#include "llvm/GlobalVariable.h"
#include "llvm/Intrinsics.h"
#include "llvm/CallingConv.h"
+#include "InstPrinter/MipsInstPrinter.h"
#include "llvm/CodeGen/CallingConvLower.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/Support/ErrorHandling.h"
using namespace llvm;
+// If I is a shifted mask, set the size (Size) and the first bit of the
+// mask (Pos), and return true.
+// For example, if I is 0x003ff800, (Pos, Size) = (11, 11).
+static bool IsShiftedMask(uint64_t I, uint64_t &Pos, uint64_t &Size) {
+ if (!isUInt<32>(I) || !isShiftedMask_32(I))
+ return false;
+
+ Size = CountPopulation_32(I);
+ Pos = CountTrailingZeros_32(I);
+ return true;
+}
+
const char *MipsTargetLowering::getTargetNodeName(unsigned Opcode) const {
switch (Opcode) {
- case MipsISD::JmpLink : return "MipsISD::JmpLink";
- case MipsISD::Hi : return "MipsISD::Hi";
- case MipsISD::Lo : return "MipsISD::Lo";
- case MipsISD::GPRel : return "MipsISD::GPRel";
- case MipsISD::Ret : return "MipsISD::Ret";
- case MipsISD::FPBrcond : return "MipsISD::FPBrcond";
- case MipsISD::FPCmp : return "MipsISD::FPCmp";
- case MipsISD::CMovFP_T : return "MipsISD::CMovFP_T";
- case MipsISD::CMovFP_F : return "MipsISD::CMovFP_F";
- case MipsISD::FPRound : return "MipsISD::FPRound";
- case MipsISD::MAdd : return "MipsISD::MAdd";
- case MipsISD::MAddu : return "MipsISD::MAddu";
- case MipsISD::MSub : return "MipsISD::MSub";
- case MipsISD::MSubu : return "MipsISD::MSubu";
- case MipsISD::DivRem : return "MipsISD::DivRem";
- case MipsISD::DivRemU : return "MipsISD::DivRemU";
- case MipsISD::BuildPairF64: return "MipsISD::BuildPairF64";
- case MipsISD::ExtractElementF64: return "MipsISD::ExtractElementF64";
- default : return NULL;
+ case MipsISD::JmpLink: return "MipsISD::JmpLink";
+ case MipsISD::Hi: return "MipsISD::Hi";
+ case MipsISD::Lo: return "MipsISD::Lo";
+ case MipsISD::GPRel: return "MipsISD::GPRel";
+ case MipsISD::TlsGd: return "MipsISD::TlsGd";
+ case MipsISD::TprelHi: return "MipsISD::TprelHi";
+ case MipsISD::TprelLo: return "MipsISD::TprelLo";
+ case MipsISD::ThreadPointer: return "MipsISD::ThreadPointer";
+ case MipsISD::Ret: return "MipsISD::Ret";
+ case MipsISD::FPBrcond: return "MipsISD::FPBrcond";
+ case MipsISD::FPCmp: return "MipsISD::FPCmp";
+ case MipsISD::CMovFP_T: return "MipsISD::CMovFP_T";
+ case MipsISD::CMovFP_F: return "MipsISD::CMovFP_F";
+ case MipsISD::FPRound: return "MipsISD::FPRound";
+ case MipsISD::MAdd: return "MipsISD::MAdd";
+ case MipsISD::MAddu: return "MipsISD::MAddu";
+ case MipsISD::MSub: return "MipsISD::MSub";
+ case MipsISD::MSubu: return "MipsISD::MSubu";
+ case MipsISD::DivRem: return "MipsISD::DivRem";
+ case MipsISD::DivRemU: return "MipsISD::DivRemU";
+ case MipsISD::BuildPairF64: return "MipsISD::BuildPairF64";
+ case MipsISD::ExtractElementF64: return "MipsISD::ExtractElementF64";
+ case MipsISD::WrapperPIC: return "MipsISD::WrapperPIC";
+ case MipsISD::DynAlloc: return "MipsISD::DynAlloc";
+ case MipsISD::Sync: return "MipsISD::Sync";
+ case MipsISD::Ext: return "MipsISD::Ext";
+ case MipsISD::Ins: return "MipsISD::Ins";
+ default: return NULL;
}
}
// Mips does not have i1 type, so use i32 for
// setcc operations results (slt, sgt, ...).
setBooleanContents(ZeroOrOneBooleanContent);
+ setBooleanVectorContents(ZeroOrOneBooleanContent); // FIXME: Is this correct?
// Set up the register classes
addRegisterClass(MVT::i32, Mips::CPURegsRegisterClass);
setOperationAction(ISD::SELECT, MVT::i32, Custom);
setOperationAction(ISD::BRCOND, MVT::Other, Custom);
setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i32, Custom);
- setOperationAction(ISD::FP_TO_SINT, MVT::i32, Custom);
setOperationAction(ISD::VASTART, MVT::Other, Custom);
setOperationAction(ISD::SDIV, MVT::i32, Expand);
setOperationAction(ISD::SHL_PARTS, MVT::i32, Expand);
setOperationAction(ISD::SRA_PARTS, MVT::i32, Expand);
setOperationAction(ISD::SRL_PARTS, MVT::i32, Expand);
- setOperationAction(ISD::FCOPYSIGN, MVT::f32, Expand);
- setOperationAction(ISD::FCOPYSIGN, MVT::f64, Expand);
+ setOperationAction(ISD::FCOPYSIGN, MVT::f32, Custom);
+ setOperationAction(ISD::FCOPYSIGN, MVT::f64, Custom);
setOperationAction(ISD::FSIN, MVT::f32, Expand);
setOperationAction(ISD::FSIN, MVT::f64, Expand);
setOperationAction(ISD::FCOS, MVT::f32, Expand);
setOperationAction(ISD::FCOS, MVT::f64, Expand);
setOperationAction(ISD::FPOWI, MVT::f32, Expand);
setOperationAction(ISD::FPOW, MVT::f32, Expand);
+ setOperationAction(ISD::FPOW, MVT::f64, Expand);
setOperationAction(ISD::FLOG, MVT::f32, Expand);
setOperationAction(ISD::FLOG2, MVT::f32, Expand);
setOperationAction(ISD::FLOG10, MVT::f32, Expand);
setOperationAction(ISD::FEXP, MVT::f32, Expand);
+ setOperationAction(ISD::FMA, MVT::f32, Expand);
+ setOperationAction(ISD::FMA, MVT::f64, Expand);
- setOperationAction(ISD::EH_LABEL, MVT::Other, Expand);
+ setOperationAction(ISD::EXCEPTIONADDR, MVT::i32, Expand);
+ setOperationAction(ISD::EHSELECTION, MVT::i32, Expand);
setOperationAction(ISD::VAARG, MVT::Other, Expand);
setOperationAction(ISD::VACOPY, MVT::Other, Expand);
// Use the default for now
setOperationAction(ISD::STACKSAVE, MVT::Other, Expand);
setOperationAction(ISD::STACKRESTORE, MVT::Other, Expand);
- setOperationAction(ISD::MEMBARRIER, MVT::Other, Expand);
+
+ setOperationAction(ISD::MEMBARRIER, MVT::Other, Custom);
+ setOperationAction(ISD::ATOMIC_FENCE, MVT::Other, Custom);
+
+ setOperationAction(ISD::ATOMIC_LOAD, MVT::i32, Expand);
+ setOperationAction(ISD::ATOMIC_STORE, MVT::i32, Expand);
+
+ setInsertFencesForAtomic(true);
if (Subtarget->isSingleFloat())
setOperationAction(ISD::SELECT_CC, MVT::f64, Expand);
setTargetDAGCombine(ISD::SDIVREM);
setTargetDAGCombine(ISD::UDIVREM);
setTargetDAGCombine(ISD::SETCC);
+ setTargetDAGCombine(ISD::AND);
+ setTargetDAGCombine(ISD::OR);
setMinFunctionAlignment(2);
setStackPointerRegisterToSaveRestore(Mips::SP);
computeRegisterProperties();
+
+ setExceptionPointerRegister(Mips::A0);
+ setExceptionSelectorRegister(Mips::A1);
+}
+
+bool MipsTargetLowering::allowsUnalignedMemoryAccesses(EVT VT) const {
+ MVT::SimpleValueType SVT = VT.getSimpleVT().SimpleTy;
+ return SVT == MVT::i32 || SVT == MVT::i16;
}
-MVT::SimpleValueType MipsTargetLowering::getSetCCResultType(EVT VT) const {
+EVT MipsTargetLowering::getSetCCResultType(EVT VT) const {
return MVT::i32;
}
// insert MFHI
if (N->hasAnyUseOfValue(1)) {
SDValue CopyFromHi = DAG.getCopyFromReg(InChain, dl,
- Mips::HI, MVT::i32, InGlue);
+ Mips::HI, MVT::i32, InGlue);
DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), CopyFromHi);
}
return CreateCMovFP(DAG, Cond, True, False, N->getDebugLoc());
}
+static SDValue PerformANDCombine(SDNode *N, SelectionDAG& DAG,
+ TargetLowering::DAGCombinerInfo &DCI,
+ const MipsSubtarget* Subtarget) {
+ // Pattern match EXT.
+ // $dst = and ((sra or srl) $src , pos), (2**size - 1)
+ // => ext $dst, $src, size, pos
+ if (DCI.isBeforeLegalizeOps() || !Subtarget->isMips32r2())
+ return SDValue();
+
+ SDValue ShiftRight = N->getOperand(0), Mask = N->getOperand(1);
+
+ // Op's first operand must be a shift right.
+ if (ShiftRight.getOpcode() != ISD::SRA && ShiftRight.getOpcode() != ISD::SRL)
+ return SDValue();
+
+ // The second operand of the shift must be an immediate.
+ uint64_t Pos;
+ ConstantSDNode *CN;
+ if (!(CN = dyn_cast<ConstantSDNode>(ShiftRight.getOperand(1))))
+ return SDValue();
+
+ Pos = CN->getZExtValue();
+
+ uint64_t SMPos, SMSize;
+ // Op's second operand must be a shifted mask.
+ if (!(CN = dyn_cast<ConstantSDNode>(Mask)) ||
+ !IsShiftedMask(CN->getZExtValue(), SMPos, SMSize))
+ return SDValue();
+
+ // Return if the shifted mask does not start at bit 0 or the sum of its size
+ // and Pos exceeds the word's size.
+ if (SMPos != 0 || Pos + SMSize > 32)
+ return SDValue();
+
+ return DAG.getNode(MipsISD::Ext, N->getDebugLoc(), MVT::i32,
+ ShiftRight.getOperand(0),
+ DAG.getConstant(Pos, MVT::i32),
+ DAG.getConstant(SMSize, MVT::i32));
+}
+
+static SDValue PerformORCombine(SDNode *N, SelectionDAG& DAG,
+ TargetLowering::DAGCombinerInfo &DCI,
+ const MipsSubtarget* Subtarget) {
+ // Pattern match INS.
+ // $dst = or (and $src1 , mask0), (and (shl $src, pos), mask1),
+ // where mask1 = (2**size - 1) << pos, mask0 = ~mask1
+ // => ins $dst, $src, size, pos, $src1
+ if (DCI.isBeforeLegalizeOps() || !Subtarget->isMips32r2())
+ return SDValue();
+
+ SDValue And0 = N->getOperand(0), And1 = N->getOperand(1);
+ uint64_t SMPos0, SMSize0, SMPos1, SMSize1;
+ ConstantSDNode *CN;
+
+ // See if Op's first operand matches (and $src1 , mask0).
+ if (And0.getOpcode() != ISD::AND)
+ return SDValue();
+
+ if (!(CN = dyn_cast<ConstantSDNode>(And0.getOperand(1))) ||
+ !IsShiftedMask(~CN->getSExtValue(), SMPos0, SMSize0))
+ return SDValue();
+
+ // See if Op's second operand matches (and (shl $src, pos), mask1).
+ if (And1.getOpcode() != ISD::AND)
+ return SDValue();
+
+ if (!(CN = dyn_cast<ConstantSDNode>(And1.getOperand(1))) ||
+ !IsShiftedMask(CN->getZExtValue(), SMPos1, SMSize1))
+ return SDValue();
+
+ // The shift masks must have the same position and size.
