1 //===-- MipsRegisterInfo.cpp - MIPS Register Information -== --------------===//
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 MIPS implementation of the TargetRegisterInfo class.
12 //===----------------------------------------------------------------------===//
14 #define DEBUG_TYPE "mips-reg-info"
16 #include "MipsRegisterInfo.h"
18 #include "MipsAnalyzeImmediate.h"
19 #include "MipsInstrInfo.h"
20 #include "MipsSubtarget.h"
21 #include "MipsMachineFunction.h"
22 #include "llvm/Constants.h"
23 #include "llvm/Type.h"
24 #include "llvm/Function.h"
25 #include "llvm/CodeGen/ValueTypes.h"
26 #include "llvm/CodeGen/MachineInstrBuilder.h"
27 #include "llvm/CodeGen/MachineFunction.h"
28 #include "llvm/CodeGen/MachineFrameInfo.h"
29 #include "llvm/Target/TargetFrameLowering.h"
30 #include "llvm/Target/TargetMachine.h"
31 #include "llvm/Target/TargetOptions.h"
32 #include "llvm/Target/TargetInstrInfo.h"
33 #include "llvm/Support/CommandLine.h"
34 #include "llvm/Support/Debug.h"
35 #include "llvm/Support/ErrorHandling.h"
36 #include "llvm/Support/raw_ostream.h"
37 #include "llvm/ADT/BitVector.h"
38 #include "llvm/ADT/STLExtras.h"
39 #include "llvm/Analysis/DebugInfo.h"
41 #define GET_REGINFO_TARGET_DESC
42 #include "MipsGenRegisterInfo.inc"
46 MipsRegisterInfo::MipsRegisterInfo(const MipsSubtarget &ST,
47 const TargetInstrInfo &tii)
48 : MipsGenRegisterInfo(Mips::RA), Subtarget(ST), TII(tii) {}
50 unsigned MipsRegisterInfo::getPICCallReg() { return Mips::T9; }
52 //===----------------------------------------------------------------------===//
53 // Callee Saved Registers methods
54 //===----------------------------------------------------------------------===//
56 /// Mips Callee Saved Registers
57 const uint16_t* MipsRegisterInfo::
58 getCalleeSavedRegs(const MachineFunction *MF) const
60 if (Subtarget.isSingleFloat())
61 return CSR_SingleFloatOnly_SaveList;
62 else if (!Subtarget.hasMips64())
63 return CSR_O32_SaveList;
64 else if (Subtarget.isABI_N32())
65 return CSR_N32_SaveList;
67 assert(Subtarget.isABI_N64());
68 return CSR_N64_SaveList;
72 MipsRegisterInfo::getCallPreservedMask(CallingConv::ID) const
74 if (Subtarget.isSingleFloat())
75 return CSR_SingleFloatOnly_RegMask;
76 else if (!Subtarget.hasMips64())
77 return CSR_O32_RegMask;
78 else if (Subtarget.isABI_N32())
79 return CSR_N32_RegMask;
81 assert(Subtarget.isABI_N64());
82 return CSR_N64_RegMask;
85 BitVector MipsRegisterInfo::
86 getReservedRegs(const MachineFunction &MF) const {
87 static const uint16_t ReservedCPURegs[] = {
88 Mips::ZERO, Mips::AT, Mips::K0, Mips::K1,
92 static const uint16_t ReservedCPU64Regs[] = {
93 Mips::ZERO_64, Mips::AT_64, Mips::K0_64, Mips::K1_64,
94 Mips::SP_64, Mips::RA_64
97 BitVector Reserved(getNumRegs());
98 typedef TargetRegisterClass::const_iterator RegIter;
100 for (unsigned I = 0; I < array_lengthof(ReservedCPURegs); ++I)
101 Reserved.set(ReservedCPURegs[I]);
103 if (Subtarget.hasMips64()) {
104 for (unsigned I = 0; I < array_lengthof(ReservedCPU64Regs); ++I)
105 Reserved.set(ReservedCPU64Regs[I]);
107 // Reserve all registers in AFGR64.
108 for (RegIter Reg = Mips::AFGR64RegClass.begin(),
109 EReg = Mips::AFGR64RegClass.end(); Reg != EReg; ++Reg)
112 // Reserve all registers in CPU64Regs & FGR64.
113 for (RegIter Reg = Mips::CPU64RegsRegClass.begin(),
114 EReg = Mips::CPU64RegsRegClass.end(); Reg != EReg; ++Reg)
117 for (RegIter Reg = Mips::FGR64RegClass.begin(),
118 EReg = Mips::FGR64RegClass.end(); Reg != EReg; ++Reg)
122 // Reserve FP if this function should have a dedicated frame pointer register.
123 if (MF.getTarget().getFrameLowering()->hasFP(MF)) {
124 Reserved.set(Mips::FP);
125 Reserved.set(Mips::FP_64);
128 // Reserve hardware registers.
