reference, declarationdefinition
definition → references, declarations, derived classes, virtual overrides
reference to multiple definitions → definitions
unreferenced
    1
    2
    3
    4
    5
    6
    7
    8
    9
   10
   11
   12
   13
   14
   15
   16
   17
   18
   19
   20
   21
   22
   23
   24
   25
   26
   27
   28
   29
   30
   31
   32
   33
   34
   35
   36
   37
   38
   39
   40
   41
   42
   43
   44
   45
   46
   47
   48
   49
   50
   51
   52
   53
   54
   55
   56
   57
   58
   59
   60
   61
   62
   63
   64
   65
   66
   67
   68
   69
   70
   71
   72
   73
   74
   75
   76
   77
   78
   79
   80
   81
   82
   83
   84
   85
   86
   87
   88
   89
   90
   91
   92
   93
   94
   95
   96
   97
   98
   99
  100
  101
  102
  103
  104
  105
  106
  107
  108
  109
  110
  111
  112
  113
  114
  115
  116
  117
  118
  119
  120
  121
  122
  123
  124
  125
  126
  127
  128
  129
  130
  131
  132
  133
  134
  135
  136
//===-- ARMInstrInfo.cpp - ARM Instruction Information --------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// 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() {}

/// Return the noop instruction to use for a noop.
void ARMInstrInfo::getNoop(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) const {
  MachineFunction &MF = *MI->getParent()->getParent();
  const ARMSubtarget &Subtarget = MF.getSubtarget<ARMSubtarget>();
  const TargetMachine &TM = MF.getTarget();

  if (!Subtarget.useMovt()) {
    if (TM.isPositionIndependent())
      expandLoadStackGuardBase(MI, ARM::LDRLIT_ga_pcrel, ARM::LDRi12);
    else
      expandLoadStackGuardBase(MI, ARM::LDRLIT_ga_abs, ARM::LDRi12);
    return;
  }

  if (!TM.isPositionIndependent()) {
    expandLoadStackGuardBase(MI, ARM::MOVi32imm, ARM::LDRi12);
    return;
  }

  const GlobalValue *GV =
      cast<GlobalValue>((*MI->memoperands_begin())->getValue());

  if (!Subtarget.isGVIndirectSymbol(GV)) {
    expandLoadStackGuardBase(MI, ARM::MOV_ga_pcrel, ARM::LDRi12);
    return;
  }

  MachineBasicBlock &MBB = *MI->getParent();
  DebugLoc DL = MI->getDebugLoc();
  Register 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);
  auto Flags = MachineMemOperand::MOLoad |
               MachineMemOperand::MODereferenceable |
               MachineMemOperand::MOInvariant;
  MachineMemOperand *MMO = MBB.getParent()->getMachineMemOperand(
      MachinePointerInfo::getGOT(*MBB.getParent()), Flags, 4, 4);
  MIB.addMemOperand(MMO);
  BuildMI(MBB, MI, DL, get(ARM::LDRi12), Reg)
      .addReg(Reg, RegState::Kill)
      .addImm(0)
      .cloneMemRefs(*MI)
      .add(predOps(ARMCC::AL));
}