PromoteMemToReg.h

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//===- PromoteMemToReg.h - Promote Allocas to Scalars -----------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file exposes an interface to promote alloca instructions to SSA
// registers, by using the SSA construction algorithm.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_TRANSFORMS_UTILS_PROMOTEMEMTOREG_H
#define LLVM_TRANSFORMS_UTILS_PROMOTEMEMTOREG_H

#include "llvm/ADT/ArrayRef.h"

namespace llvm {

class AllocaInst;
class DominatorTree;
class AliasSetTracker;
class AssumptionTracker;

/// \brief Return true if this alloca is legal for promotion.
///
/// This is true if there are only loads, stores, and lifetime markers
/// (transitively) using this alloca. This also enforces that there is only
/// ever one layer of bitcasts or GEPs between the alloca and the lifetime
/// markers.
bool isAllocaPromotable(const AllocaInst *AI);

/// \brief Promote the specified list of alloca instructions into scalar
/// registers, inserting PHI nodes as appropriate.
///
/// This function makes use of DominanceFrontier information.  This function
/// does not modify the CFG of the function at all.  All allocas must be from
/// the same function.
///
/// If AST is specified, the specified tracker is updated to reflect changes
/// made to the IR.
void PromoteMemToReg(ArrayRef<AllocaInst *> Allocas, DominatorTree &DT,
                     AliasSetTracker *AST = nullptr,
                     AssumptionTracker *AT = nullptr);

} // End llvm namespace

#endif