+ if (SMPos0 != SMPos1 || SMSize0 != SMSize1)
+ return SDValue();
+
+ SDValue Shl = And1.getOperand(0);
+ if (Shl.getOpcode() != ISD::SHL)
+ return SDValue();
+
+ if (!(CN = dyn_cast<ConstantSDNode>(Shl.getOperand(1))))
+ return SDValue();
+
+ unsigned Shamt = CN->getZExtValue();
+
+ // Return if the shift amount and the first bit position of mask are not the
+ // same.
+ if (Shamt != SMPos0)
+ return SDValue();
+
+ return DAG.getNode(MipsISD::Ins, N->getDebugLoc(), MVT::i32,
+ Shl.getOperand(0),
+ DAG.getConstant(SMPos0, MVT::i32),
+ DAG.getConstant(SMSize0, MVT::i32),
+ And0.getOperand(0));
+}
+
SDValue MipsTargetLowering::PerformDAGCombine(SDNode *N, DAGCombinerInfo &DCI)
const {
SelectionDAG &DAG = DCI.DAG;
return PerformDivRemCombine(N, DAG, DCI, Subtarget);
case ISD::SETCC:
return PerformSETCCCombine(N, DAG, DCI, Subtarget);
+ case ISD::AND:
+ return PerformANDCombine(N, DAG, DCI, Subtarget);
+ case ISD::OR:
+ return PerformORCombine(N, DAG, DCI, Subtarget);
}
return SDValue();
case ISD::BRCOND: return LowerBRCOND(Op, DAG);
case ISD::ConstantPool: return LowerConstantPool(Op, DAG);
case ISD::DYNAMIC_STACKALLOC: return LowerDYNAMIC_STACKALLOC(Op, DAG);
- case ISD::FP_TO_SINT: return LowerFP_TO_SINT(Op, DAG);
case ISD::GlobalAddress: return LowerGlobalAddress(Op, DAG);
case ISD::BlockAddress: return LowerBlockAddress(Op, DAG);
case ISD::GlobalTLSAddress: return LowerGlobalTLSAddress(Op, DAG);
case ISD::JumpTable: return LowerJumpTable(Op, DAG);
case ISD::SELECT: return LowerSELECT(Op, DAG);
case ISD::VASTART: return LowerVASTART(Op, DAG);
+ case ISD::FCOPYSIGN: return LowerFCOPYSIGN(Op, DAG);
+ case ISD::FRAMEADDR: return LowerFRAMEADDR(Op, DAG);
+ case ISD::MEMBARRIER: return LowerMEMBARRIER(Op, DAG);
+ case ISD::ATOMIC_FENCE: return LowerATOMIC_FENCE(Op, DAG);
}
return SDValue();
}
return Mips::BRANCH_INVALID;
}
-MachineBasicBlock *
-MipsTargetLowering::EmitInstrWithCustomInserter(MachineInstr *MI,
- MachineBasicBlock *BB) const {
+static MachineBasicBlock* ExpandCondMov(MachineInstr *MI, MachineBasicBlock *BB,
+ DebugLoc dl,
+ const MipsSubtarget* Subtarget,
+ const TargetInstrInfo *TII,
+ bool isFPCmp, unsigned Opc) {
// There is no need to expand CMov instructions if target has
// conditional moves.
if (Subtarget->hasCondMov())
return BB;
- const TargetInstrInfo *TII = getTargetMachine().getInstrInfo();
- bool isFPCmp = false;
- DebugLoc dl = MI->getDebugLoc();
- unsigned Opc;
-
- switch (MI->getOpcode()) {
- default: assert(false && "Unexpected instr type to insert");
- case Mips::MOVT:
- case Mips::MOVT_S:
- case Mips::MOVT_D:
- isFPCmp = true;
- Opc = Mips::BC1F;
- break;
- case Mips::MOVF:
- case Mips::MOVF_S:
- case Mips::MOVF_D:
- isFPCmp = true;
- Opc = Mips::BC1T;
- break;
- case Mips::MOVZ_I:
- case Mips::MOVZ_S:
- case Mips::MOVZ_D:
- Opc = Mips::BNE;
- break;
- case Mips::MOVN_I:
- case Mips::MOVN_S:
- case Mips::MOVN_D:
- Opc = Mips::BEQ;
- break;
- }
-
// 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
BuildMI(BB, dl, TII->get(Opc)).addReg(MI->getOperand(2).getReg())
.addReg(Mips::ZERO).addMBB(sinkMBB);
-
// copy0MBB:
// %FalseValue = ...
// # fallthrough to sinkMBB
return BB;
}
-//===----------------------------------------------------------------------===//
-// Misc Lower Operation implementation
-//===----------------------------------------------------------------------===//
+MachineBasicBlock *
+MipsTargetLowering::EmitInstrWithCustomInserter(MachineInstr *MI,
+ MachineBasicBlock *BB) const {
+ const TargetInstrInfo *TII = getTargetMachine().getInstrInfo();
+ DebugLoc dl = MI->getDebugLoc();
-SDValue MipsTargetLowering::
-LowerFP_TO_SINT(SDValue Op, SelectionDAG &DAG) const
-{
- if (!Subtarget->isMips1())
- return Op;
+ switch (MI->getOpcode()) {
+ default:
+ assert(false && "Unexpected instr type to insert");
+ return NULL;
+ case Mips::MOVT:
+ case Mips::MOVT_S:
+ case Mips::MOVT_D:
+ return ExpandCondMov(MI, BB, dl, Subtarget, TII, true, Mips::BC1F);
+ case Mips::MOVF:
+ case Mips::MOVF_S:
+ case Mips::MOVF_D:
+ return ExpandCondMov(MI, BB, dl, Subtarget, TII, true, Mips::BC1T);
+ case Mips::MOVZ_I:
+ case Mips::MOVZ_S:
+ case Mips::MOVZ_D:
+ return ExpandCondMov(MI, BB, dl, Subtarget, TII, false, Mips::BNE);
+ case Mips::MOVN_I:
+ case Mips::MOVN_S:
+ case Mips::MOVN_D:
+ return ExpandCondMov(MI, BB, dl, Subtarget, TII, false, Mips::BEQ);
+
+ case Mips::ATOMIC_LOAD_ADD_I8:
+ return EmitAtomicBinaryPartword(MI, BB, 1, Mips::ADDu);
+ case Mips::ATOMIC_LOAD_ADD_I16:
+ return EmitAtomicBinaryPartword(MI, BB, 2, Mips::ADDu);
+ case Mips::ATOMIC_LOAD_ADD_I32:
+ return EmitAtomicBinary(MI, BB, 4, Mips::ADDu);
+
+ case Mips::ATOMIC_LOAD_AND_I8:
+ return EmitAtomicBinaryPartword(MI, BB, 1, Mips::AND);
+ case Mips::ATOMIC_LOAD_AND_I16:
+ return EmitAtomicBinaryPartword(MI, BB, 2, Mips::AND);
+ case Mips::ATOMIC_LOAD_AND_I32:
+ return EmitAtomicBinary(MI, BB, 4, Mips::AND);
+
+ case Mips::ATOMIC_LOAD_OR_I8:
+ return EmitAtomicBinaryPartword(MI, BB, 1, Mips::OR);
+ case Mips::ATOMIC_LOAD_OR_I16:
+ return EmitAtomicBinaryPartword(MI, BB, 2, Mips::OR);
+ case Mips::ATOMIC_LOAD_OR_I32:
+ return EmitAtomicBinary(MI, BB, 4, Mips::OR);
+
+ case Mips::ATOMIC_LOAD_XOR_I8:
+ return EmitAtomicBinaryPartword(MI, BB, 1, Mips::XOR);
+ case Mips::ATOMIC_LOAD_XOR_I16:
+ return EmitAtomicBinaryPartword(MI, BB, 2, Mips::XOR);
+ case Mips::ATOMIC_LOAD_XOR_I32:
+ return EmitAtomicBinary(MI, BB, 4, Mips::XOR);
+
+ case Mips::ATOMIC_LOAD_NAND_I8:
+ return EmitAtomicBinaryPartword(MI, BB, 1, 0, true);
+ case Mips::ATOMIC_LOAD_NAND_I16:
+ return EmitAtomicBinaryPartword(MI, BB, 2, 0, true);
+ case Mips::ATOMIC_LOAD_NAND_I32:
+ return EmitAtomicBinary(MI, BB, 4, 0, true);
+
+ case Mips::ATOMIC_LOAD_SUB_I8:
+ return EmitAtomicBinaryPartword(MI, BB, 1, Mips::SUBu);
+ case Mips::ATOMIC_LOAD_SUB_I16:
+ return EmitAtomicBinaryPartword(MI, BB, 2, Mips::SUBu);
+ case Mips::ATOMIC_LOAD_SUB_I32:
+ return EmitAtomicBinary(MI, BB, 4, Mips::SUBu);
+
+ case Mips::ATOMIC_SWAP_I8:
+ return EmitAtomicBinaryPartword(MI, BB, 1, 0);
+ case Mips::ATOMIC_SWAP_I16:
+ return EmitAtomicBinaryPartword(MI, BB, 2, 0);
+ case Mips::ATOMIC_SWAP_I32:
+ return EmitAtomicBinary(MI, BB, 4, 0);
+
+ case Mips::ATOMIC_CMP_SWAP_I8:
+ return EmitAtomicCmpSwapPartword(MI, BB, 1);
+ case Mips::ATOMIC_CMP_SWAP_I16:
+ return EmitAtomicCmpSwapPartword(MI, BB, 2);
+ case Mips::ATOMIC_CMP_SWAP_I32:
+ return EmitAtomicCmpSwap(MI, BB, 4);
+ }
+}
- MachineFunction &MF = DAG.getMachineFunction();
- unsigned CCReg = AddLiveIn(MF, Mips::FCR31, Mips::CCRRegisterClass);
+// This function also handles Mips::ATOMIC_SWAP_I32 (when BinOpcode == 0), and
+// Mips::ATOMIC_LOAD_NAND_I32 (when Nand == true)
+MachineBasicBlock *
+MipsTargetLowering::EmitAtomicBinary(MachineInstr *MI, MachineBasicBlock *BB,
+ unsigned Size, unsigned BinOpcode,
+ bool Nand) const {
+ assert(Size == 4 && "Unsupported size for EmitAtomicBinary.");
+
+ MachineFunction *MF = BB->getParent();
+ MachineRegisterInfo &RegInfo = MF->getRegInfo();
+ const TargetRegisterClass *RC = getRegClassFor(MVT::i32);
+ const TargetInstrInfo *TII = getTargetMachine().getInstrInfo();
+ DebugLoc dl = MI->getDebugLoc();
- SDValue Chain = DAG.getEntryNode();
- DebugLoc dl = Op.getDebugLoc();
- SDValue Src = Op.getOperand(0);
-
- // Set the condition register
- SDValue CondReg = DAG.getCopyFromReg(Chain, dl, CCReg, MVT::i32);
- CondReg = DAG.getCopyToReg(Chain, dl, Mips::AT, CondReg);
- CondReg = DAG.getCopyFromReg(CondReg, dl, Mips::AT, MVT::i32);
-
- SDValue Cst = DAG.getConstant(3, MVT::i32);
- SDValue Or = DAG.getNode(ISD::OR, dl, MVT::i32, CondReg, Cst);
- Cst = DAG.getConstant(2, MVT::i32);
- SDValue Xor = DAG.getNode(ISD::XOR, dl, MVT::i32, Or, Cst);
-
- SDValue InFlag(0, 0);
- CondReg = DAG.getCopyToReg(Chain, dl, Mips::FCR31, Xor, InFlag);
-
- // Emit the round instruction and bit convert to integer
- SDValue Trunc = DAG.getNode(MipsISD::FPRound, dl, MVT::f32,
- Src, CondReg.getValue(1));
- SDValue BitCvt = DAG.getNode(ISD::BITCAST, dl, MVT::i32, Trunc);
- return BitCvt;
+ unsigned OldVal = MI->getOperand(0).getReg();
+ unsigned Ptr = MI->getOperand(1).getReg();
+ unsigned Incr = MI->getOperand(2).getReg();
+
+ unsigned StoreVal = RegInfo.createVirtualRegister(RC);
+ unsigned AndRes = RegInfo.createVirtualRegister(RC);
+ unsigned Success = RegInfo.createVirtualRegister(RC);
+
+ // insert new blocks after the current block
+ const BasicBlock *LLVM_BB = BB->getBasicBlock();
+ MachineBasicBlock *loopMBB = MF->CreateMachineBasicBlock(LLVM_BB);
+ MachineBasicBlock *exitMBB = MF->CreateMachineBasicBlock(LLVM_BB);
+ MachineFunction::iterator It = BB;
+ ++It;
+ MF->insert(It, loopMBB);
+ MF->insert(It, exitMBB);
+
+ // Transfer the remainder of BB and its successor edges to exitMBB.
