llvm-6502/lib/Target/PIC16/PIC16ISelLowering.cpp
2009-01-13 19:18:47 +00:00

1398 lines
47 KiB
C++

//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines the interfaces that PIC16 uses to lower LLVM code into a
// selection DAG.
//
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "pic16-lower"
#include "PIC16ISelLowering.h"
#include "PIC16TargetMachine.h"
#include "llvm/DerivedTypes.h"
#include "llvm/GlobalValue.h"
#include "llvm/Function.h"
#include "llvm/CallingConv.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include <cstdio>
using namespace llvm;
// PIC16TargetLowering Constructor.
PIC16TargetLowering::PIC16TargetLowering(PIC16TargetMachine &TM)
: TargetLowering(TM) {
Subtarget = &TM.getSubtarget<PIC16Subtarget>();
addRegisterClass(MVT::i8, PIC16::GPRRegisterClass);
setShiftAmountType(MVT::i8);
setShiftAmountFlavor(Extend);
// SRA library call names
setPIC16LibCallName(PIC16ISD::SRA_I8, "__intrinsics.sra.i8");
setPIC16LibCallName(PIC16ISD::SRA_I16, "__intrinsics.sra.i16");
setPIC16LibCallName(PIC16ISD::SRA_I32, "__intrinsics.sra.i32");
// SLL library call names
setPIC16LibCallName(PIC16ISD::SLL_I8, "__intrinsics.sll.i8");
setPIC16LibCallName(PIC16ISD::SLL_I16, "__intrinsics.sll.i16");
setPIC16LibCallName(PIC16ISD::SLL_I32, "__intrinsics.sll.i32");
// SRL library call names
setPIC16LibCallName(PIC16ISD::SRL_I8, "__intrinsics.srl.i8");
setPIC16LibCallName(PIC16ISD::SRL_I16, "__intrinsics.srl.i16");
setPIC16LibCallName(PIC16ISD::SRL_I32, "__intrinsics.srl.i32");
setOperationAction(ISD::GlobalAddress, MVT::i16, Custom);
setOperationAction(ISD::LOAD, MVT::i8, Legal);
setOperationAction(ISD::LOAD, MVT::i16, Custom);
setOperationAction(ISD::LOAD, MVT::i32, Custom);
setOperationAction(ISD::STORE, MVT::i8, Legal);
setOperationAction(ISD::STORE, MVT::i16, Custom);
setOperationAction(ISD::STORE, MVT::i32, Custom);
setOperationAction(ISD::ADDE, MVT::i8, Custom);
setOperationAction(ISD::ADDC, MVT::i8, Custom);
setOperationAction(ISD::SUBE, MVT::i8, Custom);
setOperationAction(ISD::SUBC, MVT::i8, Custom);
setOperationAction(ISD::ADD, MVT::i8, Legal);
setOperationAction(ISD::ADD, MVT::i16, Custom);
setOperationAction(ISD::OR, MVT::i8, Custom);
setOperationAction(ISD::AND, MVT::i8, Custom);
setOperationAction(ISD::XOR, MVT::i8, Custom);
setOperationAction(ISD::FrameIndex, MVT::i16, Custom);
setOperationAction(ISD::CALL, MVT::i16, Custom);
setOperationAction(ISD::RET, MVT::Other, Custom);
setOperationAction(ISD::SRA, MVT::i8, Custom);
setOperationAction(ISD::SRA, MVT::i16, Custom);
setOperationAction(ISD::SRA, MVT::i32, Custom);
setOperationAction(ISD::SHL, MVT::i8, Custom);
setOperationAction(ISD::SHL, MVT::i16, Custom);
setOperationAction(ISD::SHL, MVT::i32, Custom);
setOperationAction(ISD::SRL, MVT::i8, Custom);
setOperationAction(ISD::SRL, MVT::i16, Custom);
setOperationAction(ISD::SRL, MVT::i32, Custom);
// PIC16 does not have a SETCC, expand it to SELECT_CC.
setOperationAction(ISD::SETCC, MVT::i8, Expand);
setOperationAction(ISD::SELECT, MVT::i8, Expand);
setOperationAction(ISD::BRCOND, MVT::Other, Expand);
setOperationAction(ISD::BRIND, MVT::Other, Expand);
setOperationAction(ISD::SELECT_CC, MVT::i8, Custom);
setOperationAction(ISD::BR_CC, MVT::i8, Custom);
//setOperationAction(ISD::TRUNCATE, MVT::i16, Custom);
setTruncStoreAction(MVT::i16, MVT::i8, Custom);
// Now deduce the information based on the above mentioned
// actions
computeRegisterProperties();
}
static void PopulateResults(SDValue N, SmallVectorImpl<SDValue>&Results) {
if (N.getOpcode() == ISD::MERGE_VALUES) {
int NumResults = N.getNumOperands();
for( int i = 0; i < NumResults; i++)
Results.push_back(N.getOperand(i));
}
else
Results.push_back(N);
}
MVT PIC16TargetLowering::getSetCCResultType(MVT ValType) const {
return MVT::i8;
}
void
PIC16TargetLowering::setPIC16LibCallName(PIC16ISD::PIC16LibCall Call,
const char *Name) {
PIC16LibCallNames[Call] = Name;
}
const char *
PIC16TargetLowering::getPIC16LibCallName(PIC16ISD::PIC16LibCall Call) {
return PIC16LibCallNames[Call];
}
SDValue
PIC16TargetLowering::MakePIC16LibCall(PIC16ISD::PIC16LibCall Call,
MVT RetVT, const SDValue *Ops,
unsigned NumOps, bool isSigned,
SelectionDAG &DAG) {
TargetLowering::ArgListTy Args;
Args.reserve(NumOps);
TargetLowering::ArgListEntry Entry;
for (unsigned i = 0; i != NumOps; ++i) {
Entry.Node = Ops[i];
Entry.Ty = Entry.Node.getValueType().getTypeForMVT();
Entry.isSExt = isSigned;
Entry.isZExt = !isSigned;
Args.push_back(Entry);
}
SDValue Callee = DAG.getExternalSymbol(getPIC16LibCallName(Call), MVT::i8);
const Type *RetTy = RetVT.getTypeForMVT();
std::pair<SDValue,SDValue> CallInfo =
LowerCallTo(DAG.getEntryNode(), RetTy, isSigned, !isSigned, false,
false, CallingConv::C, false, Callee, Args, DAG);
return CallInfo.first;
}
SDValue
PIC16TargetLowering::getCurrentFrame(SelectionDAG &DAG) {
MachineFunction &MF = DAG.getMachineFunction();
const Function *Func = MF.getFunction();
const std::string FuncName = Func->getName();
// this is causing memory waste
// because for every call new memory will be allocated
char *tmpName = new char [strlen(FuncName.c_str()) + 6];
sprintf(tmpName, "%s.tmp", FuncName.c_str());
// if the external symbol of the same name already exists then
// it will not create the new one.
return DAG.getTargetExternalSymbol(tmpName, MVT::i8);
}
void
PIC16TargetLowering::getCurrentFrameIndex(SelectionDAG &DAG, SDValue &ES,
unsigned SlotSize, int &FromFI) {
MachineFunction &MF = DAG.getMachineFunction();
const Function *Func = MF.getFunction();
const std::string FuncName = Func->getName();
// this is causing memory waste
// because for every call new memory will be allocated
char *tmpName = new char [strlen(FuncName.c_str()) + 6];
sprintf(tmpName, "%s.tmp", FuncName.c_str());
// if the external symbol of the same name already exists then
// it will not create the new one.
