LLVM  9.0.0svn
ARCMCInstLower.cpp
Go to the documentation of this file.
1 //===- ARCMCInstLower.cpp - ARC MachineInstr to MCInst ----------*- C++ -*-===//
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 /// \file
10 /// This file contains code to lower ARC MachineInstrs to their
11 /// corresponding MCInst records.
12 ///
13 //===----------------------------------------------------------------------===//
14 
15 #include "ARCMCInstLower.h"
20 #include "llvm/MC/MCContext.h"
21 #include "llvm/MC/MCExpr.h"
22 #include "llvm/MC/MCInst.h"
23 
24 using namespace llvm;
25 
27  : Ctx(C), Printer(AsmPrinter) {}
28 
29 MCOperand ARCMCInstLower::LowerSymbolOperand(const MachineOperand &MO,
30  MachineOperandType MOTy,
31  unsigned Offset) const {
33  const MCSymbol *Symbol;
34 
35  switch (MOTy) {
37  Symbol = MO.getMBB()->getSymbol();
38  break;
40  Symbol = Printer.getSymbol(MO.getGlobal());
41  Offset += MO.getOffset();
42  break;
44  Symbol = Printer.GetBlockAddressSymbol(MO.getBlockAddress());
45  Offset += MO.getOffset();
46  break;
48  Symbol = Printer.GetExternalSymbolSymbol(MO.getSymbolName());
49  Offset += MO.getOffset();
50  break;
52  Symbol = Printer.GetJTISymbol(MO.getIndex());
53  break;
55  Symbol = Printer.GetCPISymbol(MO.getIndex());
56  Offset += MO.getOffset();
57  break;
58  default:
59  llvm_unreachable("<unknown operand type>");
60  }
61 
62  assert(Symbol && "Symbol creation failed.\n");
63  const MCSymbolRefExpr *MCSym = MCSymbolRefExpr::create(Symbol, Kind, *Ctx);
64 
65  if (!Offset)
66  return MCOperand::createExpr(MCSym);
67 
68  // Assume offset is never negative.
69  assert(Offset > 0);
70 
71  const MCConstantExpr *OffsetExpr = MCConstantExpr::create(Offset, *Ctx);
72  const MCBinaryExpr *Add = MCBinaryExpr::createAdd(MCSym, OffsetExpr, *Ctx);
73  return MCOperand::createExpr(Add);
74 }
75 
77  unsigned Offset) const {
78  MachineOperandType MOTy = MO.getType();
79 
80  switch (MOTy) {
81  default:
82  llvm_unreachable("unknown operand type");
84  // Ignore all implicit register operands.
85  if (MO.isImplicit())
86  break;
87  return MCOperand::createReg(MO.getReg());
89  return MCOperand::createImm(MO.getImm() + Offset);
96  return LowerSymbolOperand(MO, MOTy, Offset);
98  break;
99  }
100 
101  return {};
102 }
103 
104 void ARCMCInstLower::Lower(const MachineInstr *MI, MCInst &OutMI) const {
105  OutMI.setOpcode(MI->getOpcode());
106 
107  for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
108  const MachineOperand &MO = MI->getOperand(i);
109  MCOperand MCOp = LowerOperand(MO);
110 
111  if (MCOp.isValid())
112  OutMI.addOperand(MCOp);
113  }
114 }
uint64_t CallInst * C
MachineBasicBlock * getMBB() const
MCSymbol * GetExternalSymbolSymbol(StringRef Sym) const
Return the MCSymbol for the specified ExternalSymbol.
static const MCSymbolRefExpr * create(const MCSymbol *Symbol, MCContext &Ctx)
Definition: MCExpr.h:322
This class represents lattice values for constants.
Definition: AllocatorList.h:23
MCSymbol - Instances of this class represent a symbol name in the MC file, and MCSymbols are created ...
Definition: MCSymbol.h:41
static MCOperand createExpr(const MCExpr *Val)
Definition: MCInst.h:136
unsigned getReg() const
getReg - Returns the register number.
Address of indexed Jump Table for switch.
MachineBasicBlock reference.
print alias Alias Set Printer
void Lower(const MachineInstr *MI, MCInst &OutMI) const
Mask of preserved registers.
static MCOperand createReg(unsigned Reg)
Definition: MCInst.h:115
unsigned getNumOperands() const
Retuns the total number of operands.
Definition: MachineInstr.h:411
Name of external global symbol.
Represent a reference to a symbol from inside an expression.
Definition: MCExpr.h:165
unsigned getOpcode() const
Returns the opcode of this MachineInstr.
Definition: MachineInstr.h:408
const char * getSymbolName() const
Context object for machine code objects.
Definition: MCContext.h:62
static const MCBinaryExpr * createAdd(const MCExpr *LHS, const MCExpr *RHS, MCContext &Ctx)
Definition: MCExpr.h:460
Instances of this class represent a single low-level machine instruction.
Definition: MCInst.h:158
Address of a global value.
const GlobalValue * getGlobal() const
This class is intended to be used as a driving class for all asm writers.
Definition: AsmPrinter.h:78
Address of a basic block.
ARCMCInstLower(MCContext *C, AsmPrinter &asmprinter)
Binary assembler expressions.
Definition: MCExpr.h:416
virtual MCSymbol * GetCPISymbol(unsigned CPID) const
Return the symbol for the specified constant pool entry.
#define llvm_unreachable(msg)
Marks that the current location is not supposed to be reachable.
void setOpcode(unsigned Op)
Definition: MCInst.h:170
MCSymbol * GetBlockAddressSymbol(const BlockAddress *BA) const
Return the MCSymbol used to satisfy BlockAddress uses of the specified basic block.
MCSymbol * getSymbol(const GlobalValue *GV) const
Definition: AsmPrinter.cpp:430
MachineOperand class - Representation of each machine instruction operand.
int64_t getImm() const
Representation of each machine instruction.
Definition: MachineInstr.h:63
MCOperand LowerOperand(const MachineOperand &MO, unsigned offset=0) const
MCSymbol * GetJTISymbol(unsigned JTID, bool isLinkerPrivate=false) const
Return the symbol for the specified jump table entry.
int64_t getOffset() const
Return the offset from the symbol in this operand.
const BlockAddress * getBlockAddress() const
MCSymbol * getSymbol() const
Return the MCSymbol for this basic block.
const unsigned Kind
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
IRTranslator LLVM IR MI
void addOperand(const MCOperand &Op)
Definition: MCInst.h:183
bool isValid() const
Definition: MCInst.h:56
Address of indexed Constant in Constant Pool.
const MachineOperand & getOperand(unsigned i) const
Definition: MachineInstr.h:413
Instances of this class represent operands of the MCInst class.
Definition: MCInst.h:34
MachineOperandType getType() const
getType - Returns the MachineOperandType for this operand.
static MCOperand createImm(int64_t Val)
Definition: MCInst.h:122
static const MCConstantExpr * create(int64_t Value, MCContext &Ctx)
Definition: MCExpr.cpp:163
bool isImplicit() const