lib/Target/PowerPC/PPCMCInstLower.cpp

   1 //===-- PPCMCInstLower.cpp - Convert PPC MachineInstr to an MCInst --------===//
   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 code to lower PPC MachineInstrs to their corresponding
  10 // MCInst records.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "MCTargetDesc/PPCMCExpr.h"
  15 #include "PPC.h"
  16 #include "PPCSubtarget.h"
  17 #include "llvm/ADT/SmallString.h"
  18 #include "llvm/ADT/Twine.h"
  19 #include "llvm/CodeGen/AsmPrinter.h"
  20 #include "llvm/CodeGen/MachineFunction.h"
  21 #include "llvm/CodeGen/MachineModuleInfoImpls.h"
  22 #include "llvm/CodeGen/TargetLowering.h"
  23 #include "llvm/IR/DataLayout.h"
  24 #include "llvm/IR/GlobalValue.h"
  25 #include "llvm/IR/Mangler.h"
  26 #include "llvm/MC/MCAsmInfo.h"
  27 #include "llvm/MC/MCExpr.h"
  28 #include "llvm/MC/MCInst.h"
  29 #include "llvm/Target/TargetLoweringObjectFile.h"
  30 using namespace llvm;
  31
  32 static MachineModuleInfoMachO &getMachOMMI(AsmPrinter &AP) {
  33   return AP.MMI->getObjFileInfo<MachineModuleInfoMachO>();
  34 }
  35
  36 static MCSymbol *GetSymbolFromOperand(const MachineOperand &MO,
  37                                       AsmPrinter &AP) {
  38   const TargetMachine &TM = AP.TM;
  39   Mangler &Mang = TM.getObjFileLowering()->getMangler();
  40   const DataLayout &DL = AP.getDataLayout();
  41   MCContext &Ctx = AP.OutContext;
  42
  43   SmallString<128> Name;
  44   StringRef Suffix;
  45   if (MO.getTargetFlags() & PPCII::MO_NLP_FLAG)
  46     Suffix = "$non_lazy_ptr";
  47
  48   if (!Suffix.empty())
  49     Name += DL.getPrivateGlobalPrefix();
  50
  51   if (!MO.isGlobal()) {
  52     assert(MO.isSymbol() && "Isn't a symbol reference");
  53     Mangler::getNameWithPrefix(Name, MO.getSymbolName(), DL);
  54   } else {
  55     const GlobalValue *GV = MO.getGlobal();
  56     TM.getNameWithPrefix(Name, GV, Mang);
  57   }
  58
  59   Name += Suffix;
  60   MCSymbol *Sym = Ctx.getOrCreateSymbol(Name);
  61
  62   // If the symbol reference is actually to a non_lazy_ptr, not to the symbol,
  63   // then add the suffix.
  64   if (MO.getTargetFlags() & PPCII::MO_NLP_FLAG) {
  65     MachineModuleInfoMachO &MachO = getMachOMMI(AP);
  66
  67     MachineModuleInfoImpl::StubValueTy &StubSym = MachO.getGVStubEntry(Sym);
  68
  69     if (!StubSym.getPointer()) {
  70       assert(MO.isGlobal() && "Extern symbol not handled yet");
  71       StubSym = MachineModuleInfoImpl::
  72                    StubValueTy(AP.getSymbol(MO.getGlobal()),
  73                                !MO.getGlobal()->hasInternalLinkage());
  74     }
  75     return Sym;
  76   }
  77
  78   return Sym;
  79 }
  80
  81 static MCOperand GetSymbolRef(const MachineOperand &MO, const MCSymbol *Symbol,
  82                               AsmPrinter &Printer, bool IsDarwin) {
  83   MCContext &Ctx = Printer.OutContext;
  84   MCSymbolRefExpr::VariantKind RefKind = MCSymbolRefExpr::VK_None;
  85
  86   unsigned access = MO.getTargetFlags() & PPCII::MO_ACCESS_MASK;
  87
  88   switch (access) {
  89     case PPCII::MO_TPREL_LO:
  90       RefKind = MCSymbolRefExpr::VK_PPC_TPREL_LO;
  91       break;
  92     case PPCII::MO_TPREL_HA:
  93       RefKind = MCSymbolRefExpr::VK_PPC_TPREL_HA;
  94       break;
  95     case PPCII::MO_DTPREL_LO:
  96       RefKind = MCSymbolRefExpr::VK_PPC_DTPREL_LO;
  97       break;
  98     case PPCII::MO_TLSLD_LO:
  99       RefKind = MCSymbolRefExpr::VK_PPC_GOT_TLSLD_LO;
 100       break;
 101     case PPCII::MO_TOC_LO:
 102       RefKind = MCSymbolRefExpr::VK_PPC_TOC_LO;
 103       break;
 104     case PPCII::MO_TLS:
 105       RefKind = MCSymbolRefExpr::VK_PPC_TLS;
 106       break;
 107   }
 108
 109  if (MO.getTargetFlags() == PPCII::MO_PLT)
 110     RefKind = MCSymbolRefExpr::VK_PLT;
 111
 112   const MachineFunction *MF = MO.getParent()->getParent()->getParent();
 113   const Module *M = MF->getFunction().getParent();
 114   const PPCSubtarget *Subtarget = &(MF->getSubtarget<PPCSubtarget>());
 115   const TargetMachine &TM = Printer.TM;
 116   const MCExpr *Expr = MCSymbolRefExpr::create(Symbol, RefKind, Ctx);
 117   // If -msecure-plt -fPIC, add 32768 to symbol.
