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llvm-6502/lib/Target/MSP430/MSP430ISelLowering.cpp
Chris Lattner f0144127b9 Rip all of the global variable lowering logic out of TargetAsmInfo. Since 
it is highly specific to the object file that will be generated in the end,
this introduces a new TargetLoweringObjectFile interface that is implemented
for each of ELF/MachO/COFF/Alpha/PIC16 and XCore.

Though still is still a brutal and ugly refactoring, this is a major step
towards goodness.

This patch also:
1. fixes a bunch of dangling pointer problems in the PIC16 backend.
2. disables the TargetLowering copy ctor which PIC16 was accidentally using.
3. gets us closer to xcore having its own crazy target section flags and
   pic16 not having to shadow sections with its own objects.
4. fixes wierdness where ELF targets would set CStringSection but not
   CStringSection_.  Factor the code better.
5. fixes some bugs in string lowering on ELF targets.




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77294 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-28 03:13:23 +00:00

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27 KiB
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//===-- MSP430ISelLowering.cpp - MSP430 DAG Lowering Implementation ------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the MSP430TargetLowering class.
//
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "msp430-lower"
#include "MSP430ISelLowering.h"
#include "MSP430.h"
#include "MSP430TargetMachine.h"
#include "MSP430Subtarget.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Function.h"
#include "llvm/Intrinsics.h"
#include "llvm/CallingConv.h"
#include "llvm/GlobalVariable.h"
#include "llvm/GlobalAlias.h"
#include "llvm/CodeGen/CallingConvLower.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/PseudoSourceValue.h"
#include "llvm/CodeGen/SelectionDAGISel.h"
#include "llvm/CodeGen/ValueTypes.h"
#include "llvm/Target/TargetLoweringObjectFile.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/ADT/VectorExtras.h"
using namespace llvm;
MSP430TargetLowering::MSP430TargetLowering(MSP430TargetMachine &tm) :
TargetLowering(tm, new TargetLoweringObjectFileELF()),
Subtarget(*tm.getSubtargetImpl()), TM(tm) {
// Set up the register classes.
addRegisterClass(MVT::i8, MSP430::GR8RegisterClass);
addRegisterClass(MVT::i16, MSP430::GR16RegisterClass);
// Compute derived properties from the register classes
computeRegisterProperties();
// Provide all sorts of operation actions
// Division is expensive
setIntDivIsCheap(false);
// Even if we have only 1 bit shift here, we can perform
// shifts of the whole bitwidth 1 bit per step.
setShiftAmountType(MVT::i8);
setStackPointerRegisterToSaveRestore(MSP430::SPW);
setBooleanContents(ZeroOrOneBooleanContent);
setSchedulingPreference(SchedulingForLatency);
setLoadExtAction(ISD::EXTLOAD, MVT::i1, Promote);
setLoadExtAction(ISD::SEXTLOAD, MVT::i1, Promote);
setLoadExtAction(ISD::ZEXTLOAD, MVT::i1, Promote);
setLoadExtAction(ISD::SEXTLOAD, MVT::i8, Expand);
setLoadExtAction(ISD::SEXTLOAD, MVT::i16, Expand);
// We don't have any truncstores
setTruncStoreAction(MVT::i16, MVT::i8, Expand);
setOperationAction(ISD::SRA, MVT::i8, Custom);
setOperationAction(ISD::SHL, MVT::i8, Custom);
setOperationAction(ISD::SRL, MVT::i8, Custom);
setOperationAction(ISD::SRA, MVT::i16, Custom);
setOperationAction(ISD::SHL, MVT::i16, Custom);
setOperationAction(ISD::SRL, MVT::i16, Custom);
setOperationAction(ISD::ROTL, MVT::i8, Expand);
setOperationAction(ISD::ROTR, MVT::i8, Expand);
setOperationAction(ISD::ROTL, MVT::i16, Expand);
setOperationAction(ISD::ROTR, MVT::i16, Expand);
setOperationAction(ISD::RET, MVT::Other, Custom);
setOperationAction(ISD::GlobalAddress, MVT::i16, Custom);
setOperationAction(ISD::ExternalSymbol, MVT::i16, Custom);