129 Reserved.set(Mips::HWR29);
130 Reserved.set(Mips::HWR29_64);
136 MipsRegisterInfo::requiresRegisterScavenging(const MachineFunction &MF) const {
141 MipsRegisterInfo::trackLivenessAfterRegAlloc(const MachineFunction &MF) const {
145 // This function eliminate ADJCALLSTACKDOWN,
146 // ADJCALLSTACKUP pseudo instructions
147 void MipsRegisterInfo::
148 eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
149 MachineBasicBlock::iterator I) const {
150 // Simply discard ADJCALLSTACKDOWN, ADJCALLSTACKUP instructions.
154 // FrameIndex represent objects inside a abstract stack.
155 // We must replace FrameIndex with an stack/frame pointer
157 void MipsRegisterInfo::
158 eliminateFrameIndex(MachineBasicBlock::iterator II, int SPAdj,
159 RegScavenger *RS) const {
160 MachineInstr &MI = *II;
161 MachineFunction &MF = *MI.getParent()->getParent();
162 MachineFrameInfo *MFI = MF.getFrameInfo();
163 MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
166 while (!MI.getOperand(i).isFI()) {
168 assert(i < MI.getNumOperands() &&
169 "Instr doesn't have FrameIndex operand!");
172 DEBUG(errs() << "\nFunction : " << MF.getFunction()->getName() << "\n";
173 errs() << "<--------->\n" << MI);
175 int FrameIndex = MI.getOperand(i).getIndex();
176 uint64_t stackSize = MF.getFrameInfo()->getStackSize();
177 int64_t spOffset = MF.getFrameInfo()->getObjectOffset(FrameIndex);
179 DEBUG(errs() << "FrameIndex : " << FrameIndex << "\n"
180 << "spOffset : " << spOffset << "\n"
181 << "stackSize : " << stackSize << "\n");
183 const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
188 MinCSFI = CSI[0].getFrameIdx();
189 MaxCSFI = CSI[CSI.size() - 1].getFrameIdx();
192 // The following stack frame objects are always referenced relative to $sp:
193 // 1. Outgoing arguments.
194 // 2. Pointer to dynamically allocated stack space.
195 // 3. Locations for callee-saved registers.
196 // Everything else is referenced relative to whatever register
197 // getFrameRegister() returns.
200 if (MipsFI->isOutArgFI(FrameIndex) || MipsFI->isDynAllocFI(FrameIndex) ||
201 (FrameIndex >= MinCSFI && FrameIndex <= MaxCSFI))
202 FrameReg = Subtarget.isABI_N64() ? Mips::SP_64 : Mips::SP;
204 FrameReg = getFrameRegister(MF);
206 // Calculate final offset.
207 // - There is no need to change the offset if the frame object is one of the
208 // following: an outgoing argument, pointer to a dynamically allocated
209 // stack space or a $gp restore location,
210 // - If the frame object is any of the following, its offset must be adjusted
211 // by adding the size of the stack:
212 // incoming argument, callee-saved register location or local variable.
215 if (MipsFI->isOutArgFI(FrameIndex) || MipsFI->isDynAllocFI(FrameIndex) ||
216 MipsFI->isGlobalRegFI(FrameIndex))
219 Offset = spOffset + (int64_t)stackSize;
221 Offset += MI.getOperand(i+1).getImm();
223 DEBUG(errs() << "Offset : " << Offset << "\n" << "<--------->\n");
225 // If MI is not a debug value, make sure Offset fits in the 16-bit immediate
227 if (!MI.isDebugValue() && !isInt<16>(Offset)) {
228 MachineBasicBlock &MBB = *MI.getParent();
229 DebugLoc DL = II->getDebugLoc();
230 unsigned ADDu = Subtarget.isABI_N64() ? Mips::DADDu : Mips::ADDu;
231 unsigned ATReg = Subtarget.isABI_N64() ? Mips::AT_64 : Mips::AT;
232 MipsAnalyzeImmediate::Inst LastInst(0, 0);
234 MipsFI->setEmitNOAT();
235 Mips::loadImmediate(Offset, Subtarget.isABI_N64(), TII, MBB, II, DL, true,
237 BuildMI(MBB, II, DL, TII.get(ADDu), ATReg).addReg(FrameReg).addReg(ATReg);
240 Offset = SignExtend64<16>(LastInst.ImmOpnd);
243 MI.getOperand(i).ChangeToRegister(FrameReg, false);
244 MI.getOperand(i+1).ChangeToImmediate(Offset);
247 unsigned MipsRegisterInfo::
248 getFrameRegister(const MachineFunction &MF) const {
249 const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
250 bool IsN64 = Subtarget.isABI_N64();
252 return TFI->hasFP(MF) ? (IsN64 ? Mips::FP_64 : Mips::FP) :
253 (IsN64 ? Mips::SP_64 : Mips::SP);
256 unsigned MipsRegisterInfo::
257 getEHExceptionRegister() const {
258 llvm_unreachable("What is the exception register");
261 unsigned MipsRegisterInfo::
262 getEHHandlerRegister() const {
263 llvm_unreachable("What is the exception handler register");