ES = DAG.getTargetExternalSymbol(tmpName, MVT::i8);
// Alignment is always 1
//FromFI = MF.getFrameInfo()->CreateStackObject(SlotSize, 1);
FromFI = MF.getFrameInfo()->CreateStackObject(1, 1);
int FI;
for(unsigned i=1;i<SlotSize; ++i) {
FI = MF.getFrameInfo()->CreateStackObject(1, 1);
}
}
const char *PIC16TargetLowering::getTargetNodeName(unsigned Opcode) const {
switch (Opcode) {
default: return NULL;
case PIC16ISD::Lo: return "PIC16ISD::Lo";
case PIC16ISD::Hi: return "PIC16ISD::Hi";
case PIC16ISD::MTLO: return "PIC16ISD::MTLO";
case PIC16ISD::MTHI: return "PIC16ISD::MTHI";
case PIC16ISD::Banksel: return "PIC16ISD::Banksel";
case PIC16ISD::PIC16Load: return "PIC16ISD::PIC16Load";
case PIC16ISD::PIC16LdWF: return "PIC16ISD::PIC16LdWF";
case PIC16ISD::PIC16Store: return "PIC16ISD::PIC16Store";
case PIC16ISD::PIC16StWF: return "PIC16ISD::PIC16StWF";
case PIC16ISD::BCF: return "PIC16ISD::BCF";
case PIC16ISD::LSLF: return "PIC16ISD::LSLF";
case PIC16ISD::LRLF: return "PIC16ISD::LRLF";
case PIC16ISD::RLF: return "PIC16ISD::RLF";
case PIC16ISD::RRF: return "PIC16ISD::RRF";
case PIC16ISD::CALL: return "PIC16ISD::CALL";
case PIC16ISD::SUBCC: return "PIC16ISD::SUBCC";
case PIC16ISD::SELECT_ICC: return "PIC16ISD::SELECT_ICC";
case PIC16ISD::BRCOND: return "PIC16ISD::BRCOND";
case PIC16ISD::Dummy: return "PIC16ISD::Dummy";
}
}
void PIC16TargetLowering::ReplaceNodeResults(SDNode *N,
SmallVectorImpl<SDValue>&Results,
SelectionDAG &DAG) {
switch (N->getOpcode()) {
case ISD::GlobalAddress:
Results.push_back(ExpandGlobalAddress(N, DAG));
return;
case ISD::ExternalSymbol:
Results.push_back(ExpandExternalSymbol(N, DAG));
return;
case ISD::STORE:
Results.push_back(ExpandStore(N, DAG));
return;
case ISD::LOAD:
PopulateResults(ExpandLoad(N, DAG), Results);
return;
case ISD::ADD:
// Results.push_back(ExpandAdd(N, DAG));
return;
case ISD::SHL:
case ISD::SRL:
case ISD::SRA:
{
SDValue Res = ExpandShift(N, DAG);
if (Res.getNode())
Results.push_back(Res);
return;
}
case ISD::FrameIndex:
Results.push_back(ExpandFrameIndex(N, DAG));
return;
default:
assert (0 && "not implemented");
return;
}
}
SDValue PIC16TargetLowering::ExpandFrameIndex(SDNode *N, SelectionDAG &DAG) {
// Currently handling FrameIndex of size MVT::i16 only
// One example of this scenario is when return value is written on
// FrameIndex#0
if (N->getValueType(0) != MVT::i16)
return SDValue();
// Expand the FrameIndex into ExternalSymbol and a Constant node
// The constant will represent the frame index number
// Get the current function frame
MachineFunction &MF = DAG.getMachineFunction();
const Function *Func = MF.getFunction();
const std::string Name = Func->getName();
FrameIndexSDNode *FR = dyn_cast<FrameIndexSDNode>(SDValue(N,0));
int Index = FR->getIndex();
SDValue FI[2];
FI[0] = DAG.getTargetFrameIndex(Index, MVT::i8);
FI[1] = DAG.getTargetFrameIndex(Index + 1, MVT::i8);
return DAG.getNode(ISD::BUILD_PAIR, N->getValueType(0), FI[0], FI[1]);
}
SDValue PIC16TargetLowering::ExpandStore(SDNode *N, SelectionDAG &DAG) {
StoreSDNode *St = cast<StoreSDNode>(N);
SDValue Chain = St->getChain();
SDValue Src = St->getValue();
SDValue Ptr = St->getBasePtr();
MVT ValueType = Src.getValueType();
unsigned StoreOffset = 0;
SDValue PtrLo, PtrHi;
LegalizeAddress(Ptr, DAG, PtrLo, PtrHi, StoreOffset);
if (ValueType == MVT::i8) {
return DAG.getNode (PIC16ISD::PIC16Store, MVT::Other, Chain, Src,
PtrLo, PtrHi,
DAG.getConstant (0 + StoreOffset, MVT::i8));
}
else if (ValueType == MVT::i16) {
// Get the Lo and Hi parts from MERGE_VALUE or BUILD_PAIR.
SDValue SrcLo, SrcHi;
GetExpandedParts(Src, DAG, SrcLo, SrcHi);
SDValue ChainLo = Chain, ChainHi = Chain;
if (Chain.getOpcode() == ISD::TokenFactor) {
ChainLo = Chain.getOperand(0);
ChainHi = Chain.getOperand(1);
}
SDValue Store1 = DAG.getNode(PIC16ISD::PIC16Store, MVT::Other,
ChainLo,
SrcLo, PtrLo, PtrHi,
DAG.getConstant (0 + StoreOffset, MVT::i8));
SDValue Store2 = DAG.getNode(PIC16ISD::PIC16Store, MVT::Other, ChainHi,
SrcHi, PtrLo, PtrHi,
DAG.getConstant (1 + StoreOffset, MVT::i8));
return DAG.getNode(ISD::TokenFactor, MVT::Other, getChain(Store1),
getChain(Store2));
}
else if (ValueType == MVT::i32) {
// Get the Lo and Hi parts from MERGE_VALUE or BUILD_PAIR.
SDValue SrcLo, SrcHi;
GetExpandedParts(Src, DAG, SrcLo, SrcHi);
// Get the expanded parts of each of SrcLo and SrcHi.
