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llvm-6502/lib/Target/PIC16/PIC16ISelLowering.cpp
Sanjiv Gupta 6396329d52 Generate libcalls for floating point arithmetic and casting operations. 
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73194 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-11 16:50:48 +00:00

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//
// 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"
using namespace llvm;
static const char *getIntrinsicName(unsigned opcode) {
std::string Basename;
switch(opcode) {
default: assert (0 && "do not know intrinsic name");
case PIC16ISD::SRA_I8: Basename = "sra.i8"; break;
case RTLIB::SRA_I16: Basename = "sra.i16"; break;
case RTLIB::SRA_I32: Basename = "sra.i32"; break;
case PIC16ISD::SLL_I8: Basename = "sll.i8"; break;
case RTLIB::SHL_I16: Basename = "sll.i16"; break;
case RTLIB::SHL_I32: Basename = "sll.i32"; break;
case PIC16ISD::SRL_I8: Basename = "srl.i8"; break;
case RTLIB::SRL_I16: Basename = "srl.i16"; break;
case RTLIB::SRL_I32: Basename = "srl.i32"; break;
case PIC16ISD::MUL_I8: Basename = "mul.i8"; break;
case RTLIB::MUL_I16: Basename = "mul.i16"; break;
case RTLIB::MUL_I32: Basename = "mul.i32"; break;
case RTLIB::SDIV_I16: Basename = "sdiv.i16"; break;
case RTLIB::SDIV_I32: Basename = "sdiv.i32"; break;
case RTLIB::UDIV_I16: Basename = "udiv.i16"; break;
case RTLIB::UDIV_I32: Basename = "udiv.i32"; break;
case RTLIB::SREM_I16: Basename = "srem.i16"; break;
case RTLIB::SREM_I32: Basename = "srem.i32"; break;
case RTLIB::UREM_I16: Basename = "urem.i16"; break;
case RTLIB::UREM_I32: Basename = "urem.i32"; break;
case RTLIB::FPTOSINT_F32_I32:
Basename = "f32_to_si32"; break;
case RTLIB::SINTTOFP_I32_F32:
Basename = "si32_to_f32"; break;
case RTLIB::ADD_F32: Basename = "add.f32"; break;
case RTLIB::SUB_F32: Basename = "sub.f32"; break;
case RTLIB::MUL_F32: Basename = "mul.f32"; break;
case RTLIB::DIV_F32: Basename = "div.f32"; break;
}
std::string prefix = PAN::getTagName(PAN::PREFIX_SYMBOL);
std::string tagname = PAN::getTagName(PAN::LIBCALL);
std::string Fullname = prefix + tagname + Basename;
// The name has to live through program life.
char *tmp = new char[Fullname.size() + 1];
strcpy (tmp, Fullname.c_str());
return tmp;
}
// PIC16TargetLowering Constructor.
PIC16TargetLowering::PIC16TargetLowering(PIC16TargetMachine &TM)
: TargetLowering(TM), TmpSize(0) {
Subtarget = &TM.getSubtarget<PIC16Subtarget>();
addRegisterClass(MVT::i8, PIC16::GPRRegisterClass);
setShiftAmountType(MVT::i8);
setShiftAmountFlavor(Extend);
// SRA library call names
setPIC16LibcallName(PIC16ISD::SRA_I8, getIntrinsicName(PIC16ISD::SRA_I8));
setLibcallName(RTLIB::SRA_I16, getIntrinsicName(RTLIB::SRA_I16));
setLibcallName(RTLIB::SRA_I32, getIntrinsicName(RTLIB::SRA_I32));
// SHL library call names
setPIC16LibcallName(PIC16ISD::SLL_I8, getIntrinsicName(PIC16ISD::SLL_I8));
setLibcallName(RTLIB::SHL_I16, getIntrinsicName(RTLIB::SHL_I16));
setLibcallName(RTLIB::SHL_I32, getIntrinsicName(RTLIB::SHL_I32));
// SRL library call names
setPIC16LibcallName(PIC16ISD::SRL_I8, getIntrinsicName(PIC16ISD::SRL_I8));
setLibcallName(RTLIB::SRL_I16, getIntrinsicName(RTLIB::SRL_I16));
setLibcallName(RTLIB::SRL_I32, getIntrinsicName(RTLIB::SRL_I32));
// MUL Library call names
setPIC16LibcallName(PIC16ISD::MUL_I8, getIntrinsicName(PIC16ISD::MUL_I8));
setLibcallName(RTLIB::MUL_I16, getIntrinsicName(RTLIB::MUL_I16));
setLibcallName(RTLIB::MUL_I32, getIntrinsicName(RTLIB::MUL_I32));
// Signed division lib call names
setLibcallName(RTLIB::SDIV_I16, getIntrinsicName(RTLIB::SDIV_I16));
setLibcallName(RTLIB::SDIV_I32, getIntrinsicName(RTLIB::SDIV_I32));
// Unsigned division lib call names
setLibcallName(RTLIB::UDIV_I16, getIntrinsicName(RTLIB::UDIV_I16));
setLibcallName(RTLIB::UDIV_I32, getIntrinsicName(RTLIB::UDIV_I32));
// Signed remainder lib call names
setLibcallName(RTLIB::SREM_I16, getIntrinsicName(RTLIB::SREM_I16));
setLibcallName(RTLIB::SREM_I32, getIntrinsicName(RTLIB::SREM_I32));
// Unsigned remainder lib call names
setLibcallName(RTLIB::UREM_I16, getIntrinsicName(RTLIB::UREM_I16));
setLibcallName(RTLIB::UREM_I32, getIntrinsicName(RTLIB::UREM_I32));
// Floating point operations
setLibcallName(RTLIB::FPTOSINT_F32_I32,
getIntrinsicName(RTLIB::FPTOSINT_F32_I32));
setLibcallName(RTLIB::SINTTOFP_I32_F32,
getIntrinsicName(RTLIB::SINTTOFP_I32_F32));
setLibcallName(RTLIB::ADD_F32, getIntrinsicName(RTLIB::ADD_F32));
