HexagonMCInstLower.cpp revision 36b56886974eae4f9c5ebc96befd3e7bfe5de338 
1//===- HexagonMCInstLower.cpp - Convert Hexagon MachineInstr to an MCInst -===//
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 code to lower Hexagon MachineInstrs to their corresponding
11// MCInst records.
12//
13//===----------------------------------------------------------------------===//
14
15#include "Hexagon.h"
16#include "HexagonAsmPrinter.h"
17#include "HexagonMachineFunctionInfo.h"
18#include "MCTargetDesc/HexagonMCInst.h"
19#include "llvm/CodeGen/MachineBasicBlock.h"
20#include "llvm/IR/Constants.h"
21#include "llvm/IR/Mangler.h"
22#include "llvm/MC/MCExpr.h"
23#include "llvm/MC/MCInst.h"
24
25using namespace llvm;
26
27static MCOperand GetSymbolRef(const MachineOperand& MO, const MCSymbol* Symbol,
28                              HexagonAsmPrinter& Printer) {
29  MCContext &MC = Printer.OutContext;
30  const MCExpr *ME;
31
32  ME = MCSymbolRefExpr::Create(Symbol, MCSymbolRefExpr::VK_None, MC);
33
34  if (!MO.isJTI() && MO.getOffset())
35    ME = MCBinaryExpr::CreateAdd(ME, MCConstantExpr::Create(MO.getOffset(), MC),
36                                 MC);
37
38  return (MCOperand::CreateExpr(ME));
39}
40
41// Create an MCInst from a MachineInstr
42void llvm::HexagonLowerToMC(const MachineInstr* MI, HexagonMCInst& MCI,
43                            HexagonAsmPrinter& AP) {
44  MCI.setOpcode(MI->getOpcode());
45  MCI.setDesc(MI->getDesc());
46
47  for (unsigned i = 0, e = MI->getNumOperands(); i < e; i++) {
48    const MachineOperand &MO = MI->getOperand(i);
49    MCOperand MCO;
50
51    switch (MO.getType()) {
52    default:
53      MI->dump();
54      llvm_unreachable("unknown operand type");
55    case MachineOperand::MO_Register:
56      // Ignore all implicit register operands.
57      if (MO.isImplicit()) continue;
58      MCO = MCOperand::CreateReg(MO.getReg());
59      break;
60    case MachineOperand::MO_FPImmediate: {
61      APFloat Val = MO.getFPImm()->getValueAPF();
62      // FP immediates are used only when setting GPRs, so they may be dealt
63      // with like regular immediates from this point on.
64      MCO = MCOperand::CreateImm(*Val.bitcastToAPInt().getRawData());
65      break;
66    }
67    case MachineOperand::MO_Immediate:
68      MCO = MCOperand::CreateImm(MO.getImm());
69      break;
70    case MachineOperand::MO_MachineBasicBlock:
71      MCO = MCOperand::CreateExpr
72              (MCSymbolRefExpr::Create(MO.getMBB()->getSymbol(),
73               AP.OutContext));
74      break;
75    case MachineOperand::MO_GlobalAddress:
76      MCO = GetSymbolRef(MO, AP.getSymbol(MO.getGlobal()), AP);
77      break;
78    case MachineOperand::MO_ExternalSymbol:
79      MCO = GetSymbolRef(MO, AP.GetExternalSymbolSymbol(MO.getSymbolName()),
80                         AP);
81      break;
82    case MachineOperand::MO_JumpTableIndex:
83      MCO = GetSymbolRef(MO, AP.GetJTISymbol(MO.getIndex()), AP);
84      break;
85    case MachineOperand::MO_ConstantPoolIndex:
86      MCO = GetSymbolRef(MO, AP.GetCPISymbol(MO.getIndex()), AP);
87      break;
88    case MachineOperand::MO_BlockAddress:
89      MCO = GetSymbolRef(MO, AP.GetBlockAddressSymbol(MO.getBlockAddress()),AP);
90      break;
91    }
92
93    MCI.addOperand(MCO);
94  }
95}
96