1 //===- ARCRegisterInfo.cpp - ARC Register Information -----------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file contains the ARC implementation of the MRegisterInfo class.
12 //===----------------------------------------------------------------------===//
14 #include "ARCRegisterInfo.h"
16 #include "ARCInstrInfo.h"
17 #include "ARCMachineFunctionInfo.h"
18 #include "ARCSubtarget.h"
19 #include "llvm/ADT/BitVector.h"
20 #include "llvm/CodeGen/MachineFrameInfo.h"
21 #include "llvm/CodeGen/MachineFunction.h"
22 #include "llvm/CodeGen/MachineInstrBuilder.h"
23 #include "llvm/CodeGen/MachineModuleInfo.h"
24 #include "llvm/CodeGen/MachineRegisterInfo.h"
25 #include "llvm/CodeGen/RegisterScavenging.h"
26 #include "llvm/IR/Function.h"
27 #include "llvm/Support/Debug.h"
28 #include "llvm/Target/TargetFrameLowering.h"
29 #include "llvm/Target/TargetMachine.h"
30 #include "llvm/Target/TargetOptions.h"
34 #define DEBUG_TYPE "arc-reg-info"
36 #define GET_REGINFO_TARGET_DESC
37 #include "ARCGenRegisterInfo.inc"
39 static void ReplaceFrameIndex(MachineBasicBlock::iterator II,
40 const ARCInstrInfo &TII, unsigned Reg,
41 unsigned FrameReg, int Offset, int StackSize,
42 int ObjSize, RegScavenger *RS, int SPAdj) {
43 assert(RS && "Need register scavenger.");
44 MachineInstr &MI = *II;
45 MachineBasicBlock &MBB = *MI.getParent();
46 DebugLoc dl = MI.getDebugLoc();
47 unsigned BaseReg = FrameReg;
48 unsigned KillState = 0;
49 if (MI.getOpcode() == ARC::LD_rs9 && (Offset >= 256 || Offset < -256)) {
50 // Loads can always be reached with LD_rlimm.
51 BuildMI(MBB, II, dl, TII.get(ARC::LD_rlimm), Reg)
54 .addMemOperand(*MI.memoperands_begin());
59 if (MI.getOpcode() != ARC::GETFI && (Offset >= 256 || Offset < -256)) {
60 // We need to use a scratch register to reach the far-away frame indexes.
61 BaseReg = RS->FindUnusedReg(&ARC::GPR32RegClass);
63 // We can be sure that the scavenged-register slot is within the range
64 // of the load offset.
65 const TargetRegisterInfo *TRI =
66 MBB.getParent()->getSubtarget().getRegisterInfo();
67 BaseReg = RS->scavengeRegister(&ARC::GPR32RegClass, II, SPAdj);
68 assert(BaseReg && "Register scavenging failed.");
69 DEBUG(dbgs() << "Scavenged register " << PrintReg(BaseReg, TRI)
70 << " for FrameReg=" << PrintReg(FrameReg, TRI)
71 << "+Offset=" << Offset << "\n");
73 RS->setRegUsed(BaseReg);
75 unsigned AddOpc = isUInt<6>(Offset) ? ARC::ADD_rru6 : ARC::ADD_rrlimm;
76 BuildMI(MBB, II, dl, TII.get(AddOpc))
77 .addReg(BaseReg, RegState::Define)
81 KillState = RegState::Kill;
83 switch (MI.getOpcode()) {
85 assert((Offset % 4 == 0) && "LD needs 4 byte alignment.");
88 assert((Offset % 2 == 0) && "LDH needs 2 byte alignment.");
91 DEBUG(dbgs() << "Building LDFI\n");
92 BuildMI(MBB, II, dl, TII.get(MI.getOpcode()), Reg)
93 .addReg(BaseReg, KillState)
95 .addMemOperand(*MI.memoperands_begin());
98 assert((Offset % 4 == 0) && "ST needs 4 byte alignment.");
100 assert((Offset % 2 == 0) && "STH needs 2 byte alignment.");
102 DEBUG(dbgs() << "Building STFI\n");
103 BuildMI(MBB, II, dl, TII.get(MI.getOpcode()))
104 .addReg(Reg, getKillRegState(MI.getOperand(0).isKill()))
105 .addReg(BaseReg, KillState)
107 .addMemOperand(*MI.memoperands_begin());
110 DEBUG(dbgs() << "Building GETFI\n");
112 TII.get(isUInt<6>(Offset) ? ARC::ADD_rru6 : ARC::ADD_rrlimm))
113 .addReg(Reg, RegState::Define)
118 llvm_unreachable("Unhandled opcode.");
121 // Erase old instruction.
