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//===-- MipsSEISelDAGToDAG.cpp - A Dag to Dag Inst Selector for MipsSE ----===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// Subclass of MipsDAGToDAGISel specialized for mips32/64.
//
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "mips-isel"
#include "MipsSEISelDAGToDAG.h"
#include "Mips.h"
#include "MCTargetDesc/MipsBaseInfo.h"
#include "MipsAnalyzeImmediate.h"
#include "MipsMachineFunction.h"
#include "MipsRegisterInfo.h"
#include "llvm/CodeGen/MachineConstantPool.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/SelectionDAGNodes.h"
#include "llvm/IR/GlobalValue.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/Intrinsics.h"
#include "llvm/IR/Type.h"
#include "llvm/Support/CFG.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetMachine.h"
using namespace llvm;
bool MipsSEDAGToDAGISel::replaceUsesWithZeroReg(MachineRegisterInfo *MRI,
const MachineInstr& MI) {
unsigned DstReg = 0, ZeroReg = 0;
// Check if MI is "addiu $dst, $zero, 0" or "daddiu $dst, $zero, 0".
if ((MI.getOpcode() == Mips::ADDiu) &&
(MI.getOperand(1).getReg() == Mips::ZERO) &&
(MI.getOperand(2).getImm() == 0)) {
DstReg = MI.getOperand(0).getReg();
ZeroReg = Mips::ZERO;
} else if ((MI.getOpcode() == Mips::DADDiu) &&
(MI.getOperand(1).getReg() == Mips::ZERO_64) &&
(MI.getOperand(2).getImm() == 0)) {
DstReg = MI.getOperand(0).getReg();
ZeroReg = Mips::ZERO_64;
}
if (!DstReg)
return false;
// Replace uses with ZeroReg.
for (MachineRegisterInfo::use_iterator U = MRI->use_begin(DstReg),
E = MRI->use_end(); U != E;) {
MachineOperand &MO = U.getOperand();
unsigned OpNo = U.getOperandNo();
MachineInstr *MI = MO.getParent();
++U;
// Do not replace if it is a phi's operand or is tied to def operand.
if (MI->isPHI() || MI->isRegTiedToDefOperand(OpNo) || MI->isPseudo())
continue;
MO.setReg(ZeroReg);
}
return true;
}
void MipsSEDAGToDAGISel::initGlobalBaseReg(MachineFunction &MF) {
MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
if (!MipsFI->globalBaseRegSet())
return;
MachineBasicBlock &MBB = MF.front();
MachineBasicBlock::iterator I = MBB.begin();
MachineRegisterInfo &RegInfo = MF.getRegInfo();
const TargetInstrInfo &TII = *MF.getTarget().getInstrInfo();
DebugLoc DL = I != MBB.end() ? I->getDebugLoc() : DebugLoc();
unsigned V0, V1, GlobalBaseReg = MipsFI->getGlobalBaseReg();
const TargetRegisterClass *RC;
if (Subtarget.isABI_N64())
RC = (const TargetRegisterClass*)&Mips::CPU64RegsRegClass;
else
RC = (const TargetRegisterClass*)&Mips::CPURegsRegClass;
V0 = RegInfo.createVirtualRegister(RC);
V1 = RegInfo.createVirtualRegister(RC);
if (Subtarget.isABI_N64()) {
MF.getRegInfo().addLiveIn(Mips::T9_64);
MBB.addLiveIn(Mips::T9_64);
// lui $v0, %hi(%neg(%gp_rel(fname)))
// daddu $v1, $v0, $t9
// daddiu $globalbasereg, $v1, %lo(%neg(%gp_rel(fname)))
const GlobalValue *FName = MF.getFunction();
BuildMI(MBB, I, DL, TII.get(Mips::LUi64), V0)
.addGlobalAddress(FName, 0, MipsII::MO_GPOFF_HI);
BuildMI(MBB, I, DL, TII.get(Mips::DADDu), V1).addReg(V0)
.addReg(Mips::T9_64);
BuildMI(MBB, I, DL, TII.get(Mips::DADDiu), GlobalBaseReg).addReg(V1)
.addGlobalAddress(FName, 0, MipsII::MO_GPOFF_LO);
return;
}
if (MF.getTarget().getRelocationModel() == Reloc::Static) {
// Set global register to __gnu_local_gp.
