1 //===-- HexagonRegisterInfo.cpp - Hexagon Register Information ------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file contains the Hexagon implementation of the TargetRegisterInfo
11 // class.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #include "HexagonRegisterInfo.h"
16 #include "Hexagon.h"
17 #include "HexagonMachineFunctionInfo.h"
18 #include "HexagonSubtarget.h"
19 #include "HexagonTargetMachine.h"
20 #include "llvm/ADT/BitVector.h"
21 #include "llvm/ADT/STLExtras.h"
22 #include "llvm/CodeGen/MachineFrameInfo.h"
23 #include "llvm/CodeGen/MachineFunction.h"
24 #include "llvm/CodeGen/MachineFunctionPass.h"
25 #include "llvm/CodeGen/MachineInstrBuilder.h"
26 #include "llvm/CodeGen/MachineRegisterInfo.h"
27 #include "llvm/CodeGen/PseudoSourceValue.h"
28 #include "llvm/CodeGen/RegisterScavenging.h"
29 #include "llvm/IR/Function.h"
30 #include "llvm/IR/Type.h"
31 #include "llvm/MC/MachineLocation.h"
32 #include "llvm/Support/CommandLine.h"
33 #include "llvm/Support/Debug.h"
34 #include "llvm/Support/ErrorHandling.h"
35 #include "llvm/Support/raw_ostream.h"
36 #include "llvm/Target/TargetInstrInfo.h"
37 #include "llvm/Target/TargetMachine.h"
38 #include "llvm/Target/TargetOptions.h"
39 
40 using namespace llvm;
41 
HexagonRegisterInfo()42 HexagonRegisterInfo::HexagonRegisterInfo()
43     : HexagonGenRegisterInfo(Hexagon::R31) {}
44 
45 
isEHReturnCalleeSaveReg(unsigned R) const46 bool HexagonRegisterInfo::isEHReturnCalleeSaveReg(unsigned R) const {
47   return R == Hexagon::R0 || R == Hexagon::R1 || R == Hexagon::R2 ||
48          R == Hexagon::R3 || R == Hexagon::D0 || R == Hexagon::D1;
49 }
50 
isCalleeSaveReg(unsigned Reg) const51 bool HexagonRegisterInfo::isCalleeSaveReg(unsigned Reg) const {
52   return Hexagon::R16 <= Reg && Reg <= Hexagon::R27;
53 }
54 
55 
56 const MCPhysReg *
getCallerSavedRegs(const MachineFunction * MF) const57 HexagonRegisterInfo::getCallerSavedRegs(const MachineFunction *MF) const {
58   static const MCPhysReg CallerSavedRegsV4[] = {
59     Hexagon::R0, Hexagon::R1, Hexagon::R2, Hexagon::R3, Hexagon::R4,
60     Hexagon::R5, Hexagon::R6, Hexagon::R7, Hexagon::R8, Hexagon::R9,
61     Hexagon::R10, Hexagon::R11, Hexagon::R12, Hexagon::R13, Hexagon::R14,
62     Hexagon::R15, 0
63   };
64 
65   auto &HST = static_cast<const HexagonSubtarget&>(MF->getSubtarget());
66   switch (HST.getHexagonArchVersion()) {
67   case HexagonSubtarget::V4:
68   case HexagonSubtarget::V5:
69   case HexagonSubtarget::V55:
70   case HexagonSubtarget::V60:
71     return CallerSavedRegsV4;
72   }
73   llvm_unreachable(
74     "Callee saved registers requested for unknown archtecture version");
75 }
76 
77 
78 const MCPhysReg *
getCalleeSavedRegs(const MachineFunction * MF) const79 HexagonRegisterInfo::getCalleeSavedRegs(const MachineFunction *MF) const {
80   static const MCPhysReg CalleeSavedRegsV3[] = {
81     Hexagon::R16,   Hexagon::R17,   Hexagon::R18,   Hexagon::R19,
82     Hexagon::R20,   Hexagon::R21,   Hexagon::R22,   Hexagon::R23,
83     Hexagon::R24,   Hexagon::R25,   Hexagon::R26,   Hexagon::R27, 0
84   };
85 
86   switch (MF->getSubtarget<HexagonSubtarget>().getHexagonArchVersion()) {
87   case HexagonSubtarget::V4:
88   case HexagonSubtarget::V5:
89   case HexagonSubtarget::V55:
90   case HexagonSubtarget::V60:
91     return CalleeSavedRegsV3;
92   }
93   llvm_unreachable("Callee saved registers requested for unknown architecture "
94                    "version");
95 }
96 
getReservedRegs(const MachineFunction & MF) const97 BitVector HexagonRegisterInfo::getReservedRegs(const MachineFunction &MF)
98   const {
99   BitVector Reserved(getNumRegs());
100   Reserved.set(HEXAGON_RESERVED_REG_1);
101   Reserved.set(HEXAGON_RESERVED_REG_2);
102   Reserved.set(Hexagon::R29);
103   Reserved.set(Hexagon::R30);
104   Reserved.set(Hexagon::R31);
105   Reserved.set(Hexagon::PC);
106   Reserved.set(Hexagon::D15);
107   Reserved.set(Hexagon::LC0);
108   Reserved.set(Hexagon::LC1);
109   Reserved.set(Hexagon::SA0);
110   Reserved.set(Hexagon::SA1);
111   return Reserved;
112 }
113 
114 
eliminateFrameIndex(MachineBasicBlock::iterator II,int SPAdj,unsigned FIOp,RegScavenger * RS) const115 void HexagonRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
116                                               int SPAdj, unsigned FIOp,
117                                               RegScavenger *RS) const {
118   //
119   // Hexagon_TODO: Do we need to enforce this for Hexagon?