setLibcallName(RTLIB::SUB_F32, getIntrinsicName(RTLIB::SUB_F32));
setLibcallName(RTLIB::MUL_F32, getIntrinsicName(RTLIB::MUL_F32));
setLibcallName(RTLIB::DIV_F32, getIntrinsicName(RTLIB::DIV_F32));
setOperationAction(ISD::GlobalAddress, MVT::i16, Custom);
setOperationAction(ISD::ExternalSymbol, 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::SUB, MVT::i8, Custom);
setOperationAction(ISD::ADD, MVT::i8, Custom);
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::MUL, MVT::i8, Custom);
setOperationAction(ISD::MUL, MVT::i16, Expand);
setOperationAction(ISD::MUL, MVT::i32, Expand);
setOperationAction(ISD::SMUL_LOHI, MVT::i8, Expand);
setOperationAction(ISD::SMUL_LOHI, MVT::i16, Expand);
setOperationAction(ISD::SMUL_LOHI, MVT::i32, Expand);
setOperationAction(ISD::UMUL_LOHI, MVT::i8, Expand);
setOperationAction(ISD::UMUL_LOHI, MVT::i16, Expand);
setOperationAction(ISD::UMUL_LOHI, MVT::i32, Expand);
setOperationAction(ISD::MULHU, MVT::i8, Expand);
setOperationAction(ISD::MULHU, MVT::i16, Expand);
setOperationAction(ISD::MULHU, MVT::i32, Expand);
setOperationAction(ISD::MULHS, MVT::i8, Expand);
setOperationAction(ISD::MULHS, MVT::i16, Expand);
setOperationAction(ISD::MULHS, MVT::i32, Expand);
setOperationAction(ISD::SRA, MVT::i8, Custom);
setOperationAction(ISD::SRA, MVT::i16, Expand);
setOperationAction(ISD::SRA, MVT::i32, Expand);
setOperationAction(ISD::SHL, MVT::i8, Custom);
setOperationAction(ISD::SHL, MVT::i16, Expand);
setOperationAction(ISD::SHL, MVT::i32, Expand);
setOperationAction(ISD::SRL, MVT::i8, Custom);
setOperationAction(ISD::SRL, MVT::i16, Expand);
setOperationAction(ISD::SRL, MVT::i32, Expand);
// PIC16 does not support shift parts
setOperationAction(ISD::SRA_PARTS, MVT::i8, Expand);
setOperationAction(ISD::SRA_PARTS, MVT::i16, Expand);
setOperationAction(ISD::SRA_PARTS, MVT::i32, Expand);
setOperationAction(ISD::SHL_PARTS, MVT::i8, Expand);
setOperationAction(ISD::SHL_PARTS, MVT::i16, Expand);
setOperationAction(ISD::SHL_PARTS, MVT::i32, Expand);
setOperationAction(ISD::SRL_PARTS, MVT::i8, Expand);
setOperationAction(ISD::SRL_PARTS, MVT::i16, Expand);
setOperationAction(ISD::SRL_PARTS, MVT::i32, Expand);
// 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();
}
// getOutFlag - Extract the flag result if the Op has it.
static SDValue getOutFlag(SDValue &Op) {
// Flag is the last value of the node.
SDValue Flag = Op.getValue(Op.getNode()->getNumValues() - 1);
assert (Flag.getValueType() == MVT::Flag
&& "Node does not have an out Flag");
return Flag;
}
// Get the TmpOffset for FrameIndex
unsigned PIC16TargetLowering::GetTmpOffsetForFI(unsigned FI, unsigned size) {
std::map<unsigned, unsigned>::iterator
MapIt = FiTmpOffsetMap.find(FI);
if (MapIt != FiTmpOffsetMap.end())
return MapIt->second;
// This FI (FrameIndex) is not yet mapped, so map it
FiTmpOffsetMap[FI] = TmpSize;
TmpSize += size;
return FiTmpOffsetMap[FI];
}
// 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.
static SDValue 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;
}
/// PopulateResults - Helper function to LowerOperation.
/// If a node wants to return multiple results after lowering,
/// it stuffs them into an array of SDValue called Results.
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;
}
/// The type legalizer framework of generating legalizer can generate libcalls
/// only when the operand/result types are illegal.
/// PIC16 needs to generate libcalls even for the legal types (i8) for some ops.
/// For example an arithmetic right shift. These functions are used to lower
/// such operations that generate libcall for legal types.
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, DebugLoc dl) {
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, dl);
return CallInfo.first;
}
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::MTPCLATH: return "PIC16ISD::MTPCLATH";
case PIC16ISD::PIC16Connect: return "PIC16ISD::PIC16Connect";
case PIC16ISD::Banksel: return "PIC16ISD::Banksel";
case PIC16ISD::PIC16Load: return "PIC16ISD::PIC16Load";
case PIC16ISD::PIC16LdArg: return "PIC16ISD::PIC16LdArg";
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::CALLW: return "PIC16ISD::CALLW";
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::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));
// FIXME there isn't really debug info here
DebugLoc dl = FR->getDebugLoc();
// Expand FrameIndex like GlobalAddress and ExternalSymbol
// Also use Offset field for lo and hi parts. The default
// offset is zero.
