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 MCSymbol *GetSymbolFromOperand(const MachineOperand &MO, 33 AsmPrinter &AP) { 34 const TargetMachine &TM = AP.TM; 35 Mangler &Mang = TM.getObjFileLowering()->getMangler(); 36 const DataLayout &DL = AP.getDataLayout(); 37 MCContext &Ctx = AP.OutContext; 38 39 SmallString<128> Name; 40 if (!MO.isGlobal()) { 41 assert(MO.isSymbol() && "Isn't a symbol reference"); 42 Mangler::getNameWithPrefix(Name, MO.getSymbolName(), DL); 43 } else { 44 const GlobalValue *GV = MO.getGlobal(); 45 TM.getNameWithPrefix(Name, GV, Mang); 46 } 47 48 MCSymbol *Sym = Ctx.getOrCreateSymbol(Name); 49 50 return Sym; 51 } 52 53 static MCOperand GetSymbolRef(const MachineOperand &MO, const MCSymbol *Symbol, 54 AsmPrinter &Printer) { 55 MCContext &Ctx = Printer.OutContext; 56 MCSymbolRefExpr::VariantKind RefKind = MCSymbolRefExpr::VK_None; 57 58 unsigned access = MO.getTargetFlags() & PPCII::MO_ACCESS_MASK; 59 60 switch (access) { 61 case PPCII::MO_TPREL_LO: 62 RefKind = MCSymbolRefExpr::VK_PPC_TPREL_LO; 63 break; 64 case PPCII::MO_TPREL_HA: 65 RefKind = MCSymbolRefExpr::VK_PPC_TPREL_HA; 66 break; 67 case PPCII::MO_DTPREL_LO: 68 RefKind = MCSymbolRefExpr::VK_PPC_DTPREL_LO; 69 break; 70 case PPCII::MO_TLSLD_LO: 71 RefKind = MCSymbolRefExpr::VK_PPC_GOT_TLSLD_LO; 72 break; 73 case PPCII::MO_TOC_LO: 74 RefKind = MCSymbolRefExpr::VK_PPC_TOC_LO; 75 break; 76 case PPCII::MO_TLS: 77 RefKind = MCSymbolRefExpr::VK_PPC_TLS; 78 break; 79 } 80 81 if (MO.getTargetFlags() == PPCII::MO_PLT) 82 RefKind = MCSymbolRefExpr::VK_PLT; 83 else if (MO.getTargetFlags() == PPCII::MO_PCREL_FLAG) 84 RefKind = MCSymbolRefExpr::VK_PCREL; 85 else if (MO.getTargetFlags() == (PPCII::MO_PCREL_FLAG | PPCII::MO_GOT_FLAG)) 86 RefKind = MCSymbolRefExpr::VK_PPC_GOT_PCREL; 87 88 const MachineInstr *MI = MO.getParent(); 89 const MachineFunction *MF = MI->getMF(); 90 const Module *M = MF->getFunction().getParent(); 91 const PPCSubtarget *Subtarget = &(MF->getSubtarget<PPCSubtarget>()); 92 const TargetMachine &TM = Printer.TM; 93 94 unsigned MIOpcode = MI->getOpcode(); 95 assert((Subtarget->isUsingPCRelativeCalls() || MIOpcode != PPC::BL8_NOTOC) && 96 "BL8_NOTOC is only valid when using PC Relative Calls."); 97 if (Subtarget->isUsingPCRelativeCalls()) { 98 if (MIOpcode == PPC::TAILB || MIOpcode == PPC::TAILB8 || 99 MIOpcode == PPC::TCRETURNdi || MIOpcode == PPC::TCRETURNdi8 || 100 MIOpcode == PPC::BL8_NOTOC) { 101 RefKind = MCSymbolRefExpr::VK_PPC_NOTOC; 102 } 103 } 104 105 const MCExpr *Expr = MCSymbolRefExpr::create(Symbol, RefKind, Ctx); 106 // If -msecure-plt -fPIC, add 32768 to symbol. 