//
// lui $v0, %hi(__gnu_local_gp)
// addiu $globalbasereg, $v0, %lo(__gnu_local_gp)
BuildMI(MBB, I, DL, TII.get(Mips::LUi), V0)
.addExternalSymbol("__gnu_local_gp", MipsII::MO_ABS_HI);
BuildMI(MBB, I, DL, TII.get(Mips::ADDiu), GlobalBaseReg).addReg(V0)
.addExternalSymbol("__gnu_local_gp", MipsII::MO_ABS_LO);
return;
}
MF.getRegInfo().addLiveIn(Mips::T9);
MBB.addLiveIn(Mips::T9);
if (Subtarget.isABI_N32()) {
// lui $v0, %hi(%neg(%gp_rel(fname)))
// addu $v1, $v0, $t9
// addiu $globalbasereg, $v1, %lo(%neg(%gp_rel(fname)))
const GlobalValue *FName = MF.getFunction();
BuildMI(MBB, I, DL, TII.get(Mips::LUi), V0)
.addGlobalAddress(FName, 0, MipsII::MO_GPOFF_HI);
BuildMI(MBB, I, DL, TII.get(Mips::ADDu), V1).addReg(V0).addReg(Mips::T9);
BuildMI(MBB, I, DL, TII.get(Mips::ADDiu), GlobalBaseReg).addReg(V1)
.addGlobalAddress(FName, 0, MipsII::MO_GPOFF_LO);
return;
}
assert(Subtarget.isABI_O32());
// For O32 ABI, the following instruction sequence is emitted to initialize
// the global base register:
//
// 0. lui $2, %hi(_gp_disp)
// 1. addiu $2, $2, %lo(_gp_disp)
// 2. addu $globalbasereg, $2, $t9
//
// We emit only the last instruction here.
//
// GNU linker requires that the first two instructions appear at the beginning
// of a function and no instructions be inserted before or between them.
// The two instructions are emitted during lowering to MC layer in order to
// avoid any reordering.
//
// Register $2 (Mips::V0) is added to the list of live-in registers to ensure
// the value instruction 1 (addiu) defines is valid when instruction 2 (addu)
// reads it.
MF.getRegInfo().addLiveIn(Mips::V0);
MBB.addLiveIn(Mips::V0);
BuildMI(MBB, I, DL, TII.get(Mips::ADDu), GlobalBaseReg)
.addReg(Mips::V0).addReg(Mips::T9);
}
void MipsSEDAGToDAGISel::processFunctionAfterISel(MachineFunction &MF) {
initGlobalBaseReg(MF);
MachineRegisterInfo *MRI = &MF.getRegInfo();
for (MachineFunction::iterator MFI = MF.begin(), MFE = MF.end(); MFI != MFE;
++MFI)
for (MachineBasicBlock::iterator I = MFI->begin(); I != MFI->end(); ++I)
replaceUsesWithZeroReg(MRI, *I);
}
/// Select multiply instructions.
std::pair<SDNode*, SDNode*>
MipsSEDAGToDAGISel::selectMULT(SDNode *N, unsigned Opc, DebugLoc DL, EVT Ty,
bool HasLo, bool HasHi) {
SDNode *Lo = 0, *Hi = 0;
SDNode *Mul = CurDAG->getMachineNode(Opc, DL, MVT::Glue, N->getOperand(0),
N->getOperand(1));
SDValue InFlag = SDValue(Mul, 0);
if (HasLo) {
unsigned Opcode = (Ty == MVT::i32 ? Mips::MFLO : Mips::MFLO64);
Lo = CurDAG->getMachineNode(Opcode, DL, Ty, MVT::Glue, InFlag);
InFlag = SDValue(Lo, 1);
}
if (HasHi) {
unsigned Opcode = (Ty == MVT::i32 ? Mips::MFHI : Mips::MFHI64);
Hi = CurDAG->getMachineNode(Opcode, DL, Ty, InFlag);
}
return std::make_pair(Lo, Hi);
}
SDNode *MipsSEDAGToDAGISel::selectAddESubE(unsigned MOp, SDValue InFlag,
SDValue CmpLHS, DebugLoc DL,
SDNode *Node) const {
unsigned Opc = InFlag.getOpcode(); (void)Opc;
assert(((Opc == ISD::ADDC || Opc == ISD::ADDE) ||
(Opc == ISD::SUBC || Opc == ISD::SUBE)) &&
"(ADD|SUB)E flag operand must come from (ADD|SUB)C/E insn");
SDValue Ops[] = { CmpLHS, InFlag.getOperand(1) };
SDValue LHS = Node->getOperand(0), RHS = Node->getOperand(1);
EVT VT = LHS.getValueType();
SDNode *Carry = CurDAG->getMachineNode(Mips::SLTu, DL, VT, Ops, 2);
SDNode *AddCarry = CurDAG->getMachineNode(Mips::ADDu, DL, VT,
SDValue(Carry, 0), RHS);
return CurDAG->SelectNodeTo(Node, MOp, VT, MVT::Glue, LHS,
SDValue(AddCarry, 0));
}
/// ComplexPattern used on MipsInstrInfo
/// Used on Mips Load/Store instructions
bool MipsSEDAGToDAGISel::selectAddrRegImm(SDValue Addr, SDValue &Base,
SDValue &Offset) const {
EVT ValTy = Addr.getValueType();
// if Address is FI, get the TargetFrameIndex.
