summaryrefslogtreecommitdiff
path: root/lib/Target/ARM/ARMExpandPseudoInsts.cpp
blob: e5f8a638eb67212ad5286ef946cd30ebad71d9ff (plain)
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
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
//===-- ARMExpandPseudoInsts.cpp - Expand pseudo instructions -----*- C++ -*-=//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains a pass that expand pseudo instructions into target
// instructions to allow proper scheduling, if-conversion, and other late
// optimizations. This pass should be run after register allocation but before
// post- regalloc scheduling pass.
//
//===----------------------------------------------------------------------===//

#define DEBUG_TYPE "arm-pseudo"
#include "ARM.h"
#include "ARMBaseInstrInfo.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/Target/TargetRegisterInfo.h"
using namespace llvm;

namespace {
  class ARMExpandPseudo : public MachineFunctionPass {
  public:
    static char ID;
    ARMExpandPseudo() : MachineFunctionPass(ID) {}

    const TargetInstrInfo *TII;
    const TargetRegisterInfo *TRI;

    virtual bool runOnMachineFunction(MachineFunction &Fn);

    virtual const char *getPassName() const {
      return "ARM pseudo instruction expansion pass";
    }

  private:
    void TransferImpOps(MachineInstr &OldMI,
                        MachineInstrBuilder &UseMI, MachineInstrBuilder &DefMI);
    bool ExpandMBB(MachineBasicBlock &MBB);
  };
  char ARMExpandPseudo::ID = 0;
}

/// TransferImpOps - Transfer implicit operands on the pseudo instruction to
/// the instructions created from the expansion.
void ARMExpandPseudo::TransferImpOps(MachineInstr &OldMI,
                                     MachineInstrBuilder &UseMI,
                                     MachineInstrBuilder &DefMI) {
  const TargetInstrDesc &Desc = OldMI.getDesc();
  for (unsigned i = Desc.getNumOperands(), e = OldMI.getNumOperands();
       i != e; ++i) {
    const MachineOperand &MO = OldMI.getOperand(i);
    assert(MO.isReg() && MO.getReg());
    if (MO.isUse())
      UseMI.addReg(MO.getReg(), getKillRegState(MO.isKill()));
    else
      DefMI.addReg(MO.getReg(),
                   getDefRegState(true) | getDeadRegState(MO.isDead()));
  }
}

bool ARMExpandPseudo::ExpandMBB(MachineBasicBlock &MBB) {
  bool Modified = false;

  MachineBasicBlock::iterator MBBI = MBB.begin(), E = MBB.end();
  while (MBBI != E) {
    MachineInstr &MI = *MBBI;
    MachineBasicBlock::iterator NMBBI = llvm::next(MBBI);

    unsigned Opcode = MI.getOpcode();
    switch (Opcode) {
    default: break;
    case ARM::tLDRpci_pic: 
    case ARM::t2LDRpci_pic: {
      unsigned NewLdOpc = (Opcode == ARM::tLDRpci_pic)
        ? ARM::tLDRpci : ARM::t2LDRpci;
      unsigned DstReg = MI.getOperand(0).getReg();
      bool DstIsDead = MI.getOperand(0).isDead();
      MachineInstrBuilder MIB1 =
        AddDefaultPred(BuildMI(MBB, MBBI, MI.getDebugLoc(),
                               TII->get(NewLdOpc), DstReg)
                       .addOperand(MI.getOperand(1)));
      (*MIB1).setMemRefs(MI.memoperands_begin(), MI.memoperands_end());
      MachineInstrBuilder MIB2 = BuildMI(MBB, MBBI, MI.getDebugLoc(),
                                         TII->get(ARM::tPICADD))
        .addReg(DstReg, getDefRegState(true) | getDeadRegState(DstIsDead))
        .addReg(DstReg)
        .addOperand(MI.getOperand(2));
      TransferImpOps(MI, MIB1, MIB2);
      MI.eraseFromParent();
      Modified = true;
      break;
    }

    case ARM::t2MOVi32imm: {
      unsigned PredReg = 0;
      ARMCC::CondCodes Pred = llvm::getInstrPredicate(&MI, PredReg);
      unsigned DstReg = MI.getOperand(0).getReg();
      bool DstIsDead = MI.getOperand(0).isDead();
      const MachineOperand &MO = MI.getOperand(1);
      MachineInstrBuilder LO16, HI16;

