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      1 //===-- ARMInstrInfo.cpp - ARM Instruction Information --------------------===//
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is distributed under the University of Illinois Open Source
      6 // License. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 //
     10 // This file contains the ARM implementation of the TargetInstrInfo class.
     11 //
     12 //===----------------------------------------------------------------------===//
     13 
     14 #include "ARMInstrInfo.h"
     15 #include "ARM.h"
     16 #include "ARMConstantPoolValue.h"
     17 #include "ARMMachineFunctionInfo.h"
     18 #include "ARMTargetMachine.h"
     19 #include "MCTargetDesc/ARMAddressingModes.h"
     20 #include "llvm/ADT/STLExtras.h"
     21 #include "llvm/CodeGen/LiveVariables.h"
     22 #include "llvm/CodeGen/MachineFrameInfo.h"
     23 #include "llvm/CodeGen/MachineInstrBuilder.h"
     24 #include "llvm/CodeGen/MachineJumpTableInfo.h"
     25 #include "llvm/CodeGen/MachineRegisterInfo.h"
     26 #include "llvm/IR/Function.h"
     27 #include "llvm/IR/GlobalVariable.h"
     28 #include "llvm/MC/MCAsmInfo.h"
     29 #include "llvm/MC/MCInst.h"
     30 using namespace llvm;
     31 
     32 ARMInstrInfo::ARMInstrInfo(const ARMSubtarget &STI)
     33     : ARMBaseInstrInfo(STI), RI() {}
     34 
     35 /// getNoopForMachoTarget - Return the noop instruction to use for a noop.
     36 void ARMInstrInfo::getNoopForMachoTarget(MCInst &NopInst) const {
     37   if (hasNOP()) {
     38     NopInst.setOpcode(ARM::HINT);
     39     NopInst.addOperand(MCOperand::createImm(0));
     40     NopInst.addOperand(MCOperand::createImm(ARMCC::AL));
     41     NopInst.addOperand(MCOperand::createReg(0));
     42   } else {
     43     NopInst.setOpcode(ARM::MOVr);
     44     NopInst.addOperand(MCOperand::createReg(ARM::R0));
     45     NopInst.addOperand(MCOperand::createReg(ARM::R0));
     46     NopInst.addOperand(MCOperand::createImm(ARMCC::AL));
     47     NopInst.addOperand(MCOperand::createReg(0));
     48     NopInst.addOperand(MCOperand::createReg(0));
     49   }
     50 }
     51 
     52 unsigned ARMInstrInfo::getUnindexedOpcode(unsigned Opc) const {
     53   switch (Opc) {
     54   default:
     55     break;
     56   case ARM::LDR_PRE_IMM:
     57   case ARM::LDR_PRE_REG:
     58   case ARM::LDR_POST_IMM:
     59   case ARM::LDR_POST_REG:
     60     return ARM::LDRi12;
     61   case ARM::LDRH_PRE:
     62   case ARM::LDRH_POST:
     63     return ARM::LDRH;
     64   case ARM::LDRB_PRE_IMM:
     65   case ARM::LDRB_PRE_REG:
     66   case ARM::LDRB_POST_IMM:
     67   case ARM::LDRB_POST_REG:
     68     return ARM::LDRBi12;
     69   case ARM::LDRSH_PRE:
     70   case ARM::LDRSH_POST:
     71     return ARM::LDRSH;
     72   case ARM::LDRSB_PRE:
     73   case ARM::LDRSB_POST:
     74     return ARM::LDRSB;
     75   case ARM::STR_PRE_IMM:
     76   case ARM::STR_PRE_REG:
     77   case ARM::STR_POST_IMM:
     78   case ARM::STR_POST_REG:
     79     return ARM::STRi12;
     80   case ARM::STRH_PRE:
     81   case ARM::STRH_POST:
     82     return ARM::STRH;
     83   case ARM::STRB_PRE_IMM:
     84   case ARM::STRB_PRE_REG:
     85   case ARM::STRB_POST_IMM:
     86   case ARM::STRB_POST_REG:
     87     return ARM::STRBi12;
     88   }
     89 
     90   return 0;
     91 }
     92 
     93 void ARMInstrInfo::expandLoadStackGuard(MachineBasicBlock::iterator MI) const {
     94   MachineFunction &MF = *MI->getParent()->getParent();
     95   const ARMSubtarget &Subtarget = MF.getSubtarget<ARMSubtarget>();
     96   const TargetMachine &TM = MF.getTarget();
     97 
     98   if (!Subtarget.useMovt(MF)) {
     99     if (TM.isPositionIndependent())
    100       expandLoadStackGuardBase(MI, ARM::LDRLIT_ga_pcrel, ARM::LDRi12);
    101     else
    102       expandLoadStackGuardBase(MI, ARM::LDRLIT_ga_abs, ARM::LDRi12);
    103     return;
    104   }
    105 
    106   if (!TM.isPositionIndependent()) {
    107     expandLoadStackGuardBase(MI, ARM::MOVi32imm, ARM::LDRi12);
    108     return;
    109   }
    110 
    111   const GlobalValue *GV =
    112       cast<GlobalValue>((*MI->memoperands_begin())->getValue());
    113 
    114   if (!Subtarget.isGVIndirectSymbol(GV)) {
    115     expandLoadStackGuardBase(MI, ARM::MOV_ga_pcrel, ARM::LDRi12);
    116     return;
    117   }
    118 
    119   MachineBasicBlock &MBB = *MI->getParent();
    120   DebugLoc DL = MI->getDebugLoc();
    121   unsigned Reg = MI->getOperand(0).getReg();
    122   MachineInstrBuilder MIB;
    123 
    124   MIB = BuildMI(MBB, MI, DL, get(ARM::MOV_ga_pcrel_ldr), Reg)
    125             .addGlobalAddress(GV, 0, ARMII::MO_NONLAZY);
    126   unsigned Flag = MachineMemOperand::MOLoad | MachineMemOperand::MOInvariant;
    127   MachineMemOperand *MMO = MBB.getParent()->getMachineMemOperand(
    128       MachinePointerInfo::getGOT(*MBB.getParent()), Flag, 4, 4);
    129   MIB.addMemOperand(MMO);
    130   MIB = BuildMI(MBB, MI, DL, get(ARM::LDRi12), Reg);
    131   MIB.addReg(Reg, RegState::Kill).addImm(0);
    132   MIB.setMemRefs(MI->memoperands_begin(), MI->memoperands_end());
    133   AddDefaultPred(MIB);
    134 }
    135