+ exitMBB->splice(exitMBB->begin(), BB,
+ llvm::next(MachineBasicBlock::iterator(MI)),
+ BB->end());
+ exitMBB->transferSuccessorsAndUpdatePHIs(BB);
+
+ // thisMBB:
+ // ...
+ // fallthrough --> loopMBB
+ BB->addSuccessor(loopMBB);
+ loopMBB->addSuccessor(loopMBB);
+ loopMBB->addSuccessor(exitMBB);
+
+ // loopMBB:
+ // ll oldval, 0(ptr)
+ // <binop> storeval, oldval, incr
+ // sc success, storeval, 0(ptr)
+ // beq success, $0, loopMBB
+ BB = loopMBB;
+ BuildMI(BB, dl, TII->get(Mips::LL), OldVal).addReg(Ptr).addImm(0);
+ if (Nand) {
+ // and andres, oldval, incr
+ // nor storeval, $0, andres
+ BuildMI(BB, dl, TII->get(Mips::AND), AndRes).addReg(OldVal).addReg(Incr);
+ BuildMI(BB, dl, TII->get(Mips::NOR), StoreVal)
+ .addReg(Mips::ZERO).addReg(AndRes);
+ } else if (BinOpcode) {
+ // <binop> storeval, oldval, incr
+ BuildMI(BB, dl, TII->get(BinOpcode), StoreVal).addReg(OldVal).addReg(Incr);
+ } else {
+ StoreVal = Incr;
+ }
+ BuildMI(BB, dl, TII->get(Mips::SC), Success)
+ .addReg(StoreVal).addReg(Ptr).addImm(0);
+ BuildMI(BB, dl, TII->get(Mips::BEQ))
+ .addReg(Success).addReg(Mips::ZERO).addMBB(loopMBB);
+
+ MI->eraseFromParent(); // The instruction is gone now.
+
+ return exitMBB;
+}
+
+MachineBasicBlock *
+MipsTargetLowering::EmitAtomicBinaryPartword(MachineInstr *MI,
+ MachineBasicBlock *BB,
+ unsigned Size, unsigned BinOpcode,
+ bool Nand) const {
+ assert((Size == 1 || Size == 2) &&
+ "Unsupported size for EmitAtomicBinaryPartial.");
+
+ MachineFunction *MF = BB->getParent();
+ MachineRegisterInfo &RegInfo = MF->getRegInfo();
+ const TargetRegisterClass *RC = getRegClassFor(MVT::i32);
+ const TargetInstrInfo *TII = getTargetMachine().getInstrInfo();
+ DebugLoc dl = MI->getDebugLoc();
+
+ unsigned Dest = MI->getOperand(0).getReg();
+ unsigned Ptr = MI->getOperand(1).getReg();
+ unsigned Incr = MI->getOperand(2).getReg();
+
+ unsigned AlignedAddr = RegInfo.createVirtualRegister(RC);
+ unsigned ShiftAmt = RegInfo.createVirtualRegister(RC);
+ unsigned Mask = RegInfo.createVirtualRegister(RC);
+ unsigned Mask2 = RegInfo.createVirtualRegister(RC);
+ unsigned NewVal = RegInfo.createVirtualRegister(RC);
+ unsigned OldVal = RegInfo.createVirtualRegister(RC);
+ unsigned Incr2 = RegInfo.createVirtualRegister(RC);
+ unsigned MaskLSB2 = RegInfo.createVirtualRegister(RC);
+ unsigned PtrLSB2 = RegInfo.createVirtualRegister(RC);
+ unsigned MaskUpper = RegInfo.createVirtualRegister(RC);
+ unsigned AndRes = RegInfo.createVirtualRegister(RC);
+ unsigned BinOpRes = RegInfo.createVirtualRegister(RC);
+ unsigned MaskedOldVal0 = RegInfo.createVirtualRegister(RC);
+ unsigned StoreVal = RegInfo.createVirtualRegister(RC);
+ unsigned MaskedOldVal1 = RegInfo.createVirtualRegister(RC);
+ unsigned SrlRes = RegInfo.createVirtualRegister(RC);
+ unsigned SllRes = RegInfo.createVirtualRegister(RC);
+ unsigned Success = RegInfo.createVirtualRegister(RC);
+
+ // insert new blocks after the current block
+ const BasicBlock *LLVM_BB = BB->getBasicBlock();
+ MachineBasicBlock *loopMBB = MF->CreateMachineBasicBlock(LLVM_BB);
+ MachineBasicBlock *sinkMBB = MF->CreateMachineBasicBlock(LLVM_BB);
+ MachineBasicBlock *exitMBB = MF->CreateMachineBasicBlock(LLVM_BB);
+ MachineFunction::iterator It = BB;
+ ++It;
+ MF->insert(It, loopMBB);
+ MF->insert(It, sinkMBB);
+ MF->insert(It, exitMBB);
+
+ // Transfer the remainder of BB and its successor edges to exitMBB.
+ exitMBB->splice(exitMBB->begin(), BB,
+ llvm::next(MachineBasicBlock::iterator(MI)),
+ BB->end());
+ exitMBB->transferSuccessorsAndUpdatePHIs(BB);
+
+ BB->addSuccessor(loopMBB);
+ loopMBB->addSuccessor(loopMBB);
+ loopMBB->addSuccessor(sinkMBB);
+ sinkMBB->addSuccessor(exitMBB);
+
+ // thisMBB:
+ // addiu masklsb2,$0,-4 # 0xfffffffc
+ // and alignedaddr,ptr,masklsb2
+ // andi ptrlsb2,ptr,3
+ // sll shiftamt,ptrlsb2,3
+ // ori maskupper,$0,255 # 0xff
+ // sll mask,maskupper,shiftamt
+ // nor mask2,$0,mask
+ // sll incr2,incr,shiftamt
+
+ int64_t MaskImm = (Size == 1) ? 255 : 65535;
+ BuildMI(BB, dl, TII->get(Mips::ADDiu), MaskLSB2)
+ .addReg(Mips::ZERO).addImm(-4);
+ BuildMI(BB, dl, TII->get(Mips::AND), AlignedAddr)
+ .addReg(Ptr).addReg(MaskLSB2);
+ BuildMI(BB, dl, TII->get(Mips::ANDi), PtrLSB2).addReg(Ptr).addImm(3);
+ BuildMI(BB, dl, TII->get(Mips::SLL), ShiftAmt).addReg(PtrLSB2).addImm(3);
+ BuildMI(BB, dl, TII->get(Mips::ORi), MaskUpper)
+ .addReg(Mips::ZERO).addImm(MaskImm);
+ BuildMI(BB, dl, TII->get(Mips::SLLV), Mask)
+ .addReg(ShiftAmt).addReg(MaskUpper);
+ BuildMI(BB, dl, TII->get(Mips::NOR), Mask2).addReg(Mips::ZERO).addReg(Mask);
+ BuildMI(BB, dl, TII->get(Mips::SLLV), Incr2).addReg(ShiftAmt).addReg(Incr);
+
+
+ // atomic.load.binop
+ // loopMBB:
+ // ll oldval,0(alignedaddr)
+ // binop binopres,oldval,incr2
+ // and newval,binopres,mask
+ // and maskedoldval0,oldval,mask2
+ // or storeval,maskedoldval0,newval
+ // sc success,storeval,0(alignedaddr)
+ // beq success,$0,loopMBB
+
+ // atomic.swap
+ // loopMBB:
+ // ll oldval,0(alignedaddr)
+ // and newval,incr2,mask
+ // and maskedoldval0,oldval,mask2
+ // or storeval,maskedoldval0,newval
+ // sc success,storeval,0(alignedaddr)
+ // beq success,$0,loopMBB
+
+ BB = loopMBB;
+ BuildMI(BB, dl, TII->get(Mips::LL), OldVal).addReg(AlignedAddr).addImm(0);
+ if (Nand) {
+ // and andres, oldval, incr2
+ // nor binopres, $0, andres
+ // and newval, binopres, mask
+ BuildMI(BB, dl, TII->get(Mips::AND), AndRes).addReg(OldVal).addReg(Incr2);
+ BuildMI(BB, dl, TII->get(Mips::NOR), BinOpRes)
+ .addReg(Mips::ZERO).addReg(AndRes);
+ BuildMI(BB, dl, TII->get(Mips::AND), NewVal).addReg(BinOpRes).addReg(Mask);
+ } else if (BinOpcode) {
+ // <binop> binopres, oldval, incr2
+ // and newval, binopres, mask
+ BuildMI(BB, dl, TII->get(BinOpcode), BinOpRes).addReg(OldVal).addReg(Incr2);
+ BuildMI(BB, dl, TII->get(Mips::AND), NewVal).addReg(BinOpRes).addReg(Mask);
+ } else {// atomic.swap
+ // and newval, incr2, mask
+ BuildMI(BB, dl, TII->get(Mips::AND), NewVal).addReg(Incr2).addReg(Mask);
+ }
+
+ BuildMI(BB, dl, TII->get(Mips::AND), MaskedOldVal0)
+ .addReg(OldVal).addReg(Mask2);
+ BuildMI(BB, dl, TII->get(Mips::OR), StoreVal)
+ .addReg(MaskedOldVal0).addReg(NewVal);
+ BuildMI(BB, dl, TII->get(Mips::SC), Success)
+ .addReg(StoreVal).addReg(AlignedAddr).addImm(0);
+ BuildMI(BB, dl, TII->get(Mips::BEQ))
+ .addReg(Success).addReg(Mips::ZERO).addMBB(loopMBB);
+
+ // sinkMBB:
+ // and maskedoldval1,oldval,mask
+ // srl srlres,maskedoldval1,shiftamt
+ // sll sllres,srlres,24
+ // sra dest,sllres,24
+ BB = sinkMBB;
+ int64_t ShiftImm = (Size == 1) ? 24 : 16;
+
+ BuildMI(BB, dl, TII->get(Mips::AND), MaskedOldVal1)
+ .addReg(OldVal).addReg(Mask);
+ BuildMI(BB, dl, TII->get(Mips::SRLV), SrlRes)
+ .addReg(ShiftAmt).addReg(MaskedOldVal1);
+ BuildMI(BB, dl, TII->get(Mips::SLL), SllRes)
+ .addReg(SrlRes).addImm(ShiftImm);
+ BuildMI(BB, dl, TII->get(Mips::SRA), Dest)
+ .addReg(SllRes).addImm(ShiftImm);
+
+ MI->eraseFromParent(); // The instruction is gone now.
+
+ return exitMBB;
+}
+
+MachineBasicBlock *
+MipsTargetLowering::EmitAtomicCmpSwap(MachineInstr *MI,
+ MachineBasicBlock *BB,
+ unsigned Size) const {
+ assert(Size == 4 && "Unsupported size for EmitAtomicCmpSwap.");
+
+ MachineFunction *MF = BB->getParent();
+ MachineRegisterInfo &RegInfo = MF->getRegInfo();
+ const TargetRegisterClass *RC = getRegClassFor(MVT::i32);
+ const TargetInstrInfo *TII = getTargetMachine().getInstrInfo();
+ DebugLoc dl = MI->getDebugLoc();
+
+ unsigned Dest = MI->getOperand(0).getReg();
+ unsigned Ptr = MI->getOperand(1).getReg();
+ unsigned OldVal = MI->getOperand(2).getReg();
+ unsigned NewVal = MI->getOperand(3).getReg();
+
+ unsigned Success = RegInfo.createVirtualRegister(RC);
+
+ // insert new blocks after the current block
+ const BasicBlock *LLVM_BB = BB->getBasicBlock();
+ MachineBasicBlock *loop1MBB = MF->CreateMachineBasicBlock(LLVM_BB);
+ MachineBasicBlock *loop2MBB = MF->CreateMachineBasicBlock(LLVM_BB);
+ MachineBasicBlock *exitMBB = MF->CreateMachineBasicBlock(LLVM_BB);
+ MachineFunction::iterator It = BB;
+ ++It;
+ MF->insert(It, loop1MBB);
+ MF->insert(It, loop2MBB);
+ MF->insert(It, exitMBB);
+
+ // Transfer the remainder of BB and its successor edges to exitMBB.