setOperationAction(ISD::BR_JT, MVT::Other, Expand);
setOperationAction(ISD::BRIND, MVT::Other, Expand);
setOperationAction(ISD::BR_CC, MVT::i8, Custom);
setOperationAction(ISD::BR_CC, MVT::i16, Custom);
setOperationAction(ISD::BRCOND, MVT::Other, Expand);
setOperationAction(ISD::SETCC, MVT::i8, Expand);
setOperationAction(ISD::SETCC, MVT::i16, Expand);
setOperationAction(ISD::SELECT, MVT::i8, Expand);
setOperationAction(ISD::SELECT, MVT::i16, Expand);
setOperationAction(ISD::SELECT_CC, MVT::i8, Custom);
setOperationAction(ISD::SELECT_CC, MVT::i16, Custom);
setOperationAction(ISD::SIGN_EXTEND, MVT::i16, Custom);
setOperationAction(ISD::CTTZ, MVT::i8, Expand);
setOperationAction(ISD::CTTZ, MVT::i16, Expand);
setOperationAction(ISD::CTLZ, MVT::i8, Expand);
setOperationAction(ISD::CTLZ, MVT::i16, Expand);
setOperationAction(ISD::CTPOP, MVT::i8, Expand);
setOperationAction(ISD::CTPOP, MVT::i16, Expand);
setOperationAction(ISD::SHL_PARTS, MVT::i8, Expand);
setOperationAction(ISD::SHL_PARTS, MVT::i16, Expand);
setOperationAction(ISD::SRL_PARTS, MVT::i8, Expand);
setOperationAction(ISD::SRL_PARTS, MVT::i16, Expand);
setOperationAction(ISD::SRA_PARTS, MVT::i8, Expand);
setOperationAction(ISD::SRA_PARTS, MVT::i16, Expand);
setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i1, Expand);
// FIXME: Implement efficiently multiplication by a constant
setOperationAction(ISD::MUL, MVT::i16, Expand);
setOperationAction(ISD::MULHS, MVT::i16, Expand);
setOperationAction(ISD::MULHU, MVT::i16, Expand);
setOperationAction(ISD::SMUL_LOHI, MVT::i16, Expand);
setOperationAction(ISD::UMUL_LOHI, MVT::i16, Expand);
setOperationAction(ISD::UDIV, MVT::i16, Expand);
setOperationAction(ISD::UDIVREM, MVT::i16, Expand);
setOperationAction(ISD::UREM, MVT::i16, Expand);
setOperationAction(ISD::SDIV, MVT::i16, Expand);
setOperationAction(ISD::SDIVREM, MVT::i16, Expand);
setOperationAction(ISD::SREM, MVT::i16, Expand);
}
SDValue MSP430TargetLowering::LowerOperation(SDValue Op, SelectionDAG &DAG) {
switch (Op.getOpcode()) {
case ISD::FORMAL_ARGUMENTS: return LowerFORMAL_ARGUMENTS(Op, DAG);
case ISD::SHL: // FALLTHROUGH
case ISD::SRL:
case ISD::SRA: return LowerShifts(Op, DAG);
case ISD::RET: return LowerRET(Op, DAG);
case ISD::CALL: return LowerCALL(Op, DAG);
case ISD::GlobalAddress: return LowerGlobalAddress(Op, DAG);
case ISD::ExternalSymbol: return LowerExternalSymbol(Op, DAG);
case ISD::BR_CC: return LowerBR_CC(Op, DAG);
case ISD::SELECT_CC: return LowerSELECT_CC(Op, DAG);
case ISD::SIGN_EXTEND: return LowerSIGN_EXTEND(Op, DAG);
default:
llvm_unreachable("unimplemented operand");
return SDValue();
}
}
/// getFunctionAlignment - Return the Log2 alignment of this function.
unsigned MSP430TargetLowering::getFunctionAlignment(const Function *F) const {
return F->hasFnAttr(Attribute::OptimizeForSize) ? 1 : 4;
}
//===----------------------------------------------------------------------===//
// Calling Convention Implementation
//===----------------------------------------------------------------------===//
#include "MSP430GenCallingConv.inc"
SDValue MSP430TargetLowering::LowerFORMAL_ARGUMENTS(SDValue Op,
SelectionDAG &DAG) {
unsigned CC = cast<ConstantSDNode>(Op.getOperand(1))->getZExtValue();
switch (CC) {
default:
llvm_unreachable("Unsupported calling convention");
case CallingConv::C:
case CallingConv::Fast:
return LowerCCCArguments(Op, DAG);
}
}
SDValue MSP430TargetLowering::LowerCALL(SDValue Op, SelectionDAG &DAG) {
CallSDNode *TheCall = cast<CallSDNode>(Op.getNode());
unsigned CallingConv = TheCall->getCallingConv();
switch (CallingConv) {
default:
llvm_unreachable("Unsupported calling convention");
case CallingConv::Fast:
case CallingConv::C:
return LowerCCCCallTo(Op, DAG, CallingConv);
}
}
/// LowerCCCArguments - transform physical registers into virtual registers and
/// generate load operations for arguments places on the stack.
