperVT.isVector())
Oper = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl,
OperVT.getVectorElementType(), Oper, Idx);
Opers.push_back(Oper);
}
SDValue ScalarOp = DAG.getNode(Node->getOpcode(), dl, ValueVTs, Opers);
SDValue ScalarResult = ScalarOp.getValue(0);
SDValue ScalarChain = ScalarOp.getValue(1);
if (Node->getOpcode() == ISD::STRICT_FSETCC ||
Node->getOpcode() == ISD::STRICT_FSETCCS)
ScalarResult = DAG.getSelect(dl, EltVT, ScalarResult,
DAG.getConstant(APInt::getAllOnesValue
(EltVT.getSizeInBits()), dl, EltVT),
DAG.getConstant(0, dl, EltVT));
OpValues.push_back(ScalarResult);
OpChains.push_back(ScalarChain);
}
SDValue Result = DAG.getBuildVector(VT, dl, OpValues);
SDValue NewChain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, OpChains);
Results.push_back(Result);
Results.push_back(NewChain);
}
SDValue VectorLegalizer::UnrollVSETCC(SDNode *Node) {
EVT VT = Node->getValueType(0);
unsigned NumElems = VT.getVectorNumElements();
EVT EltVT = VT.getVectorElementType();
SDValue LHS = Node->getOperand(0);
SDValue RHS = Node->getOperand(1);
SDValue CC = Node->getOperand(2);
EVT TmpEltVT = LHS.getValueType().getVectorElementType();
SDLoc dl(Node);
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();
}