      LO16 = BuildMI(MBB, MBBI, MI.getDebugLoc(), TII->get(ARM::t2MOVi16),
                     DstReg);
      HI16 = BuildMI(MBB, MBBI, MI.getDebugLoc(), TII->get(ARM::t2MOVTi16))
        .addReg(DstReg, getDefRegState(true) | getDeadRegState(DstIsDead))
        .addReg(DstReg);

      if (MO.isImm()) {
        unsigned Imm = MO.getImm();
        unsigned Lo16 = Imm & 0xffff;
        unsigned Hi16 = (Imm >> 16) & 0xffff;
        LO16 = LO16.addImm(Lo16);
        HI16 = HI16.addImm(Hi16);
      } else {
        const GlobalValue *GV = MO.getGlobal();
        unsigned TF = MO.getTargetFlags();
        LO16 = LO16.addGlobalAddress(GV, MO.getOffset(), TF | ARMII::MO_LO16);
        HI16 = HI16.addGlobalAddress(GV, MO.getOffset(), TF | ARMII::MO_HI16);
      }
      (*LO16).setMemRefs(MI.memoperands_begin(), MI.memoperands_end());
      (*HI16).setMemRefs(MI.memoperands_begin(), MI.memoperands_end());
      LO16.addImm(Pred).addReg(PredReg);
      HI16.addImm(Pred).addReg(PredReg);
      TransferImpOps(MI, LO16, HI16);
      MI.eraseFromParent();
      Modified = true;
      break;
    }

    case ARM::VMOVQQ: {
      unsigned DstReg = MI.getOperand(0).getReg();
      bool DstIsDead = MI.getOperand(0).isDead();
      unsigned EvenDst = TRI->getSubReg(DstReg, ARM::qsub_0);
      unsigned OddDst  = TRI->getSubReg(DstReg, ARM::qsub_1);
      unsigned SrcReg = MI.getOperand(1).getReg();
      bool SrcIsKill = MI.getOperand(1).isKill();
      unsigned EvenSrc = TRI->getSubReg(SrcReg, ARM::qsub_0);
      unsigned OddSrc  = TRI->getSubReg(SrcReg, ARM::qsub_1);
      MachineInstrBuilder Even =
        AddDefaultPred(BuildMI(MBB, MBBI, MI.getDebugLoc(),
                               TII->get(ARM::VMOVQ))
                     .addReg(EvenDst,
                             getDefRegState(true) | getDeadRegState(DstIsDead))
                     .addReg(EvenSrc, getKillRegState(SrcIsKill)));
      MachineInstrBuilder Odd =
        AddDefaultPred(BuildMI(MBB, MBBI, MI.getDebugLoc(),
                               TII->get(ARM::VMOVQ))
                     .addReg(OddDst,
                             getDefRegState(true) | getDeadRegState(DstIsDead))
                     .addReg(OddSrc, getKillRegState(SrcIsKill)));
      TransferImpOps(MI, Even, Odd);
      MI.eraseFromParent();
      Modified = true;
    }
    }
    MBBI = NMBBI;
  }

  return Modified;
}

bool ARMExpandPseudo::runOnMachineFunction(MachineFunction &MF) {
  TII = MF.getTarget().getInstrInfo();
  TRI = MF.getTarget().getRegisterInfo();

  bool Modified = false;
  for (MachineFunction::iterator MFI = MF.begin(), E = MF.end(); MFI != E;
       ++MFI)
    Modified |= ExpandMBB(*MFI);
  return Modified;
}

/// createARMExpandPseudoPass - returns an instance of the pseudo instruction
/// expansion pass.
FunctionPass *llvm::createARMExpandPseudoPass() {
  return new ARMExpandPseudo();
}