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//===-------- LegalizeTypesGeneric.cpp - Generic type legalization --------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements generic type expansion and splitting for LegalizeTypes.
// The routines here perform legalization when the details of the type (such as
// whether it is an integer or a float) do not matter.
// Expansion is the act of changing a computation in an illegal type to be a
// computation in two identical registers of a smaller type. The Lo/Hi part
// is required to be stored first in memory on little/big-endian machines.
// Splitting is the act of changing a computation in an illegal type to be a
// computation in two not necessarily identical registers of a smaller type.
// There are no requirements on how the type is represented in memory.
//
//===----------------------------------------------------------------------===//
#include "LegalizeTypes.h"
#include "llvm/IR/DataLayout.h"
using namespace llvm;
#define DEBUG_TYPE "legalize-types"
//===----------------------------------------------------------------------===//
// Generic Result Expansion.
//===----------------------------------------------------------------------===//
// These routines assume that the Lo/Hi part is stored first in memory on
// little/big-endian machines, followed by the Hi/Lo part. This means that
// they cannot be used as is on vectors, for which Lo is always stored first.
void DAGTypeLegalizer::ExpandRes_MERGE_VALUES(SDNode *N, unsigned ResNo,
SDValue &Lo, SDValue &Hi) {
SDValue Op = DisintegrateMERGE_VALUES(N, ResNo);
GetExpandedOp(Op, Lo, Hi);
}
void DAGTypeLegalizer::ExpandRes_BITCAST(SDNode *N, SDValue &Lo, SDValue &Hi) {
EVT OutVT = N->getValueType(0);
EVT NOutVT = TLI.getTypeToTransformTo(*DAG.getContext(), OutVT);
SDValue InOp = N->getOperand(0);
EVT InVT = InOp.getValueType();
SDLoc dl(N);
// Handle some special cases efficiently.
switch (getTypeAction(InVT)) {
case TargetLowering::TypeLegal:
case TargetLowering::TypePromoteInteger:
break;
case TargetLowering::TypePromoteFloat:
llvm_unreachable("Bitcast of a promotion-needing float should never need"
"expansion");
case TargetLowering::TypeSoftenFloat:
// Convert the integer operand instead.
SplitInteger(GetSoftenedFloat(InOp), Lo, Hi);
Lo = DAG.getNode(ISD::BITCAST, dl, NOutVT, Lo);
Hi = DAG.getNode(ISD::BITCAST, dl, NOutVT, Hi);
return;
case TargetLowering::TypeExpandInteger:
case TargetLowering::TypeExpandFloat:
// Convert the expanded pieces of the input.
GetExpandedOp(InOp, Lo, Hi);
if (TLI.hasBigEndianPartOrdering(InVT) !=
TLI.hasBigEndianPartOrdering(OutVT))
std::swap(Lo, Hi);
Lo = DAG.getNode(ISD::BITCAST, dl, NOutVT, Lo);
Hi = DAG.getNode(ISD::BITCAST, dl, NOutVT, Hi);
return;
case TargetLowering::TypeSplitVector:
GetSplitVector(InOp, Lo, Hi);
if (TLI.hasBigEndianPartOrdering(OutVT))
std::swap(Lo, Hi);
Lo = DAG.getNode(ISD::BITCAST, dl, NOutVT, Lo);
Hi = DAG.getNode(ISD::BITCAST, dl, NOutVT, Hi);
return;
case TargetLowering::TypeScalarizeVector:
// Convert the element instead.
SplitInteger(BitConvertToInteger(GetScalarizedVector(InOp)), Lo, Hi);
Lo = DAG.getNode(ISD::BITCAST, dl, NOutVT, Lo);
Hi = DAG.getNode(ISD::BITCAST, dl, NOutVT, Hi);
return;
case TargetLowering::TypeWidenVector: {
assert(!(InVT.getVectorNumElements() & 1) && "Unsupported BITCAST");
InOp = GetWidenedVector(InOp);
EVT LoVT, HiVT;
std::tie(LoVT, HiVT) = DAG.GetSplitDestVTs(InVT);
std::tie(Lo, Hi) = DAG.SplitVector(InOp, dl, LoVT, HiVT);
if (TLI.hasBigEndianPartOrdering(OutVT))
std::swap(Lo, Hi);
Lo = DAG.getNode(ISD::BITCAST, dl, NOutVT, Lo);
Hi = DAG.getNode(ISD::BITCAST, dl, NOutVT, Hi);
return;
}
}
if (InVT.isVector() && OutVT.isInteger()) {
// Handle cases like i64 = BITCAST v1i64 on x86, where the operand
// is legal but the result is not.