SDValue SrcLo1, SrcLo2, SrcHi1, SrcHi2;
GetExpandedParts(SrcLo, DAG, SrcLo1, SrcLo2);
GetExpandedParts(SrcHi, DAG, SrcHi1, SrcHi2);
SDValue ChainLo = Chain, ChainHi = Chain;
if (Chain.getOpcode() == ISD::TokenFactor) {
ChainLo = Chain.getOperand(0);
ChainHi = Chain.getOperand(1);
}
SDValue ChainLo1 = ChainLo, ChainLo2 = ChainLo, ChainHi1 = ChainHi,
ChainHi2 = ChainHi;
if (ChainLo.getOpcode() == ISD::TokenFactor) {
ChainLo1 = ChainLo.getOperand(0);
ChainLo2 = ChainLo.getOperand(1);
}
if (ChainHi.getOpcode() == ISD::TokenFactor) {
ChainHi1 = ChainHi.getOperand(0);
ChainHi2 = ChainHi.getOperand(1);
}
SDValue Store1 = DAG.getNode(PIC16ISD::PIC16Store, MVT::Other,
ChainLo1,
SrcLo1, PtrLo, PtrHi,
DAG.getConstant (0 + StoreOffset, MVT::i8));
SDValue Store2 = DAG.getNode(PIC16ISD::PIC16Store, MVT::Other, ChainLo2,
SrcLo2, PtrLo, PtrHi,
DAG.getConstant (1 + StoreOffset, MVT::i8));
SDValue Store3 = DAG.getNode(PIC16ISD::PIC16Store, MVT::Other, ChainHi1,
SrcHi1, PtrLo, PtrHi,
DAG.getConstant (2 + StoreOffset, MVT::i8));
SDValue Store4 = DAG.getNode(PIC16ISD::PIC16Store, MVT::Other, ChainHi2,
SrcHi2, PtrLo, PtrHi,
DAG.getConstant (3 + StoreOffset, MVT::i8));
SDValue RetLo = DAG.getNode(ISD::TokenFactor, MVT::Other, getChain(Store1),
getChain(Store2));
SDValue RetHi = DAG.getNode(ISD::TokenFactor, MVT::Other, getChain(Store3),
getChain(Store4));
return DAG.getNode(ISD::TokenFactor, MVT::Other, RetLo, RetHi);
}
else {
assert (0 && "value type not supported");
return SDValue();
}
}
SDValue PIC16TargetLowering::ExpandExternalSymbol(SDNode *N, SelectionDAG &DAG)
{
ExternalSymbolSDNode *ES = dyn_cast<ExternalSymbolSDNode>(SDValue(N, 0));
SDValue TES = DAG.getTargetExternalSymbol(ES->getSymbol(), MVT::i8);
SDValue Lo = DAG.getNode(PIC16ISD::Lo, MVT::i8, TES);
SDValue Hi = DAG.getNode(PIC16ISD::Hi, MVT::i8, TES);
return DAG.getNode(ISD::BUILD_PAIR, MVT::i16, Lo, Hi);
}
// ExpandGlobalAddress -
SDValue PIC16TargetLowering::ExpandGlobalAddress(SDNode *N, SelectionDAG &DAG) {
GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(SDValue(N, 0));
SDValue TGA = DAG.getTargetGlobalAddress(G->getGlobal(), MVT::i8,
G->getOffset());
SDValue Lo = DAG.getNode(PIC16ISD::Lo, MVT::i8, TGA);
SDValue Hi = DAG.getNode(PIC16ISD::Hi, MVT::i8, TGA);
return DAG.getNode(ISD::BUILD_PAIR, MVT::i16, Lo, Hi);
}
bool PIC16TargetLowering::isDirectAddress(const SDValue &Op) {
assert (Op.getNode() != NULL && "Can't operate on NULL SDNode!!");
if (Op.getOpcode() == ISD::BUILD_PAIR) {
if (Op.getOperand(0).getOpcode() == PIC16ISD::Lo)
return true;
}
return false;
}
// Return true if DirectAddress is in ROM_SPACE
bool PIC16TargetLowering::isRomAddress(const SDValue &Op) {
// RomAddress is a GlobalAddress in ROM_SPACE_
// If the Op is not a GlobalAddress return NULL without checking
// anything further.
if (!isDirectAddress(Op))
return false;
// Its a GlobalAddress.
// It is BUILD_PAIR((PIC16Lo TGA), (PIC16Hi TGA)) and Op is BUILD_PAIR
SDValue TGA = Op.getOperand(0).getOperand(0);
GlobalAddressSDNode *GSDN = dyn_cast<GlobalAddressSDNode>(TGA);
const Type *ValueType = GSDN->getGlobal()->getType();
if (!isa<PointerType>(ValueType)) {
assert(0 && "TGA must be of a PointerType");
}
int AddrSpace = dyn_cast<PointerType>(ValueType)->getAddressSpace();
if (AddrSpace == PIC16ISD::ROM_SPACE)
return true;
// Any other address space return it false
return false;
}
// Extract the out flag
SDValue PIC16TargetLowering::getOutFlag(SDValue &Op) {
SDValue Flag = Op.getValue(Op.getNode()->getNumValues() - 1);
assert (Flag.getValueType() == MVT::Flag && "Node does not have an out Flag");
return Flag;
}
// To extract chain value from the SDValue Nodes
// This function will help to maintain the chain extracting
// code at one place. In case of any change in future it will
// help maintain the code.
SDValue PIC16TargetLowering::getChain(SDValue &Op) {
SDValue Chain = Op.getValue(Op.getNode()->getNumValues() - 1);
// If the last value returned in Flag then the chain is
// second last value returned.
if (Chain.getValueType() == MVT::Flag)
Chain = Op.getValue(Op.getNode()->getNumValues() - 2);
// All nodes may not produce a chain. Therefore following assert
// verifies that the node is returning a chain only.
assert (Chain.getValueType() == MVT::Other && "Node does not have a chain");
return Chain;
}
void PIC16TargetLowering::GetExpandedParts(SDValue Op, SelectionDAG &DAG,
SDValue &Lo, SDValue &Hi) {
SDNode *N = Op.getNode();
MVT NewVT;
std::vector<SDValue> Opers;
NewVT = getTypeToTransformTo(N->getValueType(0));
// extract the lo component
Opers.push_back(Op);
Opers.push_back(DAG.getConstant(0,MVT::i8));
Lo = DAG.getNode(ISD::EXTRACT_ELEMENT,NewVT,&Opers[0],Opers.size());
// extract the hi component
Opers.clear();
Opers.push_back(Op);
Opers.push_back(DAG.getConstant(1,MVT::i8));
Hi = DAG.getNode(ISD::EXTRACT_ELEMENT,NewVT,&Opers[0],Opers.size());
}
// Legalize FrameIndex into ExternalSymbol and offset.
void
PIC16TargetLowering::LegalizeFrameIndex(SDValue Op, SelectionDAG &DAG,
SDValue &ES, int &Offset) {
MachineFunction &MF = DAG.getMachineFunction();
const Function *Func = MF.getFunction();
const std::string Name = Func->getName();
char *tmpName = new char [strlen(Name.c_str()) + 8];
sprintf(tmpName, "%s.args", Name.c_str());
ES = DAG.getTargetExternalSymbol(tmpName, MVT::i8);
FrameIndexSDNode *FR = dyn_cast<FrameIndexSDNode>(Op);
Offset = FR->getIndex();
return;
}
// This function legalizes the PIC16 Addresses. If the Pointer is
// -- Direct address variable residing
// --> then a Banksel for that variable will be created.