+ exitMBB->splice(exitMBB->begin(), BB,
+ llvm::next(MachineBasicBlock::iterator(MI)),
+ BB->end());
+ exitMBB->transferSuccessorsAndUpdatePHIs(BB);
+
+ // thisMBB:
+ // ...
+ // fallthrough --> loop1MBB
+ BB->addSuccessor(loop1MBB);
+ loop1MBB->addSuccessor(exitMBB);
+ loop1MBB->addSuccessor(loop2MBB);
+ loop2MBB->addSuccessor(loop1MBB);
+ loop2MBB->addSuccessor(exitMBB);
+
+ // loop1MBB:
+ // ll dest, 0(ptr)
+ // bne dest, oldval, exitMBB
+ BB = loop1MBB;
+ BuildMI(BB, dl, TII->get(Mips::LL), Dest).addReg(Ptr).addImm(0);
+ BuildMI(BB, dl, TII->get(Mips::BNE))
+ .addReg(Dest).addReg(OldVal).addMBB(exitMBB);
+
+ // loop2MBB:
+ // sc success, newval, 0(ptr)
+ // beq success, $0, loop1MBB
+ BB = loop2MBB;
+ BuildMI(BB, dl, TII->get(Mips::SC), Success)
+ .addReg(NewVal).addReg(Ptr).addImm(0);
+ BuildMI(BB, dl, TII->get(Mips::BEQ))
+ .addReg(Success).addReg(Mips::ZERO).addMBB(loop1MBB);
+
+ MI->eraseFromParent(); // The instruction is gone now.
+
+ return exitMBB;
+}
+
+MachineBasicBlock *
+MipsTargetLowering::EmitAtomicCmpSwapPartword(MachineInstr *MI,
+ MachineBasicBlock *BB,
+ unsigned Size) const {
+ assert((Size == 1 || Size == 2) &&
+ "Unsupported size for EmitAtomicCmpSwapPartial.");
+
+ MachineFunction *MF = BB->getParent();
+ MachineRegisterInfo &RegInfo = MF->getRegInfo();
+ const TargetRegisterClass *RC = getRegClassFor(MVT::i32);
+ const TargetInstrInfo *TII = getTargetMachine().getInstrInfo();
+ DebugLoc dl = MI->getDebugLoc();
+
+ unsigned Dest = MI->getOperand(0).getReg();
+ unsigned Ptr = MI->getOperand(1).getReg();
+ unsigned CmpVal = MI->getOperand(2).getReg();
+ unsigned NewVal = MI->getOperand(3).getReg();
+
+ unsigned AlignedAddr = RegInfo.createVirtualRegister(RC);
+ unsigned ShiftAmt = RegInfo.createVirtualRegister(RC);
+ unsigned Mask = RegInfo.createVirtualRegister(RC);
+ unsigned Mask2 = RegInfo.createVirtualRegister(RC);
+ unsigned ShiftedCmpVal = RegInfo.createVirtualRegister(RC);
+ unsigned OldVal = RegInfo.createVirtualRegister(RC);
+ unsigned MaskedOldVal0 = RegInfo.createVirtualRegister(RC);
+ unsigned ShiftedNewVal = RegInfo.createVirtualRegister(RC);
+ unsigned MaskLSB2 = RegInfo.createVirtualRegister(RC);
+ unsigned PtrLSB2 = RegInfo.createVirtualRegister(RC);
+ unsigned MaskUpper = RegInfo.createVirtualRegister(RC);
+ unsigned MaskedCmpVal = RegInfo.createVirtualRegister(RC);
+ unsigned MaskedNewVal = RegInfo.createVirtualRegister(RC);
+ unsigned MaskedOldVal1 = RegInfo.createVirtualRegister(RC);
+ unsigned StoreVal = RegInfo.createVirtualRegister(RC);
+ unsigned SrlRes = RegInfo.createVirtualRegister(RC);
+ unsigned SllRes = RegInfo.createVirtualRegister(RC);
+ unsigned Success = RegInfo.createVirtualRegister(RC);
+
+ // insert new blocks after the current block
+ const BasicBlock *LLVM_BB = BB->getBasicBlock();
+ MachineBasicBlock *loop1MBB = MF->CreateMachineBasicBlock(LLVM_BB);
+ MachineBasicBlock *loop2MBB = MF->CreateMachineBasicBlock(LLVM_BB);
+ MachineBasicBlock *sinkMBB = MF->CreateMachineBasicBlock(LLVM_BB);
+ MachineBasicBlock *exitMBB = MF->CreateMachineBasicBlock(LLVM_BB);
+ MachineFunction::iterator It = BB;
+ ++It;
+ MF->insert(It, loop1MBB);
+ MF->insert(It, loop2MBB);
+ MF->insert(It, sinkMBB);
+ MF->insert(It, exitMBB);
+
+ // Transfer the remainder of BB and its successor edges to exitMBB.
+ exitMBB->splice(exitMBB->begin(), BB,
+ llvm::next(MachineBasicBlock::iterator(MI)),
+ BB->end());
+ exitMBB->transferSuccessorsAndUpdatePHIs(BB);
+
+ BB->addSuccessor(loop1MBB);
+ loop1MBB->addSuccessor(sinkMBB);
+ loop1MBB->addSuccessor(loop2MBB);
+ loop2MBB->addSuccessor(loop1MBB);
+ loop2MBB->addSuccessor(sinkMBB);
+ sinkMBB->addSuccessor(exitMBB);
+
+ // FIXME: computation of newval2 can be moved to loop2MBB.
+ // thisMBB:
+ // addiu masklsb2,$0,-4 # 0xfffffffc
+ // and alignedaddr,ptr,masklsb2
+ // andi ptrlsb2,ptr,3
+ // sll shiftamt,ptrlsb2,3
+ // ori maskupper,$0,255 # 0xff
+ // sll mask,maskupper,shiftamt
+ // nor mask2,$0,mask
+ // andi maskedcmpval,cmpval,255
+ // sll shiftedcmpval,maskedcmpval,shiftamt
+ // andi maskednewval,newval,255
+ // sll shiftednewval,maskednewval,shiftamt
+ int64_t MaskImm = (Size == 1) ? 255 : 65535;
+ BuildMI(BB, dl, TII->get(Mips::ADDiu), MaskLSB2)
+ .addReg(Mips::ZERO).addImm(-4);
+ BuildMI(BB, dl, TII->get(Mips::AND), AlignedAddr)
+ .addReg(Ptr).addReg(MaskLSB2);
+ BuildMI(BB, dl, TII->get(Mips::ANDi), PtrLSB2).addReg(Ptr).addImm(3);
+ BuildMI(BB, dl, TII->get(Mips::SLL), ShiftAmt).addReg(PtrLSB2).addImm(3);
+ BuildMI(BB, dl, TII->get(Mips::ORi), MaskUpper)
+ .addReg(Mips::ZERO).addImm(MaskImm);
+ BuildMI(BB, dl, TII->get(Mips::SLLV), Mask)
+ .addReg(ShiftAmt).addReg(MaskUpper);
+ BuildMI(BB, dl, TII->get(Mips::NOR), Mask2).addReg(Mips::ZERO).addReg(Mask);
+ BuildMI(BB, dl, TII->get(Mips::ANDi), MaskedCmpVal)
+ .addReg(CmpVal).addImm(MaskImm);
+ BuildMI(BB, dl, TII->get(Mips::SLLV), ShiftedCmpVal)
+ .addReg(ShiftAmt).addReg(MaskedCmpVal);
+ BuildMI(BB, dl, TII->get(Mips::ANDi), MaskedNewVal)
+ .addReg(NewVal).addImm(MaskImm);
+ BuildMI(BB, dl, TII->get(Mips::SLLV), ShiftedNewVal)
+ .addReg(ShiftAmt).addReg(MaskedNewVal);
+
+ // loop1MBB:
+ // ll oldval,0(alginedaddr)
+ // and maskedoldval0,oldval,mask
+ // bne maskedoldval0,shiftedcmpval,sinkMBB
+ BB = loop1MBB;
+ BuildMI(BB, dl, TII->get(Mips::LL), OldVal).addReg(AlignedAddr).addImm(0);
+ BuildMI(BB, dl, TII->get(Mips::AND), MaskedOldVal0)
+ .addReg(OldVal).addReg(Mask);
+ BuildMI(BB, dl, TII->get(Mips::BNE))
+ .addReg(MaskedOldVal0).addReg(ShiftedCmpVal).addMBB(sinkMBB);
+
+ // loop2MBB:
+ // and maskedoldval1,oldval,mask2
+ // or storeval,maskedoldval1,shiftednewval
+ // sc success,storeval,0(alignedaddr)
+ // beq success,$0,loop1MBB
+ BB = loop2MBB;
+ BuildMI(BB, dl, TII->get(Mips::AND), MaskedOldVal1)
+ .addReg(OldVal).addReg(Mask2);
+ BuildMI(BB, dl, TII->get(Mips::OR), StoreVal)
+ .addReg(MaskedOldVal1).addReg(ShiftedNewVal);
+ BuildMI(BB, dl, TII->get(Mips::SC), Success)
+ .addReg(StoreVal).addReg(AlignedAddr).addImm(0);
+ BuildMI(BB, dl, TII->get(Mips::BEQ))
+ .addReg(Success).addReg(Mips::ZERO).addMBB(loop1MBB);
+
+ // sinkMBB:
+ // srl srlres,maskedoldval0,shiftamt
+ // sll sllres,srlres,24
+ // sra dest,sllres,24
+ BB = sinkMBB;
+ int64_t ShiftImm = (Size == 1) ? 24 : 16;
+
+ BuildMI(BB, dl, TII->get(Mips::SRLV), SrlRes)
+ .addReg(ShiftAmt).addReg(MaskedOldVal0);
+ BuildMI(BB, dl, TII->get(Mips::SLL), SllRes)
+ .addReg(SrlRes).addImm(ShiftImm);
+ BuildMI(BB, dl, TII->get(Mips::SRA), Dest)
+ .addReg(SllRes).addImm(ShiftImm);
+
+ MI->eraseFromParent(); // The instruction is gone now.
+
+ return exitMBB;
}
+//===----------------------------------------------------------------------===//
+// Misc Lower Operation implementation
+//===----------------------------------------------------------------------===//
SDValue MipsTargetLowering::
LowerDYNAMIC_STACKALLOC(SDValue Op, SelectionDAG &DAG) const
{
+ MachineFunction &MF = DAG.getMachineFunction();
+ MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
+
+ assert(getTargetMachine().getFrameLowering()->getStackAlignment() >=
+ cast<ConstantSDNode>(Op.getOperand(2).getNode())->getZExtValue() &&
+ "Cannot lower if the alignment of the allocated space is larger than \
+ that of the stack.");
+
SDValue Chain = Op.getOperand(0);
SDValue Size = Op.getOperand(1);
DebugLoc dl = Op.getDebugLoc();
// The Sub result contains the new stack start address, so it
// must be placed in the stack pointer register.
- Chain = DAG.getCopyToReg(StackPointer.getValue(1), dl, Mips::SP, Sub);
+ Chain = DAG.getCopyToReg(StackPointer.getValue(1), dl, Mips::SP, Sub,
+ SDValue());
// This node always has two return values: a new stack pointer
// value and a chain
- SDValue Ops[2] = { Sub, Chain };
- return DAG.getMergeValues(Ops, 2, dl);
+ SDVTList VTLs = DAG.getVTList(MVT::i32, MVT::Other);
+ SDValue Ptr = DAG.getFrameIndex(MipsFI->getDynAllocFI(), getPointerTy());
+ SDValue Ops[] = { Chain, Ptr, Chain.getValue(1) };
+
+ return DAG.getNode(MipsISD::DynAlloc, dl, VTLs, Ops, 3);
}
SDValue MipsTargetLowering::
SDValue HiPart = DAG.getNode(MipsISD::Hi, dl, VTs, &GAHi, 1);
SDValue Lo = DAG.getNode(MipsISD::Lo, dl, MVT::i32, GALo);
return DAG.getNode(ISD::ADD, dl, MVT::i32, HiPart, Lo);
- } else {
- SDValue GA = DAG.getTargetGlobalAddress(GV, dl, MVT::i32, 0,
- MipsII::MO_GOT);
- SDValue ResNode = DAG.getLoad(MVT::i32, dl,
- DAG.getEntryNode(), GA, MachinePointerInfo(),
- false, false, 0);
- // On functions and global targets not internal linked only
- // a load from got/GP is necessary for PIC to work.