unsigned NumElems = 2;
EVT ElemVT = NOutVT;
EVT NVT = EVT::getVectorVT(*DAG.getContext(), ElemVT, NumElems);
// If <ElemVT * N> is not a legal type, try <ElemVT/2 * (N*2)>.
while (!isTypeLegal(NVT)) {
unsigned NewSizeInBits = ElemVT.getSizeInBits() / 2;
// If the element size is smaller than byte, bail.
if (NewSizeInBits < 8)
break;
NumElems *= 2;
ElemVT = EVT::getIntegerVT(*DAG.getContext(), NewSizeInBits);
NVT = EVT::getVectorVT(*DAG.getContext(), ElemVT, NumElems);
}
if (isTypeLegal(NVT)) {
SDValue CastInOp = DAG.getNode(ISD::BITCAST, dl, NVT, InOp);
SmallVector<SDValue, 8> Vals;
for (unsigned i = 0; i < NumElems; ++i)
Vals.push_back(DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, ElemVT,
CastInOp, DAG.getConstant(i,
TLI.getVectorIdxTy())));
// Build Lo, Hi pair by pairing extracted elements if needed.
unsigned Slot = 0;
for (unsigned e = Vals.size(); e - Slot > 2; Slot += 2, e += 1) {
// Each iteration will BUILD_PAIR two nodes and append the result until
// there are only two nodes left, i.e. Lo and Hi.
SDValue LHS = Vals[Slot];
SDValue RHS = Vals[Slot + 1];
if (TLI.isBigEndian())
std::swap(LHS, RHS);
Vals.push_back(DAG.getNode(ISD::BUILD_PAIR, dl,
EVT::getIntegerVT(
*DAG.getContext(),
LHS.getValueType().getSizeInBits() << 1),
LHS, RHS));
}
Lo = Vals[Slot++];
Hi = Vals[Slot++];
if (TLI.isBigEndian())
std::swap(Lo, Hi);
return;
}
}
// Lower the bit-convert to a store/load from the stack.
assert(NOutVT.isByteSized() && "Expanded type not byte sized!");
// Create the stack frame object. Make sure it is aligned for both
// the source and expanded destination types.
unsigned Alignment =
TLI.getDataLayout()->getPrefTypeAlignment(NOutVT.
getTypeForEVT(*DAG.getContext()));
SDValue StackPtr = DAG.CreateStackTemporary(InVT, Alignment);
int SPFI = cast<FrameIndexSDNode>(StackPtr.getNode())->getIndex();
MachinePointerInfo PtrInfo = MachinePointerInfo::getFixedStack(SPFI);
// Emit a store to the stack slot.
SDValue Store = DAG.getStore(DAG.getEntryNode(), dl, InOp, StackPtr, PtrInfo,
false, false, 0);
// Load the first half from the stack slot.
Lo = DAG.getLoad(NOutVT, dl, Store, StackPtr, PtrInfo,
false, false, false, 0);
// Increment the pointer to the other half.
unsigned IncrementSize = NOutVT.getSizeInBits() / 8;
StackPtr = DAG.getNode(ISD::ADD, dl, StackPtr.getValueType(), StackPtr,
DAG.getConstant(IncrementSize,
StackPtr.getValueType()));
// Load the second half from the stack slot.
Hi = DAG.getLoad(NOutVT, dl, Store, StackPtr,
PtrInfo.getWithOffset(IncrementSize), false,
false, false, MinAlign(Alignment, IncrementSize));
// Handle endianness of the load.
if (TLI.hasBigEndianPartOrdering(OutVT))
std::swap(Lo, Hi);
}
void DAGTypeLegalizer::ExpandRes_BUILD_PAIR(SDNode *N, SDValue &Lo,
SDValue &Hi) {
// Return the operands.