 118   if (Subtarget->isSecurePlt() && TM.isPositionIndependent() &&
 119       M->getPICLevel() == PICLevel::BigPIC &&
 120       MO.getTargetFlags() == PPCII::MO_PLT)
 121     Expr =
 122         MCBinaryExpr::createAdd(Expr, MCConstantExpr::create(32768, Ctx), Ctx);
 123
 124   if (!MO.isJTI() && MO.getOffset())
 125     Expr = MCBinaryExpr::createAdd(Expr,
 126                                    MCConstantExpr::create(MO.getOffset(), Ctx),
 127                                    Ctx);
 128
 129   // Subtract off the PIC base if required.
 130   if (MO.getTargetFlags() & PPCII::MO_PIC_FLAG) {
 131     const MachineFunction *MF = MO.getParent()->getParent()->getParent();
 132
 133     const MCExpr *PB = MCSymbolRefExpr::create(MF->getPICBaseSymbol(), Ctx);
 134     Expr = MCBinaryExpr::createSub(Expr, PB, Ctx);
 135   }
 136
 137   // Add ha16() / lo16() markers if required.
 138   switch (access) {
 139     case PPCII::MO_LO:
 140       Expr = PPCMCExpr::createLo(Expr, IsDarwin, Ctx);
 141       break;
 142     case PPCII::MO_HA:
 143       Expr = PPCMCExpr::createHa(Expr, IsDarwin, Ctx);
 144       break;
 145   }
 146
 147   return MCOperand::createExpr(Expr);
 148 }
 149
 150 void llvm::LowerPPCMachineInstrToMCInst(const MachineInstr *MI, MCInst &OutMI,
 151                                         AsmPrinter &AP, bool IsDarwin) {
 152   OutMI.setOpcode(MI->getOpcode());
 153
 154   for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
 155     MCOperand MCOp;
 156     if (LowerPPCMachineOperandToMCOperand(MI->getOperand(i), MCOp, AP,
 157                                           IsDarwin))
 158       OutMI.addOperand(MCOp);
 159   }
 160 }
 161
 162 bool llvm::LowerPPCMachineOperandToMCOperand(const MachineOperand &MO,
 163                                              MCOperand &OutMO, AsmPrinter &AP,
 164                                              bool IsDarwin) {
 165   switch (MO.getType()) {
 166   default:
 167     llvm_unreachable("unknown operand type");
 168   case MachineOperand::MO_Register:
 169     assert(!MO.getSubReg() && "Subregs should be eliminated!");
 170     assert(MO.getReg() > PPC::NoRegister &&
 171            MO.getReg() < PPC::NUM_TARGET_REGS &&
 172            "Invalid register for this target!");
 173     OutMO = MCOperand::createReg(MO.getReg());
 174     return true;
 175   case MachineOperand::MO_Immediate:
 176     OutMO = MCOperand::createImm(MO.getImm());
 177     return true;
 178   case MachineOperand::MO_MachineBasicBlock:
 179     OutMO = MCOperand::createExpr(
 180         MCSymbolRefExpr::create(MO.getMBB()->getSymbol(), AP.OutContext));
 181     return true;
 182   case MachineOperand::MO_GlobalAddress:
 183   case MachineOperand::MO_ExternalSymbol:
 184     OutMO = GetSymbolRef(MO, GetSymbolFromOperand(MO, AP), AP, IsDarwin);
 185     return true;
 186   case MachineOperand::MO_JumpTableIndex:
 187     OutMO = GetSymbolRef(MO, AP.GetJTISymbol(MO.getIndex()), AP, IsDarwin);
 188     return true;
 189   case MachineOperand::MO_ConstantPoolIndex:
 190     OutMO = GetSymbolRef(MO, AP.GetCPISymbol(MO.getIndex()), AP, IsDarwin);
 191     return true;
 192   case MachineOperand::MO_BlockAddress:
 193     OutMO = GetSymbolRef(MO, AP.GetBlockAddressSymbol(MO.getBlockAddress()), AP,
 194                          IsDarwin);
 195     return true;
 196   case MachineOperand::MO_MCSymbol:
 197     OutMO = GetSymbolRef(MO, MO.getMCSymbol(), AP, IsDarwin);
 198     return true;
 199   case MachineOperand::MO_RegisterMask:
 200     return false;
 201   }
 202 }