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 
20 namespace llvm {
21 
22 class AllocaInst;
23 class DominatorTree;
24 class AliasSetTracker;
25 class AssumptionCache;
26 
27 /// \brief Return true if this alloca is legal for promotion.
28 ///
29 /// This is true if there are only loads, stores, and lifetime markers
30 /// (transitively) using this alloca. This also enforces that there is only
31 /// ever one layer of bitcasts or GEPs between the alloca and the lifetime
32 /// markers.
33 bool isAllocaPromotable(const AllocaInst *AI);
34 
35 /// \brief Promote the specified list of alloca instructions into scalar
36 /// registers, inserting PHI nodes as appropriate.
37 ///
38 /// This function makes use of DominanceFrontier information.  This function
39 /// does not modify the CFG of the function at all.  All allocas must be from
40 /// the same function.
41 ///
42 /// If AST is specified, the specified tracker is updated to reflect changes
43 /// made to the IR.
44 void PromoteMemToReg(ArrayRef<AllocaInst *> Allocas, DominatorTree &DT,
45                      AliasSetTracker *AST = nullptr,
46                      AssumptionCache *AC = nullptr);
47 
48 } // End llvm namespace
49 
50 #endif
51