1 //===-- Thumb1InstrInfo.cpp - Thumb-1 Instruction Information -------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file contains the Thumb-1 implementation of the TargetInstrInfo class.
10 //
11 //===----------------------------------------------------------------------===//
12
13 #include "Thumb1InstrInfo.h"
14 #include "ARMSubtarget.h"
15 #include "llvm/CodeGen/MachineFrameInfo.h"
16 #include "llvm/CodeGen/MachineInstrBuilder.h"
17 #include "llvm/CodeGen/MachineMemOperand.h"
18 #include "llvm/MC/MCInst.h"
19 #include "llvm/MC/MCInstBuilder.h"
20
21 using namespace llvm;
22
Thumb1InstrInfo(const ARMSubtarget & STI)23 Thumb1InstrInfo::Thumb1InstrInfo(const ARMSubtarget &STI)
24 : ARMBaseInstrInfo(STI) {}
25
26 /// Return the noop instruction to use for a noop.
getNop() const27 MCInst Thumb1InstrInfo::getNop() const {
28 return MCInstBuilder(ARM::tMOVr)
29 .addReg(ARM::R8)
30 .addReg(ARM::R8)
31 .addImm(ARMCC::AL)
32 .addReg(0);
33 }
34
getUnindexedOpcode(unsigned Opc) const35 unsigned Thumb1InstrInfo::getUnindexedOpcode(unsigned Opc) const {
36 return 0;
37 }
38
copyPhysReg(MachineBasicBlock & MBB,MachineBasicBlock::iterator I,const DebugLoc & DL,MCRegister DestReg,MCRegister SrcReg,bool KillSrc) const39 void Thumb1InstrInfo::copyPhysReg(MachineBasicBlock &MBB,
40 MachineBasicBlock::iterator I,
41 const DebugLoc &DL, MCRegister DestReg,
42 MCRegister SrcReg, bool KillSrc) const {
43 // Need to check the arch.
44 MachineFunction &MF = *MBB.getParent();
45 const ARMSubtarget &st = MF.getSubtarget<ARMSubtarget>();
46
47 assert(ARM::GPRRegClass.contains(DestReg, SrcReg) &&
48 "Thumb1 can only copy GPR registers");
49
50 if (st.hasV6Ops() || ARM::hGPRRegClass.contains(SrcReg)
51 || !ARM::tGPRRegClass.contains(DestReg))
52 BuildMI(MBB, I, DL, get(ARM::tMOVr), DestReg)
53 .addReg(SrcReg, getKillRegState(KillSrc))
54 .add(predOps(ARMCC::AL));
55 else {
56 // FIXME: Can also use 'mov hi, $src; mov $dst, hi',
57 // with hi as either r10 or r11.
58
59 const TargetRegisterInfo *RegInfo = st.getRegisterInfo();
60 if (MBB.computeRegisterLiveness(RegInfo, ARM::CPSR, I)
61 == MachineBasicBlock::LQR_Dead) {
62 BuildMI(MBB, I, DL, get(ARM::tMOVSr), DestReg)
63 .addReg(SrcReg, getKillRegState(KillSrc))
64 ->addRegisterDead(ARM::CPSR, RegInfo);
65 return;
66 }
67
68 // 'MOV lo, lo' is unpredictable on < v6, so use the stack to do it
69 BuildMI(MBB, I, DL, get(ARM::tPUSH))
70 .add(predOps(ARMCC::AL))
71 .addReg(SrcReg, getKillRegState(KillSrc));
72 BuildMI(MBB, I, DL, get(ARM::tPOP))
73 .add(predOps(ARMCC::AL))
74 .addReg(DestReg, getDefRegState(true));
75 }
76 }
77
storeRegToStackSlot(MachineBasicBlock & MBB,MachineBasicBlock::iterator I,Register SrcReg,bool isKill,int FI,const TargetRegisterClass * RC,const TargetRegisterInfo * TRI,Register VReg) const78 void Thumb1InstrInfo::storeRegToStackSlot(MachineBasicBlock &MBB,
79 MachineBasicBlock::iterator I,
80 Register SrcReg, bool isKill, int FI,
81 const TargetRegisterClass *RC,
82 const TargetRegisterInfo *TRI,
83 Register VReg) const {
84 assert((RC == &ARM::tGPRRegClass ||
85 (SrcReg.isPhysical() && isARMLowRegister(SrcReg))) &&
86 "Unknown regclass!");
87
88 if (RC == &ARM::tGPRRegClass ||