// FIXME: struct return stuff
// FIXME: varargs
SDValue MSP430TargetLowering::LowerCCCArguments(SDValue Op,
SelectionDAG &DAG) {
MachineFunction &MF = DAG.getMachineFunction();
MachineFrameInfo *MFI = MF.getFrameInfo();
MachineRegisterInfo &RegInfo = MF.getRegInfo();
SDValue Root = Op.getOperand(0);
bool isVarArg = cast<ConstantSDNode>(Op.getOperand(2))->getZExtValue() != 0;
unsigned CC = MF.getFunction()->getCallingConv();
DebugLoc dl = Op.getDebugLoc();
// Assign locations to all of the incoming arguments.
SmallVector<CCValAssign, 16> ArgLocs;
CCState CCInfo(CC, isVarArg, getTargetMachine(), ArgLocs, *DAG.getContext());
CCInfo.AnalyzeFormalArguments(Op.getNode(), CC_MSP430);
assert(!isVarArg && "Varargs not supported yet");
SmallVector<SDValue, 16> ArgValues;
for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
CCValAssign &VA = ArgLocs[i];
if (VA.isRegLoc()) {
// Arguments passed in registers
MVT RegVT = VA.getLocVT();
switch (RegVT.getSimpleVT()) {
default:
{
#ifndef NDEBUG
cerr << "LowerFORMAL_ARGUMENTS Unhandled argument type: "
<< RegVT.getSimpleVT() << "\n";
#endif
llvm_unreachable(0);
}
case MVT::i16:
unsigned VReg =
RegInfo.createVirtualRegister(MSP430::GR16RegisterClass);
RegInfo.addLiveIn(VA.getLocReg(), VReg);
SDValue ArgValue = DAG.getCopyFromReg(Root, dl, VReg, RegVT);
// If this is an 8-bit value, it is really passed promoted to 16
// bits. Insert an assert[sz]ext to capture this, then truncate to the
// right size.
if (VA.getLocInfo() == CCValAssign::SExt)
ArgValue = DAG.getNode(ISD::AssertSext, dl, RegVT, ArgValue,
DAG.getValueType(VA.getValVT()));
else if (VA.getLocInfo() == CCValAssign::ZExt)
ArgValue = DAG.getNode(ISD::AssertZext, dl, RegVT, ArgValue,
DAG.getValueType(VA.getValVT()));
if (VA.getLocInfo() != CCValAssign::Full)
ArgValue = DAG.getNode(ISD::TRUNCATE, dl, VA.getValVT(), ArgValue);
ArgValues.push_back(ArgValue);
}
} else {
// Sanity check
assert(VA.isMemLoc());
// Load the argument to a virtual register
unsigned ObjSize = VA.getLocVT().getSizeInBits()/8;
if (ObjSize > 2) {
cerr << "LowerFORMAL_ARGUMENTS Unhandled argument type: "
<< VA.getLocVT().getSimpleVT()
<< "\n";
}
// Create the frame index object for this incoming parameter...
int FI = MFI->CreateFixedObject(ObjSize, VA.getLocMemOffset());
// Create the SelectionDAG nodes corresponding to a load
//from this parameter
SDValue FIN = DAG.getFrameIndex(FI, MVT::i16);
ArgValues.push_back(DAG.getLoad(VA.getLocVT(), dl, Root, FIN,
PseudoSourceValue::getFixedStack(FI), 0));
}
}
ArgValues.push_back(Root);
// Return the new list of results.
return DAG.getNode(ISD::MERGE_VALUES, dl, Op.getNode()->getVTList(),
&ArgValues[0], ArgValues.size()).getValue(Op.getResNo());
}
SDValue MSP430TargetLowering::LowerRET(SDValue Op, SelectionDAG &DAG) {
// CCValAssign - represent the assignment of the return value to a location
SmallVector<CCValAssign, 16> RVLocs;
unsigned CC = DAG.getMachineFunction().getFunction()->getCallingConv();
bool isVarArg = DAG.getMachineFunction().getFunction()->isVarArg();
DebugLoc dl = Op.getDebugLoc();
// CCState - Info about the registers and stack slot.
