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"
30using namespace llvm;
31
32static MCSymbol *GetSymbolFromOperand(const MachineOperand &MO,
33 AsmPrinter &AP) {
34 if (MO.isGlobal()) {
35 // Get the symbol from the global, accounting for XCOFF-specific
36 // intricacies (see TargetLoweringObjectFileXCOFF::getTargetSymbol).
37 const GlobalValue *GV = MO.getGlobal();
38 return AP.getSymbol(GV);
39 }
40
41 assert(MO.isSymbol() && "Isn't a symbol reference");
42
43 SmallString<128> Name;
44 const DataLayout &DL = AP.getDataLayout();
45 Mangler::getNameWithPrefix(OutName&: Name, GVName: MO.getSymbolName(), DL);
46
47 MCContext &Ctx = AP.OutContext;
48 MCSymbol *Sym = Ctx.getOrCreateSymbol(Name);
49 return Sym;
50}
51
52static MCOperand GetSymbolRef(const MachineOperand &MO, const MCSymbol *Symbol,
53 AsmPrinter &Printer) {
54 MCContext &Ctx = Printer.OutContext;
55 MCSymbolRefExpr::VariantKind RefKind = MCSymbolRefExpr::VK_None;
56
57 unsigned access = MO.getTargetFlags();
58
59 switch (access) {
60 case PPCII::MO_TPREL_LO:
61 RefKind = MCSymbolRefExpr::VK_PPC_TPREL_LO;
62 break;
63 case PPCII::MO_TPREL_HA:
64 RefKind = MCSymbolRefExpr::VK_PPC_TPREL_HA;
65 break;
66 case PPCII::MO_DTPREL_LO:
67 RefKind = MCSymbolRefExpr::VK_PPC_DTPREL_LO;
68 break;
69 case PPCII::MO_TLSLD_LO:
70 RefKind = MCSymbolRefExpr::VK_PPC_GOT_TLSLD_LO;
71 break;
72 case PPCII::MO_TOC_LO:
73 RefKind = MCSymbolRefExpr::VK_PPC_TOC_LO;
74 break;
75 case PPCII::MO_TLS:
76 RefKind = MCSymbolRefExpr::VK_PPC_TLS;
77 break;
78 case PPCII::MO_TLS_PCREL_FLAG:
79 RefKind = MCSymbolRefExpr::VK_PPC_TLS_PCREL;
80 break;
81 }
82
83 const TargetMachine &TM = Printer.TM;
84
85 if (MO.getTargetFlags() == PPCII::MO_PLT)
86 RefKind = MCSymbolRefExpr::VK_PLT;
87 else if (MO.getTargetFlags() == PPCII::MO_PCREL_FLAG)
88 RefKind = MCSymbolRefExpr::VK_PCREL;
89 else if (MO.getTargetFlags() == PPCII::MO_GOT_PCREL_FLAG)
90 RefKind = MCSymbolRefExpr::VK_PPC_GOT_PCREL;
91 else if (MO.getTargetFlags() == PPCII::MO_TPREL_PCREL_FLAG)
92 RefKind = MCSymbolRefExpr::VK_TPREL;
93 else if (MO.getTargetFlags() == PPCII::MO_GOT_TLSGD_PCREL_FLAG)
94 RefKind = MCSymbolRefExpr::VK_PPC_GOT_TLSGD_PCREL;
95 else if (MO.getTargetFlags() == PPCII::MO_GOT_TLSLD_PCREL_FLAG)
96 RefKind = MCSymbolRefExpr::VK_PPC_GOT_TLSLD_PCREL;
97 else if (MO.getTargetFlags() == PPCII::MO_GOT_TPREL_PCREL_FLAG)
98 RefKind = MCSymbolRefExpr::VK_PPC_GOT_TPREL_PCREL;
99 else if (MO.getTargetFlags() == PPCII::MO_TPREL_FLAG ||
100 MO.getTargetFlags() == PPCII::MO_TLSLD_FLAG) {
101 assert(MO.isGlobal() && "Only expecting a global MachineOperand here!");
102 TLSModel::Model Model = TM.getTLSModel(GV: MO.getGlobal());
103 // For the local-[exec|dynamic] TLS model, we may generate the offset from
104 // the TLS base as an immediate operand (instead of using a TOC entry). Set
105 // the relocation type in case the result is used for purposes other than a
106 // TOC reference. In TOC reference cases, this result is discarded.
107 if (Model == TLSModel::LocalExec)
108 RefKind = MCSymbolRefExpr::VK_PPC_AIX_TLSLE;
109 else if (Model == TLSModel::LocalDynamic)
110 RefKind = MCSymbolRefExpr::VK_PPC_AIX_TLSLD;
111 }
112
113 const MachineInstr *MI = MO.getParent();
114 const MachineFunction *MF = MI->getMF();
115 const Module *M = MF->getFunction().getParent();
116 const PPCSubtarget *Subtarget = &(MF->getSubtarget<PPCSubtarget>());
117
118 unsigned MIOpcode = MI->getOpcode();
119 assert((Subtarget->isUsingPCRelativeCalls() || MIOpcode != PPC::BL8_NOTOC) &&
120 "BL8_NOTOC is only valid when using PC Relative Calls.");
121 if (Subtarget->isUsingPCRelativeCalls()) {
122 if (MIOpcode == PPC::TAILB || MIOpcode == PPC::TAILB8 ||
123 MIOpcode == PPC::TCRETURNdi || MIOpcode == PPC::TCRETURNdi8 ||
124 MIOpcode == PPC::BL8_NOTOC || MIOpcode == PPC::BL8_NOTOC_RM) {
125 RefKind = MCSymbolRefExpr::VK_PPC_NOTOC;
126 }
127 if (MO.getTargetFlags() == PPCII::MO_PCREL_OPT_FLAG)
128 RefKind = MCSymbolRefExpr::VK_PPC_PCREL_OPT;
129 }
130
131 const MCExpr *Expr = MCSymbolRefExpr::create(Symbol, Kind: RefKind, Ctx);
132 // If -msecure-plt -fPIC, add 32768 to symbol.
