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"
16 #include "llvm/CodeGen/AsmPrinter.h"
17 #include "llvm/CodeGen/MachineFunction.h"
18 #include "llvm/CodeGen/MachineInstr.h"
19 #include "llvm/CodeGen/MachineOperand.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
ARCMCInstLower(MCContext * C,AsmPrinter & AsmPrinter)26 ARCMCInstLower::ARCMCInstLower(MCContext *C, AsmPrinter &AsmPrinter)
27 : Ctx(C), Printer(AsmPrinter) {}
28
LowerSymbolOperand(const MachineOperand & MO,MachineOperandType MOTy,unsigned Offset) const29 MCOperand ARCMCInstLower::LowerSymbolOperand(const MachineOperand &MO,
30 MachineOperandType MOTy,
31 unsigned Offset) const {
32 const MCSymbol *Symbol;
33
34 switch (MOTy) {
35 case MachineOperand::MO_MachineBasicBlock:
36 Symbol = MO.getMBB()->getSymbol();
37 break;
38 case MachineOperand::MO_GlobalAddress:
39 Symbol = Printer.getSymbol(MO.getGlobal());
40 Offset += MO.getOffset();
41 break;
42 case MachineOperand::MO_BlockAddress:
43 Symbol = Printer.GetBlockAddressSymbol(MO.getBlockAddress());
44 Offset += MO.getOffset();
45 break;
46 case MachineOperand::MO_ExternalSymbol:
47 Symbol = Printer.GetExternalSymbolSymbol(MO.getSymbolName());
48 Offset += MO.getOffset();
49 break;
50 case MachineOperand::MO_JumpTableIndex:
51 Symbol = Printer.GetJTISymbol(MO.getIndex());
52 break;
53 case MachineOperand::MO_ConstantPoolIndex:
54 Symbol = Printer.GetCPISymbol(MO.getIndex());
55 Offset += MO.getOffset();
56 break;
57 default:
58 llvm_unreachable("<unknown operand type>");
59 }
60
61 assert(Symbol && "Symbol creation failed.\n");
62 const MCSymbolRefExpr *MCSym = MCSymbolRefExpr::create(Symbol, *Ctx);
63
64 if (!Offset)
65 return MCOperand::createExpr(MCSym);
66
67 // Assume offset is never negative.
68 assert(Offset > 0);
69
70 const MCConstantExpr *OffsetExpr = MCConstantExpr::create(Offset, *Ctx);
71 const MCBinaryExpr *Add = MCBinaryExpr::createAdd(MCSym, OffsetExpr, *Ctx);
72 return MCOperand::createExpr(Add);
73 }
74
LowerOperand(const MachineOperand & MO,unsigned Offset) const75 MCOperand ARCMCInstLower::LowerOperand(const MachineOperand &MO,
76 unsigned Offset) const {
77 MachineOperandType MOTy = MO.getType();
78
79 switch (MOTy) {
80 default:
81 llvm_unreachable("unknown operand type");
82 case MachineOperand::MO_Register:
83 // Ignore all implicit register operands.
84 if (MO.isImplicit())
85 break;
86 return MCOperand::createReg(MO.getReg());
87 case MachineOperand::MO_Immediate:
88 return MCOperand::createImm(MO.getImm() + Offset);
89 case MachineOperand::MO_MachineBasicBlock:
90 case MachineOperand::MO_GlobalAddress:
91 case MachineOperand::MO_ExternalSymbol:
92 case MachineOperand::MO_JumpTableIndex:
93 case MachineOperand::MO_ConstantPoolIndex:
94 case MachineOperand::MO_BlockAddress:
95 return LowerSymbolOperand(MO, MOTy, Offset);
96 case MachineOperand::MO_RegisterMask:
97 break;
98 }
99
100 return {};
101 }
102
Lower(const MachineInstr * MI,MCInst & OutMI) const103 void ARCMCInstLower::Lower(const MachineInstr *MI, MCInst &OutMI) const {
104 OutMI.setOpcode(MI->getOpcode());
105
106 for (const MachineOperand &MO : MI->operands()) {
107 MCOperand MCOp = LowerOperand(MO);
108
109 if (MCOp.isValid())
110 OutMI.addOperand(MCOp);
111 }
112 }
113