/3rd_party/llvm/lib/Target/MBlaze/MBlazeMCInstLower.cpp

  1//===-- MBlazeMCInstLower.cpp - Convert MBlaze 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 MBlaze MachineInstrs to their corresponding
 11// MCInst records.
 12//
 13//===----------------------------------------------------------------------===//
 14
 15#include "MBlazeMCInstLower.h"
 16#include "MBlazeInstrInfo.h"
 17#include "llvm/Constants.h"
 18#include "llvm/CodeGen/AsmPrinter.h"
 19#include "llvm/CodeGen/MachineBasicBlock.h"
 20#include "llvm/CodeGen/MachineInstr.h"
 21#include "llvm/MC/MCAsmInfo.h"
 22#include "llvm/MC/MCContext.h"
 23#include "llvm/MC/MCExpr.h"
 24#include "llvm/MC/MCInst.h"
 25#include "llvm/Target/Mangler.h"
 26#include "llvm/Support/Debug.h"
 27#include "llvm/Support/raw_ostream.h"
 28#include "llvm/Support/ErrorHandling.h"
 29#include "llvm/ADT/SmallString.h"
 30using namespace llvm;
 31
 32MCSymbol *MBlazeMCInstLower::
 33GetGlobalAddressSymbol(const MachineOperand &MO) const {
 34  switch (MO.getTargetFlags()) {
 35  default: llvm_unreachable("Unknown target flag on GV operand");
 36  case 0:  break;
 37  }
 38
 39  return Printer.Mang->getSymbol(MO.getGlobal());
 40}
 41
 42MCSymbol *MBlazeMCInstLower::
 43GetExternalSymbolSymbol(const MachineOperand &MO) const {
 44  switch (MO.getTargetFlags()) {
 45  default: llvm_unreachable("Unknown target flag on GV operand");
 46  case 0:  break;
 47  }
 48
 49  return Printer.GetExternalSymbolSymbol(MO.getSymbolName());
 50}
 51
 52MCSymbol *MBlazeMCInstLower::
 53GetJumpTableSymbol(const MachineOperand &MO) const {
 54  SmallString<256> Name;
 55  raw_svector_ostream(Name) << Printer.MAI->getPrivateGlobalPrefix() << "JTI"
 56                            << Printer.getFunctionNumber() << '_'
 57                            << MO.getIndex();
 58  switch (MO.getTargetFlags()) {
 59  default: llvm_unreachable("Unknown target flag on GV operand");
 60  case 0:  break;
 61  }
 62
 63  // Create a symbol for the name.
 64  return Ctx.GetOrCreateSymbol(Name.str());
 65}
 66
 67MCSymbol *MBlazeMCInstLower::
 68GetConstantPoolIndexSymbol(const MachineOperand &MO) const {
 69  SmallString<256> Name;
 70  raw_svector_ostream(Name) << Printer.MAI->getPrivateGlobalPrefix() << "CPI"
 71                            << Printer.getFunctionNumber() << '_'
 72                            << MO.getIndex();
 73
 74  switch (MO.getTargetFlags()) {
 75  default:
 76      llvm_unreachable("Unknown target flag on GV operand");
 77
 78  case 0: break;
 79  }
 80
 81  // Create a symbol for the name.
 82  return Ctx.GetOrCreateSymbol(Name.str());
 83}
 84
 85MCSymbol *MBlazeMCInstLower::
 86GetBlockAddressSymbol(const MachineOperand &MO) const {
 87  switch (MO.getTargetFlags()) {
 88  default: llvm_unreachable("Unknown target flag on GV operand");
 89  case 0: break;
 90  }
 91
 92  return Printer.GetBlockAddressSymbol(MO.getBlockAddress());
 93}
 94
 95MCOperand MBlazeMCInstLower::
 96LowerSymbolOperand(const MachineOperand &MO, MCSymbol *Sym) const {
 97  // FIXME: We would like an efficient form for this, so we don't have to do a
 98  // lot of extra uniquing.
 99  const MCExpr *Expr = MCSymbolRefExpr::Create(Sym, Ctx);
100
101  switch (MO.getTargetFlags()) {
102  default:
103      llvm_unreachable("Unknown target flag on GV operand");
104
105  case 0: break;
106  }
107
108  if (!MO.isJTI() && MO.getOffset())
109    Expr = MCBinaryExpr::CreateAdd(Expr,
110                                   MCConstantExpr::Create(MO.getOffset(), Ctx),
111                                   Ctx);
112  return MCOperand::CreateExpr(Expr);
113}
114
115void MBlazeMCInstLower::Lower(const MachineInstr *MI, MCInst &OutMI) const {
116  OutMI.setOpcode(MI->getOpcode());
117
118  for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
119    const MachineOperand &MO = MI->getOperand(i);
120
121    MCOperand MCOp;
122    switch (MO.getType()) {
123    default: llvm_unreachable("unknown operand type");
124    case MachineOperand::MO_Register:
125      // Ignore all implicit register operands.
126      if (MO.isImplicit()) continue;
127      MCOp = MCOperand::CreateReg(MO.getReg());
128      break;
129    case MachineOperand::MO_Immediate:
130      MCOp = MCOperand::CreateImm(MO.getImm());
131      break;
132    case MachineOperand::MO_MachineBasicBlock:
133      MCOp = MCOperand::CreateExpr(MCSymbolRefExpr::Create(
134                         MO.getMBB()->getSymbol(), Ctx));
135      break;
136    case MachineOperand::MO_GlobalAddress:
137      MCOp = LowerSymbolOperand(MO, GetGlobalAddressSymbol(MO));
138      break;
139    case MachineOperand::MO_ExternalSymbol:
140      MCOp = LowerSymbolOperand(MO, GetExternalSymbolSymbol(MO));
141      break;
142    case MachineOperand::MO_JumpTableIndex:
143      MCOp = LowerSymbolOperand(MO, GetJumpTableSymbol(MO));
144      break;
145    case MachineOperand::MO_ConstantPoolIndex:
146      MCOp = LowerSymbolOperand(MO, GetConstantPoolIndexSymbol(MO));
147      break;
148    case MachineOperand::MO_BlockAddress:
149      MCOp = LowerSymbolOperand(MO, GetBlockAddressSymbol(MO));
150      break;
151    case MachineOperand::MO_FPImmediate: {
152      bool ignored;
153      APFloat FVal = MO.getFPImm()->getValueAPF();
154      FVal.convert(APFloat::IEEEsingle, APFloat::rmTowardZero, &ignored);
155
156      APInt IVal = FVal.bitcastToAPInt();
157      uint64_t Val = *IVal.getRawData();
158      MCOp = MCOperand::CreateImm(Val);
159      break;
160    }
161    case MachineOperand::MO_RegisterMask:
162      continue;
163    }
164
165    OutMI.addOperand(MCOp);
166  }
167}