CCState CCInfo(CC, isVarArg, getTargetMachine(), RVLocs, *DAG.getContext());
// Analize return values of ISD::RET
CCInfo.AnalyzeReturn(Op.getNode(), RetCC_MSP430);
// If this is the first return lowered for this function, add the regs to the
// liveout set for the function.
if (DAG.getMachineFunction().getRegInfo().liveout_empty()) {
for (unsigned i = 0; i != RVLocs.size(); ++i)
if (RVLocs[i].isRegLoc())
DAG.getMachineFunction().getRegInfo().addLiveOut(RVLocs[i].getLocReg());
}
// The chain is always operand #0
SDValue Chain = Op.getOperand(0);
SDValue Flag;
// Copy the result values into the output registers.
for (unsigned i = 0; i != RVLocs.size(); ++i) {
CCValAssign &VA = RVLocs[i];
assert(VA.isRegLoc() && "Can only return in registers!");
// ISD::RET => ret chain, (regnum1,val1), ...
// So i*2+1 index only the regnums
Chain = DAG.getCopyToReg(Chain, dl, VA.getLocReg(),
Op.getOperand(i*2+1), Flag);
// Guarantee that all emitted copies are stuck together,
// avoiding something bad.
Flag = Chain.getValue(1);
}
if (Flag.getNode())
return DAG.getNode(MSP430ISD::RET_FLAG, dl, MVT::Other, Chain, Flag);
// Return Void
return DAG.getNode(MSP430ISD::RET_FLAG, dl, MVT::Other, Chain);
}
/// LowerCCCCallTo - functions arguments are copied from virtual regs to
/// (physical regs)/(stack frame), CALLSEQ_START and CALLSEQ_END are emitted.
/// TODO: sret.
SDValue MSP430TargetLowering::LowerCCCCallTo(SDValue Op, SelectionDAG &DAG,
unsigned CC) {
CallSDNode *TheCall = cast<CallSDNode>(Op.getNode());
SDValue Chain = TheCall->getChain();
SDValue Callee = TheCall->getCallee();
bool isVarArg = TheCall->isVarArg();
DebugLoc dl = Op.getDebugLoc();
// Analyze operands of the call, assigning locations to each operand.
SmallVector<CCValAssign, 16> ArgLocs;
CCState CCInfo(CC, isVarArg, getTargetMachine(), ArgLocs, *DAG.getContext());
CCInfo.AnalyzeCallOperands(TheCall, CC_MSP430);
// Get a count of how many bytes are to be pushed on the stack.
unsigned NumBytes = CCInfo.getNextStackOffset();
Chain = DAG.getCALLSEQ_START(Chain ,DAG.getConstant(NumBytes,
getPointerTy(), true));
SmallVector<std::pair<unsigned, SDValue>, 4> RegsToPass;
SmallVector<SDValue, 12> MemOpChains;
SDValue StackPtr;
// Walk the register/memloc assignments, inserting copies/loads.
for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
CCValAssign &VA = ArgLocs[i];
// Arguments start after the 5 first operands of ISD::CALL
SDValue Arg = TheCall->getArg(i);
// Promote the value if needed.
switch (VA.getLocInfo()) {
default: llvm_unreachable("Unknown loc info!");
case CCValAssign::Full: break;
case CCValAssign::SExt:
Arg = DAG.getNode(ISD::SIGN_EXTEND, dl, VA.getLocVT(), Arg);
break;
case CCValAssign::ZExt:
Arg = DAG.getNode(ISD::ZERO_EXTEND, dl, VA.getLocVT(), Arg);
break;
case CCValAssign::AExt:
Arg = DAG.getNode(ISD::ANY_EXTEND, dl, VA.getLocVT(), Arg);
break;
}
// Arguments that can be passed on register must be kept at RegsToPass
// vector
if (VA.isRegLoc()) {
RegsToPass.push_back(std::make_pair(VA.getLocReg(), Arg));
} else {
assert(VA.isMemLoc());
if (StackPtr.getNode() == 0)
StackPtr = DAG.getCopyFromReg(Chain, dl, MSP430::SPW, getPointerTy());
SDValue PtrOff = DAG.getNode(ISD::ADD, dl, getPointerTy(),
StackPtr,
DAG.getIntPtrConstant(VA.getLocMemOffset()));
MemOpChains.push_back(DAG.getStore(Chain, dl, Arg, PtrOff,
PseudoSourceValue::getStack(),
VA.getLocMemOffset()));
}
}
// Transform all store nodes into one single node because all store nodes are
// independent of each other.
