aboutsummaryrefslogtreecommitdiff
path: root/lib/Target/ARM/Thumb1InstrInfo.cpp
blob: f57d93a2e83df154ebe242d0d50c4cfca4bb62ec (plain) (blame)
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
//===-- Thumb1InstrInfo.cpp - Thumb-1 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 Thumb-1 implementation of the TargetInstrInfo class.
//
//===----------------------------------------------------------------------===//

#include "Thumb1InstrInfo.h"
#include "ARMSubtarget.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineMemOperand.h"
#include "llvm/MC/MCInst.h"

using namespace llvm;

Thumb1InstrInfo::Thumb1InstrInfo(const ARMSubtarget &STI)
    : ARMBaseInstrInfo(STI), RI() {}

/// Return the noop instruction to use for a noop.
void Thumb1InstrInfo::getNoop(MCInst &NopInst) const {
  NopInst.setOpcode(ARM::tMOVr);
  NopInst.addOperand(MCOperand::createReg(ARM::R8));
  NopInst.addOperand(MCOperand::createReg(ARM::R8));
  NopInst.addOperand(MCOperand::createImm(ARMCC::AL));
  NopInst.addOperand(MCOperand::createReg(0));
}

unsigned Thumb1InstrInfo::getUnindexedOpcode(unsigned Opc) const {
  return 0;
}

void Thumb1InstrInfo::copyPhysReg(MachineBasicBlock &MBB,
                                  MachineBasicBlock::iterator I,
                                  const DebugLoc &DL, unsigned DestReg,
                                  unsigned SrcReg, bool KillSrc) const {
  // Need to check the arch.
  MachineFunction &MF = *MBB.getParent();
  const ARMSubtarget &st = MF.getSubtarget<ARMSubtarget>();

  assert(ARM::GPRRegClass.contains(DestReg, SrcReg) &&
         "Thumb1 can only copy GPR registers");

  if (st.hasV6Ops() || ARM::hGPRRegClass.contains(SrcReg)
      || !ARM::tGPRRegClass.contains(DestReg))
    BuildMI(MBB, I, DL, get(ARM::tMOVr), DestReg)
        .addReg(SrcReg, getKillRegState(KillSrc))
        .add(predOps(ARMCC::AL));
  else {
    // FIXME: Can also use 'mov hi, $src; mov $dst, hi',
    // with hi as either r10 or r11.

    const TargetRegisterInfo *RegInfo = st.getRegisterInfo();
    if (MBB.computeRegisterLiveness(RegInfo, ARM::CPSR, I)
        == MachineBasicBlock::LQR_Dead) {
      BuildMI(MBB, I, DL, get(ARM::tMOVSr), DestReg)
          .addReg(SrcReg, getKillRegState(KillSrc))
          ->addRegisterDead(ARM::CPSR, RegInfo);
      return;
    }

    // 'MOV lo, lo' is unpredictable on < v6, so use the stack to do it
    BuildMI(MBB, I, DL, get(ARM::tPUSH))
        .add(predOps(ARMCC::AL))
        .addReg(SrcReg, getKillRegState(KillSrc));
    BuildMI(MBB, I, DL, get(ARM::tPOP))
        .add(predOps(ARMCC::AL))
        .addReg(DestReg, getDefRegState(true));
  }
}

void Thumb1InstrInfo::
storeRegToStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
                    unsigned SrcReg, bool isKill, int FI,
                    const TargetRegisterClass *RC,
                    const TargetRegisterInfo *TRI) const {
  assert((RC == &ARM::tGPRRegClass ||
          (TargetRegisterInfo::isPhysicalRegister(SrcReg) &&
           isARMLowRegister(SrcReg))) && "Unknown regclass!");

  if (RC == &ARM::tGPRRegClass ||
      (TargetRegisterInfo::isPhysicalRegister(SrcReg) &&
       isARMLowRegister(SrcReg))) {
    DebugLoc DL;
    if (I != MBB.end()) DL = I->getDebugLoc();

    MachineFunction &MF = *MBB.getParent();
    MachineFrameInfo &MFI = MF.getFrameInfo();
    MachineMemOperand *MMO = MF.getMachineMemOperand(
        MachinePointerInfo::getFixedStack(MF, FI), MachineMemOperand::MOStore,
        MFI.getObjectSize(FI), MFI.getObjectAlignment(FI));
    BuildMI(MBB, I, DL, get(ARM::tSTRspi))
        .addReg(SrcReg, getKillRegState(isKill))
        .addFrameIndex(FI)
        .addImm(0)
        .addMemOperand(MMO)
        .add(predOps(ARMCC::AL));
  }
}

void Thumb1InstrInfo::
loadRegFromStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
                     unsigned DestReg, int FI,
                     const TargetRegisterClass *RC,
                     const TargetRegisterInfo *TRI) const {
  assert((RC->hasSuperClassEq(&ARM::tGPRRegClass) ||
          (TargetRegisterInfo::isPhysicalRegister(DestReg) &&
           isARMLowRegister(DestReg))) && "Unknown regclass!");

  if (RC->hasSuperClassEq(&ARM::tGPRRegClass) ||
      (TargetRegisterInfo::isPhysicalRegister(DestReg) &&
       isARMLowRegister(DestReg))) {
    DebugLoc DL;
    if (I != MBB.end()) DL = I->getDebugLoc();

    MachineFunction &MF = *MBB.getParent();
    MachineFrameInfo &MFI = MF.getFrameInfo();
    MachineMemOperand *MMO = MF.getMachineMemOperand(
        MachinePointerInfo::getFixedStack(MF, FI), MachineMemOperand::MOLoad,
        MFI.getObjectSize(FI), MFI.getObjectAlignment(FI));
    BuildMI(MBB, I, DL, get(ARM::tLDRspi), DestReg)
        .addFrameIndex(FI)
        .addImm(0)
        .addMemOperand(MMO)
        .add(predOps(ARMCC::AL));
  }
}

void Thumb1InstrInfo::expandLoadStackGuard(
    MachineBasicBlock::iterator MI) const {
  MachineFunction &MF = *MI->getParent()->getParent();
  const TargetMachine &TM = MF.getTarget();
  if (TM.isPositionIndependent())
    expandLoadStackGuardBase(MI, ARM::tLDRLIT_ga_pcrel, ARM::tLDRi);
  else
    expandLoadStackGuardBase(MI, ARM::tLDRLIT_ga_abs, ARM::tLDRi);
}

bool Thumb1InstrInfo::canCopyGluedNodeDuringSchedule(SDNode *N) const {
  // In Thumb1 the scheduler may need to schedule a cross-copy between GPRS and CPSR
  // but this is not always possible there, so allow the Scheduler to clone tADCS and tSBCS
  // even if they have glue.
  // FIXME. Actually implement the cross-copy where it is possible (post v6)
  // because these copies entail more spilling.
  unsigned Opcode = N->getMachineOpcode();
  if (Opcode == ARM::tADCS || Opcode == ARM::tSBCS)
    return true;

  return false;
}