LLVM  9.0.0svn
Mips16RegisterInfo.cpp
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1 //===-- Mips16RegisterInfo.cpp - MIPS16 Register 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 MIPS16 implementation of the TargetRegisterInfo class.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "Mips16RegisterInfo.h"
14 #include "Mips.h"
15 #include "Mips16InstrInfo.h"
16 #include "MipsInstrInfo.h"
17 #include "MipsMachineFunction.h"
18 #include "MipsSubtarget.h"
19 #include "llvm/ADT/STLExtras.h"
26 #include "llvm/IR/Constants.h"
27 #include "llvm/IR/DebugInfo.h"
28 #include "llvm/IR/Function.h"
29 #include "llvm/IR/Type.h"
30 #include "llvm/Support/Debug.h"
35 
36 using namespace llvm;
37 
38 #define DEBUG_TYPE "mips16-registerinfo"
39 
41 
43  (const MachineFunction &MF) const {
44  return false;
45 }
47  (const MachineFunction &MF) const {
48  return false;
49 }
50 
52  (const MachineFunction &MF) const {
53  return false;
54 }
55 
60  const TargetRegisterClass *RC,
61  unsigned Reg) const {
62  DebugLoc DL;
64  TII.copyPhysReg(MBB, I, DL, Mips::T0, Reg, true);
65  TII.copyPhysReg(MBB, UseMI, DL, Reg, Mips::T0, true);
66  return true;
67 }
68 
69 const TargetRegisterClass *
71  assert(Size == 4);
72  return &Mips::CPU16RegsRegClass;
73 }
74 
75 void Mips16RegisterInfo::eliminateFI(MachineBasicBlock::iterator II,
76  unsigned OpNo, int FrameIndex,
77  uint64_t StackSize,
78  int64_t SPOffset) const {
79  MachineInstr &MI = *II;
80  MachineFunction &MF = *MI.getParent()->getParent();
81  MachineFrameInfo &MFI = MF.getFrameInfo();
82 
83  const std::vector<CalleeSavedInfo> &CSI = MFI.getCalleeSavedInfo();
84  int MinCSFI = 0;
85  int MaxCSFI = -1;
86 
87  if (CSI.size()) {
88  MinCSFI = CSI[0].getFrameIdx();
89  MaxCSFI = CSI[CSI.size() - 1].getFrameIdx();
90  }
91 
92  // The following stack frame objects are always
93  // referenced relative to $sp:
94  // 1. Outgoing arguments.
95  // 2. Pointer to dynamically allocated stack space.
96  // 3. Locations for callee-saved registers.
97  // Everything else is referenced relative to whatever register
98  // getFrameRegister() returns.
99  unsigned FrameReg;
100 
101  if (FrameIndex >= MinCSFI && FrameIndex <= MaxCSFI)
102  FrameReg = Mips::SP;
103  else {
105  if (TFI->hasFP(MF)) {
106  FrameReg = Mips::S0;
107  }
108  else {
109  if ((MI.getNumOperands()> OpNo+2) && MI.getOperand(OpNo+2).isReg())
110  FrameReg = MI.getOperand(OpNo+2).getReg();
111  else
112  FrameReg = Mips::SP;
113  }
114  }
115  // Calculate final offset.
116  // - There is no need to change the offset if the frame object
117  // is one of the
118  // following: an outgoing argument, pointer to a dynamically allocated
119  // stack space or a $gp restore location,
120  // - If the frame object is any of the following,
121  // its offset must be adjusted
122  // by adding the size of the stack:
123  // incoming argument, callee-saved register location or local variable.