- if (!GV->hasInternalLinkage() &&
- (!GV->hasLocalLinkage() || isa<Function>(GV)))
- return ResNode;
- SDValue GALo = DAG.getTargetGlobalAddress(GV, dl, MVT::i32, 0,
- MipsII::MO_ABS_LO);
- SDValue Lo = DAG.getNode(MipsISD::Lo, dl, MVT::i32, GALo);
- return DAG.getNode(ISD::ADD, dl, MVT::i32, ResNode, Lo);
}
- llvm_unreachable("Dont know how to handle GlobalAddress");
- return SDValue(0,0);
+ SDValue GA = DAG.getTargetGlobalAddress(GV, dl, MVT::i32, 0,
+ MipsII::MO_GOT);
+ GA = DAG.getNode(MipsISD::WrapperPIC, dl, MVT::i32, GA);
+ SDValue ResNode = DAG.getLoad(MVT::i32, dl,
+ DAG.getEntryNode(), GA, MachinePointerInfo(),
+ false, false, 0);
+ // On functions and global targets not internal linked only
+ // a load from got/GP is necessary for PIC to work.
+ if (!GV->hasInternalLinkage() &&
+ (!GV->hasLocalLinkage() || isa<Function>(GV)))
+ return ResNode;
+ SDValue GALo = DAG.getTargetGlobalAddress(GV, dl, MVT::i32, 0,
+ MipsII::MO_ABS_LO);
+ SDValue Lo = DAG.getNode(MipsISD::Lo, dl, MVT::i32, GALo);
+ return DAG.getNode(ISD::ADD, dl, MVT::i32, ResNode, Lo);
}
SDValue MipsTargetLowering::LowerBlockAddress(SDValue Op,
SDValue BAGOTOffset = DAG.getBlockAddress(BA, MVT::i32, true,
MipsII::MO_GOT);
+ BAGOTOffset = DAG.getNode(MipsISD::WrapperPIC, dl, MVT::i32, BAGOTOffset);
SDValue BALOOffset = DAG.getBlockAddress(BA, MVT::i32, true,
MipsII::MO_ABS_LO);
SDValue Load = DAG.getLoad(MVT::i32, dl,
SDValue MipsTargetLowering::
LowerGlobalTLSAddress(SDValue Op, SelectionDAG &DAG) const
{
- llvm_unreachable("TLS not implemented for MIPS.");
- return SDValue(); // Not reached
+ // If the relocation model is PIC, use the General Dynamic TLS Model,
+ // otherwise use the Initial Exec or Local Exec TLS Model.
+ // TODO: implement Local Dynamic TLS model
+
+ GlobalAddressSDNode *GA = cast<GlobalAddressSDNode>(Op);
+ DebugLoc dl = GA->getDebugLoc();
+ const GlobalValue *GV = GA->getGlobal();
+ EVT PtrVT = getPointerTy();
+
+ if (getTargetMachine().getRelocationModel() == Reloc::PIC_) {
+ // General Dynamic TLS Model
+ SDValue TGA = DAG.getTargetGlobalAddress(GV, dl, MVT::i32,
+ 0, MipsII::MO_TLSGD);
+ SDValue Tlsgd = DAG.getNode(MipsISD::TlsGd, dl, MVT::i32, TGA);
+ SDValue GP = DAG.getRegister(Mips::GP, MVT::i32);
+ SDValue Argument = DAG.getNode(ISD::ADD, dl, MVT::i32, GP, Tlsgd);
+
+ ArgListTy Args;
+ ArgListEntry Entry;
+ Entry.Node = Argument;
+ Entry.Ty = (Type *) Type::getInt32Ty(*DAG.getContext());
+ Args.push_back(Entry);
+ std::pair<SDValue, SDValue> CallResult =
+ LowerCallTo(DAG.getEntryNode(),
+ (Type *) Type::getInt32Ty(*DAG.getContext()),
+ false, false, false, false, 0, CallingConv::C, false, true,
+ DAG.getExternalSymbol("__tls_get_addr", PtrVT), Args, DAG,
+ dl);
+
+ return CallResult.first;
+ }
+
+ SDValue Offset;
+ if (GV->isDeclaration()) {
+ // Initial Exec TLS Model
+ SDValue TGA = DAG.getTargetGlobalAddress(GV, dl, MVT::i32, 0,
+ MipsII::MO_GOTTPREL);
+ Offset = DAG.getLoad(MVT::i32, dl,
+ DAG.getEntryNode(), TGA, MachinePointerInfo(),
+ false, false, 0);
+ } else {
+ // Local Exec TLS Model
+ SDVTList VTs = DAG.getVTList(MVT::i32);
+ SDValue TGAHi = DAG.getTargetGlobalAddress(GV, dl, MVT::i32, 0,
+ MipsII::MO_TPREL_HI);
+ SDValue TGALo = DAG.getTargetGlobalAddress(GV, dl, MVT::i32, 0,
+ MipsII::MO_TPREL_LO);
+ SDValue Hi = DAG.getNode(MipsISD::TprelHi, dl, VTs, &TGAHi, 1);
+ SDValue Lo = DAG.getNode(MipsISD::TprelLo, dl, MVT::i32, TGALo);
+ Offset = DAG.getNode(ISD::ADD, dl, MVT::i32, Hi, Lo);
+ }
+
+ SDValue ThreadPointer = DAG.getNode(MipsISD::ThreadPointer, dl, PtrVT);
+ return DAG.getNode(ISD::ADD, dl, PtrVT, ThreadPointer, Offset);
}
SDValue MipsTargetLowering::
if (!IsPIC) {
SDValue Ops[] = { JTI };
HiPart = DAG.getNode(MipsISD::Hi, dl, DAG.getVTList(MVT::i32), Ops, 1);
- } else // Emit Load from Global Pointer
+ } else {// Emit Load from Global Pointer
+ JTI = DAG.getNode(MipsISD::WrapperPIC, dl, MVT::i32, JTI);
HiPart = DAG.getLoad(MVT::i32, dl, DAG.getEntryNode(), JTI,
MachinePointerInfo(),
false, false, 0);
+ }
SDValue JTILo = DAG.getTargetJumpTable(JT->getIndex(), PtrVT,
MipsII::MO_ABS_LO);
} else {
SDValue CP = DAG.getTargetConstantPool(C, MVT::i32, N->getAlignment(),
N->getOffset(), MipsII::MO_GOT);
+ CP = DAG.getNode(MipsISD::WrapperPIC, dl, MVT::i32, CP);
SDValue Load = DAG.getLoad(MVT::i32, dl, DAG.getEntryNode(),
CP, MachinePointerInfo::getConstantPool(),
false, false, 0);
false, false, 0);
}
+static SDValue LowerFCOPYSIGN32(SDValue Op, SelectionDAG &DAG) {
+ // FIXME: Use ext/ins instructions if target architecture is Mips32r2.
+ DebugLoc dl = Op.getDebugLoc();
+ SDValue Op0 = DAG.getNode(ISD::BITCAST, dl, MVT::i32, Op.getOperand(0));
+ SDValue Op1 = DAG.getNode(ISD::BITCAST, dl, MVT::i32, Op.getOperand(1));
+ SDValue And0 = DAG.getNode(ISD::AND, dl, MVT::i32, Op0,
+ DAG.getConstant(0x7fffffff, MVT::i32));
+ SDValue And1 = DAG.getNode(ISD::AND, dl, MVT::i32, Op1,
+ DAG.getConstant(0x80000000, MVT::i32));
+ SDValue Result = DAG.getNode(ISD::OR, dl, MVT::i32, And0, And1);
+ return DAG.getNode(ISD::BITCAST, dl, MVT::f32, Result);
+}
+
+static SDValue LowerFCOPYSIGN64(SDValue Op, SelectionDAG &DAG, bool isLittle) {
+ // FIXME:
+ // Use ext/ins instructions if target architecture is Mips32r2.
+ // Eliminate redundant mfc1 and mtc1 instructions.
+ unsigned LoIdx = 0, HiIdx = 1;
+
+ if (!isLittle)
+ std::swap(LoIdx, HiIdx);
+
+ DebugLoc dl = Op.getDebugLoc();
+ SDValue Word0 = DAG.getNode(MipsISD::ExtractElementF64, dl, MVT::i32,
+ Op.getOperand(0),
+ DAG.getConstant(LoIdx, MVT::i32));
+ SDValue Hi0 = DAG.getNode(MipsISD::ExtractElementF64, dl, MVT::i32,
+ Op.getOperand(0), DAG.getConstant(HiIdx, MVT::i32));
+ SDValue Hi1 = DAG.getNode(MipsISD::ExtractElementF64, dl, MVT::i32,
+ Op.getOperand(1), DAG.getConstant(HiIdx, MVT::i32));
+ SDValue And0 = DAG.getNode(ISD::AND, dl, MVT::i32, Hi0,
+ DAG.getConstant(0x7fffffff, MVT::i32));
+ SDValue And1 = DAG.getNode(ISD::AND, dl, MVT::i32, Hi1,
+ DAG.getConstant(0x80000000, MVT::i32));
+ SDValue Word1 = DAG.getNode(ISD::OR, dl, MVT::i32, And0, And1);
+
+ if (!isLittle)
+ std::swap(Word0, Word1);
+
+ return DAG.getNode(MipsISD::BuildPairF64, dl, MVT::f64, Word0, Word1);
+}
+
+SDValue MipsTargetLowering::LowerFCOPYSIGN(SDValue Op, SelectionDAG &DAG)
+ const {
+ EVT Ty = Op.getValueType();
+
+ assert(Ty == MVT::f32 || Ty == MVT::f64);
+
+ if (Ty == MVT::f32)
+ return LowerFCOPYSIGN32(Op, DAG);
+ else
+ return LowerFCOPYSIGN64(Op, DAG, Subtarget->isLittle());
+}
+
+SDValue MipsTargetLowering::
+LowerFRAMEADDR(SDValue Op, SelectionDAG &DAG) const {
+ // check the depth
+ assert((cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue() == 0) &&
+ "Frame address can only be determined for current frame.");
+
+ MachineFrameInfo *MFI = DAG.getMachineFunction().getFrameInfo();
+ MFI->setFrameAddressIsTaken(true);
+ EVT VT = Op.getValueType();
+ DebugLoc dl = Op.getDebugLoc();
+ SDValue FrameAddr = DAG.getCopyFromReg(DAG.getEntryNode(), dl, Mips::FP, VT);
+ return FrameAddr;
+}
+
+// TODO: set SType according to the desired memory barrier behavior.
+SDValue MipsTargetLowering::LowerMEMBARRIER(SDValue Op,
+ SelectionDAG& DAG) const {
+ unsigned SType = 0;
+ DebugLoc dl = Op.getDebugLoc();
+ return DAG.getNode(MipsISD::Sync, dl, MVT::Other, Op.getOperand(0),
+ DAG.getConstant(SType, MVT::i32));
+}
+
+SDValue MipsTargetLowering::LowerATOMIC_FENCE(SDValue Op,
+ SelectionDAG& DAG) const {
+ // FIXME: Need pseudo-fence for 'singlethread' fences
+ // FIXME: Set SType for weaker fences where supported/appropriate.
+ unsigned SType = 0;
+ DebugLoc dl = Op.getDebugLoc();
+ return DAG.getNode(MipsISD::Sync, dl, MVT::Other, Op.getOperand(0),
+ DAG.getConstant(SType, MVT::i32));
+}
+
//===----------------------------------------------------------------------===//
// Calling Convention Implementation
//===----------------------------------------------------------------------===//
// yet to hold an argument. Otherwise, use A2, A3 and stack. If A1 is
// not used, it must be shadowed. If only A3 is avaiable, shadow it and
// go to stack.
