PromoteMemToReg.h revision 263508 
1//===- PromoteMemToReg.h - Promote Allocas to Scalars -----------*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file exposes an interface to promote alloca instructions to SSA
11// registers, by using the SSA construction algorithm.
12//
13//===----------------------------------------------------------------------===//
14
15#ifndef LLVM_TRANSFORMS_UTILS_PROMOTEMEMTOREG_H
16#define LLVM_TRANSFORMS_UTILS_PROMOTEMEMTOREG_H
17
18#include "llvm/ADT/ArrayRef.h"
19
20namespace llvm {
21
22class AllocaInst;
23class DominatorTree;
24class AliasSetTracker;
25
26/// \brief Return true if this alloca is legal for promotion.
27///
28/// This is true if there are only loads, stores, and lifetime markers
29/// (transitively) using this alloca. This also enforces that there is only
30/// ever one layer of bitcasts or GEPs between the alloca and the lifetime
31/// markers.
32bool isAllocaPromotable(const AllocaInst *AI);
33
34/// \brief Promote the specified list of alloca instructions into scalar
35/// registers, inserting PHI nodes as appropriate.
36///
37/// This function makes use of DominanceFrontier information.  This function
38/// does not modify the CFG of the function at all.  All allocas must be from
39/// the same function.
40///
41/// If AST is specified, the specified tracker is updated to reflect changes
42/// made to the IR.
43void PromoteMemToReg(ArrayRef<AllocaInst *> Allocas, DominatorTree &DT,
44                     AliasSetTracker *AST = 0);
45
46} // End llvm namespace
47
48#endif
49