llvm/llvm/lib/Target/X86/X86DynAllocaExpander.cpp

//===----- X86DynAllocaExpander.cpp - Expand DynAlloca pseudo instruction -===//
//
// 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 a pass that expands DynAlloca pseudo-instructions.
//
// It performs a conservative analysis to determine whether each allocation
// falls within a region of the stack that is safe to use, or whether stack
// probes must be emitted.
//
//===----------------------------------------------------------------------===//

#include "X86.h"
#include "X86InstrBuilder.h"
#include "X86InstrInfo.h"
#include "X86MachineFunctionInfo.h"
#include "X86Subtarget.h"
#include "llvm/ADT/MapVector.h"
#include "llvm/ADT/PostOrderIterator.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/Passes.h"
#include "llvm/CodeGen/TargetInstrInfo.h"
#include "llvm/IR/Function.h"
#include "llvm/Support/raw_ostream.h"

usingnamespacellvm;

namespace {

class X86DynAllocaExpander : public MachineFunctionPass { … };

char X86DynAllocaExpander::ID = …;

} // end anonymous namespace

INITIALIZE_PASS(…)

FunctionPass *llvm::createX86DynAllocaExpander() { … }

/// Return the allocation amount for a DynAlloca instruction, or -1 if unknown.
static int64_t getDynAllocaAmount(MachineInstr *MI, MachineRegisterInfo *MRI) { … }

X86DynAllocaExpander::Lowering
X86DynAllocaExpander::getLowering(int64_t CurrentOffset,
                                  int64_t AllocaAmount) { … }

static bool isPushPop(const MachineInstr &MI) { … }

void X86DynAllocaExpander::computeLowerings(MachineFunction &MF,
                                            LoweringMap &Lowerings) { … }

static unsigned getSubOpcode(bool Is64Bit) { … }

void X86DynAllocaExpander::lower(MachineInstr *MI, Lowering L) { … }

bool X86DynAllocaExpander::runOnMachineFunction(MachineFunction &MF) { … }