LLVM  9.0.0svn
OrderedInstructions.h
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1 //===- llvm/Transforms/Utils/OrderedInstructions.h -------------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file defines an efficient way to check for dominance relation between 2
10 // instructions.
11 //
12 // This interface dispatches to appropriate dominance check given 2
13 // instructions, i.e. in case the instructions are in the same basic block,
14 // OrderedBasicBlock (with instruction numbering and caching) are used.
15 // Otherwise, dominator tree is used.
16 //
17 //===----------------------------------------------------------------------===//
18 
19 #ifndef LLVM_ANALYSIS_ORDEREDINSTRUCTIONS_H
20 #define LLVM_ANALYSIS_ORDEREDINSTRUCTIONS_H
21 
22 #include "llvm/ADT/DenseMap.h"
24 #include "llvm/IR/Dominators.h"
25 #include "llvm/IR/Operator.h"
26 
27 namespace llvm {
28 
30  /// Used to check dominance for instructions in same basic block.
32  OBBMap;
33 
34  /// The dominator tree of the parent function.
35  DominatorTree *DT;
36 
37  /// Return true if the first instruction comes before the second in the
38  /// same basic block. It will create an ordered basic block, if it does
39  /// not yet exist in OBBMap.
40  bool localDominates(const Instruction *, const Instruction *) const;
41 
42 public:
43  /// Constructor.
45 
46  /// Return true if first instruction dominates the second.
47  bool dominates(const Instruction *, const Instruction *) const;
48 
49  /// Return true if the first instruction comes before the second in the
50  /// dominator tree DFS traversal if they are in different basic blocks,
51  /// or if the first instruction comes before the second in the same basic
52  /// block.
53  bool dfsBefore(const Instruction *, const Instruction *) const;
54 
55  /// Invalidate the OrderedBasicBlock cache when its basic block changes.
56  /// i.e. If an instruction is deleted or added to the basic block, the user
57  /// should call this function to invalidate the OrderedBasicBlock cache for
58  /// this basic block.
59  void invalidateBlock(const BasicBlock *BB) { OBBMap.erase(BB); }
60 };
61 
62 } // end namespace llvm
63 
64 #endif // LLVM_ANALYSIS_ORDEREDINSTRUCTIONS_H
This class represents lattice values for constants.
Definition: AllocatorList.h:23
bool dominates(const Instruction *, const Instruction *) const
Return true if first instruction dominates the second.
Concrete subclass of DominatorTreeBase that is used to compute a normal dominator tree...
Definition: Dominators.h:144
LLVM Basic Block Representation.
Definition: BasicBlock.h:57
bool dfsBefore(const Instruction *, const Instruction *) const
Return true if the first instruction comes before the second in the dominator tree DFS traversal if t...
void invalidateBlock(const BasicBlock *BB)
Invalidate the OrderedBasicBlock cache when its basic block changes.
OrderedInstructions(DominatorTree *DT)
Constructor.