SDValue ES;
int FrameOffset;
SDValue FI = SDValue(N,0);
LegalizeFrameIndex(FI, DAG, ES, FrameOffset);
SDValue Offset = DAG.getConstant(FrameOffset, MVT::i8);
SDValue Lo = DAG.getNode(PIC16ISD::Lo, dl, MVT::i8, ES, Offset);
SDValue Hi = DAG.getNode(PIC16ISD::Hi, dl, MVT::i8, ES, Offset);
return DAG.getNode(ISD::BUILD_PAIR, dl, N->getValueType(0), Lo, Hi);
}
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;
DebugLoc dl = N->getDebugLoc();
SDValue PtrLo, PtrHi;
LegalizeAddress(Ptr, DAG, PtrLo, PtrHi, StoreOffset, dl);
if (ValueType == MVT::i8) {
return DAG.getNode (PIC16ISD::PIC16Store, dl, 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, dl, MVT::Other,
ChainLo,
SrcLo, PtrLo, PtrHi,
DAG.getConstant (0 + StoreOffset, MVT::i8));
SDValue Store2 = DAG.getNode(PIC16ISD::PIC16Store, dl, MVT::Other, ChainHi,
SrcHi, PtrLo, PtrHi,
DAG.getConstant (1 + StoreOffset, MVT::i8));
return DAG.getNode(ISD::TokenFactor, dl, 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, dl, MVT::Other,
ChainLo1,
SrcLo1, PtrLo, PtrHi,
DAG.getConstant (0 + StoreOffset, MVT::i8));
SDValue Store2 = DAG.getNode(PIC16ISD::PIC16Store, dl, MVT::Other, ChainLo2,
SrcLo2, PtrLo, PtrHi,
DAG.getConstant (1 + StoreOffset, MVT::i8));
SDValue Store3 = DAG.getNode(PIC16ISD::PIC16Store, dl, MVT::Other, ChainHi1,
SrcHi1, PtrLo, PtrHi,
DAG.getConstant (2 + StoreOffset, MVT::i8));
SDValue Store4 = DAG.getNode(PIC16ISD::PIC16Store, dl, MVT::Other, ChainHi2,
SrcHi2, PtrLo, PtrHi,
DAG.getConstant (3 + StoreOffset, MVT::i8));
SDValue RetLo = DAG.getNode(ISD::TokenFactor, dl, MVT::Other,
getChain(Store1), getChain(Store2));
SDValue RetHi = DAG.getNode(ISD::TokenFactor, dl, MVT::Other,
getChain(Store3), getChain(Store4));
return DAG.getNode(ISD::TokenFactor, dl, 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));
// FIXME there isn't really debug info here
DebugLoc dl = ES->getDebugLoc();
SDValue TES = DAG.getTargetExternalSymbol(ES->getSymbol(), MVT::i8);
SDValue Offset = DAG.getConstant(0, MVT::i8);
SDValue Lo = DAG.getNode(PIC16ISD::Lo, dl, MVT::i8, TES, Offset);
SDValue Hi = DAG.getNode(PIC16ISD::Hi, dl, MVT::i8, TES, Offset);
return DAG.getNode(ISD::BUILD_PAIR, dl, MVT::i16, Lo, Hi);
}
// ExpandGlobalAddress -
SDValue PIC16TargetLowering::ExpandGlobalAddress(SDNode *N, SelectionDAG &DAG) {
GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(SDValue(N, 0));
// FIXME there isn't really debug info here
DebugLoc dl = G->getDebugLoc();
SDValue TGA = DAG.getTargetGlobalAddress(G->getGlobal(), MVT::i8,
G->getOffset());
SDValue Offset = DAG.getConstant(0, MVT::i8);
SDValue Lo = DAG.getNode(PIC16ISD::Lo, dl, MVT::i8, TGA, Offset);
SDValue Hi = DAG.getNode(PIC16ISD::Hi, dl, MVT::i8, TGA, Offset);
return DAG.getNode(ISD::BUILD_PAIR, dl, 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);
if (GSDN->getAddressSpace() == PIC16ISD::ROM_SPACE)
return true;
// Any other address space return it false
return false;
}
// GetExpandedParts - This function is on the similiar lines as
// the GetExpandedInteger in type legalizer is. This returns expanded
// parts of Op in Lo and Hi.
void PIC16TargetLowering::GetExpandedParts(SDValue Op, SelectionDAG &DAG,
SDValue &Lo, SDValue &Hi) {
SDNode *N = Op.getNode();
DebugLoc dl = N->getDebugLoc();
MVT NewVT = getTypeToTransformTo(N->getValueType(0));
// Extract the lo component.
Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, NewVT, Op,
DAG.getConstant(0, MVT::i8));
// extract the hi component
Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, NewVT, Op,
DAG.getConstant(1, MVT::i8));
}
// 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();
MachineFrameInfo *MFI = MF.getFrameInfo();
const std::string Name = Func->getName();
FrameIndexSDNode *FR = dyn_cast<FrameIndexSDNode>(Op);
// FrameIndices are not stack offsets. But they represent the request
// for space on stack. That space requested may be more than one byte.
// Therefore, to calculate the stack offset that a FrameIndex aligns
// with, we need to traverse all the FrameIndices available earlier in
// the list and add their requested size.
unsigned FIndex = FR->getIndex();
const char *tmpName;
if (FIndex < ReservedFrameCount) {
tmpName = createESName(PAN::getFrameLabel(Name));
ES = DAG.getTargetExternalSymbol(tmpName, MVT::i8);
Offset = 0;
for (unsigned i=0; i<FIndex ; ++i) {
Offset += MFI->getObjectSize(i);
}
} else {
// FrameIndex has been made for some temporary storage
tmpName = createESName(PAN::getTempdataLabel(Name));
ES = DAG.getTargetExternalSymbol(tmpName, MVT::i8);
Offset = GetTmpOffsetForFI(FIndex, MFI->getObjectSize(FIndex));
}
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, DebugLoc dl) {
// 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;
}
}
// Expansion of FrameIndex has Lo/Hi parts
if (isDirectAddress(Ptr)) {
SDValue TFI = Ptr.getOperand(0).getOperand(0);
int FrameOffset;
if (TFI.getOpcode() == ISD::TargetFrameIndex) {
LegalizeFrameIndex(TFI, DAG, Lo, FrameOffset);
Hi = DAG.getConstant(1, MVT::i8);
Offset += FrameOffset;
return;
} else if (TFI.getOpcode() == ISD::TargetExternalSymbol) {
// FrameIndex has already been expanded.
