llvm/llvm/lib/Target/X86/X86InstrBuilder.h

//===-- X86InstrBuilder.h - Functions to aid building x86 insts -*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file exposes functions that may be used with BuildMI from the
// MachineInstrBuilder.h file to handle X86'isms in a clean way.
//
// The BuildMem function may be used with the BuildMI function to add entire
// memory references in a single, typed, function call.  X86 memory references
// can be very complex expressions (described in the README), so wrapping them
// up behind an easier to use interface makes sense.  Descriptions of the
// functions are included below.
//
// For reference, the order of operands for memory references is:
// (Operand), Base, Scale, Index, Displacement.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_LIB_TARGET_X86_X86INSTRBUILDER_H
#define LLVM_LIB_TARGET_X86_X86INSTRBUILDER_H

#include "llvm/ADT/SmallVector.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineMemOperand.h"
#include "llvm/CodeGen/MachineOperand.h"
#include "llvm/MC/MCInstrDesc.h"
#include <cassert>

namespace llvm {

/// X86AddressMode - This struct holds a generalized full x86 address mode.
/// The base register can be a frame index, which will eventually be replaced
/// with BP or SP and Disp being offsetted accordingly.  The displacement may
/// also include the offset of a global value.
struct X86AddressMode { … };

/// Compute the addressing mode from an machine instruction starting with the
/// given operand.
static inline X86AddressMode getAddressFromInstr(const MachineInstr *MI,
                                                 unsigned Operand) { … }

/// addDirectMem - This function is used to add a direct memory reference to the
/// current instruction -- that is, a dereference of an address in a register,
/// with no scale, index or displacement. An example is: DWORD PTR [EAX].
///
static inline const MachineInstrBuilder &
addDirectMem(const MachineInstrBuilder &MIB, unsigned Reg) { … }

/// Replace the address used in the instruction with the direct memory
/// reference.
static inline void setDirectAddressInInstr(MachineInstr *MI, unsigned Operand,
                                           unsigned Reg) { … }

static inline const MachineInstrBuilder &
addOffset(const MachineInstrBuilder &MIB, int Offset) { … }

static inline const MachineInstrBuilder &
addOffset(const MachineInstrBuilder &MIB, const MachineOperand& Offset) { … }

/// addRegOffset - This function is used to add a memory reference of the form
/// [Reg + Offset], i.e., one with no scale or index, but with a
/// displacement. An example is: DWORD PTR [EAX + 4].
///
static inline const MachineInstrBuilder &
addRegOffset(const MachineInstrBuilder &MIB,
             unsigned Reg, bool isKill, int Offset) { … }

/// addRegReg - This function is used to add a memory reference of the form:
/// [Reg + Reg].
static inline const MachineInstrBuilder &addRegReg(const MachineInstrBuilder &MIB,
                                            unsigned Reg1, bool isKill1,
                                            unsigned Reg2, bool isKill2) { … }

static inline const MachineInstrBuilder &
addFullAddress(const MachineInstrBuilder &MIB,
               const X86AddressMode &AM) { … }

/// addFrameReference - This function is used to add a reference to the base of
/// an abstract object on the stack frame of the current function.  This
/// reference has base register as the FrameIndex offset until it is resolved.
/// This allows a constant offset to be specified as well...
///
static inline const MachineInstrBuilder &
addFrameReference(const MachineInstrBuilder &MIB, int FI, int Offset = 0) { … }

/// addConstantPoolReference - This function is used to add a reference to the
/// base of a constant value spilled to the per-function constant pool.  The
/// reference uses the abstract ConstantPoolIndex which is retained until
/// either machine code emission or assembly output. In PIC mode on x86-32,
/// the GlobalBaseReg parameter can be used to make this a
/// GlobalBaseReg-relative reference.
///
static inline const MachineInstrBuilder &
addConstantPoolReference(const MachineInstrBuilder &MIB, unsigned CPI,
                         unsigned GlobalBaseReg, unsigned char OpFlags) { … }

} // end namespace llvm

#endif // LLVM_LIB_TARGET_X86_X86INSTRBUILDER_H