llvm/llvm/lib/Target/X86/X86InsertWait.cpp

//-  X86Insertwait.cpp - Strict-Fp:Insert wait instruction X87 instructions --//
//
// 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 defines the pass which insert x86 wait instructions after each
// X87 instructions when strict float is enabled.
//
// The logic to insert a wait instruction after an X87 instruction is as below:
// 1. If the X87 instruction don't raise float exception nor is a load/store
//    instruction, or is a x87 control instruction, don't insert wait.
// 2. If the X87 instruction is an instruction which the following instruction
//    is an X87 exception synchronizing X87 instruction, don't insert wait.
// 3. For other situations, insert wait instruction.
//
//===----------------------------------------------------------------------===//

#include "X86.h"
#include "X86InstrInfo.h"
#include "X86Subtarget.h"
#include "llvm/CodeGen/MachineBasicBlock.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineOperand.h"
#include "llvm/IR/DebugLoc.h"
#include "llvm/Support/Debug.h"

usingnamespacellvm;

#define DEBUG_TYPE …

namespace {

class WaitInsert : public MachineFunctionPass { … };

} // namespace

char WaitInsert::ID = …;

FunctionPass *llvm::createX86InsertX87waitPass() { … }

static bool isX87ControlInstruction(MachineInstr &MI) { … }

static bool isX87NonWaitingControlInstruction(MachineInstr &MI) { … }

bool WaitInsert::runOnMachineFunction(MachineFunction &MF) { … }