if (!MemOpChains.empty())
Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other,
&MemOpChains[0], MemOpChains.size());
// Build a sequence of copy-to-reg nodes chained together with token chain and
// flag operands which copy the outgoing args into registers. The InFlag in
// necessary since all emited instructions must be stuck together.
SDValue InFlag;
for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) {
Chain = DAG.getCopyToReg(Chain, dl, RegsToPass[i].first,
RegsToPass[i].second, InFlag);
InFlag = Chain.getValue(1);
}
// If the callee is a GlobalAddress node (quite common, every direct call is)
// turn it into a TargetGlobalAddress node so that legalize doesn't hack it.
// Likewise ExternalSymbol -> TargetExternalSymbol.
if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee))
Callee = DAG.getTargetGlobalAddress(G->getGlobal(), MVT::i16);
else if (ExternalSymbolSDNode *E = dyn_cast<ExternalSymbolSDNode>(Callee))
Callee = DAG.getTargetExternalSymbol(E->getSymbol(), MVT::i16);
// Returns a chain & a flag for retval copy to use.
SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Flag);
SmallVector<SDValue, 8> Ops;
Ops.push_back(Chain);
Ops.push_back(Callee);
// Add argument registers to the end of the list so that they are
// known live into the call.
for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i)
Ops.push_back(DAG.getRegister(RegsToPass[i].first,
RegsToPass[i].second.getValueType()));
if (InFlag.getNode())
Ops.push_back(InFlag);
Chain = DAG.getNode(MSP430ISD::CALL, dl, NodeTys, &Ops[0], Ops.size());
InFlag = Chain.getValue(1);
// Create the CALLSEQ_END node.
Chain = DAG.getCALLSEQ_END(Chain,
DAG.getConstant(NumBytes, getPointerTy(), true),
DAG.getConstant(0, getPointerTy(), true),
InFlag);
InFlag = Chain.getValue(1);
// Handle result values, copying them out of physregs into vregs that we
// return.
return SDValue(LowerCallResult(Chain, InFlag, TheCall, CC, DAG),
Op.getResNo());
}
/// LowerCallResult - Lower the result values of an ISD::CALL into the
/// appropriate copies out of appropriate physical registers. This assumes that
/// Chain/InFlag are the input chain/flag to use, and that TheCall is the call
/// being lowered. Returns a SDNode with the same number of values as the
/// ISD::CALL.
SDNode*
MSP430TargetLowering::LowerCallResult(SDValue Chain, SDValue InFlag,
CallSDNode *TheCall,
unsigned CallingConv,
SelectionDAG &DAG) {
bool isVarArg = TheCall->isVarArg();
DebugLoc dl = TheCall->getDebugLoc();
// Assign locations to each value returned by this call.
SmallVector<CCValAssign, 16> RVLocs;
CCState CCInfo(CallingConv, isVarArg, getTargetMachine(),
RVLocs, *DAG.getContext());
CCInfo.AnalyzeCallResult(TheCall, RetCC_MSP430);
SmallVector<SDValue, 8> ResultVals;
// Copy all of the result registers out of their specified physreg.
for (unsigned i = 0; i != RVLocs.size(); ++i) {
Chain = DAG.getCopyFromReg(Chain, dl, RVLocs[i].getLocReg(),
RVLocs[i].getValVT(), InFlag).getValue(1);
InFlag = Chain.getValue(2);
ResultVals.push_back(Chain.getValue(0));
}
ResultVals.push_back(Chain);
// Merge everything together with a MERGE_VALUES node.
return DAG.getNode(ISD::MERGE_VALUES, dl, TheCall->getVTList(),
&ResultVals[0], ResultVals.size()).getNode();
}
SDValue MSP430TargetLowering::LowerShifts(SDValue Op,
SelectionDAG &DAG) {
unsigned Opc = Op.getOpcode();
SDNode* N = Op.getNode();
MVT VT = Op.getValueType();
DebugLoc dl = N->getDebugLoc();
// We currently only lower shifts of constant argument.
if (!isa<ConstantSDNode>(N->getOperand(1)))
return SDValue();
uint64_t ShiftAmount = cast<ConstantSDNode>(N->getOperand(1))->getZExtValue();
// Expand the stuff into sequence of shifts.