Lo = N->getOperand(0);
Hi = N->getOperand(1);
}
void DAGTypeLegalizer::ExpandRes_EXTRACT_ELEMENT(SDNode *N, SDValue &Lo,
SDValue &Hi) {
GetExpandedOp(N->getOperand(0), Lo, Hi);
SDValue Part = cast<ConstantSDNode>(N->getOperand(1))->getZExtValue() ?
Hi : Lo;
assert(Part.getValueType() == N->getValueType(0) &&
"Type twice as big as expanded type not itself expanded!");
GetPairElements(Part, Lo, Hi);
}
void DAGTypeLegalizer::ExpandRes_EXTRACT_VECTOR_ELT(SDNode *N, SDValue &Lo,
SDValue &Hi) {
SDValue OldVec = N->getOperand(0);
unsigned OldElts = OldVec.getValueType().getVectorNumElements();
EVT OldEltVT = OldVec.getValueType().getVectorElementType();
SDLoc dl(N);
// Convert to a vector of the expanded element type, for example
// <3 x i64> -> <6 x i32>.
EVT OldVT = N->getValueType(0);
EVT NewVT = TLI.getTypeToTransformTo(*DAG.getContext(), OldVT);
if (OldVT != OldEltVT) {
// The result of EXTRACT_VECTOR_ELT may be larger than the element type of
// the input vector. If so, extend the elements of the input vector to the
// same bitwidth as the result before expanding.
assert(OldEltVT.bitsLT(OldVT) && "Result type smaller then element type!");
EVT NVecVT = EVT::getVectorVT(*DAG.getContext(), OldVT, OldElts);
OldVec = DAG.getNode(ISD::ANY_EXTEND, dl, NVecVT, N->getOperand(0));
}
SDValue NewVec = DAG.getNode(ISD::BITCAST, dl,
EVT::getVectorVT(*DAG.getContext(),
NewVT, 2*OldElts),
OldVec);
// Extract the elements at 2 * Idx and 2 * Idx + 1 from the new vector.
SDValue Idx = N->getOperand(1);
Idx = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx, Idx);
Lo = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, NewVT, NewVec, Idx);
Idx = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx,
DAG.getConstant(1, Idx.getValueType()));
Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, NewVT, NewVec, Idx);
if (TLI.isBigEndian())
std::swap(Lo, Hi);
}
void DAGTypeLegalizer::ExpandRes_NormalLoad(SDNode *N, SDValue &Lo,
SDValue &Hi) {
assert(ISD::isNormalLoad(N) && "This routine only for normal loads!");
SDLoc dl(N);
LoadSDNode *LD = cast<LoadSDNode>(N);
EVT ValueVT = LD->getValueType(0);
EVT NVT = TLI.getTypeToTransformTo(*DAG.getContext(), ValueVT);
SDValue Chain = LD->getChain();
SDValue Ptr = LD->getBasePtr();
unsigned Alignment = LD->getAlignment();
bool isVolatile = LD->isVolatile();
bool isNonTemporal = LD->isNonTemporal();
bool isInvariant = LD->isInvariant();
AAMDNodes AAInfo = LD->getAAInfo();
assert(NVT.isByteSized() && "Expanded type not byte sized!");
Lo = DAG.getLoad(NVT, dl, Chain, Ptr, LD->getPointerInfo(),
isVolatile, isNonTemporal, isInvariant, Alignment,
AAInfo);
// Increment the pointer to the other half.
unsigned IncrementSize = NVT.getSizeInBits() / 8;
Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
DAG.getConstant(IncrementSize, Ptr.getValueType()));
Hi = DAG.getLoad(NVT, dl, Chain, Ptr,
LD->getPointerInfo().getWithOffset(IncrementSize),
isVolatile, isNonTemporal, isInvariant,
MinAlign(Alignment, IncrementSize), AAInfo);
// Build a factor node to remember that this load is independent of the
// other one.
Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo.getValue(1),
Hi.getValue(1));
// Handle endianness of the load.
if (TLI.hasBigEndianPartOrdering(ValueVT))
std::swap(Lo, Hi);
// Modified the chain - switch anything that used the old chain to use
// the new one.
ReplaceValueWith(SDValue(N, 1), Chain);
}
void DAGTypeLegalizer::ExpandRes_VAARG(SDNode *N, SDValue &Lo, SDValue &Hi) {
EVT OVT = N->getValueType(0);
EVT NVT = TLI.getTypeToTransformTo(*DAG.getContext(), OVT);
SDValue Chain = N->getOperand(0);
SDValue Ptr = N->getOperand(1);
SDLoc dl(N);
const unsigned Align = N->getConstantOperandVal(3);
Lo = DAG.getVAArg(NVT, dl, Chain, Ptr, N->getOperand(2), Align);
Hi = DAG.getVAArg(NVT, dl, Lo.getValue(1), Ptr, N->getOperand(2), 0);
// Handle endianness of the load.
if (TLI.hasBigEndianPartOrdering(OVT))
std::swap(Lo, Hi);
// Modified the chain - switch anything that used the old chain to use
// the new one.
ReplaceValueWith(SDValue(N, 1), Hi.getValue(1));
}
//===--------------------------------------------------------------------===//
// Generic Operand Expansion.
//===--------------------------------------------------------------------===//
void DAGTypeLegalizer::IntegerToVector(SDValue Op, unsigned NumElements,
SmallVectorImpl<SDValue> &Ops,
EVT EltVT) {
assert(Op.getValueType().isInteger());
SDLoc DL(Op);
SDValue Parts[2];
if (NumElements > 1) {
NumElements >>= 1;
SplitInteger(Op, Parts[0], Parts[1]);
if (TLI.isBigEndian())
std::swap(Parts[0], Parts[1]);
IntegerToVector(Parts[0], NumElements, Ops, EltVT);
IntegerToVector(Parts[1], NumElements, Ops, EltVT);
} else {
Ops.push_back(DAG.getNode(ISD::BITCAST, DL, EltVT, Op));
}
}
SDValue DAGTypeLegalizer::ExpandOp_BITCAST(SDNode *N) {
SDLoc dl(N);
if (N->getValueType(0).isVector()) {
// An illegal expanding type is being converted to a legal vector type.
// Make a two element vector out of the expanded parts and convert that
// instead, but only if the new vector type is legal (otherwise there
// is no point, and it might create expansion loops). For example, on
// x86 this turns v1i64 = BITCAST i64 into v1i64 = BITCAST v2i32.
//
// FIXME: I'm not sure why we are first trying to split the input into
// a 2 element vector, so I'm leaving it here to maintain the current
// behavior.
unsigned NumElts = 2;
EVT OVT = N->getOperand(0).getValueType();
EVT NVT = EVT::getVectorVT(*DAG.getContext(),
TLI.getTypeToTransformTo(*DAG.getContext(), OVT),
NumElts);
if (!isTypeLegal(NVT)) {
// If we can't find a legal type by splitting the integer in half,
// then we can use the node's value type.
NumElts = N->getValueType(0).getVectorNumElements();
NVT = N->getValueType(0);
}
SmallVector<SDValue, 8> Ops;
IntegerToVector(N->getOperand(0), NumElts, Ops, NVT.getVectorElementType());
SDValue Vec = DAG.getNode(ISD::BUILD_VECTOR, dl, NVT,
makeArrayRef(Ops.data(), NumElts));
return DAG.getNode(ISD::BITCAST, dl, N->getValueType(0), Vec);
}
// Otherwise, store to a temporary and load out again as the new type.
return CreateStackStoreLoad(N->getOperand(0), N->getValueType(0));
}
SDValue DAGTypeLegalizer::ExpandOp_BUILD_VECTOR(SDNode *N) {
// The vector type is legal but the element type needs expansion.