125 ARCRegisterInfo::ARCRegisterInfo() : ARCGenRegisterInfo(ARC::BLINK) {}
127 bool ARCRegisterInfo::needsFrameMoves(const MachineFunction &MF) {
128 return MF.getMMI().hasDebugInfo() ||
129 MF.getFunction()->needsUnwindTableEntry();
133 ARCRegisterInfo::getCalleeSavedRegs(const MachineFunction *MF) const {
134 return CSR_ARC_SaveList;
137 BitVector ARCRegisterInfo::getReservedRegs(const MachineFunction &MF) const {
138 BitVector Reserved(getNumRegs());
140 Reserved.set(ARC::ILINK);
141 Reserved.set(ARC::SP);
142 Reserved.set(ARC::GP);
143 Reserved.set(ARC::R25);
144 Reserved.set(ARC::BLINK);
145 Reserved.set(ARC::FP);
149 bool ARCRegisterInfo::requiresRegisterScavenging(
150 const MachineFunction &MF) const {
154 bool ARCRegisterInfo::trackLivenessAfterRegAlloc(
155 const MachineFunction &MF) const {
159 bool ARCRegisterInfo::useFPForScavengingIndex(const MachineFunction &MF) const {
163 void ARCRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
164 int SPAdj, unsigned FIOperandNum,
165 RegScavenger *RS) const {
166 assert(SPAdj == 0 && "Unexpected");
167 MachineInstr &MI = *II;
168 MachineOperand &FrameOp = MI.getOperand(FIOperandNum);
169 int FrameIndex = FrameOp.getIndex();
171 MachineFunction &MF = *MI.getParent()->getParent();
172 const ARCInstrInfo &TII = *MF.getSubtarget<ARCSubtarget>().getInstrInfo();
173 const ARCFrameLowering *TFI = getFrameLowering(MF);
174 int Offset = MF.getFrameInfo().getObjectOffset(FrameIndex);
175 int ObjSize = MF.getFrameInfo().getObjectSize(FrameIndex);
176 int StackSize = MF.getFrameInfo().getStackSize();
177 int LocalFrameSize = MF.getFrameInfo().getLocalFrameSize();
179 DEBUG(dbgs() << "\nFunction : " << MF.getName() << "\n");
180 DEBUG(dbgs() << "<--------->\n");
181 DEBUG(dbgs() << MI << "\n");
182 DEBUG(dbgs() << "FrameIndex : " << FrameIndex << "\n");
183 DEBUG(dbgs() << "ObjSize : " << ObjSize << "\n");
184 DEBUG(dbgs() << "FrameOffset : " << Offset << "\n");
185 DEBUG(dbgs() << "StackSize : " << StackSize << "\n");
186 DEBUG(dbgs() << "LocalFrameSize : " << LocalFrameSize << "\n");
187 (void)LocalFrameSize;
189 // Special handling of DBG_VALUE instructions.
190 if (MI.isDebugValue()) {
191 unsigned FrameReg = getFrameRegister(MF);
192 MI.getOperand(FIOperandNum).ChangeToRegister(FrameReg, false /*isDef*/);
193 MI.getOperand(FIOperandNum + 1).ChangeToImmediate(Offset);
197 // fold constant into offset.
198 Offset += MI.getOperand(FIOperandNum + 1).getImm();
200 // TODO: assert based on the load type:
201 // ldb needs no alignment,
202 // ldh needs 2 byte alignment
203 // ld needs 4 byte alignment
204 DEBUG(dbgs() << "Offset : " << Offset << "\n"
207 unsigned Reg = MI.getOperand(0).getReg();
208 assert(ARC::GPR32RegClass.contains(Reg) && "Unexpected register operand");
210 if (!TFI->hasFP(MF)) {
211 Offset = StackSize + Offset;
213 assert((Offset >= 0 && Offset < StackSize) && "SP Offset not in bounds.");
215 if (FrameIndex >= 0) {
216 assert((Offset < 0 && -Offset <= StackSize) &&
217 "FP Offset not in bounds.");
220 ReplaceFrameIndex(II, TII, Reg, getFrameRegister(MF), Offset, StackSize,
224 unsigned ARCRegisterInfo::getFrameRegister(const MachineFunction &MF) const {
225 const ARCFrameLowering *TFI = getFrameLowering(MF);
226 return TFI->hasFP(MF) ? ARC::FP : ARC::SP;
230 ARCRegisterInfo::getCallPreservedMask(const MachineFunction &MF,
231 CallingConv::ID CC) const {
232 return CSR_ARC_RegMask;