// FIXME: for some shift amounts this might be done better!
// E.g.: foo >> (8 + N) => sxt(swpb(foo)) >> N
SDValue Victim = N->getOperand(0);
if (Opc == ISD::SRL && ShiftAmount) {
// Emit a special goodness here:
// srl A, 1 => clrc; rrc A
Victim = DAG.getNode(MSP430ISD::RRC, dl, VT, Victim);
ShiftAmount -= 1;
}
while (ShiftAmount--)
Victim = DAG.getNode((Opc == ISD::SHL ? MSP430ISD::RLA : MSP430ISD::RRA),
dl, VT, Victim);
return Victim;
}
SDValue MSP430TargetLowering::LowerGlobalAddress(SDValue Op, SelectionDAG &DAG) {
const GlobalValue *GV = cast<GlobalAddressSDNode>(Op)->getGlobal();
int64_t Offset = cast<GlobalAddressSDNode>(Op)->getOffset();
// Create the TargetGlobalAddress node, folding in the constant offset.
SDValue Result = DAG.getTargetGlobalAddress(GV, getPointerTy(), Offset);
return DAG.getNode(MSP430ISD::Wrapper, Op.getDebugLoc(),
getPointerTy(), Result);
}
SDValue MSP430TargetLowering::LowerExternalSymbol(SDValue Op,
SelectionDAG &DAG) {
DebugLoc dl = Op.getDebugLoc();
const char *Sym = cast<ExternalSymbolSDNode>(Op)->getSymbol();
SDValue Result = DAG.getTargetExternalSymbol(Sym, getPointerTy());
return DAG.getNode(MSP430ISD::Wrapper, dl, getPointerTy(), Result);;
}
static SDValue EmitCMP(SDValue &LHS, SDValue &RHS, unsigned &TargetCC,
ISD::CondCode CC,
DebugLoc dl, SelectionDAG &DAG) {
// FIXME: Handle bittests someday
assert(!LHS.getValueType().isFloatingPoint() && "We don't handle FP yet");
// FIXME: Handle jump negative someday
TargetCC = MSP430::COND_INVALID;
switch (CC) {
default: llvm_unreachable("Invalid integer condition!");
case ISD::SETEQ:
TargetCC = MSP430::COND_E; // aka COND_Z
break;
case ISD::SETNE:
TargetCC = MSP430::COND_NE; // aka COND_NZ
break;
case ISD::SETULE:
std::swap(LHS, RHS); // FALLTHROUGH
case ISD::SETUGE:
TargetCC = MSP430::COND_HS; // aka COND_C
break;
case ISD::SETUGT:
std::swap(LHS, RHS); // FALLTHROUGH
case ISD::SETULT:
TargetCC = MSP430::COND_LO; // aka COND_NC
break;
case ISD::SETLE:
std::swap(LHS, RHS); // FALLTHROUGH
case ISD::SETGE:
TargetCC = MSP430::COND_GE;
break;
case ISD::SETGT:
std::swap(LHS, RHS); // FALLTHROUGH
case ISD::SETLT:
TargetCC = MSP430::COND_L;
break;
}
return DAG.getNode(MSP430ISD::CMP, dl, MVT::Flag, LHS, RHS);
}
SDValue MSP430TargetLowering::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);
SDValue RHS = Op.getOperand(3);
SDValue Dest = Op.getOperand(4);
DebugLoc dl = Op.getDebugLoc();
unsigned TargetCC = MSP430::COND_INVALID;
SDValue Flag = EmitCMP(LHS, RHS, TargetCC, CC, dl, DAG);
return DAG.getNode(MSP430ISD::BR_CC, dl, Op.getValueType(),
Chain,
Dest, DAG.getConstant(TargetCC, MVT::i8),
Flag);
}
SDValue MSP430TargetLowering::LowerSELECT_CC(SDValue Op, SelectionDAG &DAG) {
SDValue LHS = Op.getOperand(0);
SDValue RHS = Op.getOperand(1);
SDValue TrueV = Op.getOperand(2);
SDValue FalseV = Op.getOperand(3);
ISD::CondCode CC = cast<CondCodeSDNode>(Op.getOperand(4))->get();
DebugLoc dl = Op.getDebugLoc();