89 (SrcReg.isPhysical() && isARMLowRegister(SrcReg))) {
90 DebugLoc DL;
91 if (I != MBB.end()) DL = I->getDebugLoc();
92
93 MachineFunction &MF = *MBB.getParent();
94 MachineFrameInfo &MFI = MF.getFrameInfo();
95 MachineMemOperand *MMO = MF.getMachineMemOperand(
96 MachinePointerInfo::getFixedStack(MF, FI), MachineMemOperand::MOStore,
97 MFI.getObjectSize(FI), MFI.getObjectAlign(FI));
98 BuildMI(MBB, I, DL, get(ARM::tSTRspi))
99 .addReg(SrcReg, getKillRegState(isKill))
100 .addFrameIndex(FI)
101 .addImm(0)
102 .addMemOperand(MMO)
103 .add(predOps(ARMCC::AL));
104 }
105 }
106
loadRegFromStackSlot(MachineBasicBlock & MBB,MachineBasicBlock::iterator I,Register DestReg,int FI,const TargetRegisterClass * RC,const TargetRegisterInfo * TRI,Register VReg) const107 void Thumb1InstrInfo::loadRegFromStackSlot(MachineBasicBlock &MBB,
108 MachineBasicBlock::iterator I,
109 Register DestReg, int FI,
110 const TargetRegisterClass *RC,
111 const TargetRegisterInfo *TRI,
112 Register VReg) const {
113 assert((RC->hasSuperClassEq(&ARM::tGPRRegClass) ||
114 (DestReg.isPhysical() && isARMLowRegister(DestReg))) &&
115 "Unknown regclass!");
116
117 if (RC->hasSuperClassEq(&ARM::tGPRRegClass) ||
118 (DestReg.isPhysical() && isARMLowRegister(DestReg))) {
119 DebugLoc DL;
120 if (I != MBB.end()) DL = I->getDebugLoc();
121
122 MachineFunction &MF = *MBB.getParent();
123 MachineFrameInfo &MFI = MF.getFrameInfo();
124 MachineMemOperand *MMO = MF.getMachineMemOperand(
125 MachinePointerInfo::getFixedStack(MF, FI), MachineMemOperand::MOLoad,
126 MFI.getObjectSize(FI), MFI.getObjectAlign(FI));
127 BuildMI(MBB, I, DL, get(ARM::tLDRspi), DestReg)
128 .addFrameIndex(FI)
129 .addImm(0)
130 .addMemOperand(MMO)
131 .add(predOps(ARMCC::AL));
132 }
133 }
134
expandLoadStackGuard(MachineBasicBlock::iterator MI) const135 void Thumb1InstrInfo::expandLoadStackGuard(
136 MachineBasicBlock::iterator MI) const {
137 MachineFunction &MF = *MI->getParent()->getParent();
138 const ARMSubtarget &ST = MF.getSubtarget<ARMSubtarget>();
139 const auto *GV = cast<GlobalValue>((*MI->memoperands_begin())->getValue());
140
141 assert(MF.getFunction().getParent()->getStackProtectorGuard() != "tls" &&
142 "TLS stack protector not supported for Thumb1 targets");
143
144 unsigned Instr;
145 if (!GV->isDSOLocal())
146 Instr = ARM::tLDRLIT_ga_pcrel;
147 else if (ST.genExecuteOnly() && ST.hasV8MBaselineOps())
148 Instr = ARM::t2MOVi32imm;
149 else if (ST.genExecuteOnly())
150 Instr = ARM::tMOVi32imm;
151 else
152 Instr = ARM::tLDRLIT_ga_abs;
153 expandLoadStackGuardBase(MI, Instr, ARM::tLDRi);
154 }
155
canCopyGluedNodeDuringSchedule(SDNode * N) const156 bool Thumb1InstrInfo::canCopyGluedNodeDuringSchedule(SDNode *N) const {
157 // In Thumb1 the scheduler may need to schedule a cross-copy between GPRS and CPSR
158 // but this is not always possible there, so allow the Scheduler to clone tADCS and tSBCS
159 // even if they have glue.
160 // FIXME. Actually implement the cross-copy where it is possible (post v6)
161 // because these copies entail more spilling.
162 unsigned Opcode = N->getMachineOpcode();
163 if (Opcode == ARM::tADCS || Opcode == ARM::tSBCS)
164 return true;
165
166 return false;
167 }
168