120   assert(SPAdj == 0 && "Unexpected");
121 
122   MachineInstr &MI = *II;
123   MachineBasicBlock &MB = *MI.getParent();
124   MachineFunction &MF = *MB.getParent();
125   auto &HST = MF.getSubtarget<HexagonSubtarget>();
126   auto &HII = *HST.getInstrInfo();
127   auto &HFI = *HST.getFrameLowering();
128 
129   unsigned BP = 0;
130   int FI = MI.getOperand(FIOp).getIndex();
131   // Select the base pointer (BP) and calculate the actual offset from BP
132   // to the beginning of the object at index FI.
133   int Offset = HFI.getFrameIndexReference(MF, FI, BP);
134   // Add the offset from the instruction.
135   int RealOffset = Offset + MI.getOperand(FIOp+1).getImm();
136 
137   unsigned Opc = MI.getOpcode();
138   switch (Opc) {
139     case Hexagon::TFR_FIA:
140       MI.setDesc(HII.get(Hexagon::A2_addi));
141       MI.getOperand(FIOp).ChangeToImmediate(RealOffset);
142       MI.RemoveOperand(FIOp+1);
143       return;
144     case Hexagon::TFR_FI:
145       // Set up the instruction for updating below.
146       MI.setDesc(HII.get(Hexagon::A2_addi));
147       break;
148   }
149 
150   if (HII.isValidOffset(Opc, RealOffset)) {
151     MI.getOperand(FIOp).ChangeToRegister(BP, false);
152     MI.getOperand(FIOp+1).ChangeToImmediate(RealOffset);
153     return;
154   }
155 
156 #ifndef NDEBUG
157   const Function *F = MF.getFunction();
158   dbgs() << "In function ";
159   if (F) dbgs() << F->getName();
160   else   dbgs() << "<?>";
161   dbgs() << ", BB#" << MB.getNumber() << "\n" << MI;
162 #endif
163   llvm_unreachable("Unhandled instruction");
164 }
165 
166 
getRARegister() const167 unsigned HexagonRegisterInfo::getRARegister() const {
168   return Hexagon::R31;
169 }
170 
171 
getFrameRegister(const MachineFunction & MF) const172 unsigned HexagonRegisterInfo::getFrameRegister(const MachineFunction
173                                                &MF) const {
174   const HexagonFrameLowering *TFI = getFrameLowering(MF);
175   if (TFI->hasFP(MF))
176     return getFrameRegister();
177   return getStackRegister();
178 }
179 
180 
getFrameRegister() const181 unsigned HexagonRegisterInfo::getFrameRegister() const {
182   return Hexagon::R30;
183 }
184 
185 
getStackRegister() const186 unsigned HexagonRegisterInfo::getStackRegister() const {
187   return Hexagon::R29;
188 }
189 
190 
useFPForScavengingIndex(const MachineFunction & MF) const191 bool HexagonRegisterInfo::useFPForScavengingIndex(const MachineFunction &MF)
192       const {
193   return MF.getSubtarget<HexagonSubtarget>().getFrameLowering()->hasFP(MF);
194 }
195 
196 
getFirstCallerSavedNonParamReg() const197 unsigned HexagonRegisterInfo::getFirstCallerSavedNonParamReg() const {
198   return Hexagon::R6;
199 }
200 
201 
202 #define GET_REGINFO_TARGET_DESC
203 #include "HexagonGenRegisterInfo.inc"
204