unsigned TargetCC = MSP430::COND_INVALID;
SDValue Flag = EmitCMP(LHS, RHS, TargetCC, CC, dl, DAG);
SDVTList VTs = DAG.getVTList(Op.getValueType(), MVT::Flag);
SmallVector<SDValue, 4> Ops;
Ops.push_back(TrueV);
Ops.push_back(FalseV);
Ops.push_back(DAG.getConstant(TargetCC, MVT::i8));
Ops.push_back(Flag);
return DAG.getNode(MSP430ISD::SELECT_CC, dl, VTs, &Ops[0], Ops.size());
}
SDValue MSP430TargetLowering::LowerSIGN_EXTEND(SDValue Op,
SelectionDAG &DAG) {
SDValue Val = Op.getOperand(0);
MVT VT = Op.getValueType();
DebugLoc dl = Op.getDebugLoc();
assert(VT == MVT::i16 && "Only support i16 for now!");
return DAG.getNode(ISD::SIGN_EXTEND_INREG, dl, VT,
DAG.getNode(ISD::ANY_EXTEND, dl, VT, Val),
DAG.getValueType(Val.getValueType()));
}
const char *MSP430TargetLowering::getTargetNodeName(unsigned Opcode) const {
switch (Opcode) {
default: return NULL;
case MSP430ISD::RET_FLAG: return "MSP430ISD::RET_FLAG";
case MSP430ISD::RRA: return "MSP430ISD::RRA";
case MSP430ISD::RLA: return "MSP430ISD::RLA";
case MSP430ISD::RRC: return "MSP430ISD::RRC";
case MSP430ISD::CALL: return "MSP430ISD::CALL";
case MSP430ISD::Wrapper: return "MSP430ISD::Wrapper";
case MSP430ISD::BR_CC: return "MSP430ISD::BR_CC";
case MSP430ISD::CMP: return "MSP430ISD::CMP";
case MSP430ISD::SELECT_CC: return "MSP430ISD::SELECT_CC";
}
}
//===----------------------------------------------------------------------===//
// Other Lowering Code
//===----------------------------------------------------------------------===//
MachineBasicBlock*
MSP430TargetLowering::EmitInstrWithCustomInserter(MachineInstr *MI,
MachineBasicBlock *BB) const {
const TargetInstrInfo &TII = *getTargetMachine().getInstrInfo();
DebugLoc dl = MI->getDebugLoc();
assert((MI->getOpcode() == MSP430::Select16 ||
MI->getOpcode() == MSP430::Select8) &&
"Unexpected instr type to insert");
// To "insert" a SELECT 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 I = BB;
++I;
// thisMBB:
// ...
// TrueVal = ...
// cmpTY ccX, r1, r2
// jCC copy1MBB
// fallthrough --> copy0MBB
MachineBasicBlock *thisMBB = BB;
MachineFunction *F = BB->getParent();
MachineBasicBlock *copy0MBB = F->CreateMachineBasicBlock(LLVM_BB);
MachineBasicBlock *copy1MBB = F->CreateMachineBasicBlock(LLVM_BB);
BuildMI(BB, dl, TII.get(MSP430::JCC))
.addMBB(copy1MBB)
.addImm(MI->getOperand(3).getImm());
F->insert(I, copy0MBB);
F->insert(I, copy1MBB);
// 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.
copy1MBB->transferSuccessors(BB);
// Next, add the true and fallthrough blocks as its successors.
BB->addSuccessor(copy0MBB);
BB->addSuccessor(copy1MBB);
// copy0MBB:
// %FalseValue = ...
// # fallthrough to copy1MBB
BB = copy0MBB;
// Update machine-CFG edges
BB->addSuccessor(copy1MBB);
// copy1MBB:
// %Result = phi [ %FalseValue, copy0MBB ], [ %TrueValue, thisMBB ]
// ...
BB = copy1MBB;
BuildMI(BB, dl, TII.get(MSP430::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;
}
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