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//===-- ARMInstrInfo.cpp - ARM Instruction Information --------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains the ARM implementation of the TargetInstrInfo class.
//
//===----------------------------------------------------------------------===//
#include "ARMInstrInfo.h"
#include "ARM.h"
#include "ARMConstantPoolValue.h"
#include "ARMMachineFunctionInfo.h"
#include "ARMTargetMachine.h"
#include "MCTargetDesc/ARMAddressingModes.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/CodeGen/LiveVariables.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineJumpTableInfo.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/GlobalVariable.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCInst.h"
using namespace llvm;
ARMInstrInfo::ARMInstrInfo(const ARMSubtarget &STI)
: ARMBaseInstrInfo(STI), RI() {}
/// getNoopForMachoTarget - Return the noop instruction to use for a noop.
void ARMInstrInfo::getNoopForMachoTarget(MCInst &NopInst) const {
if (hasNOP()) {
NopInst.setOpcode(ARM::HINT);
NopInst.addOperand(MCOperand::createImm(0));
NopInst.addOperand(MCOperand::createImm(ARMCC::AL));
NopInst.addOperand(MCOperand::createReg(0));
} else {
NopInst.setOpcode(ARM::MOVr);
NopInst.addOperand(MCOperand::createReg(ARM::R0));
NopInst.addOperand(MCOperand::createReg(ARM::R0));
NopInst.addOperand(MCOperand::createImm(ARMCC::AL));
NopInst.addOperand(MCOperand::createReg(0));
NopInst.addOperand(MCOperand::createReg(0));
}
}
unsigned ARMInstrInfo::getUnindexedOpcode(unsigned Opc) const {
switch (Opc) {
default: break;
case ARM::LDR_PRE_IMM:
case ARM::LDR_PRE_REG:
case ARM::LDR_POST_IMM:
case ARM::LDR_POST_REG:
return ARM::LDRi12;
case ARM::LDRH_PRE:
case ARM::LDRH_POST:
return ARM::LDRH;
case ARM::LDRB_PRE_IMM:
case ARM::LDRB_PRE_REG:
case ARM::LDRB_POST_IMM:
case ARM::LDRB_POST_REG:
return ARM::LDRBi12;
case ARM::LDRSH_PRE:
case ARM::LDRSH_POST:
return ARM::LDRSH;
case ARM::LDRSB_PRE:
case ARM::LDRSB_POST:
return ARM::LDRSB;
case ARM::STR_PRE_IMM:
case ARM::STR_PRE_REG:
case ARM::STR_POST_IMM:
case ARM::STR_POST_REG:
return ARM::STRi12;
case ARM::STRH_PRE:
case ARM::STRH_POST:
return ARM::STRH;
case ARM::STRB_PRE_IMM:
case ARM::STRB_PRE_REG:
case ARM::STRB_POST_IMM:
case ARM::STRB_POST_REG:
return ARM::STRBi12;
}
return 0;
}
void ARMInstrInfo::expandLoadStackGuard(MachineBasicBlock::iterator MI,
Reloc::Model RM) const {
MachineFunction &MF = *MI->getParent()->getParent();
const ARMSubtarget &Subtarget = MF.getSubtarget<ARMSubtarget>();
if (!Subtarget.useMovt(MF)) {
if (RM == Reloc::PIC_)
expandLoadStackGuardBase(MI, ARM::LDRLIT_ga_pcrel, ARM::LDRi12, RM);
else
expandLoadStackGuardBase(MI, ARM::LDRLIT_ga_abs, ARM::LDRi12, RM);
return;
}
if (RM != Reloc::PIC_) {
expandLoadStackGuardBase(MI, ARM::MOVi32imm, ARM::LDRi12, RM);
return;
}
const GlobalValue *GV =
cast<GlobalValue>((*MI->memoperands_begin())->getValue());
if (!Subtarget.GVIsIndirectSymbol(GV, RM)) {
expandLoadStackGuardBase(MI, ARM::MOV_ga_pcrel, ARM::LDRi12, RM);
return;
}
MachineBasicBlock &MBB = *MI->getParent();
DebugLoc DL = MI->getDebugLoc();
unsigned Reg = MI->getOperand(0).getReg();
MachineInstrBuilder MIB;
MIB = BuildMI(MBB, MI, DL, get(ARM::MOV_ga_pcrel_ldr), Reg)
.addGlobalAddress(GV, 0, ARMII::MO_NONLAZY);
unsigned Flag = MachineMemOperand::MOLoad | MachineMemOperand::MOInvariant;
MachineMemOperand *MMO = MBB.getParent()->getMachineMemOperand(
MachinePointerInfo::getGOT(), Flag, 4, 4);
MIB.addMemOperand(MMO);
MIB = BuildMI(MBB, MI, DL, get(ARM::LDRi12), Reg);
MIB.addReg(Reg, RegState::Kill).addImm(0);
MIB.setMemRefs(MI->memoperands_begin(), MI->memoperands_end());
AddDefaultPred(MIB);
}
namespace {
/// ARMCGBR - Create Global Base Reg pass. This initializes the PIC
/// global base register for ARM ELF.