// -- Rom variable
// --> then it will be treated as an indirect address.
// -- Indirect address
// --> then the address will be loaded into FSR
// -- ADD with constant operand
// --> then constant operand of ADD will be returned as Offset
// and non-constant operand of ADD will be treated as pointer.
// Returns the high and lo part of the address, and the offset(in case of ADD).
void PIC16TargetLowering:: LegalizeAddress(SDValue Ptr, SelectionDAG &DAG,
SDValue &Lo, SDValue &Hi,
unsigned &Offset) {
// Offset, by default, should be 0
Offset = 0;
// If the pointer is ADD with constant,
// return the constant value as the offset
if (Ptr.getOpcode() == ISD::ADD) {
SDValue OperLeft = Ptr.getOperand(0);
SDValue OperRight = Ptr.getOperand(1);
if (OperLeft.getOpcode() == ISD::Constant) {
Offset = dyn_cast<ConstantSDNode>(OperLeft)->getZExtValue();
Ptr = OperRight;
} else if (OperRight.getOpcode() == ISD::Constant) {
Offset = dyn_cast<ConstantSDNode>(OperRight)->getZExtValue();
Ptr = OperLeft;
}
}
// If the pointer is Type i8 and an external symbol
// then treat it as direct address.
// One example for such case is storing and loading
// from function frame during a call
if (Ptr.getValueType() == MVT::i8) {
switch (Ptr.getOpcode()) {
case ISD::TargetExternalSymbol:
Lo = Ptr;
Hi = DAG.getConstant(1, MVT::i8);
return;
}
}
if (Ptr.getOpcode() == ISD::BUILD_PAIR &&
Ptr.getOperand(0).getOpcode() == ISD::TargetFrameIndex) {
int FrameOffset;
LegalizeFrameIndex(Ptr.getOperand(0), DAG, Lo, FrameOffset);
Hi = DAG.getConstant(1, MVT::i8);
Offset += FrameOffset;
return;
}
if (isDirectAddress(Ptr) && !isRomAddress(Ptr)) {
// Direct addressing case for RAM variables. The Hi part is constant
// and the Lo part is the TGA itself.
Lo = Ptr.getOperand(0).getOperand(0);
// For direct addresses Hi is a constant. Value 1 for the constant
// signifies that banksel needs to generated for it. Value 0 for
// the constant signifies that banksel does not need to be generated
// for it. Mark it as 1 now and optimize later.
Hi = DAG.getConstant(1, MVT::i8);
return;
}
// Indirect addresses. Get the hi and lo parts of ptr.
GetExpandedParts(Ptr, DAG, Lo, Hi);
// Put the hi and lo parts into FSR.
Lo = DAG.getNode(PIC16ISD::MTLO, MVT::i8, Lo);
Hi = DAG.getNode(PIC16ISD::MTHI, MVT::i8, Hi);
return;
}
//SDValue PIC16TargetLowering::ExpandAdd(SDNode *N, SelectionDAG &DAG) {
//SDValue OperLeft = N->getOperand(0);
//SDValue OperRight = N->getOperand(1);
//if((OperLeft.getOpcode() == ISD::Constant) ||
//(OperRight.getOpcode() == ISD::Constant)) {
//return SDValue();
//}
// These case are yet to be handled
//return SDValue();
//}
SDValue PIC16TargetLowering::ExpandLoad(SDNode *N, SelectionDAG &DAG) {
LoadSDNode *LD = dyn_cast<LoadSDNode>(SDValue(N, 0));
SDValue Chain = LD->getChain();
SDValue Ptr = LD->getBasePtr();
SDValue Load, Offset;
SDVTList Tys;
MVT VT, NewVT;
SDValue PtrLo, PtrHi;
unsigned LoadOffset;
// Legalize direct/indirect addresses. This will give the lo and hi parts
// of the address and the offset.
LegalizeAddress(Ptr, DAG, PtrLo, PtrHi, LoadOffset);
// Load from the pointer (direct address or FSR)
VT = N->getValueType(0);
unsigned NumLoads = VT.getSizeInBits() / 8;
std::vector<SDValue> PICLoads;
unsigned iter;
MVT MemVT = LD->getMemoryVT();
if(ISD::isNON_EXTLoad(N)) {
for (iter=0; iter<NumLoads ; ++iter) {
// Add the pointer offset if any
Offset = DAG.getConstant(iter + LoadOffset, MVT::i8);
Tys = DAG.getVTList(MVT::i8, MVT::Other);
Load = DAG.getNode(PIC16ISD::PIC16Load, Tys, Chain, PtrLo, PtrHi,
Offset);
PICLoads.push_back(Load);
}
} else {
// If it is extended load then use PIC16Load for Memory Bytes
// and for all extended bytes perform action based on type of
// extention - i.e. SignExtendedLoad or ZeroExtendedLoad
// For extended loads this is the memory value type
// i.e. without any extension
MVT MemVT = LD->getMemoryVT();
unsigned MemBytes = MemVT.getSizeInBits() / 8;
unsigned ExtdBytes = VT.getSizeInBits() / 8;
Offset = DAG.getConstant(LoadOffset, MVT::i8);
Tys = DAG.getVTList(MVT::i8, MVT::Other);
// For MemBytes generate PIC16Load with proper offset
for (iter=0; iter<MemBytes; ++iter) {
// Add the pointer offset if any
Offset = DAG.getConstant(iter + LoadOffset, MVT::i8);
Load = DAG.getNode(PIC16ISD::PIC16Load, Tys, Chain, PtrLo, PtrHi,
Offset);
PICLoads.push_back(Load);
}
// For SignExtendedLoad
if (ISD::isSEXTLoad(N)) {
// For all ExtdBytes use the Right Shifted(Arithmetic) Value of the
// highest MemByte
SDValue SRA = DAG.getNode(ISD::SRA, MVT::i8, Load,
DAG.getConstant(7, MVT::i8));
for (iter=MemBytes; iter<ExtdBytes; ++iter) {
PICLoads.push_back(SRA);
}
} else if (ISD::isZEXTLoad(N)) {
// ZeroExtendedLoad -- For all ExtdBytes use constant 0
SDValue ConstZero = DAG.getConstant(0, MVT::i8);
for (iter=MemBytes; iter<ExtdBytes; ++iter) {
PICLoads.push_back(ConstZero);
}
}
}
SDValue BP;
if (VT == MVT::i8) {
// Operand of Load is illegal -- Load itself is legal
return PICLoads[0];
}
else if (VT == MVT::i16) {
BP = DAG.getNode(ISD::BUILD_PAIR, VT, PICLoads[0], PICLoads[1]);
if (MemVT == MVT::i8)
Chain = getChain(PICLoads[0]);
else
Chain = DAG.getNode(ISD::TokenFactor, MVT::Other, getChain(PICLoads[0]),
getChain(PICLoads[1]));
} else if (VT == MVT::i32) {