// Now just make use of its expansion
Lo = TFI;
Hi = DAG.getConstant(1, MVT::i8);
SDValue FOffset = Ptr.getOperand(0).getOperand(1);
assert (FOffset.getOpcode() == ISD::Constant &&
"Invalid operand of PIC16ISD::Lo");
Offset += dyn_cast<ConstantSDNode>(FOffset)->getZExtValue();
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, dl, MVT::i8, Lo);
Hi = DAG.getNode(PIC16ISD::MTHI, dl, MVT::i8, Hi);
return;
}
SDValue PIC16TargetLowering::ExpandLoad(SDNode *N, SelectionDAG &DAG) {
LoadSDNode *LD = dyn_cast<LoadSDNode>(SDValue(N, 0));
SDValue Chain = LD->getChain();
SDValue Ptr = LD->getBasePtr();
DebugLoc dl = LD->getDebugLoc();
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, dl);
// 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, dl, 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, dl, 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, dl, MVT::i8, Load,
DAG.getConstant(7, MVT::i8));
for (iter=MemBytes; iter<ExtdBytes; ++iter) {
PICLoads.push_back(SRA);
}
} else if (ISD::isZEXTLoad(N) || ISD::isEXTLoad(N)) {
//} 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, dl, VT, PICLoads[0], PICLoads[1]);
if (MemVT == MVT::i8)
Chain = getChain(PICLoads[0]);
else
Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other,
getChain(PICLoads[0]), getChain(PICLoads[1]));
} else if (VT == MVT::i32) {
SDValue BPs[2];
BPs[0] = DAG.getNode(ISD::BUILD_PAIR, dl, MVT::i16,
PICLoads[0], PICLoads[1]);
BPs[1] = DAG.getNode(ISD::BUILD_PAIR, dl, MVT::i16,
PICLoads[2], PICLoads[3]);
BP = DAG.getNode(ISD::BUILD_PAIR, dl, VT, BPs[0], BPs[1]);
if (MemVT == MVT::i8)
Chain = getChain(PICLoads[0]);
else if (MemVT == MVT::i16)
Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other,
getChain(PICLoads[0]), getChain(PICLoads[1]));
else {
SDValue Chains[2];
Chains[0] = DAG.getNode(ISD::TokenFactor, dl, MVT::Other,
getChain(PICLoads[0]), getChain(PICLoads[1]));
Chains[1] = DAG.getNode(ISD::TokenFactor, dl, MVT::Other,
getChain(PICLoads[2]), getChain(PICLoads[3]));
Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other,
Chains[0], Chains[1]);
}
}
Tys = DAG.getVTList(VT, MVT::Other);
return DAG.getNode(ISD::MERGE_VALUES, dl, Tys, BP, Chain);
}
SDValue PIC16TargetLowering::LowerShift(SDValue Op, SelectionDAG &DAG) {
// We should have handled larger operands in type legalizer itself.
assert (Op.getValueType() == MVT::i8 && "illegal shift to lower");
SDNode *N = Op.getNode();
SDValue Value = N->getOperand(0);
SDValue Amt = N->getOperand(1);
PIC16ISD::PIC16Libcall CallCode;
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();
}
SmallVector<SDValue, 2> Ops(2);
Ops[0] = Value;
Ops[1] = Amt;
SDValue Call = MakePIC16Libcall(CallCode, N->getValueType(0), &Ops[0], 2,
true, DAG, N->getDebugLoc());
return Call;
}
void
PIC16TargetLowering::LowerOperationWrapper(SDNode *N,
SmallVectorImpl<SDValue>&Results,
SelectionDAG &DAG) {
SDValue Op = SDValue(N, 0);
SDValue Res;
unsigned i;
switch (Op.getOpcode()) {
case ISD::FORMAL_ARGUMENTS:
Res = LowerFORMAL_ARGUMENTS(Op, DAG); break;
case ISD::LOAD:
Res = ExpandLoad(Op.getNode(), DAG); break;
case ISD::CALL:
Res = LowerCALL(Op, DAG); break;
default: {
// All other operations are handled in LowerOperation.
Res = LowerOperation(Op, DAG);
if (Res.getNode())
Results.push_back(Res);
return;
}
}
N = Res.getNode();
unsigned NumValues = N->getNumValues();
for (i = 0; i < NumValues ; i++) {
Results.push_back(SDValue(N, i));
}
}
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 LowerShift(Op, DAG);
case ISD::OR:
case ISD::AND:
case ISD::XOR:
return LowerBinOp(Op, DAG);
case ISD::CALL:
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,
DebugLoc dl) {
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();
// Put the value on stack.
// Get a stack slot index and convert to es.
int FI = MF.getFrameInfo()->CreateStackObject(1, 1);
const char *tmpName = createESName(PAN::getTempdataLabel(FuncName));
SDValue ES = DAG.getTargetExternalSymbol(tmpName, MVT::i8);
// Store the value to ES.
SDValue Store = DAG.getNode (PIC16ISD::PIC16Store, dl, MVT::Other,
DAG.getEntryNode(),
Op, ES,
DAG.getConstant (1, MVT::i8), // Banksel.
DAG.getConstant (GetTmpOffsetForFI(FI, 1),
MVT::i8));
// Load the value from ES.