struct ARMCGBR : public MachineFunctionPass {
static char ID;
ARMCGBR() : MachineFunctionPass(ID) {}
bool runOnMachineFunction(MachineFunction &MF) override {
ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
if (AFI->getGlobalBaseReg() == 0)
return false;
const ARMSubtarget &STI =
static_cast<const ARMSubtarget &>(MF.getSubtarget());
// Don't do this for Thumb1.
if (STI.isThumb1Only())
return false;
const TargetMachine &TM = MF.getTarget();
if (TM.getRelocationModel() != Reloc::PIC_)
return false;
LLVMContext *Context = &MF.getFunction()->getContext();
unsigned ARMPCLabelIndex = AFI->createPICLabelUId();
unsigned PCAdj = STI.isThumb() ? 4 : 8;
ARMConstantPoolValue *CPV = ARMConstantPoolSymbol::Create(
*Context, "_GLOBAL_OFFSET_TABLE_", ARMPCLabelIndex, PCAdj);
unsigned Align = TM.getDataLayout()->getPrefTypeAlignment(
Type::getInt32PtrTy(*Context));
unsigned Idx = MF.getConstantPool()->getConstantPoolIndex(CPV, Align);
MachineBasicBlock &FirstMBB = MF.front();
MachineBasicBlock::iterator MBBI = FirstMBB.begin();
DebugLoc DL = FirstMBB.findDebugLoc(MBBI);
unsigned TempReg =
MF.getRegInfo().createVirtualRegister(&ARM::rGPRRegClass);
unsigned Opc = STI.isThumb2() ? ARM::t2LDRpci : ARM::LDRcp;
const TargetInstrInfo &TII = *STI.getInstrInfo();
MachineInstrBuilder MIB = BuildMI(FirstMBB, MBBI, DL,
TII.get(Opc), TempReg)
.addConstantPoolIndex(Idx);
if (Opc == ARM::LDRcp)
MIB.addImm(0);
AddDefaultPred(MIB);
// Fix the GOT address by adding pc.
unsigned GlobalBaseReg = AFI->getGlobalBaseReg();
Opc = STI.isThumb2() ? ARM::tPICADD : ARM::PICADD;
MIB = BuildMI(FirstMBB, MBBI, DL, TII.get(Opc), GlobalBaseReg)
.addReg(TempReg)
.addImm(ARMPCLabelIndex);
if (Opc == ARM::PICADD)
AddDefaultPred(MIB);
return true;
}
const char *getPassName() const override {
return "ARM PIC Global Base Reg Initialization";
}
void getAnalysisUsage(AnalysisUsage &AU) const override {
AU.setPreservesCFG();
MachineFunctionPass::getAnalysisUsage(AU);
}
};
}
char ARMCGBR::ID = 0;
FunctionPass*
llvm::createARMGlobalBaseRegPass() { return new ARMCGBR(); }
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