SDValue BPs[2];
BPs[0] = DAG.getNode(ISD::BUILD_PAIR, MVT::i16, PICLoads[0], PICLoads[1]);
BPs[1] = DAG.getNode(ISD::BUILD_PAIR, MVT::i16, PICLoads[2], PICLoads[3]);
BP = DAG.getNode(ISD::BUILD_PAIR, VT, BPs[0], BPs[1]);
if (MemVT == MVT::i8)
Chain = getChain(PICLoads[0]);
else if (MemVT == MVT::i16)
Chain = DAG.getNode(ISD::TokenFactor, MVT::Other, getChain(PICLoads[0]),
getChain(PICLoads[1]));
else {
SDValue Chains[2];
Chains[0] = DAG.getNode(ISD::TokenFactor, MVT::Other,
getChain(PICLoads[0]), getChain(PICLoads[1]));
Chains[1] = DAG.getNode(ISD::TokenFactor, MVT::Other,
getChain(PICLoads[2]), getChain(PICLoads[3]));
Chain = DAG.getNode(ISD::TokenFactor, MVT::Other, Chains[0], Chains[1]);
}
}
Tys = DAG.getVTList(VT, MVT::Other);
return DAG.getNode(ISD::MERGE_VALUES, Tys, BP, Chain);
}
SDValue PIC16TargetLowering::ExpandShift(SDNode *N, SelectionDAG &DAG) {
SDValue Value = N->getOperand(0);
SDValue Amt = N->getOperand(1);
SDValue BCF, BCFInput;
SDValue ShfCom; // Shift Component - Lo component should be shifted
SDValue RotCom; // Rotate Component- Hi component should be rotated
PIC16ISD::PIC16LibCall CallCode;
// Shift amount should be MVT::i8 only. If it is more than that then
// extract MVT::i8 from that
if (Amt.getValueType() == MVT::i8) {
// Do Nothing - This is ok
} else if (Amt.getValueType() == MVT::i16) {
SDValue Lo, Hi;
GetExpandedParts(Amt, DAG, Lo, Hi);
Amt = Lo; // Take the Lo part as amount
} else if (Amt.getValueType() == MVT::i32) {
SDValue Lo, Hi;
// Get MVT::i16 Components
GetExpandedParts(Amt, DAG, Lo, Hi);
// Get MVT::i8 Components
GetExpandedParts(Lo, DAG, Lo, Hi);
Amt = Lo;
} else {
assert ( 0 && "Invalid Shift amount");
}
// Shift library call will always have two operands
if (N->getValueType(0) == MVT::i8) {
switch (N->getOpcode()) {
case ISD::SRA:
CallCode = PIC16ISD::SRA_I8;
break;
case ISD::SHL:
CallCode = PIC16ISD::SLL_I8;
break;
case ISD::SRL:
CallCode = PIC16ISD::SRL_I8;
break;
default:
assert ( 0 && "This shift is not implemented yet.");
return SDValue();
}
} else if (N->getValueType(0) == MVT::i16) {
switch (N->getOpcode()) {
case ISD::SRA:
CallCode = PIC16ISD::SRA_I16;
break;
case ISD::SHL:
CallCode = PIC16ISD::SLL_I16;
break;
case ISD::SRL:
CallCode = PIC16ISD::SRL_I16;
break;
default:
assert ( 0 && "This shift is not implemented yet.");
return SDValue();
}
} else if (N->getValueType(0) == MVT::i32) {
switch (N->getOpcode()) {
case ISD::SRA:
CallCode = PIC16ISD::SRA_I32;
break;
case ISD::SHL:
CallCode = PIC16ISD::SLL_I32;
break;
case ISD::SRL:
CallCode = PIC16ISD::SRL_I32;
break;
default:
assert ( 0 && "This shift is not implemented yet.");
return SDValue();
}
} else {
//assert ( 0 && "Shift for this value type not yet implemented.");
return SDValue();
}
SmallVector<SDValue, 2> Ops(2);
Ops[0] = Value;
Ops[1] = Amt;
SDValue Call = MakePIC16LibCall(CallCode, N->getValueType(0), &Ops[0], 2, true, DAG);
return Call;
}
SDValue PIC16TargetLowering::LowerOperation(SDValue Op, SelectionDAG &DAG) {
switch (Op.getOpcode()) {
case ISD::FORMAL_ARGUMENTS:
return LowerFORMAL_ARGUMENTS(Op, DAG);
case ISD::ADD:
case ISD::ADDC:
case ISD::ADDE:
return LowerADD(Op, DAG);
case ISD::SUB:
case ISD::SUBC:
case ISD::SUBE:
return LowerSUB(Op, DAG);
case ISD::LOAD:
return ExpandLoad(Op.getNode(), DAG);
case ISD::STORE:
return ExpandStore(Op.getNode(), DAG);
case ISD::SHL:
case ISD::SRA:
case ISD::SRL:
return ExpandShift(Op.getNode(), DAG);
case ISD::OR:
case ISD::AND:
case ISD::XOR:
return LowerBinOp(Op, DAG);
case ISD::CALL:
// This is called only from LegalizeDAG. No call is made to
// legalize CALL node from LegalizeType.
return LowerCALL(Op, DAG);
case ISD::RET:
return LowerRET(Op, DAG);
case ISD::BR_CC:
return LowerBR_CC(Op, DAG);
case ISD::SELECT_CC:
return LowerSELECT_CC(Op, DAG);
}
return SDValue();
}
SDValue PIC16TargetLowering::ConvertToMemOperand(SDValue Op,
SelectionDAG &DAG) {
assert (Op.getValueType() == MVT::i8
&& "illegal value type to store on stack.");
MachineFunction &MF = DAG.getMachineFunction();
const Function *Func = MF.getFunction();
const std::string FuncName = Func->getName();
char *tmpName = new char [strlen(FuncName.c_str()) + 6];
// Put the value on stack.
// Get a stack slot index and convert to es.
int FI = MF.getFrameInfo()->CreateStackObject(1, 1);
sprintf(tmpName, "%s.tmp", FuncName.c_str());
SDValue ES = DAG.getTargetExternalSymbol(tmpName, MVT::i8);
// Store the value to ES.
SDValue Store = DAG.getNode (PIC16ISD::PIC16Store, MVT::Other,
DAG.getEntryNode(),
Op, ES,
DAG.getConstant (1, MVT::i8), // Banksel.
DAG.getConstant (FI, MVT::i8));
// Load the value from ES.
SDVTList Tys = DAG.getVTList(MVT::i8, MVT::Other);
SDValue Load = DAG.getNode(PIC16ISD::PIC16Load, Tys, Store,
ES, DAG.getConstant (1, MVT::i8),
DAG.getConstant (FI, MVT::i8));
return Load.getValue(0);
}
SDValue
PIC16TargetLowering::LowerCallArguments(SDValue Op, SDValue Chain,
SDValue FrameAddress,
SDValue InFlag,
SelectionDAG &DAG) {
CallSDNode *TheCall = dyn_cast<CallSDNode>(Op);
unsigned NumOps = TheCall->getNumArgs();
std::string Name;
SDValue Arg, StoreAt;
MVT ArgVT;
unsigned Size=0;
unsigned ArgCount=0;
// FIXME: This portion of code currently assumes only
// primitive types being passed as arguments.