SDVTList Tys = DAG.getVTList(MVT::i8, MVT::Other);
SDValue Load = DAG.getNode(PIC16ISD::PIC16Load, dl, Tys, Store,
ES, DAG.getConstant (1, MVT::i8),
DAG.getConstant (GetTmpOffsetForFI(FI, 1),
MVT::i8));
return Load.getValue(0);
}
SDValue PIC16TargetLowering::
LowerIndirectCallArguments(SDValue Op, SDValue Chain, SDValue InFlag,
SDValue DataAddr_Lo, SDValue DataAddr_Hi,
SelectionDAG &DAG) {
CallSDNode *TheCall = dyn_cast<CallSDNode>(Op);
unsigned NumOps = TheCall->getNumArgs();
DebugLoc dl = TheCall->getDebugLoc();
// If call has no arguments then do nothing and return.
if (NumOps == 0)
return Chain;
std::vector<SDValue> Ops;
SDVTList Tys = DAG.getVTList(MVT::Other, MVT::Flag);
SDValue Arg, StoreRet;
// For PIC16 ABI the arguments come after the return value.
unsigned RetVals = TheCall->getNumRetVals();
for (unsigned i = 0, ArgOffset = RetVals; i < NumOps; i++) {
// Get the arguments
Arg = TheCall->getArg(i);
Ops.clear();
Ops.push_back(Chain);
Ops.push_back(Arg);
Ops.push_back(DataAddr_Lo);
Ops.push_back(DataAddr_Hi);
Ops.push_back(DAG.getConstant(ArgOffset, MVT::i8));
Ops.push_back(InFlag);
StoreRet = DAG.getNode (PIC16ISD::PIC16StWF, dl, Tys, &Ops[0], Ops.size());
Chain = getChain(StoreRet);
InFlag = getOutFlag(StoreRet);
ArgOffset++;
}
return Chain;
}
SDValue PIC16TargetLowering::
LowerDirectCallArguments(SDValue Op, SDValue Chain, SDValue ArgLabel,
SDValue InFlag, SelectionDAG &DAG) {
CallSDNode *TheCall = dyn_cast<CallSDNode>(Op);
unsigned NumOps = TheCall->getNumArgs();
DebugLoc dl = TheCall->getDebugLoc();
std::string Name;
SDValue Arg, StoreAt;
MVT ArgVT;
unsigned Size=0;
unsigned ArgCount=0;
// If call has no arguments then do nothing and return.
if (NumOps == 0)
return Chain;
// 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(ArgLabel, DAG, PtrLo, PtrHi, AddressOffset, dl);
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);
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, dl, 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::
LowerIndirectCallReturn (SDValue Op, SDValue Chain, SDValue InFlag,
SDValue DataAddr_Lo, SDValue DataAddr_Hi,
SelectionDAG &DAG) {
CallSDNode *TheCall = dyn_cast<CallSDNode>(Op);
DebugLoc dl = TheCall->getDebugLoc();
unsigned RetVals = TheCall->getNumRetVals();
// If call does not have anything to return
// then do nothing and go back.
if (RetVals == 0)
return Chain;
// Call has something to return
std::vector<SDValue> ResultVals;
SDValue LoadRet;
SDVTList Tys = DAG.getVTList(MVT::i8, MVT::Other, MVT::Flag);
for(unsigned i=0;i<RetVals;i++) {
LoadRet = DAG.getNode(PIC16ISD::PIC16LdWF, dl, Tys, Chain, DataAddr_Lo,
DataAddr_Hi, DAG.getConstant(i, MVT::i8),
InFlag);
InFlag = getOutFlag(LoadRet);
Chain = getChain(LoadRet);
ResultVals.push_back(LoadRet);
}
ResultVals.push_back(Chain);
SDValue Res = DAG.getMergeValues(&ResultVals[0], ResultVals.size(), dl);
return Res;
}
SDValue PIC16TargetLowering::
LowerDirectCallReturn(SDValue Op, SDValue Chain, SDValue RetLabel,
SDValue InFlag, SelectionDAG &DAG) {
CallSDNode *TheCall = dyn_cast<CallSDNode>(Op);
DebugLoc dl = TheCall->getDebugLoc();
// 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(RetLabel, DAG, LdLo, LdHi, LdOffset, dl);
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, dl, 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(), dl);
return Res;
}
SDValue PIC16TargetLowering::LowerRET(SDValue Op, SelectionDAG &DAG) {
SDValue Chain = Op.getOperand(0);
DebugLoc dl = Op.getDebugLoc();
if (Op.getNumOperands() == 1) // return void
return Op;
// return should have odd number of operands
if ((Op.getNumOperands() % 2) == 0 ) {
assert(0 && "Do not know how to return this many arguments!");
abort();
}
// Number of values to return
unsigned NumRet = (Op.getNumOperands() / 2);
// Function returns value always on stack with the offset starting
// from 0
MachineFunction &MF = DAG.getMachineFunction();
const Function *F = MF.getFunction();
std::string FuncName = F->getName();
const char *tmpName = createESName(PAN::getFrameLabel(FuncName));
SDVTList VTs = DAG.getVTList (MVT::i8, MVT::Other);
SDValue ES = DAG.getTargetExternalSymbol(tmpName, MVT::i8);
SDValue BS = DAG.getConstant(1, MVT::i8);
SDValue RetVal;
for(unsigned i=0;i<NumRet; ++i) {
RetVal = Op.getNode()->getOperand(2*i + 1);
Chain = DAG.getNode (PIC16ISD::PIC16Store, dl, MVT::Other, Chain, RetVal,
ES, BS,
DAG.getConstant (i, MVT::i8));
}
return DAG.getNode(ISD::RET, dl, MVT::Other, Chain);
}
// CALL node may have some operands non-legal to PIC16. Generate new CALL
// node with all the operands legal.
// Currently only Callee operand of the CALL node is non-legal. This function
// legalizes the Callee operand and uses all other operands as are to generate
// new CALL node.
SDValue PIC16TargetLowering::LegalizeCALL(SDValue Op, SelectionDAG &DAG) {
CallSDNode *TheCall = dyn_cast<CallSDNode>(Op);
SDValue Chain = TheCall->getChain();
SDValue Callee = TheCall->getCallee();
DebugLoc dl = TheCall->getDebugLoc();
unsigned i =0;
assert(Callee.getValueType() == MVT::i16 &&
"Don't know how to legalize this call node!!!");
assert(Callee.getOpcode() == ISD::BUILD_PAIR &&
"Don't know how to legalize this call node!!!");
if (isDirectAddress(Callee)) {
// Come here for direct calls
Callee = Callee.getOperand(0).getOperand(0);
} else {
// Come here for indirect calls
SDValue Lo, Hi;
// Indirect addresses. Get the hi and lo parts of ptr.