+//
+// For vararg functions, all arguments are passed in A0, A1, A2, A3 and stack.
//===----------------------------------------------------------------------===//
static bool CC_MipsO32(unsigned ValNo, MVT ValVT,
Mips::D6, Mips::D7
};
- unsigned Reg = 0;
- static bool IntRegUsed = false;
-
- // This must be the first arg of the call if no regs have been allocated.
- // Initialize IntRegUsed in that case.
- if (IntRegs[State.getFirstUnallocated(IntRegs, IntRegsSize)] == Mips::A0 &&
- F32Regs[State.getFirstUnallocated(F32Regs, FloatRegsSize)] == Mips::F12 &&
- F64Regs[State.getFirstUnallocated(F64Regs, FloatRegsSize)] == Mips::D6)
- IntRegUsed = false;
-
- // Promote i8 and i16
- if (LocVT == MVT::i8 || LocVT == MVT::i16) {
- LocVT = MVT::i32;
- if (ArgFlags.isSExt())
- LocInfo = CCValAssign::SExt;
- else if (ArgFlags.isZExt())
- LocInfo = CCValAssign::ZExt;
- else
- LocInfo = CCValAssign::AExt;
+ // ByVal Args
+ if (ArgFlags.isByVal()) {
+ State.HandleByVal(ValNo, ValVT, LocVT, LocInfo,
+ 1 /*MinSize*/, 4 /*MinAlign*/, ArgFlags);
+ unsigned NextReg = (State.getNextStackOffset() + 3) / 4;
+ for (unsigned r = State.getFirstUnallocated(IntRegs, IntRegsSize);
+ r < std::min(IntRegsSize, NextReg); ++r)
+ State.AllocateReg(IntRegs[r]);
+ return false;
}
- if (ValVT == MVT::i32) {
- Reg = State.AllocateReg(IntRegs, IntRegsSize);
- IntRegUsed = true;
- } else if (ValVT == MVT::f32) {
- // An int reg has to be marked allocated regardless of whether or not
- // IntRegUsed is true.
- Reg = State.AllocateReg(IntRegs, IntRegsSize);
-
- if (IntRegUsed) {
- if (Reg) // Int reg is available
- LocVT = MVT::i32;
- } else {
- unsigned FReg = State.AllocateReg(F32Regs, FloatRegsSize);
- if (FReg) // F32 reg is available
- Reg = FReg;
- else if (Reg) // No F32 regs are available, but an int reg is available.
- LocVT = MVT::i32;
- }
- } else if (ValVT == MVT::f64) {
- // Int regs have to be marked allocated regardless of whether or not
- // IntRegUsed is true.
- Reg = State.AllocateReg(IntRegs, IntRegsSize);
- if (Reg == Mips::A1)
- Reg = State.AllocateReg(IntRegs, IntRegsSize);
- else if (Reg == Mips::A3)
- Reg = 0;
- State.AllocateReg(IntRegs, IntRegsSize);
-
- // At this point, Reg is A0, A2 or 0, and all the unavailable integer regs
- // are marked as allocated.
- if (IntRegUsed) {
- if (Reg)// if int reg is available
- LocVT = MVT::i32;
- } else {
- unsigned FReg = State.AllocateReg(F64Regs, FloatRegsSize);
- if (FReg) // F64 reg is available.
- Reg = FReg;
- else if (Reg) // No F64 regs are available, but an int reg is available.
- LocVT = MVT::i32;
- }
- } else
- assert(false && "cannot handle this ValVT");
-
- if (!Reg) {
- unsigned SizeInBytes = ValVT.getSizeInBits() >> 3;
- unsigned Offset = State.AllocateStack(SizeInBytes, SizeInBytes);
- State.addLoc(CCValAssign::getMem(ValNo, ValVT, Offset, LocVT, LocInfo));
- } else
- State.addLoc(CCValAssign::getReg(ValNo, ValVT, Reg, LocVT, LocInfo));
-
- return false; // CC must always match
-}
-
-static bool CC_MipsO32_VarArgs(unsigned ValNo, MVT ValVT,
- MVT LocVT, CCValAssign::LocInfo LocInfo,
- ISD::ArgFlagsTy ArgFlags, CCState &State) {
-
- static const unsigned IntRegsSize=4;
-
- static const unsigned IntRegs[] = {
- Mips::A0, Mips::A1, Mips::A2, Mips::A3
- };
-
// Promote i8 and i16
if (LocVT == MVT::i8 || LocVT == MVT::i16) {
LocVT = MVT::i32;
unsigned Reg;
- if (ValVT == MVT::i32 || ValVT == MVT::f32) {
+ // f32 and f64 are allocated in A0, A1, A2, A3 when either of the following
+ // is true: function is vararg, argument is 3rd or higher, there is previous
+ // argument which is not f32 or f64.
+ bool AllocateFloatsInIntReg = State.isVarArg() || ValNo > 1
+ || State.getFirstUnallocated(F32Regs, FloatRegsSize) != ValNo;
+ unsigned OrigAlign = ArgFlags.getOrigAlign();
+ bool isI64 = (ValVT == MVT::i32 && OrigAlign == 8);
+
+ if (ValVT == MVT::i32 || (ValVT == MVT::f32 && AllocateFloatsInIntReg)) {
Reg = State.AllocateReg(IntRegs, IntRegsSize);
+ // If this is the first part of an i64 arg,
+ // the allocated register must be either A0 or A2.
+ if (isI64 && (Reg == Mips::A1 || Reg == Mips::A3))
+ Reg = State.AllocateReg(IntRegs, IntRegsSize);
LocVT = MVT::i32;
- } else if (ValVT == MVT::f64) {
+ } else if (ValVT == MVT::f64 && AllocateFloatsInIntReg) {
+ // Allocate int register and shadow next int register. If first
+ // available register is Mips::A1 or Mips::A3, shadow it too.
Reg = State.AllocateReg(IntRegs, IntRegsSize);
if (Reg == Mips::A1 || Reg == Mips::A3)
Reg = State.AllocateReg(IntRegs, IntRegsSize);
State.AllocateReg(IntRegs, IntRegsSize);
LocVT = MVT::i32;
+ } else if (ValVT.isFloatingPoint() && !AllocateFloatsInIntReg) {
+ // we are guaranteed to find an available float register
+ if (ValVT == MVT::f32) {
+ Reg = State.AllocateReg(F32Regs, FloatRegsSize);
+ // Shadow int register
+ State.AllocateReg(IntRegs, IntRegsSize);
+ } else {
+ Reg = State.AllocateReg(F64Regs, FloatRegsSize);
+ // Shadow int registers
+ unsigned Reg2 = State.AllocateReg(IntRegs, IntRegsSize);
+ if (Reg2 == Mips::A1 || Reg2 == Mips::A3)
+ State.AllocateReg(IntRegs, IntRegsSize);
+ State.AllocateReg(IntRegs, IntRegsSize);
+ }
} else
llvm_unreachable("Cannot handle this ValVT.");
- if (!Reg) {
- unsigned SizeInBytes = ValVT.getSizeInBits() >> 3;
- unsigned Offset = State.AllocateStack(SizeInBytes, SizeInBytes);
+ unsigned SizeInBytes = ValVT.getSizeInBits() >> 3;
+ unsigned Offset = State.AllocateStack(SizeInBytes, OrigAlign);
+
+ if (!Reg)
State.addLoc(CCValAssign::getMem(ValNo, ValVT, Offset, LocVT, LocInfo));
- } else
+ else
State.addLoc(CCValAssign::getReg(ValNo, ValVT, Reg, LocVT, LocInfo));
return false; // CC must always match
// Call Calling Convention Implementation
//===----------------------------------------------------------------------===//
+static const unsigned O32IntRegsSize = 4;
+
+static const unsigned O32IntRegs[] = {
+ Mips::A0, Mips::A1, Mips::A2, Mips::A3
+};
+
+// Write ByVal Arg to arg registers and stack.
+static void
+WriteByValArg(SDValue& ByValChain, SDValue Chain, DebugLoc dl,
+ SmallVector<std::pair<unsigned, SDValue>, 16>& RegsToPass,
+ SmallVector<SDValue, 8>& MemOpChains, int& LastFI,
+ MachineFrameInfo *MFI, SelectionDAG &DAG, SDValue Arg,
+ const CCValAssign &VA, const ISD::ArgFlagsTy& Flags,
+ MVT PtrType, bool isLittle) {
+ unsigned LocMemOffset = VA.getLocMemOffset();
+ unsigned Offset = 0;
+ uint32_t RemainingSize = Flags.getByValSize();
+ unsigned ByValAlign = Flags.getByValAlign();
+
+ // Copy the first 4 words of byval arg to registers A0 - A3.
+ // FIXME: Use a stricter alignment if it enables better optimization in passes
+ // run later.
+ for (; RemainingSize >= 4 && LocMemOffset < 4 * 4;
+ Offset += 4, RemainingSize -= 4, LocMemOffset += 4) {
+ SDValue LoadPtr = DAG.getNode(ISD::ADD, dl, MVT::i32, Arg,
+ DAG.getConstant(Offset, MVT::i32));
+ SDValue LoadVal = DAG.getLoad(MVT::i32, dl, Chain, LoadPtr,
+ MachinePointerInfo(),
+ false, false, std::min(ByValAlign,
+ (unsigned )4));
+ MemOpChains.push_back(LoadVal.getValue(1));
+ unsigned DstReg = O32IntRegs[LocMemOffset / 4];
+ RegsToPass.push_back(std::make_pair(DstReg, LoadVal));
+ }
+
+ if (RemainingSize == 0)
+ return;
+
+ // If there still is a register available for argument passing, write the
+ // remaining part of the structure to it using subword loads and shifts.
+ if (LocMemOffset < 4 * 4) {
+ assert(RemainingSize <= 3 && RemainingSize >= 1 &&
+ "There must be one to three bytes remaining.");
+ unsigned LoadSize = (RemainingSize == 3 ? 2 : RemainingSize);
+ SDValue LoadPtr = DAG.getNode(ISD::ADD, dl, MVT::i32, Arg,
+ DAG.getConstant(Offset, MVT::i32));
+ unsigned Alignment = std::min(ByValAlign, (unsigned )4);
+ SDValue LoadVal = DAG.getExtLoad(ISD::ZEXTLOAD, dl, MVT::i32, Chain,
+ LoadPtr, MachinePointerInfo(),
+ MVT::getIntegerVT(LoadSize * 8), false,
+ false, Alignment);
+ MemOpChains.push_back(LoadVal.getValue(1));
+
+ // If target is big endian, shift it to the most significant half-word or
+ // byte.
+ if (!isLittle)
+ LoadVal = DAG.getNode(ISD::SHL, dl, MVT::i32, LoadVal,
+ DAG.getConstant(32 - LoadSize * 8, MVT::i32));
+
+ Offset += LoadSize;
+ RemainingSize -= LoadSize;
+
+ // Read second subword if necessary.
+ if (RemainingSize != 0) {
+ assert(RemainingSize == 1 && "There must be one byte remaining.");
+ LoadPtr = DAG.getNode(ISD::ADD, dl, MVT::i32, Arg,
+ DAG.getConstant(Offset, MVT::i32));
+ unsigned Alignment = std::min(ByValAlign, (unsigned )2);
+ SDValue Subword = DAG.getExtLoad(ISD::ZEXTLOAD, dl, MVT::i32, Chain,
+ LoadPtr, MachinePointerInfo(),
+ MVT::i8, false, false, Alignment);
+ MemOpChains.push_back(Subword.getValue(1));
+ // Insert the loaded byte to LoadVal.
+ // FIXME: Use INS if supported by target.
+ unsigned ShiftAmt = isLittle ? 16 : 8;
+ SDValue Shift = DAG.getNode(ISD::SHL, dl, MVT::i32, Subword,
+ DAG.getConstant(ShiftAmt, MVT::i32));
+ LoadVal = DAG.getNode(ISD::OR, dl, MVT::i32, LoadVal, Shift);
+ }
+
+ unsigned DstReg = O32IntRegs[LocMemOffset / 4];
+ RegsToPass.push_back(std::make_pair(DstReg, LoadVal));
+ return;
+ }
+
+ // Create a fixed object on stack at offset LocMemOffset and copy
+ // remaining part of byval arg to it using memcpy.