// Legalize the address before use
SDValue PtrLo, PtrHi;
unsigned AddressOffset;
int StoreOffset = 0;
LegalizeAddress(FrameAddress, DAG, PtrLo, PtrHi, AddressOffset);
SDValue StoreRet;
std::vector<SDValue> Ops;
SDVTList Tys = DAG.getVTList(MVT::Other, MVT::Flag);
for (unsigned i=ArgCount, Offset = 0; i<NumOps; i++) {
// Get the argument
Arg = TheCall->getArg(i);
StoreOffset = (Offset + AddressOffset);
// Store the argument on frame
Ops.clear();
Ops.push_back(Chain);
Ops.push_back(Arg.getValue(0));
Ops.push_back(PtrLo);
Ops.push_back(PtrHi);
Ops.push_back(DAG.getConstant(StoreOffset, MVT::i8));
Ops.push_back(InFlag);
StoreRet = DAG.getNode (PIC16ISD::PIC16StWF, Tys, &Ops[0], Ops.size());
Chain = getChain(StoreRet);
InFlag = getOutFlag(StoreRet);
// Update the frame offset to be used for next argument
ArgVT = Arg.getValueType();
Size = ArgVT.getSizeInBits();
Size = Size/8; // Calculate size in bytes
Offset += Size; // Increase the frame offset
}
return Chain;
}
SDValue
PIC16TargetLowering::LowerCallReturn(SDValue Op, SDValue Chain,
SDValue FrameAddress,
SDValue InFlag,
SelectionDAG &DAG) {
CallSDNode *TheCall = dyn_cast<CallSDNode>(Op);
// Currently handling primitive types only. They will come in
// i8 parts
unsigned RetVals = TheCall->getNumRetVals();
std::vector<SDValue> ResultVals;
// Return immediately if the return type is void
if (RetVals == 0)
return Chain;
// Call has something to return
// Legalize the address before use
SDValue LdLo, LdHi;
unsigned LdOffset;
LegalizeAddress(FrameAddress, DAG, LdLo, LdHi, LdOffset);
SDVTList Tys = DAG.getVTList(MVT::i8, MVT::Other, MVT::Flag);
SDValue LoadRet;
for(unsigned i=0, Offset=0;i<RetVals;i++) {
LoadRet = DAG.getNode(PIC16ISD::PIC16LdWF, Tys, Chain, LdLo, LdHi,
DAG.getConstant(LdOffset + Offset, MVT::i8),
InFlag);
InFlag = getOutFlag(LoadRet);
Chain = getChain(LoadRet);
Offset++;
ResultVals.push_back(LoadRet);
}
// To return use MERGE_VALUES
ResultVals.push_back(Chain);
SDValue Res = DAG.getMergeValues(&ResultVals[0], ResultVals.size());
return Res;
}
SDValue PIC16TargetLowering::LowerRET(SDValue Op, SelectionDAG &DAG) {
//int NumOps = Op.getNode()->getNumOperands();
// For default cases LLVM returns the value on the function frame
// So let LLVM do this for all the cases other than character
return Op;
}
SDValue PIC16TargetLowering::LowerCALL(SDValue Op, SelectionDAG &DAG) {
CallSDNode *TheCall = dyn_cast<CallSDNode>(Op);
SDValue Chain = TheCall->getChain();
SDValue Callee = TheCall->getCallee();
unsigned i =0;
if (Callee.getValueType() == MVT::i16 &&
Callee.getOpcode() == ISD::BUILD_PAIR) {
// It has come from TypeLegalizer for lowering
Callee = Callee.getOperand(0).getOperand(0);
std::vector<SDValue> Ops;
Ops.push_back(Chain);
Ops.push_back(Callee);
// Add the call arguments and their flags
unsigned NumArgs = TheCall->getNumArgs();
for(i=0;i<NumArgs;i++) {
Ops.push_back(TheCall->getArg(i));
Ops.push_back(TheCall->getArgFlagsVal(i));
}
std::vector<MVT> NodeTys;
unsigned NumRets = TheCall->getNumRetVals();
for(i=0;i<NumRets;i++)
NodeTys.push_back(TheCall->getRetValType(i));
// Return a Chain as well
NodeTys.push_back(MVT::Other);
SDVTList VTs = DAG.getVTList(&NodeTys[0], NodeTys.size());
SDValue NewCall =
DAG.getCall(TheCall->getCallingConv(), TheCall->isVarArg(),
TheCall->isTailCall(), TheCall->isInreg(), VTs,
&Ops[0], Ops.size());
return NewCall;
}
SDValue ZeroOperand = DAG.getConstant(0, MVT::i8);
// Start the call sequence.
// Carring the Constant 0 along the CALLSEQSTART
// because there is nothing else to carry.
SDValue SeqStart = DAG.getCALLSEQ_START(Chain, ZeroOperand);
Chain = getChain(SeqStart);
// For any direct call - callee will be GlobalAddressNode or
// ExternalSymbol
// Considering the GlobalAddressNode case here.
if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee)) {
GlobalValue *GV = G->getGlobal();
Callee = DAG.getTargetGlobalAddress(GV, MVT::i8);
}
// Considering the ExternalSymbol case here
if (ExternalSymbolSDNode *ES = dyn_cast<ExternalSymbolSDNode>(Callee)) {
Callee = DAG.getTargetExternalSymbol(ES->getSymbol(), MVT::i8);
}
SDValue OperFlag = getOutFlag(Chain); // To manage the data dependency
std::string Name;
// Considering GlobalAddress here
if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee))
Name = G->getGlobal()->getName();
// Considering ExternalSymbol here
if (ExternalSymbolSDNode *ES = dyn_cast<ExternalSymbolSDNode>(Callee))
Name = ES->getSymbol();
char *argFrame = new char [strlen(Name.c_str()) + 8];
sprintf(argFrame, "%s.args", Name.c_str());
SDValue ArgLabel = DAG.getTargetExternalSymbol(argFrame, MVT::i8);
char *retName = new char [strlen(Name.c_str()) + 8];
sprintf(retName, "%s.retval", Name.c_str());
SDValue RetLabel = DAG.getTargetExternalSymbol(retName, MVT::i8);
// Pass the argument to function before making the call.
SDValue CallArgs = LowerCallArguments(Op, Chain, ArgLabel, OperFlag, DAG);
Chain = getChain(CallArgs);
OperFlag = getOutFlag(CallArgs);
SDVTList Tys = DAG.getVTList(MVT::Other, MVT::Flag);
SDValue PICCall = DAG.getNode(PIC16ISD::CALL, Tys, Chain, Callee,
OperFlag);
Chain = getChain(PICCall);
OperFlag = getOutFlag(PICCall);
// Carrying the Constant 0 along the CALLSEQSTART
// because there is nothing else to carry.
