LLVM 18.0.0git
SSAUpdaterBulk.h
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1//===- SSAUpdaterBulk.h - Unstructured SSA Update Tool ----------*- 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 declares the SSAUpdaterBulk class.
10//
11//===----------------------------------------------------------------------===//
12
13#ifndef LLVM_TRANSFORMS_UTILS_SSAUPDATERBULK_H
14#define LLVM_TRANSFORMS_UTILS_SSAUPDATERBULK_H
15
16#include "llvm/ADT/DenseMap.h"
17#include "llvm/ADT/StringRef.h"
19
20namespace llvm {
21
22class BasicBlock;
23class PHINode;
24template <typename T> class SmallVectorImpl;
25class Type;
26class Use;
27class Value;
28class DominatorTree;
29
30/// Helper class for SSA formation on a set of values defined in multiple
31/// blocks.
32///
33/// This is used when code duplication or another unstructured transformation
34/// wants to rewrite a set of uses of one value with uses of a set of values.
35/// The update is done only when RewriteAllUses is called, all other methods are
36/// used for book-keeping. That helps to share some common computations between
37/// updates of different uses (which is not the case when traditional SSAUpdater
38/// is used).
40 struct RewriteInfo {
43 StringRef Name;
44 Type *Ty;
45 RewriteInfo() = default;
46 RewriteInfo(StringRef &N, Type *T) : Name(N), Ty(T){};
47 };
49
50 PredIteratorCache PredCache;
51
52 Value *computeValueAt(BasicBlock *BB, RewriteInfo &R, DominatorTree *DT);
53
54public:
55 explicit SSAUpdaterBulk() = default;
56 SSAUpdaterBulk(const SSAUpdaterBulk &) = delete;
58 ~SSAUpdaterBulk() = default;
59
60 /// Add a new variable to the SSA rewriter. This needs to be called before
61 /// AddAvailableValue or AddUse calls. The return value is the variable ID,
62 /// which needs to be passed to AddAvailableValue and AddUse.
63 unsigned AddVariable(StringRef Name, Type *Ty);
64
65 /// Indicate that a rewritten value is available in the specified block with
66 /// the specified value.
67 void AddAvailableValue(unsigned Var, BasicBlock *BB, Value *V);
68
69 /// Record a use of the symbolic value. This use will be updated with a
70 /// rewritten value when RewriteAllUses is called.
71 void AddUse(unsigned Var, Use *U);
72
73 /// Perform all the necessary updates, including new PHI-nodes insertion and
74 /// the requested uses update.
75 ///
76 /// The function requires dominator tree DT, which is used for computing
77 /// locations for new phi-nodes insertions. If a nonnull pointer to a vector
78 /// InsertedPHIs is passed, all the new phi-nodes will be added to this
79 /// vector.
81 SmallVectorImpl<PHINode *> *InsertedPHIs = nullptr);
82};
83
84} // end namespace llvm
85
86#endif // LLVM_TRANSFORMS_UTILS_SSAUPDATERBULK_H
RelocType Type
Definition: COFFYAML.cpp:391
This file defines the DenseMap class.
std::string Name
Rewrite Partial Register Uses
LLVM Basic Block Representation.
Definition: BasicBlock.h:60
Concrete subclass of DominatorTreeBase that is used to compute a normal dominator tree.
Definition: Dominators.h:164
PredIteratorCache - This class is an extremely trivial cache for predecessor iterator queries.
Helper class for SSA formation on a set of values defined in multiple blocks.
SSAUpdaterBulk()=default
SSAUpdaterBulk & operator=(const SSAUpdaterBulk &)=delete
~SSAUpdaterBulk()=default
unsigned AddVariable(StringRef Name, Type *Ty)
Add a new variable to the SSA rewriter.
void AddAvailableValue(unsigned Var, BasicBlock *BB, Value *V)
Indicate that a rewritten value is available in the specified block with the specified value.
void RewriteAllUses(DominatorTree *DT, SmallVectorImpl< PHINode * > *InsertedPHIs=nullptr)
Perform all the necessary updates, including new PHI-nodes insertion and the requested uses update.
SSAUpdaterBulk(const SSAUpdaterBulk &)=delete
void AddUse(unsigned Var, Use *U)
Record a use of the symbolic value.
This class consists of common code factored out of the SmallVector class to reduce code duplication b...
Definition: SmallVector.h:577
This is a 'vector' (really, a variable-sized array), optimized for the case when the array is small.
Definition: SmallVector.h:1200
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:50
The instances of the Type class are immutable: once they are created, they are never changed.
Definition: Type.h:45
A Use represents the edge between a Value definition and its users.
Definition: Use.h:43
LLVM Value Representation.
Definition: Value.h:74
@ BasicBlock
Various leaf nodes.
Definition: ISDOpcodes.h:71
NodeAddr< UseNode * > Use
Definition: RDFGraph.h:385
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:18
#define N