+ SDValue Src = DAG.getNode(ISD::ADD, dl, MVT::i32, Arg,
+ DAG.getConstant(Offset, MVT::i32));
+ LastFI = MFI->CreateFixedObject(RemainingSize, LocMemOffset, true);
+ SDValue Dst = DAG.getFrameIndex(LastFI, PtrType);
+ ByValChain = DAG.getMemcpy(ByValChain, dl, Dst, Src,
+ DAG.getConstant(RemainingSize, MVT::i32),
+ std::min(ByValAlign, (unsigned)4),
+ /*isVolatile=*/false, /*AlwaysInline=*/false,
+ MachinePointerInfo(0), MachinePointerInfo(0));
+}
+
/// LowerCall - functions arguments are copied from virtual regs to
/// (physical regs)/(stack frame), CALLSEQ_START and CALLSEQ_END are emitted.
/// TODO: isTailCall.
SDValue
-MipsTargetLowering::LowerCall(SDValue Chain, SDValue Callee,
+MipsTargetLowering::LowerCall(SDValue InChain, SDValue Callee,
CallingConv::ID CallConv, bool isVarArg,
bool &isTailCall,
const SmallVectorImpl<ISD::OutputArg> &Outs,
MachineFunction &MF = DAG.getMachineFunction();
MachineFrameInfo *MFI = MF.getFrameInfo();
+ const TargetFrameLowering *TFL = MF.getTarget().getFrameLowering();
bool IsPIC = getTargetMachine().getRelocationModel() == Reloc::PIC_;
+ MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
// Analyze operands of the call, assigning locations to each operand.
SmallVector<CCValAssign, 16> ArgLocs;
- CCState CCInfo(CallConv, isVarArg, getTargetMachine(), ArgLocs,
- *DAG.getContext());
-
- // To meet O32 ABI, Mips must always allocate 16 bytes on
- // the stack (even if less than 4 are used as arguments)
- if (Subtarget->isABI_O32()) {
- int VTsize = MVT(MVT::i32).getSizeInBits()/8;
- MFI->CreateFixedObject(VTsize, (VTsize*3), true);
- CCInfo.AnalyzeCallOperands(Outs,
- isVarArg ? CC_MipsO32_VarArgs : CC_MipsO32);
- } else
+ CCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(),
+ getTargetMachine(), ArgLocs, *DAG.getContext());
+
+ if (Subtarget->isABI_O32())
+ CCInfo.AnalyzeCallOperands(Outs, CC_MipsO32);
+ else
CCInfo.AnalyzeCallOperands(Outs, CC_Mips);
// Get a count of how many bytes are to be pushed on the stack.
- unsigned NumBytes = CCInfo.getNextStackOffset();
- Chain = DAG.getCALLSEQ_START(Chain, DAG.getIntPtrConstant(NumBytes, true));
+ unsigned NextStackOffset = CCInfo.getNextStackOffset();
+
+ // Chain is the output chain of the last Load/Store or CopyToReg node.
+ // ByValChain is the output chain of the last Memcpy node created for copying
+ // byval arguments to the stack.
+ SDValue Chain, CallSeqStart, ByValChain;
+ SDValue NextStackOffsetVal = DAG.getIntPtrConstant(NextStackOffset, true);
+ Chain = CallSeqStart = DAG.getCALLSEQ_START(InChain, NextStackOffsetVal);
+ ByValChain = InChain;
+
+ // If this is the first call, create a stack frame object that points to
+ // a location to which .cprestore saves $gp.
+ if (IsPIC && !MipsFI->getGPFI())
+ MipsFI->setGPFI(MFI->CreateFixedObject(4, 0, true));
+
+ // Get the frame index of the stack frame object that points to the location
+ // of dynamically allocated area on the stack.
+ int DynAllocFI = MipsFI->getDynAllocFI();
+
+ // Update size of the maximum argument space.
+ // For O32, a minimum of four words (16 bytes) of argument space is
+ // allocated.
+ if (Subtarget->isABI_O32())
+ NextStackOffset = std::max(NextStackOffset, (unsigned)16);
+
+ unsigned MaxCallFrameSize = MipsFI->getMaxCallFrameSize();
+
+ if (MaxCallFrameSize < NextStackOffset) {
+ MipsFI->setMaxCallFrameSize(NextStackOffset);
+
+ // Set the offsets relative to $sp of the $gp restore slot and dynamically
+ // allocated stack space. These offsets must be aligned to a boundary
+ // determined by the stack alignment of the ABI.
+ unsigned StackAlignment = TFL->getStackAlignment();
+ NextStackOffset = (NextStackOffset + StackAlignment - 1) /
+ StackAlignment * StackAlignment;
+
+ if (IsPIC)
+ MFI->setObjectOffset(MipsFI->getGPFI(), NextStackOffset);
+
+ MFI->setObjectOffset(DynAllocFI, NextStackOffset);
+ }
// With EABI is it possible to have 16 args on registers.
SmallVector<std::pair<unsigned, SDValue>, 16> RegsToPass;
SmallVector<SDValue, 8> MemOpChains;
- // First/LastArgStackLoc contains the first/last
- // "at stack" argument location.
- int LastArgStackLoc = 0;
- unsigned FirstStackArgLoc = (Subtarget->isABI_EABI() ? 0 : 16);
+ int FirstFI = -MFI->getNumFixedObjects() - 1, LastFI = 0;
// Walk the register/memloc assignments, inserting copies/loads.
for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
// Register can't get to this point...
assert(VA.isMemLoc());
- // Create the frame index object for this incoming parameter
- // This guarantees that when allocating Local Area the firsts
- // 16 bytes which are alwayes reserved won't be overwritten
- // if O32 ABI is used. For EABI the first address is zero.
- LastArgStackLoc = (FirstStackArgLoc + VA.getLocMemOffset());
- int FI = MFI->CreateFixedObject(VA.getValVT().getSizeInBits()/8,
- LastArgStackLoc, true);
+ // ByVal Arg.
+ ISD::ArgFlagsTy Flags = Outs[i].Flags;
+ if (Flags.isByVal()) {
+ assert(Subtarget->isABI_O32() &&
+ "No support for ByVal args by ABIs other than O32 yet.");
+ assert(Flags.getByValSize() &&
+ "ByVal args of size 0 should have been ignored by front-end.");
+ WriteByValArg(ByValChain, Chain, dl, RegsToPass, MemOpChains, LastFI, MFI,
+ DAG, Arg, VA, Flags, getPointerTy(), Subtarget->isLittle());
+ continue;
+ }
- SDValue PtrOff = DAG.getFrameIndex(FI,getPointerTy());
+ // Create the frame index object for this incoming parameter
+ LastFI = MFI->CreateFixedObject(VA.getValVT().getSizeInBits()/8,
+ VA.getLocMemOffset(), true);
+ SDValue PtrOff = DAG.getFrameIndex(LastFI, getPointerTy());
// emit ISD::STORE whichs stores the
// parameter value to a stack Location
false, false, 0));
}
+ // Extend range of indices of frame objects for outgoing arguments that were
+ // created during this function call. Skip this step if no such objects were
+ // created.
+ if (LastFI)
+ MipsFI->extendOutArgFIRange(FirstFI, LastFI);
+
+ // If a memcpy has been created to copy a byval arg to a stack, replace the
+ // chain input of CallSeqStart with ByValChain.
+ if (InChain != ByValChain)
+ DAG.UpdateNodeOperands(CallSeqStart.getNode(), ByValChain,
+ NextStackOffsetVal);
+
// 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 emitted 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/ExternalSymbol node (quite common, every
// direct call is) turn it into a TargetGlobalAddress/TargetExternalSymbol
// node so that legalize doesn't hack it.
LoadSymAddr = true;
}
+ SDValue InFlag;
+
// Create nodes that load address of callee and copy it to T9
if (IsPIC) {
if (LoadSymAddr) {
// Load callee address
- SDValue LoadValue = DAG.getLoad(MVT::i32, dl, Chain, Callee,
+ Callee = DAG.getNode(MipsISD::WrapperPIC, dl, MVT::i32, Callee);
+ SDValue LoadValue = DAG.getLoad(MVT::i32, dl, DAG.getEntryNode(), Callee,
MachinePointerInfo::getGOT(),
false, false, 0);
Callee = DAG.getNode(ISD::ADD, dl, MVT::i32, LoadValue, Lo);
} else
Callee = LoadValue;
-
- // Use chain output from LoadValue
- Chain = LoadValue.getValue(1);
}
// copy to T9
Callee = DAG.getRegister(Mips::T9, MVT::i32);
}
+ // 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 emitted instructions must be
+ // stuck together.
+ 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);
+ }
+
// MipsJmpLink = #chain, #target_address, #opt_in_flags...
// = Chain, Callee, Reg#1, Reg#2, ...
//
Chain = DAG.getNode(MipsISD::JmpLink, dl, NodeTys, &Ops[0], Ops.size());
InFlag = Chain.getValue(1);
- // Create a stack location to hold GP when PIC is used. This stack
- // location is used on function prologue to save GP and also after all
- // emitted CALL's to restore GP.
- if (IsPIC) {
- // Function can have an arbitrary number of calls, so
- // hold the LastArgStackLoc with the biggest offset.
- int FI;
- MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
- if (LastArgStackLoc >= MipsFI->getGPStackOffset()) {
- LastArgStackLoc = (!LastArgStackLoc) ? (16) : (LastArgStackLoc+4);
- // Create the frame index only once. SPOffset here can be anything
- // (this will be fixed on processFunctionBeforeFrameFinalized)
- if (MipsFI->getGPStackOffset() == -1) {
- FI = MFI->CreateFixedObject(4, 0, true);
- MipsFI->setGPFI(FI);
- }
- MipsFI->setGPStackOffset(LastArgStackLoc);
- }
- }
-
// Create the CALLSEQ_END node.
- Chain = DAG.getCALLSEQ_END(Chain, DAG.getIntPtrConstant(NumBytes, true),
+ Chain = DAG.getCALLSEQ_END(Chain,
+ DAG.getIntPtrConstant(NextStackOffset, true),
DAG.getIntPtrConstant(0, true), InFlag);
InFlag = Chain.getValue(1);
const SmallVectorImpl<ISD::InputArg> &Ins,
DebugLoc dl, SelectionDAG &DAG,
SmallVectorImpl<SDValue> &InVals) const {
-
// Assign locations to each value returned by this call.
SmallVector<CCValAssign, 16> RVLocs;
- CCState CCInfo(CallConv, isVarArg, getTargetMachine(),
- RVLocs, *DAG.getContext());
+ CCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(),
+ getTargetMachine(), RVLocs, *DAG.getContext());
CCInfo.AnalyzeCallResult(Ins, RetCC_Mips);
//===----------------------------------------------------------------------===//
// Formal Arguments Calling Convention Implementation
//===----------------------------------------------------------------------===//
+static void ReadByValArg(MachineFunction &MF, SDValue Chain, DebugLoc dl,
+ std::vector<SDValue>& OutChains,
+ SelectionDAG &DAG, unsigned NumWords, SDValue FIN,
+ const CCValAssign &VA, const ISD::ArgFlagsTy& Flags) {
+ unsigned LocMem = VA.getLocMemOffset();
+ unsigned FirstWord = LocMem / 4;
+
+ // copy register A0 - A3 to frame object
+ for (unsigned i = 0; i < NumWords; ++i) {
+ unsigned CurWord = FirstWord + i;
+ if (CurWord >= O32IntRegsSize)
+ break;
+
+ unsigned SrcReg = O32IntRegs[CurWord];
+ unsigned Reg = AddLiveIn(MF, SrcReg, Mips::CPURegsRegisterClass);
+ SDValue StorePtr = DAG.getNode(ISD::ADD, dl, MVT::i32, FIN,
+ DAG.getConstant(i * 4, MVT::i32));
+ SDValue Store = DAG.getStore(Chain, dl, DAG.getRegister(Reg, MVT::i32),
+ StorePtr, MachinePointerInfo(), false,
+ false, 0);
+ OutChains.push_back(Store);
+ }
+}
/// LowerFormalArguments - transform physical registers into virtual registers
/// and generate load operations for arguments places on the stack.