107 if (Subtarget->isSecurePlt() && TM.isPositionIndependent() && 108 M->getPICLevel() == PICLevel::BigPIC && 109 MO.getTargetFlags() == PPCII::MO_PLT) 110 Expr = 111 MCBinaryExpr::createAdd(Expr, MCConstantExpr::create(32768, Ctx), Ctx); 112 113 if (!MO.isJTI() && MO.getOffset()) 114 Expr = MCBinaryExpr::createAdd(Expr, 115 MCConstantExpr::create(MO.getOffset(), Ctx), 116 Ctx); 117 118 // Subtract off the PIC base if required. 119 if (MO.getTargetFlags() & PPCII::MO_PIC_FLAG) { 120 const MachineFunction *MF = MO.getParent()->getParent()->getParent(); 121 122 const MCExpr *PB = MCSymbolRefExpr::create(MF->getPICBaseSymbol(), Ctx); 123 Expr = MCBinaryExpr::createSub(Expr, PB, Ctx); 124 } 125 126 // Add ha16() / lo16() markers if required. 127 switch (access) { 128 case PPCII::MO_LO: 129 Expr = PPCMCExpr::createLo(Expr, Ctx); 130 break; 131 case PPCII::MO_HA: 132 Expr = PPCMCExpr::createHa(Expr, Ctx); 133 break; 134 } 135 136 return MCOperand::createExpr(Expr); 137 } 138 139 void llvm::LowerPPCMachineInstrToMCInst(const MachineInstr *MI, MCInst &OutMI, 140 AsmPrinter &AP) { 141 OutMI.setOpcode(MI->getOpcode()); 142 143 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) { 144 MCOperand MCOp; 145 if (LowerPPCMachineOperandToMCOperand(MI->getOperand(i), MCOp, AP)) 146 OutMI.addOperand(MCOp); 147 } 148 } 149 150 bool llvm::LowerPPCMachineOperandToMCOperand(const MachineOperand &MO, 151 MCOperand &OutMO, AsmPrinter &AP) { 152 switch (MO.getType()) { 153 default: 154 llvm_unreachable("unknown operand type"); 155 case MachineOperand::MO_Register: 156 assert(!MO.getSubReg() && "Subregs should be eliminated!"); 157 assert(MO.getReg() > PPC::NoRegister && 158 MO.getReg() < PPC::NUM_TARGET_REGS && 159 "Invalid register for this target!"); 160 // Ignore all implicit register operands. 161 if (MO.isImplicit()) 162 return false; 163 OutMO = MCOperand::createReg(MO.getReg()); 164 return true; 165 case MachineOperand::MO_Immediate: 166 OutMO = MCOperand::createImm(MO.getImm()); 167 return true; 168 case MachineOperand::MO_MachineBasicBlock: 169 OutMO = MCOperand::createExpr( 170 MCSymbolRefExpr::create(MO.getMBB()->getSymbol(), AP.OutContext)); 171 return true; 172 case MachineOperand::MO_GlobalAddress: 173 case MachineOperand::MO_ExternalSymbol: 174 OutMO = GetSymbolRef(MO, GetSymbolFromOperand(MO, AP), AP); 175 return true; 176 case MachineOperand::MO_JumpTableIndex: 177 OutMO = GetSymbolRef(MO, AP.GetJTISymbol(MO.getIndex()), AP); 178 return true; 179 case MachineOperand::MO_ConstantPoolIndex: 180 OutMO = GetSymbolRef(MO, AP.GetCPISymbol(MO.getIndex()), AP); 181 return true; 182 case MachineOperand::MO_BlockAddress: 183 OutMO = 184 GetSymbolRef(MO, AP.GetBlockAddressSymbol(MO.getBlockAddress()), AP); 185 return true; 186 case MachineOperand::MO_MCSymbol: 187 OutMO = GetSymbolRef(MO, MO.getMCSymbol(), AP); 188 return true; 189 case MachineOperand::MO_RegisterMask: 190 return false; 191 } 192 } 193