if (FrameIndexSDNode *FIN = dyn_cast<FrameIndexSDNode>(Addr)) {
Base = CurDAG->getTargetFrameIndex(FIN->getIndex(), ValTy);
Offset = CurDAG->getTargetConstant(0, ValTy);
return true;
}
// on PIC code Load GA
if (Addr.getOpcode() == MipsISD::Wrapper) {
Base = Addr.getOperand(0);
Offset = Addr.getOperand(1);
return true;
}
if (TM.getRelocationModel() != Reloc::PIC_) {
if ((Addr.getOpcode() == ISD::TargetExternalSymbol ||
Addr.getOpcode() == ISD::TargetGlobalAddress))
return false;
}
// Addresses of the form FI+const or FI|const
if (CurDAG->isBaseWithConstantOffset(Addr)) {
ConstantSDNode *CN = dyn_cast<ConstantSDNode>(Addr.getOperand(1));
if (isInt<16>(CN->getSExtValue())) {
// If the first operand is a FI, get the TargetFI Node
if (FrameIndexSDNode *FIN = dyn_cast<FrameIndexSDNode>
(Addr.getOperand(0)))
Base = CurDAG->getTargetFrameIndex(FIN->getIndex(), ValTy);
else
Base = Addr.getOperand(0);
Offset = CurDAG->getTargetConstant(CN->getZExtValue(), ValTy);
return true;
}
}
// Operand is a result from an ADD.
if (Addr.getOpcode() == ISD::ADD) {
// When loading from constant pools, load the lower address part in
// the instruction itself. Example, instead of:
// lui $2, %hi($CPI1_0)
// addiu $2, $2, %lo($CPI1_0)
// lwc1 $f0, 0($2)
// Generate:
// lui $2, %hi($CPI1_0)
// lwc1 $f0, %lo($CPI1_0)($2)
if (Addr.getOperand(1).getOpcode() == MipsISD::Lo ||
Addr.getOperand(1).getOpcode() == MipsISD::GPRel) {
SDValue Opnd0 = Addr.getOperand(1).getOperand(0);
if (isa<ConstantPoolSDNode>(Opnd0) || isa<GlobalAddressSDNode>(Opnd0) ||
isa<JumpTableSDNode>(Opnd0)) {
Base = Addr.getOperand(0);
Offset = Opnd0;
return true;
}
}
}
return false;
}
bool MipsSEDAGToDAGISel::selectAddrDefault(SDValue Addr, SDValue &Base,
SDValue &Offset) const {
Base = Addr;
Offset = CurDAG->getTargetConstant(0, Addr.getValueType());
return true;
}
bool MipsSEDAGToDAGISel::selectIntAddr(SDValue Addr, SDValue &Base,
SDValue &Offset) const {
return selectAddrRegImm(Addr, Base, Offset) ||
selectAddrDefault(Addr, Base, Offset);
}
std::pair<bool, SDNode*> MipsSEDAGToDAGISel::selectNode(SDNode *Node) {
unsigned Opcode = Node->getOpcode();
DebugLoc DL = Node->getDebugLoc();
///
// Instruction Selection not handled by the auto-generated
// tablegen selection should be handled here.
///
EVT NodeTy = Node->getValueType(0);
SDNode *Result;
unsigned MultOpc;
switch(Opcode) {
default: break;
case ISD::SUBE: {
SDValue InFlag = Node->getOperand(2);
Result = selectAddESubE(Mips::SUBu, InFlag, InFlag.getOperand(0), DL, Node);
return std::make_pair(true, Result);
}
case ISD::ADDE: {
SDValue InFlag = Node->getOperand(2);
Result = selectAddESubE(Mips::ADDu, InFlag, InFlag.getValue(0), DL, Node);
return std::make_pair(true, Result);
}
/// Mul with two results
case ISD::SMUL_LOHI:
case ISD::UMUL_LOHI: {
if (NodeTy == MVT::i32)
MultOpc = (Opcode == ISD::UMUL_LOHI ? Mips::MULTu : Mips::MULT);
else
MultOpc = (Opcode == ISD::UMUL_LOHI ? Mips::DMULTu : Mips::DMULT);
std::pair<SDNode*, SDNode*> LoHi = selectMULT(Node, MultOpc, DL, NodeTy,
true, true);
if (!SDValue(Node, 0).use_empty())
ReplaceUses(SDValue(Node, 0), SDValue(LoHi.first, 0));
if (!SDValue(Node, 1).use_empty())
ReplaceUses(SDValue(Node, 1), SDValue(LoHi.second, 0));
return std::make_pair(true, (SDNode*)NULL);
}
/// Special Muls
case ISD::MUL: {
// Mips32 has a 32-bit three operand mul instruction.