GetExpandedParts(Callee, DAG, Lo, Hi);
// Connect Lo and Hi parts of the callee with the PIC16Connect
Callee = DAG.getNode(PIC16ISD::PIC16Connect, dl, MVT::i8, Lo, Hi);
}
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());
// Generate new call with all the operands legal
return DAG.getCall(TheCall->getCallingConv(), dl,
TheCall->isVarArg(), TheCall->isTailCall(),
TheCall->isInreg(), VTs, &Ops[0], Ops.size());
}
void PIC16TargetLowering::
GetDataAddress(DebugLoc dl, SDValue Callee, SDValue &Chain,
SDValue &DataAddr_Lo, SDValue &DataAddr_Hi,
SelectionDAG &DAG) {
assert (Callee.getOpcode() == PIC16ISD::PIC16Connect
&& "Don't know what to do of such callee!!");
SDValue ZeroOperand = DAG.getConstant(0, MVT::i8);
SDValue SeqStart = DAG.getCALLSEQ_START(Chain, ZeroOperand);
Chain = getChain(SeqStart);
SDValue OperFlag = getOutFlag(SeqStart); // To manage the data dependency
// Get the Lo and Hi part of code address
SDValue Lo = Callee.getOperand(0);
SDValue Hi = Callee.getOperand(1);
SDValue Data_Lo, Data_Hi;
SDVTList Tys = DAG.getVTList(MVT::i8, MVT::Other, MVT::Flag);
// Subtract 2 from Address to get the Lower part of DataAddress.
SDVTList VTList = DAG.getVTList(MVT::i8, MVT::Flag);
Data_Lo = DAG.getNode(ISD::SUBC, dl, VTList, Lo,
DAG.getConstant(2, MVT::i8));
SDValue Ops[3] = { Hi, DAG.getConstant(0, MVT::i8), Data_Lo.getValue(1)};
Data_Hi = DAG.getNode(ISD::SUBE, dl, VTList, Ops, 3);
SDValue PCLATH = DAG.getNode(PIC16ISD::MTPCLATH, dl, MVT::i8, Data_Hi);
Callee = DAG.getNode(PIC16ISD::PIC16Connect, dl, MVT::i8, Data_Lo, PCLATH);
SDValue Call = DAG.getNode(PIC16ISD::CALLW, dl, Tys, Chain, Callee,
OperFlag);
Chain = getChain(Call);
OperFlag = getOutFlag(Call);
SDValue SeqEnd = DAG.getCALLSEQ_END(Chain, ZeroOperand, ZeroOperand,
OperFlag);
Chain = getChain(SeqEnd);
OperFlag = getOutFlag(SeqEnd);
// Low part of Data Address
DataAddr_Lo = DAG.getNode(PIC16ISD::MTLO, dl, MVT::i8, Call, OperFlag);
// Make the second call.
SeqStart = DAG.getCALLSEQ_START(Chain, ZeroOperand);
Chain = getChain(SeqStart);
OperFlag = getOutFlag(SeqStart); // To manage the data dependency
// Subtract 1 from Address to get high part of data address.
Data_Lo = DAG.getNode(ISD::SUBC, dl, VTList, Lo,
DAG.getConstant(1, MVT::i8));
SDValue HiOps[3] = { Hi, DAG.getConstant(0, MVT::i8), Data_Lo.getValue(1)};
Data_Hi = DAG.getNode(ISD::SUBE, dl, VTList, HiOps, 3);
PCLATH = DAG.getNode(PIC16ISD::MTPCLATH, dl, MVT::i8, Data_Hi);
// Use new Lo to make another CALLW
Callee = DAG.getNode(PIC16ISD::PIC16Connect, dl, MVT::i8, Data_Lo, PCLATH);
Call = DAG.getNode(PIC16ISD::CALLW, dl, Tys, Chain, Callee, OperFlag);
Chain = getChain(Call);
OperFlag = getOutFlag(Call);
SeqEnd = DAG.getCALLSEQ_END(Chain, ZeroOperand, ZeroOperand,
OperFlag);
Chain = getChain(SeqEnd);
OperFlag = getOutFlag(SeqEnd);
// Hi part of Data Address
DataAddr_Hi = DAG.getNode(PIC16ISD::MTHI, dl, MVT::i8, Call, OperFlag);
}
SDValue PIC16TargetLowering::LowerCALL(SDValue Op, SelectionDAG &DAG) {
CallSDNode *TheCall = dyn_cast<CallSDNode>(Op);
SDValue Chain = TheCall->getChain();
SDValue Callee = TheCall->getCallee();
DebugLoc dl = TheCall->getDebugLoc();
if (Callee.getValueType() == MVT::i16 &&
Callee.getOpcode() == ISD::BUILD_PAIR) {
// Control should come here only from TypeLegalizer for lowering
// Legalize the non-legal arguments of call and return the
// new call with legal arguments.
return LegalizeCALL(Op, DAG);
}
// Control should come here from Legalize DAG.
// Here all the operands of CALL node should be legal.
// If this is an indirect call then to pass the arguments
// and read the return value back, we need the data address
// of the function being called.
// To get the data address two more calls need to be made.