DebugLoc dl, SelectionDAG &DAG,
SmallVectorImpl<SDValue> &InVals)
const {
-
MachineFunction &MF = DAG.getMachineFunction();
MachineFrameInfo *MFI = MF.getFrameInfo();
MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
// Used with vargs to acumulate store chains.
std::vector<SDValue> OutChains;
- // Keep track of the last register used for arguments
- unsigned ArgRegEnd = 0;
-
// Assign locations to all of the incoming arguments.
SmallVector<CCValAssign, 16> ArgLocs;
- CCState CCInfo(CallConv, isVarArg, getTargetMachine(),
- ArgLocs, *DAG.getContext());
+ CCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(),
+ getTargetMachine(), ArgLocs, *DAG.getContext());
if (Subtarget->isABI_O32())
- CCInfo.AnalyzeFormalArguments(Ins,
- isVarArg ? CC_MipsO32_VarArgs : CC_MipsO32);
+ CCInfo.AnalyzeFormalArguments(Ins, CC_MipsO32);
else
CCInfo.AnalyzeFormalArguments(Ins, CC_Mips);
- unsigned FirstStackArgLoc = (Subtarget->isABI_EABI() ? 0 : 16);
- unsigned LastStackArgEndOffset = 0;
- EVT LastRegArgValVT;
+ int LastFI = 0;// MipsFI->LastInArgFI is 0 at the entry of this function.
for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
CCValAssign &VA = ArgLocs[i];
// Arguments stored on registers
if (VA.isRegLoc()) {
EVT RegVT = VA.getLocVT();
- ArgRegEnd = VA.getLocReg();
- LastRegArgValVT = VA.getValVT();
+ unsigned ArgReg = VA.getLocReg();
TargetRegisterClass *RC = 0;
if (RegVT == MVT::i32)
// Transform the arguments stored on
// physical registers into virtual ones
- unsigned Reg = AddLiveIn(DAG.getMachineFunction(), ArgRegEnd, RC);
+ unsigned Reg = AddLiveIn(DAG.getMachineFunction(), ArgReg, RC);
SDValue ArgValue = DAG.getCopyFromReg(Chain, dl, Reg, RegVT);
// If this is an 8 or 16-bit value, it has been passed promoted
// sanity check
assert(VA.isMemLoc());
- // The last argument is not a register anymore
- ArgRegEnd = 0;
+ ISD::ArgFlagsTy Flags = Ins[i].Flags;
+
+ if (Flags.isByVal()) {
+ assert(Subtarget->isABI_O32() &&
+ "No support for ByVal args by ABIs other than O32 yet.");
+ assert(Flags.getByValSize() &&
+ "ByVal args of size 0 should have been ignored by front-end.");
+ unsigned NumWords = (Flags.getByValSize() + 3) / 4;
+ LastFI = MFI->CreateFixedObject(NumWords * 4, VA.getLocMemOffset(),
+ true);
+ SDValue FIN = DAG.getFrameIndex(LastFI, getPointerTy());
+ InVals.push_back(FIN);
+ ReadByValArg(MF, Chain, dl, OutChains, DAG, NumWords, FIN, VA, Flags);
+
+ continue;
+ }
// The stack pointer offset is relative to the caller stack frame.
- // Since the real stack size is unknown here, a negative SPOffset
- // is used so there's a way to adjust these offsets when the stack
- // size get known (on EliminateFrameIndex). A dummy SPOffset is
- // used instead of a direct negative address (which is recorded to
- // be used on emitPrologue) to avoid mis-calc of the first stack
- // offset on PEI::calculateFrameObjectOffsets.
- unsigned ArgSize = VA.getValVT().getSizeInBits()/8;
- LastStackArgEndOffset = FirstStackArgLoc + VA.getLocMemOffset() + ArgSize;
- int FI = MFI->CreateFixedObject(ArgSize, 0, true);
- MipsFI->recordLoadArgsFI(FI, -(4 +
- (FirstStackArgLoc + VA.getLocMemOffset())));
+ LastFI = MFI->CreateFixedObject(VA.getValVT().getSizeInBits()/8,
+ VA.getLocMemOffset(), true);
// Create load nodes to retrieve arguments from the stack
- SDValue FIN = DAG.getFrameIndex(FI, getPointerTy());
+ SDValue FIN = DAG.getFrameIndex(LastFI, getPointerTy());
InVals.push_back(DAG.getLoad(VA.getValVT(), dl, Chain, FIN,
- MachinePointerInfo::getFixedStack(FI),
+ MachinePointerInfo::getFixedStack(LastFI),
false, false, 0));
}
}
Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Copy, Chain);
}
- // To meet ABI, when VARARGS are passed on registers, the registers
- // must have their values written to the caller stack frame. If the last
- // argument was placed in the stack, there's no need to save any register.
if (isVarArg && Subtarget->isABI_O32()) {
- if (ArgRegEnd) {
- // Last named formal argument is passed in register.
-
- // The last register argument that must be saved is Mips::A3
+ // Record the frame index of the first variable argument
+ // which is a value necessary to VASTART.
+ unsigned NextStackOffset = CCInfo.getNextStackOffset();
+ assert(NextStackOffset % 4 == 0 &&
+ "NextStackOffset must be aligned to 4-byte boundaries.");
+ LastFI = MFI->CreateFixedObject(4, NextStackOffset, true);
+ MipsFI->setVarArgsFrameIndex(LastFI);
+
+ // If NextStackOffset is smaller than o32's 16-byte reserved argument area,
+ // copy the integer registers that have not been used for argument passing
+ // to the caller's stack frame.
+ for (; NextStackOffset < 16; NextStackOffset += 4) {
TargetRegisterClass *RC = Mips::CPURegsRegisterClass;
- if (LastRegArgValVT == MVT::f64)
- ArgRegEnd++;
-
- if (ArgRegEnd < Mips::A3) {
- // Both the last named formal argument and the first variable
- // argument are passed in registers.
- for (++ArgRegEnd; ArgRegEnd <= Mips::A3; ++ArgRegEnd) {
- unsigned Reg = AddLiveIn(DAG.getMachineFunction(), ArgRegEnd, RC);
- SDValue ArgValue = DAG.getCopyFromReg(Chain, dl, Reg, MVT::i32);
-
- int FI = MFI->CreateFixedObject(4, 0, true);
- MipsFI->recordStoreVarArgsFI(FI, -(4+(ArgRegEnd-Mips::A0)*4));
- SDValue PtrOff = DAG.getFrameIndex(FI, getPointerTy());
- OutChains.push_back(DAG.getStore(Chain, dl, ArgValue, PtrOff,
- MachinePointerInfo(),
- false, false, 0));
-
- // Record the frame index of the first variable argument
- // which is a value necessary to VASTART.
- if (!MipsFI->getVarArgsFrameIndex()) {
- MFI->setObjectAlignment(FI, 4);
- MipsFI->setVarArgsFrameIndex(FI);
- }
- }
- } else {
- // Last named formal argument is in register Mips::A3, and the first
- // variable argument is on stack. Record the frame index of the first
- // variable argument.
- int FI = MFI->CreateFixedObject(4, 0, true);
- MFI->setObjectAlignment(FI, 4);
- MipsFI->recordStoreVarArgsFI(FI, -20);
- MipsFI->setVarArgsFrameIndex(FI);
- }
- } else {
- // Last named formal argument and all the variable arguments are passed
- // on stack. Record the frame index of the first variable argument.
- int FI = MFI->CreateFixedObject(4, 0, true);
- MFI->setObjectAlignment(FI, 4);
- MipsFI->recordStoreVarArgsFI(FI, -(4+LastStackArgEndOffset));
- MipsFI->setVarArgsFrameIndex(FI);
+ unsigned Idx = NextStackOffset / 4;
+ unsigned Reg = AddLiveIn(DAG.getMachineFunction(), O32IntRegs[Idx], RC);
+ SDValue ArgValue = DAG.getCopyFromReg(Chain, dl, Reg, MVT::i32);
+ LastFI = MFI->CreateFixedObject(4, NextStackOffset, true);
+ SDValue PtrOff = DAG.getFrameIndex(LastFI, getPointerTy());
+ OutChains.push_back(DAG.getStore(Chain, dl, ArgValue, PtrOff,
+ MachinePointerInfo(),
+ false, false, 0));
}
}
+ MipsFI->setLastInArgFI(LastFI);
+
// All stores are grouped in one node to allow the matching between
// the size of Ins and InVals. This only happens when on varg functions
if (!OutChains.empty()) {
SmallVector<CCValAssign, 16> RVLocs;
// CCState - Info about the registers and stack slot.
- CCState CCInfo(CallConv, isVarArg, getTargetMachine(),
- RVLocs, *DAG.getContext());
+ CCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(),
+ getTargetMachine(), RVLocs, *DAG.getContext());
// Analize return values.
CCInfo.AnalyzeReturn(Outs, RetCC_Mips);
// but allow it at the lowest weight.
if (CallOperandVal == NULL)
return CW_Default;
- const Type *type = CallOperandVal->getType();
+ Type *type = CallOperandVal->getType();
// Look at the constraint type.
switch (*constraint) {
default:
return weight;
}
-/// getRegClassForInlineAsmConstraint - Given a constraint letter (e.g. "r"),
-/// return a list of registers that can be used to satisfy the constraint.
-/// This should only be used for C_RegisterClass constraints.
+/// Given a register class constraint, like 'r', if this corresponds directly
+/// to an LLVM register class, return a register of 0 and the register class
+/// pointer.
std::pair<unsigned, const TargetRegisterClass*> MipsTargetLowering::
getRegForInlineAsmConstraint(const std::string &Constraint, EVT VT) const
{
if (Constraint.size() == 1) {
switch (Constraint[0]) {
+ case 'd': // Address register. Same as 'r' unless generating MIPS16 code.
+ case 'y': // Same as 'r'. Exists for compatibility.
case 'r':
return std::make_pair(0U, Mips::CPURegsRegisterClass);
case 'f':
if (VT == MVT::f64)
if ((!Subtarget->isSingleFloat()) && (!Subtarget->isFP64bit()))
return std::make_pair(0U, Mips::AFGR64RegisterClass);
+ break;
}
}
return TargetLowering::getRegForInlineAsmConstraint(Constraint, VT);
}
-/// Given a register class constraint, like 'r', if this corresponds directly
-/// to an LLVM register class, return a register of 0 and the register class
-/// pointer.
-std::vector<unsigned> MipsTargetLowering::
-getRegClassForInlineAsmConstraint(const std::string &Constraint,
- EVT VT) const
-{
- if (Constraint.size() != 1)
- return std::vector<unsigned>();
-
- switch (Constraint[0]) {
- default : break;
- case 'r':
- // GCC Mips Constraint Letters
- case 'd':
- case 'y':
- return make_vector<unsigned>(Mips::T0, Mips::T1, Mips::T2, Mips::T3,
- Mips::T4, Mips::T5, Mips::T6, Mips::T7, Mips::S0, Mips::S1,
- Mips::S2, Mips::S3, Mips::S4, Mips::S5, Mips::S6, Mips::S7,
- Mips::T8, 0);
-
- case 'f':
- if (VT == MVT::f32) {
- if (Subtarget->isSingleFloat())
- return make_vector<unsigned>(Mips::F2, Mips::F3, Mips::F4, Mips::F5,
- Mips::F6, Mips::F7, Mips::F8, Mips::F9, Mips::F10, Mips::F11,
- Mips::F20, Mips::F21, Mips::F22, Mips::F23, Mips::F24,
- Mips::F25, Mips::F26, Mips::F27, Mips::F28, Mips::F29,
- Mips::F30, Mips::F31, 0);
- else
- return make_vector<unsigned>(Mips::F2, Mips::F4, Mips::F6, Mips::F8,
- Mips::F10, Mips::F20, Mips::F22, Mips::F24, Mips::F26,
- Mips::F28, Mips::F30, 0);
- }
-
- if (VT == MVT::f64)
- if ((!Subtarget->isSingleFloat()) && (!Subtarget->isFP64bit()))
- return make_vector<unsigned>(Mips::D1, Mips::D2, Mips::D3, Mips::D4,
- Mips::D5, Mips::D10, Mips::D11, Mips::D12, Mips::D13,
- Mips::D14, Mips::D15, 0);
- }
- return std::vector<unsigned>();
-}
-
bool
MipsTargetLowering::isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const {
// The Mips target isn't yet aware of offsets.