| 1 | //=-- BPFMCInstLower.cpp - Convert BPF 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 BPF MachineInstrs to their corresponding |
| 10 | // MCInst records. |
| 11 | // |
| 12 | //===----------------------------------------------------------------------===// |
| 13 | |
| 14 | #include "BPFMCInstLower.h" |
| 15 | #include "llvm/CodeGen/AsmPrinter.h" |
| 16 | #include "llvm/CodeGen/MachineBasicBlock.h" |
| 17 | #include "llvm/CodeGen/MachineInstr.h" |
| 18 | #include "llvm/MC/MCAsmInfo.h" |
| 19 | #include "llvm/MC/MCContext.h" |
| 20 | #include "llvm/MC/MCExpr.h" |
| 21 | #include "llvm/MC/MCInst.h" |
| 22 | #include "llvm/Support/ErrorHandling.h" |
| 23 | #include "llvm/Support/raw_ostream.h" |
| 24 | using namespace llvm; |
| 25 | |
| 26 | MCSymbol * |
| 27 | BPFMCInstLower::GetGlobalAddressSymbol(const MachineOperand &MO) const { |
| 28 | return Printer.getSymbol(GV: MO.getGlobal()); |
| 29 | } |
| 30 | |
| 31 | MCSymbol * |
| 32 | BPFMCInstLower::GetExternalSymbolSymbol(const MachineOperand &MO) const { |
| 33 | return Printer.GetExternalSymbolSymbol(Sym: MO.getSymbolName()); |
| 34 | } |
| 35 | |
| 36 | MCOperand BPFMCInstLower::LowerSymbolOperand(const MachineOperand &MO, |
| 37 | MCSymbol *Sym) const { |
| 38 | |
| 39 | const MCExpr *Expr = MCSymbolRefExpr::create(Symbol: Sym, Ctx); |
| 40 | |
| 41 | if (!MO.isJTI() && MO.getOffset()) |
| 42 | llvm_unreachable("unknown symbol op"); |
| 43 | |
| 44 | return MCOperand::createExpr(Val: Expr); |
| 45 | } |
| 46 | |
| 47 | void BPFMCInstLower::Lower(const MachineInstr *MI, MCInst &OutMI) const { |
| 48 | OutMI.setOpcode(MI->getOpcode()); |
| 49 | |
| 50 | for (const MachineOperand &MO : MI->operands()) { |
| 51 | MCOperand MCOp; |
| 52 | switch (MO.getType()) { |
| 53 | default: |
| 54 | MI->print(OS&: errs()); |
| 55 | llvm_unreachable("unknown operand type"); |
| 56 | case MachineOperand::MO_Register: |
| 57 | // Ignore all implicit register operands. |
| 58 | if (MO.isImplicit()) |
| 59 | continue; |
| 60 | MCOp = MCOperand::createReg(Reg: MO.getReg()); |
| 61 | break; |
| 62 | case MachineOperand::MO_Immediate: |
| 63 | MCOp = MCOperand::createImm(Val: MO.getImm()); |
| 64 | break; |
| 65 | case MachineOperand::MO_MachineBasicBlock: |
| 66 | MCOp = MCOperand::createExpr( |
| 67 | Val: MCSymbolRefExpr::create(Symbol: MO.getMBB()->getSymbol(), Ctx)); |
| 68 | break; |
| 69 | case MachineOperand::MO_RegisterMask: |
| 70 | continue; |
| 71 | case MachineOperand::MO_ExternalSymbol: |
| 72 | MCOp = LowerSymbolOperand(MO, Sym: GetExternalSymbolSymbol(MO)); |
| 73 | break; |
| 74 | case MachineOperand::MO_GlobalAddress: |
| 75 | MCOp = LowerSymbolOperand(MO, Sym: GetGlobalAddressSymbol(MO)); |
| 76 | break; |
| 77 | case MachineOperand::MO_ConstantPoolIndex: |
| 78 | MCOp = LowerSymbolOperand(MO, Sym: Printer.GetCPISymbol(CPID: MO.getIndex())); |
| 79 | break; |
| 80 | } |
| 81 | |
| 82 | OutMI.addOperand(Op: MCOp); |
| 83 | } |
| 84 | } |
| 85 |