// The flag to track if this is a direct or indirect call.
bool IsDirectCall = true;
unsigned RetVals = TheCall->getNumRetVals();
unsigned NumArgs = TheCall->getNumArgs();
SDValue DataAddr_Lo, DataAddr_Hi;
if (Callee.getOpcode() == PIC16ISD::PIC16Connect) {
IsDirectCall = false; // This is indirect call
// Read DataAddress only if we have to pass arguments or
// read return value.
if ((RetVals > 0) || (NumArgs > 0))
GetDataAddress(dl, Callee, Chain, DataAddr_Lo, DataAddr_Hi, DAG);
}
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);
SDValue OperFlag = getOutFlag(SeqStart); // To manage the data dependency
std::string Name;
// For any direct call - callee will be GlobalAddressNode or
// ExternalSymbol
SDValue ArgLabel, RetLabel;
if (IsDirectCall) {
// Considering the GlobalAddressNode case here.
if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee)) {
GlobalValue *GV = G->getGlobal();
Callee = DAG.getTargetGlobalAddress(GV, MVT::i8);
Name = G->getGlobal()->getName();
} else {// Considering the ExternalSymbol case here
ExternalSymbolSDNode *ES = dyn_cast<ExternalSymbolSDNode>(Callee);
Callee = DAG.getTargetExternalSymbol(ES->getSymbol(), MVT::i8);
Name = ES->getSymbol();
}
// Label for argument passing
const char *argFrame = createESName(PAN::getArgsLabel(Name));
ArgLabel = DAG.getTargetExternalSymbol(argFrame, MVT::i8);
// Label for reading return value
const char *retName = createESName(PAN::getRetvalLabel(Name));
RetLabel = DAG.getTargetExternalSymbol(retName, MVT::i8);
} else {
// if indirect call
SDValue CodeAddr_Lo = Callee.getOperand(0);
SDValue CodeAddr_Hi = Callee.getOperand(1);
/*CodeAddr_Lo = DAG.getNode(ISD::ADD, dl, MVT::i8, CodeAddr_Lo,
DAG.getConstant(2, MVT::i8));*/
// move Hi part in PCLATH
CodeAddr_Hi = DAG.getNode(PIC16ISD::MTPCLATH, dl, MVT::i8, CodeAddr_Hi);
Callee = DAG.getNode(PIC16ISD::PIC16Connect, dl, MVT::i8, CodeAddr_Lo,
CodeAddr_Hi);
}
// Pass the argument to function before making the call.
SDValue CallArgs;
if (IsDirectCall) {
CallArgs = LowerDirectCallArguments(Op, Chain, ArgLabel, OperFlag, DAG);
Chain = getChain(CallArgs);
OperFlag = getOutFlag(CallArgs);
} else {
CallArgs = LowerIndirectCallArguments(Op, Chain, OperFlag, DataAddr_Lo,
DataAddr_Hi, DAG);
Chain = getChain(CallArgs);
OperFlag = getOutFlag(CallArgs);
}
SDVTList Tys = DAG.getVTList(MVT::Other, MVT::Flag);
SDValue PICCall = DAG.getNode(PIC16ISD::CALL, dl, 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.
if (IsDirectCall)
return LowerDirectCallReturn(Op, Chain, RetLabel, OperFlag, DAG);
else
return LowerIndirectCallReturn(Op, Chain, OperFlag, DataAddr_Lo,
DataAddr_Hi, 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;
}
// NeedToConvertToMemOp - Returns true if one of the operands of the
// operation 'Op' needs to be put into memory. Also returns the
// operand no. of the operand to be converted in 'MemOp'. Remember, PIC16 has
// no instruction that can operation on two registers. Most insns take
// one register and one memory operand (addwf) / Constant (addlw).
bool PIC16TargetLowering::NeedToConvertToMemOp(SDValue Op, unsigned &MemOp) {
// If one of the operand is a constant, return false.
if (Op.getOperand(0).getOpcode() == ISD::Constant ||
Op.getOperand(1).getOpcode() == ISD::Constant)
return false;
// Return false if one of the operands is already a direct
// load and that operand has only one use.
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;
}
// LowerBinOp - Lower a commutative binary operation that does not
// affect status flag carry.
SDValue PIC16TargetLowering::LowerBinOp(SDValue Op, SelectionDAG &DAG) {
DebugLoc dl = Op.getDebugLoc();
// 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, dl);
return DAG.getNode(Op.getOpcode(), dl, MVT::i8, Op.getOperand(MemOp ^ 1),
NewVal);
}
else {
return Op;
}
}
// LowerADD - Lower all types of ADD operations including the ones
// that affects carry.
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");
DebugLoc dl = Op.getDebugLoc();
unsigned MemOp = 1;
if (NeedToConvertToMemOp(Op, MemOp)) {
// Put one value on stack.
SDValue NewVal = ConvertToMemOperand (Op.getOperand(MemOp), DAG, dl);
// ADDC and ADDE produce two results.
SDVTList Tys = DAG.getVTList(MVT::i8, MVT::Flag);
// ADDE has three operands, the last one is the carry bit.
if (Op.getOpcode() == ISD::ADDE)
return DAG.getNode(Op.getOpcode(), dl, Tys, Op.getOperand(MemOp ^ 1),
NewVal, Op.getOperand(2));
// ADDC has two operands.
else if (Op.getOpcode() == ISD::ADDC)
return DAG.getNode(Op.getOpcode(), dl, Tys, Op.getOperand(MemOp ^ 1),
NewVal);
// ADD it is. It produces only one result.
else
return DAG.getNode(Op.getOpcode(), dl, MVT::i8, Op.getOperand(MemOp ^ 1),
NewVal);
}
else
return Op;
}
SDValue PIC16TargetLowering::LowerSUB(SDValue Op, SelectionDAG &DAG) {
DebugLoc dl = Op.getDebugLoc();
// 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 Op;
// Put first operand on stack.