SDValue SeqEnd = DAG.getCALLSEQ_END(Chain, ZeroOperand, ZeroOperand,
OperFlag);
Chain = getChain(SeqEnd);
OperFlag = getOutFlag(SeqEnd);
// Lower the return value reading after the call.
return LowerCallReturn(Op, Chain, RetLabel, OperFlag, DAG);
}
bool PIC16TargetLowering::isDirectLoad(const SDValue Op) {
if (Op.getOpcode() == PIC16ISD::PIC16Load)
if (Op.getOperand(1).getOpcode() == ISD::TargetGlobalAddress
|| Op.getOperand(1).getOpcode() == ISD::TargetExternalSymbol)
return true;
return false;
}
bool PIC16TargetLowering::NeedToConvertToMemOp(SDValue Op, unsigned &MemOp) {
// Return false if one of the operands is already a direct
// load and that operand has only one use.
if (Op.getOperand(0).getOpcode() == ISD::Constant ||
Op.getOperand(1).getOpcode() == ISD::Constant)
return false;
if (isDirectLoad(Op.getOperand(0))) {
if (Op.getOperand(0).hasOneUse())
return false;
else
MemOp = 0;
}
if (isDirectLoad(Op.getOperand(1))) {
if (Op.getOperand(1).hasOneUse())
return false;
else
MemOp = 1;
}
return true;
}
SDValue PIC16TargetLowering:: LowerBinOp(SDValue Op, SelectionDAG &DAG) {
// We should have handled larger operands in type legalizer itself.
assert (Op.getValueType() == MVT::i8 && "illegal Op to lower");
unsigned MemOp = 1;
if (NeedToConvertToMemOp(Op, MemOp)) {
// Put one value on stack.
SDValue NewVal = ConvertToMemOperand (Op.getOperand(MemOp), DAG);
return DAG.getNode(Op.getOpcode(), MVT::i8, Op.getOperand(MemOp ^ 1),
NewVal);
}
else {
return Op;
}
}
SDValue PIC16TargetLowering:: LowerADD(SDValue Op, SelectionDAG &DAG) {
// We should have handled larger operands in type legalizer itself.
assert (Op.getValueType() == MVT::i8 && "illegal add to lower");
unsigned MemOp = 1;
if (NeedToConvertToMemOp(Op, MemOp)) {
// Put one value on stack.
SDValue NewVal = ConvertToMemOperand (Op.getOperand(MemOp), DAG);
SDVTList Tys = DAG.getVTList(MVT::i8, MVT::Flag);
if (Op.getOpcode() == ISD::ADDE)
return DAG.getNode(Op.getOpcode(), Tys, Op.getOperand(MemOp ^ 1), NewVal,
Op.getOperand(2));
else
return DAG.getNode(Op.getOpcode(), Tys, Op.getOperand(MemOp ^ 1), NewVal);
}
else {
return SDValue();
}
}
SDValue PIC16TargetLowering::LowerSUB(SDValue Op, SelectionDAG &DAG) {
// We should have handled larger operands in type legalizer itself.
assert (Op.getValueType() == MVT::i8 && "illegal sub to lower");
// Nothing to do if the first operand is already a direct load and it has
// only one use.
if (isDirectLoad(Op.getOperand(0)) && Op.getOperand(0).hasOneUse())
return SDValue();
// Put first operand on stack.
SDValue NewVal = ConvertToMemOperand (Op.getOperand(0), DAG);
SDVTList Tys = DAG.getVTList(MVT::i8, MVT::Flag);
if (Op.getOpcode() == ISD::SUBE)
return DAG.getNode(Op.getOpcode(), Tys, NewVal, Op.getOperand(1),
Op.getOperand(2));
else
return DAG.getNode(Op.getOpcode(), Tys, NewVal, Op.getOperand(1));
}
// LowerFORMAL_ARGUMENTS - In Lowering FORMAL ARGUMENTS - MERGE_VALUES nodes
// is returned. MERGE_VALUES nodes number of operands and number of values are
// equal. Therefore to construct MERGE_VALUE node, UNDEF nodes equal to the
// number of arguments of function have been created.
SDValue PIC16TargetLowering:: LowerFORMAL_ARGUMENTS(SDValue Op,
SelectionDAG &DAG) {
SmallVector<SDValue, 8> ArgValues;
unsigned NumArgs = Op.getNumOperands() - 3;
// Creating UNDEF nodes to meet the requirement of MERGE_VALUES node.
for(unsigned i = 0 ; i<NumArgs ; i++) {
SDValue TempNode = DAG.getNode(ISD::UNDEF, Op.getNode()->getValueType(i));
ArgValues.push_back(TempNode);
}
ArgValues.push_back(Op.getOperand(0));
return DAG.getNode(ISD::MERGE_VALUES, Op.getNode()->getVTList(),
&ArgValues[0],
ArgValues.size()).getValue(Op.getResNo());
}
// Perform DAGCombine of PIC16Load
SDValue PIC16TargetLowering::
PerformPIC16LoadCombine(SDNode *N, DAGCombinerInfo &DCI) const {
SelectionDAG &DAG = DCI.DAG;
SDValue Chain = N->getOperand(0);
if (N->hasNUsesOfValue(0, 0)) {
DAG.ReplaceAllUsesOfValueWith(SDValue(N,1), Chain);
}
return SDValue();
}
SDValue PIC16TargetLowering::PerformDAGCombine(SDNode *N,
DAGCombinerInfo &DCI) const {
switch (N->getOpcode()) {
case PIC16ISD::PIC16Load:
return PerformPIC16LoadCombine(N, DCI);
}
return SDValue();
}
static PIC16CC::CondCodes IntCCToPIC16CC(ISD::CondCode CC) {
switch (CC) {
default: assert(0 && "Unknown condition code!");
case ISD::SETNE: return PIC16CC::NE;
case ISD::SETEQ: return PIC16CC::EQ;
case ISD::SETGT: return PIC16CC::GT;
case ISD::SETGE: return PIC16CC::GE;
case ISD::SETLT: return PIC16CC::LT;
case ISD::SETLE: return PIC16CC::LE;
case ISD::SETULT: return PIC16CC::LT;
case ISD::SETULE: return PIC16CC::LE;
case ISD::SETUGE: return PIC16CC::GE;
case ISD::SETUGT: return PIC16CC::GT;
}
}
// Look at LHS/RHS/CC and see if they are a lowered setcc instruction. If so
// set LHS/RHS and SPCC to the LHS/RHS of the setcc and SPCC to the condition.