124  int64_t Offset;
125  bool IsKill = false;
126  Offset = SPOffset + (int64_t)StackSize;
127  Offset += MI.getOperand(OpNo + 1).getImm();
128 
129  LLVM_DEBUG(errs() << "Offset : " << Offset << "\n"
130  << "<--------->\n");
131 
132  if (!MI.isDebugValue() &&
134  MachineBasicBlock &MBB = *MI.getParent();
135  DebugLoc DL = II->getDebugLoc();
136  unsigned NewImm;
137  const Mips16InstrInfo &TII =
138  *static_cast<const Mips16InstrInfo *>(MF.getSubtarget().getInstrInfo());
139  FrameReg = TII.loadImmediate(FrameReg, Offset, MBB, II, DL, NewImm);
140  Offset = SignExtend64<16>(NewImm);
141  IsKill = true;
142  }
143  MI.getOperand(OpNo).ChangeToRegister(FrameReg, false, false, IsKill);
144  MI.getOperand(OpNo + 1).ChangeToImmediate(Offset);
145 
146 
147 }
raw_ostream & errs()
This returns a reference to a raw_ostream for standard error.
This class represents lattice values for constants.
Definition: AllocatorList.h:23
void ChangeToRegister(unsigned Reg, bool isDef, bool isImp=false, bool isKill=false, bool isDead=false, bool isUndef=false, bool isDebug=false)
ChangeToRegister - Replace this operand with a new register operand of the specified value...
bool useFPForScavengingIndex(const MachineFunction &MF) const override
bool requiresFrameIndexScavenging(const MachineFunction &MF) const override
unsigned getReg() const
getReg - Returns the register number.
unsigned Reg
A debug info location.
Definition: DebugLoc.h:33
bool saveScavengerRegister(MachineBasicBlock &MBB, MachineBasicBlock::iterator I, MachineBasicBlock::iterator &UseMI, const TargetRegisterClass *RC, unsigned Reg) const override
bool requiresRegisterScavenging(const MachineFunction &MF) const override
const HexagonInstrInfo * TII
unsigned getNumOperands() const
Retuns the total number of operands.
Definition: MachineInstr.h:413
virtual bool hasFP(const MachineFunction &MF) const =0
hasFP - Return true if the specified function should have a dedicated frame pointer register...
unsigned loadImmediate(unsigned FrameReg, int64_t Imm, MachineBasicBlock &MBB, MachineBasicBlock::iterator II, const DebugLoc &DL, unsigned &NewImm) const
Emit a series of instructions to load an immediate.
The MachineFrameInfo class represents an abstract stack frame until prolog/epilog code is inserted...
unsigned getOpcode() const
Returns the opcode of this MachineInstr.
Definition: MachineInstr.h:410
static bool validImmediate(unsigned Opcode, unsigned Reg, int64_t Amount)
virtual void copyPhysReg(MachineBasicBlock &MBB, MachineBasicBlock::iterator MI, const DebugLoc &DL, unsigned DestReg, unsigned SrcReg, bool KillSrc) const
Emit instructions to copy a pair of physical registers.
const TargetRegisterClass * intRegClass(unsigned Size) const override
Return GPR register class.
virtual const TargetInstrInfo * getInstrInfo() const
void ChangeToImmediate(int64_t ImmVal)
ChangeToImmediate - Replace this operand with a new immediate operand of the specified value...
TargetInstrInfo - Interface to description of machine instruction set.
const TargetSubtargetInfo & getSubtarget() const
getSubtarget - Return the subtarget for which this machine code is being compiled.
MachineFrameInfo & getFrameInfo()
getFrameInfo - Return the frame info object for the current function.
MachineInstrBuilder & UseMI
This file contains the declarations for the subclasses of Constant, which represent the different fla...
bool isDebugValue() const
Information about stack frame layout on the target.
int64_t getImm() const
const MachineBasicBlock * getParent() const
Definition: MachineInstr.h:255
Representation of each machine instruction.
Definition: MachineInstr.h:63
const MachineFunction * getParent() const
Return the MachineFunction containing this basic block.
const std::vector< CalleeSavedInfo > & getCalleeSavedInfo() const
Returns a reference to call saved info vector for the current function.
#define I(x, y, z)
Definition: MD5.cpp:58
virtual const TargetFrameLowering * getFrameLowering() const
uint32_t Size
Definition: Profile.cpp:46
bool isReg() const
isReg - Tests if this is a MO_Register operand.
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
IRTranslator LLVM IR MI
#define LLVM_DEBUG(X)
Definition: Debug.h:122
const MachineOperand & getOperand(unsigned i) const
Definition: MachineInstr.h:415