EVT VecVT = N->getValueType(0);
unsigned NumElts = VecVT.getVectorNumElements();
EVT OldVT = N->getOperand(0).getValueType();
EVT NewVT = TLI.getTypeToTransformTo(*DAG.getContext(), OldVT);
SDLoc dl(N);
assert(OldVT == VecVT.getVectorElementType() &&
"BUILD_VECTOR operand type doesn't match vector element type!");
// Build a vector of twice the length out of the expanded elements.
// For example <3 x i64> -> <6 x i32>.
std::vector<SDValue> NewElts;
NewElts.reserve(NumElts*2);
for (unsigned i = 0; i < NumElts; ++i) {
SDValue Lo, Hi;
GetExpandedOp(N->getOperand(i), Lo, Hi);
if (TLI.isBigEndian())
std::swap(Lo, Hi);
NewElts.push_back(Lo);
NewElts.push_back(Hi);
}
SDValue NewVec = DAG.getNode(ISD::BUILD_VECTOR, dl,
EVT::getVectorVT(*DAG.getContext(),
NewVT, NewElts.size()),
NewElts);
// Convert the new vector to the old vector type.
return DAG.getNode(ISD::BITCAST, dl, VecVT, NewVec);
}
SDValue DAGTypeLegalizer::ExpandOp_EXTRACT_ELEMENT(SDNode *N) {
SDValue Lo, Hi;
GetExpandedOp(N->getOperand(0), Lo, Hi);
return cast<ConstantSDNode>(N->getOperand(1))->getZExtValue() ? Hi : Lo;
}
SDValue DAGTypeLegalizer::ExpandOp_INSERT_VECTOR_ELT(SDNode *N) {
// The vector type is legal but the element type needs expansion.
EVT VecVT = N->getValueType(0);
unsigned NumElts = VecVT.getVectorNumElements();
SDLoc dl(N);
SDValue Val = N->getOperand(1);
EVT OldEVT = Val.getValueType();
EVT NewEVT = TLI.getTypeToTransformTo(*DAG.getContext(), OldEVT);
assert(OldEVT == VecVT.getVectorElementType() &&
"Inserted element type doesn't match vector element type!");
// Bitconvert to a vector of twice the length with elements of the expanded
// type, insert the expanded vector elements, and then convert back.
EVT NewVecVT = EVT::getVectorVT(*DAG.getContext(), NewEVT, NumElts*2);
SDValue NewVec = DAG.getNode(ISD::BITCAST, dl,
NewVecVT, N->getOperand(0));
SDValue Lo, Hi;
GetExpandedOp(Val, Lo, Hi);
if (TLI.isBigEndian())
std::swap(Lo, Hi);
SDValue Idx = N->getOperand(2);
Idx = DAG.getNode(ISD::ADD, dl, Idx.getValueType(), Idx, Idx);
NewVec = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, NewVecVT, NewVec, Lo, Idx);
Idx = DAG.getNode(ISD::ADD, dl,
Idx.getValueType(), Idx,
DAG.getConstant(1, Idx.getValueType()));
NewVec = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, NewVecVT, NewVec, Hi, Idx);
// Convert the new vector to the old vector type.