133 if (Subtarget->isSecurePlt() && TM.isPositionIndependent() &&
134 M->getPICLevel() == PICLevel::BigPIC &&
135 MO.getTargetFlags() == PPCII::MO_PLT)
136 Expr =
137 MCBinaryExpr::createAdd(LHS: Expr, RHS: MCConstantExpr::create(Value: 32768, Ctx), Ctx);
138
139 if (!MO.isJTI() && MO.getOffset())
140 Expr = MCBinaryExpr::createAdd(LHS: Expr,
141 RHS: MCConstantExpr::create(Value: MO.getOffset(), Ctx),
142 Ctx);
143
144 // Subtract off the PIC base if required.
145 if (MO.getTargetFlags() == PPCII::MO_PIC_FLAG ||
146 MO.getTargetFlags() == PPCII::MO_PIC_HA_FLAG ||
147 MO.getTargetFlags() == PPCII::MO_PIC_LO_FLAG) {
148 const MachineFunction *MF = MO.getParent()->getParent()->getParent();
149
150 const MCExpr *PB = MCSymbolRefExpr::create(Symbol: MF->getPICBaseSymbol(), Ctx);
151 Expr = MCBinaryExpr::createSub(LHS: Expr, RHS: PB, Ctx);
152 }
153
154 // Add ha16() / lo16() markers if required.
155 switch (access) {
156 case PPCII::MO_LO:
157 case PPCII::MO_PIC_LO_FLAG:
158 Expr = PPCMCExpr::createLo(Expr, Ctx);
159 break;
160 case PPCII::MO_HA:
161 case PPCII::MO_PIC_HA_FLAG:
162 Expr = PPCMCExpr::createHa(Expr, Ctx);
163 break;
164 }
165
166 return MCOperand::createExpr(Val: Expr);
167}
168
169void llvm::LowerPPCMachineInstrToMCInst(const MachineInstr *MI, MCInst &OutMI,
170 AsmPrinter &AP) {
171 OutMI.setOpcode(MI->getOpcode());
172
173 for (const MachineOperand &MO : MI->operands()) {
174 MCOperand MCOp;
175 if (LowerPPCMachineOperandToMCOperand(MO, OutMO&: MCOp, AP))
176 OutMI.addOperand(Op: MCOp);
177 }
178}
179
180bool llvm::LowerPPCMachineOperandToMCOperand(const MachineOperand &MO,
181 MCOperand &OutMO, AsmPrinter &AP) {
182 switch (MO.getType()) {
183 default:
184 llvm_unreachable("unknown operand type");
185 case MachineOperand::MO_Register:
186 assert(!MO.getSubReg() && "Subregs should be eliminated!");
187 assert(MO.getReg() > PPC::NoRegister &&
188 MO.getReg() < PPC::NUM_TARGET_REGS &&
189 "Invalid register for this target!");
190 // Ignore all implicit register operands.
191 if (MO.isImplicit())
192 return false;
193 OutMO = MCOperand::createReg(Reg: MO.getReg());
194 return true;
195 case MachineOperand::MO_Immediate:
196 OutMO = MCOperand::createImm(Val: MO.getImm());
197 return true;
198 case MachineOperand::MO_MachineBasicBlock:
199 OutMO = MCOperand::createExpr(
200 Val: MCSymbolRefExpr::create(Symbol: MO.getMBB()->getSymbol(), Ctx&: AP.OutContext));
201 return true;
202 case MachineOperand::MO_GlobalAddress:
203 case MachineOperand::MO_ExternalSymbol:
204 OutMO = GetSymbolRef(MO, Symbol: GetSymbolFromOperand(MO, AP), Printer&: AP);
205 return true;
206 case MachineOperand::MO_JumpTableIndex:
207 OutMO = GetSymbolRef(MO, Symbol: AP.GetJTISymbol(JTID: MO.getIndex()), Printer&: AP);
208 return true;
209 case MachineOperand::MO_ConstantPoolIndex:
210 OutMO = GetSymbolRef(MO, Symbol: AP.GetCPISymbol(CPID: MO.getIndex()), Printer&: AP);
211 return true;
212 case MachineOperand::MO_BlockAddress:
213 OutMO =
214 GetSymbolRef(MO, Symbol: AP.GetBlockAddressSymbol(BA: MO.getBlockAddress()), Printer&: AP);
215 return true;
216 case MachineOperand::MO_MCSymbol:
217 OutMO = GetSymbolRef(MO, Symbol: MO.getMCSymbol(), Printer&: AP);
218 return true;
219 case MachineOperand::MO_RegisterMask:
220 return false;
221 }
222}
223

source code of llvm/lib/Target/PowerPC/PPCMCInstLower.cpp