SDValue NewVal = ConvertToMemOperand (Op.getOperand(0), DAG, dl);
SDVTList Tys = DAG.getVTList(MVT::i8, MVT::Flag);
if (Op.getOpcode() == ISD::SUBE)
return DAG.getNode(Op.getOpcode(), dl, Tys, NewVal, Op.getOperand(1),
Op.getOperand(2));
else
return DAG.getNode(Op.getOpcode(), dl, Tys, NewVal, Op.getOperand(1));
}
void PIC16TargetLowering::InitReservedFrameCount(const Function *F) {
unsigned NumArgs = F->arg_size();
bool isVoidFunc = (F->getReturnType()->getTypeID() == Type::VoidTyID);
if (isVoidFunc)
ReservedFrameCount = NumArgs;
else
ReservedFrameCount = NumArgs + 1;
}
// LowerFORMAL_ARGUMENTS - Argument values are loaded from the
// <fname>.args + offset. All arguments are already broken to leaglized
// types, so the offset just runs from 0 to NumArgVals - 1.
SDValue PIC16TargetLowering::LowerFORMAL_ARGUMENTS(SDValue Op,
SelectionDAG &DAG) {
SmallVector<SDValue, 8> ArgValues;
unsigned NumArgVals = Op.getNode()->getNumValues() - 1;
DebugLoc dl = Op.getDebugLoc();
SDValue Chain = Op.getOperand(0); // Formal arguments' chain
// Get the callee's name to create the <fname>.args label to pass args.
MachineFunction &MF = DAG.getMachineFunction();
const Function *F = MF.getFunction();
std::string FuncName = F->getName();
// Reset the map of FI and TmpOffset
ResetTmpOffsetMap();
// Initialize the ReserveFrameCount
InitReservedFrameCount(F);
// Create the <fname>.args external symbol.
const char *tmpName = createESName(PAN::getArgsLabel(FuncName));
SDValue ES = DAG.getTargetExternalSymbol(tmpName, MVT::i8);
// Load arg values from the label + offset.
SDVTList VTs = DAG.getVTList (MVT::i8, MVT::Other);
SDValue BS = DAG.getConstant(1, MVT::i8);
for (unsigned i = 0; i < NumArgVals ; ++i) {
SDValue Offset = DAG.getConstant(i, MVT::i8);
SDValue PICLoad = DAG.getNode(PIC16ISD::PIC16LdArg, dl, VTs, Chain, ES, BS,
Offset);
Chain = getChain(PICLoad);
ArgValues.push_back(PICLoad);
}
// Return a MERGE_VALUE node.
ArgValues.push_back(Op.getOperand(0));
return DAG.getNode(ISD::MERGE_VALUES, dl, Op.getNode()->getVTList(),
&ArgValues[0], ArgValues.size()).getValue(Op.getResNo());
}
// Perform DAGCombine of PIC16Load.
// FIXME - Need a more elaborate comment here.
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();
}
// For all the functions with arguments some STORE nodes are generated
// that store the argument on the frameindex. However in PIC16 the arguments
// are passed on stack only. Therefore these STORE nodes are redundant.
// To remove these STORE nodes will be removed in PerformStoreCombine
//
// Currently this function is doint nothing and will be updated for removing
// unwanted store operations
SDValue PIC16TargetLowering::
PerformStoreCombine(SDNode *N, DAGCombinerInfo &DCI) const {
return SDValue(N, 0);
/*
// Storing an undef value is of no use, so remove it
if (isStoringUndef(N, Chain, DAG)) {
return Chain; // remove the store and return the chain
}
//else everything is ok.
return SDValue(N, 0);
*/
}
SDValue PIC16TargetLowering::PerformDAGCombine(SDNode *N,
DAGCombinerInfo &DCI) const {
switch (N->getOpcode()) {
case ISD::STORE:
return PerformStoreCombine(N, DCI);
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::ULT;
case ISD::SETULE: return PIC16CC::ULE;
case ISD::SETUGE: return PIC16CC::UGE;
case ISD::SETUGT: return PIC16CC::UGT;
}
}
// 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, DebugLoc dl) {
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::ULT:
CondCode = PIC16CC::UGT;
break;
case PIC16CC::UGT:
CondCode = PIC16CC::ULT;
break;
case PIC16CC::GE:
CondCode = PIC16CC::LE;
break;
case PIC16CC::LE:
CondCode = PIC16CC::GE;
break;
case PIC16CC::ULE:
CondCode = PIC16CC::UGE;
break;
case PIC16CC::UGE:
CondCode = PIC16CC::ULE;
break;
}
}
PIC16CC = DAG.getConstant(CondCode, MVT::i8);
// These are signed comparisons.
SDValue Mask = DAG.getConstant(128, MVT::i8);
if (isSignedComparison(CondCode)) {
LHS = DAG.getNode (ISD::XOR, dl, MVT::i8, LHS, Mask);
RHS = DAG.getNode (ISD::XOR, dl, MVT::i8, RHS, Mask);
}
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 valid type (direct load
// for subwf and literal for sublw) and it is used by this operation only.
if ((LHS.getOpcode() == ISD::Constant || isDirectLoad(LHS))
&& LHS.hasOneUse())
return DAG.getNode(PIC16ISD::SUBCC, dl, VTs, LHS, RHS);
// else convert the first operand to mem.
LHS = ConvertToMemOperand (LHS, DAG, dl);
return DAG.getNode(PIC16ISD::SUBCC, dl, 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;
DebugLoc dl = Op.getDebugLoc();
// 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, dl);
return DAG.getNode (PIC16ISD::SELECT_ICC, dl, TrueVal.getValueType(), TrueVal,
FalseVal, PIC16CC, Cmp.getValue(1));
}
MachineBasicBlock *
PIC16TargetLowering::EmitInstrWithCustomInserter(MachineInstr *MI,
MachineBasicBlock *BB) const {
const TargetInstrInfo &TII = *getTargetMachine().getInstrInfo();
unsigned CC = (PIC16CC::CondCodes)MI->getOperand(3).getImm();
DebugLoc dl = MI->getDebugLoc();
// 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, dl, 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, dl, 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;
DebugLoc dl = Op.getDebugLoc();
// 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, dl);
return DAG.getNode(PIC16ISD::BRCOND, dl, MVT::Other, Chain, Dest, PIC16CC,
Cmp.getValue(1));
}
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