static void LookThroughSetCC(SDValue &LHS, SDValue &RHS,
ISD::CondCode CC, unsigned &SPCC) {
if (isa<ConstantSDNode>(RHS) &&
cast<ConstantSDNode>(RHS)->getZExtValue() == 0 &&
CC == ISD::SETNE &&
(LHS.getOpcode() == PIC16ISD::SELECT_ICC &&
LHS.getOperand(3).getOpcode() == PIC16ISD::SUBCC) &&
isa<ConstantSDNode>(LHS.getOperand(0)) &&
isa<ConstantSDNode>(LHS.getOperand(1)) &&
cast<ConstantSDNode>(LHS.getOperand(0))->getZExtValue() == 1 &&
cast<ConstantSDNode>(LHS.getOperand(1))->getZExtValue() == 0) {
SDValue CMPCC = LHS.getOperand(3);
SPCC = cast<ConstantSDNode>(LHS.getOperand(2))->getZExtValue();
LHS = CMPCC.getOperand(0);
RHS = CMPCC.getOperand(1);
}
}
// Returns appropriate CMP insn and corresponding condition code in PIC16CC
SDValue PIC16TargetLowering::getPIC16Cmp(SDValue LHS, SDValue RHS,
unsigned CC, SDValue &PIC16CC,
SelectionDAG &DAG) {
PIC16CC::CondCodes CondCode = (PIC16CC::CondCodes) CC;
// PIC16 sub is literal - W. So Swap the operands and condition if needed.
// i.e. a < 12 can be rewritten as 12 > a.
if (RHS.getOpcode() == ISD::Constant) {
SDValue Tmp = LHS;
LHS = RHS;
RHS = Tmp;
switch (CondCode) {
default: break;
case PIC16CC::LT:
CondCode = PIC16CC::GT;
break;
case PIC16CC::GT:
CondCode = PIC16CC::LT;
break;
case PIC16CC::GE:
CondCode = PIC16CC::LE;
break;
case PIC16CC::LE:
CondCode = PIC16CC::GE;
break;
}
}
PIC16CC = DAG.getConstant(CondCode, MVT::i8);
SDVTList VTs = DAG.getVTList (MVT::i8, MVT::Flag);
// We can use a subtract operation to set the condition codes. But
// we need to put one operand in memory if required.
// Nothing to do if the first operand is already a direct load and it has
// only one use.
if (! (isDirectLoad(LHS) && LHS.hasOneUse()))
// Put first operand on stack.
LHS = ConvertToMemOperand (LHS, DAG);
SDVTList Tys = DAG.getVTList(MVT::i8, MVT::Flag);
return DAG.getNode(PIC16ISD::SUBCC, VTs, LHS, RHS);
}
SDValue PIC16TargetLowering::LowerSELECT_CC(SDValue Op, SelectionDAG &DAG) {
SDValue LHS = Op.getOperand(0);
SDValue RHS = Op.getOperand(1);
ISD::CondCode CC = cast<CondCodeSDNode>(Op.getOperand(4))->get();
SDValue TrueVal = Op.getOperand(2);
SDValue FalseVal = Op.getOperand(3);
unsigned ORIGCC = ~0;
// If this is a select_cc of a "setcc", and if the setcc got lowered into
// an CMP[IF]CC/SELECT_[IF]CC pair, find the original compared values.
// i.e.
// A setcc: lhs, rhs, cc is expanded by llvm to
// select_cc: result of setcc, 0, 1, 0, setne
// We can think of it as:
// select_cc: lhs, rhs, 1, 0, cc
LookThroughSetCC(LHS, RHS, CC, ORIGCC);
if (ORIGCC == ~0U) ORIGCC = IntCCToPIC16CC (CC);
SDValue PIC16CC;
SDValue Cmp = getPIC16Cmp(LHS, RHS, ORIGCC, PIC16CC, DAG);
return DAG.getNode (PIC16ISD::SELECT_ICC, TrueVal.getValueType(), TrueVal,
FalseVal, PIC16CC, Cmp.getValue(1));
}
MachineBasicBlock *
PIC16TargetLowering::EmitInstrWithCustomInserter(MachineInstr *MI,
MachineBasicBlock *BB) {
const TargetInstrInfo &TII = *getTargetMachine().getInstrInfo();
unsigned CC = (PIC16CC::CondCodes)MI->getOperand(3).getImm();
// To "insert" a SELECT_CC instruction, we actually have to insert the diamond
// control-flow pattern. The incoming instruction knows the destination vreg
// to set, the condition code register to branch on, the true/false values to
// select between, and a branch opcode to use.
const BasicBlock *LLVM_BB = BB->getBasicBlock();
MachineFunction::iterator It = BB;
++It;
// thisMBB:
// ...
// TrueVal = ...
// [f]bCC copy1MBB
// fallthrough --> copy0MBB
MachineBasicBlock *thisMBB = BB;
MachineFunction *F = BB->getParent();
MachineBasicBlock *copy0MBB = F->CreateMachineBasicBlock(LLVM_BB);
MachineBasicBlock *sinkMBB = F->CreateMachineBasicBlock(LLVM_BB);
BuildMI(BB, TII.get(PIC16::pic16brcond)).addMBB(sinkMBB).addImm(CC);
F->insert(It, copy0MBB);
F->insert(It, sinkMBB);
// Update machine-CFG edges by transferring all successors of the current
// block to the new block which will contain the Phi node for the select.
sinkMBB->transferSuccessors(BB);
// Next, add the true and fallthrough blocks as its successors.
BB->addSuccessor(copy0MBB);
BB->addSuccessor(sinkMBB);
// copy0MBB:
// %FalseValue = ...
// # fallthrough to sinkMBB
BB = copy0MBB;
// Update machine-CFG edges
BB->addSuccessor(sinkMBB);
// sinkMBB:
// %Result = phi [ %FalseValue, copy0MBB ], [ %TrueValue, thisMBB ]
// ...
BB = sinkMBB;
BuildMI(BB, TII.get(PIC16::PHI), MI->getOperand(0).getReg())
.addReg(MI->getOperand(2).getReg()).addMBB(copy0MBB)
.addReg(MI->getOperand(1).getReg()).addMBB(thisMBB);
F->DeleteMachineInstr(MI); // The pseudo instruction is gone now.
return BB;
}
SDValue PIC16TargetLowering::LowerBR_CC(SDValue Op, SelectionDAG &DAG) {
SDValue Chain = Op.getOperand(0);
ISD::CondCode CC = cast<CondCodeSDNode>(Op.getOperand(1))->get();
SDValue LHS = Op.getOperand(2); // LHS of the condition.
SDValue RHS = Op.getOperand(3); // RHS of the condition.
SDValue Dest = Op.getOperand(4); // BB to jump to
unsigned ORIGCC = ~0;
// If this is a br_cc of a "setcc", and if the setcc got lowered into
// an CMP[IF]CC/SELECT_[IF]CC pair, find the original compared values.
LookThroughSetCC(LHS, RHS, CC, ORIGCC);
if (ORIGCC == ~0U) ORIGCC = IntCCToPIC16CC (CC);
// Get the Compare insn and condition code.
SDValue PIC16CC;
SDValue Cmp = getPIC16Cmp(LHS, RHS, ORIGCC, PIC16CC, DAG);
return DAG.getNode(PIC16ISD::BRCOND, MVT::Other, Chain, Dest, PIC16CC,
Cmp.getValue(1));
}