if (Subtarget.hasMips32() && NodeTy == MVT::i32)
break;
MultOpc = NodeTy == MVT::i32 ? Mips::MULT : Mips::DMULT;
Result = selectMULT(Node, MultOpc, DL, NodeTy, true, false).first;
return std::make_pair(true, Result);
}
case ISD::MULHS:
case ISD::MULHU: {
if (NodeTy == MVT::i32)
MultOpc = (Opcode == ISD::MULHU ? Mips::MULTu : Mips::MULT);
else
MultOpc = (Opcode == ISD::MULHU ? Mips::DMULTu : Mips::DMULT);
Result = selectMULT(Node, MultOpc, DL, NodeTy, false, true).second;
return std::make_pair(true, Result);
}
case ISD::ConstantFP: {
ConstantFPSDNode *CN = dyn_cast<ConstantFPSDNode>(Node);
if (Node->getValueType(0) == MVT::f64 && CN->isExactlyValue(+0.0)) {
if (Subtarget.hasMips64()) {
SDValue Zero = CurDAG->getCopyFromReg(CurDAG->getEntryNode(), DL,
Mips::ZERO_64, MVT::i64);
Result = CurDAG->getMachineNode(Mips::DMTC1, DL, MVT::f64, Zero);
} else {
SDValue Zero = CurDAG->getCopyFromReg(CurDAG->getEntryNode(), DL,
Mips::ZERO, MVT::i32);
Result = CurDAG->getMachineNode(Mips::BuildPairF64, DL, MVT::f64, Zero,
Zero);
}
return std::make_pair(true, Result);
}
break;
}
case ISD::Constant: {
const ConstantSDNode *CN = dyn_cast<ConstantSDNode>(Node);
unsigned Size = CN->getValueSizeInBits(0);
if (Size == 32)
break;
MipsAnalyzeImmediate AnalyzeImm;
int64_t Imm = CN->getSExtValue();
const MipsAnalyzeImmediate::InstSeq &Seq =
AnalyzeImm.Analyze(Imm, Size, false);
MipsAnalyzeImmediate::InstSeq::const_iterator Inst = Seq.begin();
DebugLoc DL = CN->getDebugLoc();
SDNode *RegOpnd;
SDValue ImmOpnd = CurDAG->getTargetConstant(SignExtend64<16>(Inst->ImmOpnd),
MVT::i64);
// The first instruction can be a LUi which is different from other
// instructions (ADDiu, ORI and SLL) in that it does not have a register
// operand.
if (Inst->Opc == Mips::LUi64)
RegOpnd = CurDAG->getMachineNode(Inst->Opc, DL, MVT::i64, ImmOpnd);
else
RegOpnd =
CurDAG->getMachineNode(Inst->Opc, DL, MVT::i64,
CurDAG->getRegister(Mips::ZERO_64, MVT::i64),
ImmOpnd);
// The remaining instructions in the sequence are handled here.
for (++Inst; Inst != Seq.end(); ++Inst) {
ImmOpnd = CurDAG->getTargetConstant(SignExtend64<16>(Inst->ImmOpnd),
MVT::i64);
RegOpnd = CurDAG->getMachineNode(Inst->Opc, DL, MVT::i64,
SDValue(RegOpnd, 0), ImmOpnd);
}
return std::make_pair(true, RegOpnd);
}
case MipsISD::ThreadPointer: {
EVT PtrVT = TLI.getPointerTy();
unsigned RdhwrOpc, SrcReg, DestReg;
if (PtrVT == MVT::i32) {
RdhwrOpc = Mips::RDHWR;
SrcReg = Mips::HWR29;
DestReg = Mips::V1;
} else {
RdhwrOpc = Mips::RDHWR64;
SrcReg = Mips::HWR29_64;
DestReg = Mips::V1_64;
}
SDNode *Rdhwr =
CurDAG->getMachineNode(RdhwrOpc, Node->getDebugLoc(),
Node->getValueType(0),
CurDAG->getRegister(SrcReg, PtrVT));
SDValue Chain = CurDAG->getCopyToReg(CurDAG->getEntryNode(), DL, DestReg,
SDValue(Rdhwr, 0));
SDValue ResNode = CurDAG->getCopyFromReg(Chain, DL, DestReg, PtrVT);
ReplaceUses(SDValue(Node, 0), ResNode);
return std::make_pair(true, ResNode.getNode());
}
}
return std::make_pair(false, (SDNode*)NULL);
}
FunctionPass *llvm::createMipsSEISelDag(MipsTargetMachine &TM) {
return new MipsSEDAGToDAGISel(TM);
}