return DAG.getNode(ISD::BITCAST, dl, VecVT, NewVec);
}
SDValue DAGTypeLegalizer::ExpandOp_SCALAR_TO_VECTOR(SDNode *N) {
SDLoc dl(N);
EVT VT = N->getValueType(0);
assert(VT.getVectorElementType() == N->getOperand(0).getValueType() &&
"SCALAR_TO_VECTOR operand type doesn't match vector element type!");
unsigned NumElts = VT.getVectorNumElements();
SmallVector<SDValue, 16> Ops(NumElts);
Ops[0] = N->getOperand(0);
SDValue UndefVal = DAG.getUNDEF(Ops[0].getValueType());
for (unsigned i = 1; i < NumElts; ++i)
Ops[i] = UndefVal;
return DAG.getNode(ISD::BUILD_VECTOR, dl, VT, Ops);
}
SDValue DAGTypeLegalizer::ExpandOp_NormalStore(SDNode *N, unsigned OpNo) {
assert(ISD::isNormalStore(N) && "This routine only for normal stores!");
assert(OpNo == 1 && "Can only expand the stored value so far");
SDLoc dl(N);
StoreSDNode *St = cast<StoreSDNode>(N);
EVT ValueVT = St->getValue().getValueType();
EVT NVT = TLI.getTypeToTransformTo(*DAG.getContext(), ValueVT);
SDValue Chain = St->getChain();
SDValue Ptr = St->getBasePtr();
unsigned Alignment = St->getAlignment();
bool isVolatile = St->isVolatile();
bool isNonTemporal = St->isNonTemporal();
AAMDNodes AAInfo = St->getAAInfo();
assert(NVT.isByteSized() && "Expanded type not byte sized!");
unsigned IncrementSize = NVT.getSizeInBits() / 8;
SDValue Lo, Hi;
GetExpandedOp(St->getValue(), Lo, Hi);
if (TLI.hasBigEndianPartOrdering(ValueVT))
std::swap(Lo, Hi);
Lo = DAG.getStore(Chain, dl, Lo, Ptr, St->getPointerInfo(),
isVolatile, isNonTemporal, Alignment, AAInfo);
Ptr = DAG.getNode(ISD::ADD, dl, Ptr.getValueType(), Ptr,
DAG.getConstant(IncrementSize, Ptr.getValueType()));
Hi = DAG.getStore(Chain, dl, Hi, Ptr,
St->getPointerInfo().getWithOffset(IncrementSize),
isVolatile, isNonTemporal,
MinAlign(Alignment, IncrementSize), AAInfo);
return DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo, Hi);
}
//===--------------------------------------------------------------------===//
// Generic Result Splitting.
//===--------------------------------------------------------------------===//
// Be careful to make no assumptions about which of Lo/Hi is stored first in
// memory (for vectors it is always Lo first followed by Hi in the following
// bytes; for integers and floats it is Lo first if and only if the machine is
// little-endian).
void DAGTypeLegalizer::SplitRes_MERGE_VALUES(SDNode *N, unsigned ResNo,
SDValue &Lo, SDValue &Hi) {
SDValue Op = DisintegrateMERGE_VALUES(N, ResNo);
GetSplitOp(Op, Lo, Hi);
}
void DAGTypeLegalizer::SplitRes_SELECT(SDNode *N, SDValue &Lo,
SDValue &Hi) {
SDValue LL, LH, RL, RH, CL, CH;
SDLoc dl(N);
GetSplitOp(N->getOperand(1), LL, LH);
GetSplitOp(N->getOperand(2), RL, RH);
SDValue Cond = N->getOperand(0);
CL = CH = Cond;
if (Cond.getValueType().isVector()) {
// Check if there are already splitted versions of the vector available and
// use those instead of splitting the mask operand again.
if (getTypeAction(Cond.getValueType()) == TargetLowering::TypeSplitVector)
GetSplitVector(Cond, CL, CH);
else
std::tie(CL, CH) = DAG.SplitVector(Cond, dl);
}
Lo = DAG.getNode(N->getOpcode(), dl, LL.getValueType(), CL, LL, RL);
Hi = DAG.getNode(N->getOpcode(), dl, LH.getValueType(), CH, LH, RH);
}
void DAGTypeLegalizer::SplitRes_SELECT_CC(SDNode *N, SDValue &Lo,
SDValue &Hi) {
SDValue LL, LH, RL, RH;
SDLoc dl(N);
GetSplitOp(N->getOperand(2), LL, LH);
GetSplitOp(N->getOperand(3), RL, RH);
Lo = DAG.getNode(ISD::SELECT_CC, dl, LL.getValueType(), N->getOperand(0),
N->getOperand(1), LL, RL, N->getOperand(4));
Hi = DAG.getNode(ISD::SELECT_CC, dl, LH.getValueType(), N->getOperand(0),
N->getOperand(1), LH, RH, N->getOperand(4));
}
void DAGTypeLegalizer::SplitRes_UNDEF(SDNode *N, SDValue &Lo, SDValue &Hi) {
EVT LoVT, HiVT;
std::tie(LoVT, HiVT) = DAG.GetSplitDestVTs(N->getValueType(0));
Lo = DAG.getUNDEF(LoVT);
Hi = DAG.getUNDEF(HiVT);
}