LLVM 17.0.0git
LazyValueInfo.h
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1//===- LazyValueInfo.h - Value constraint analysis --------------*- 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 the interface for lazy computation of value constraint
10// information.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_ANALYSIS_LAZYVALUEINFO_H
15#define LLVM_ANALYSIS_LAZYVALUEINFO_H
16
17#include "llvm/IR/PassManager.h"
18#include "llvm/Pass.h"
19
20namespace llvm {
21 class AssumptionCache;
22 class Constant;
23 class ConstantRange;
24 class DataLayout;
25 class DominatorTree;
26 class Instruction;
27 class TargetLibraryInfo;
28 class Value;
29
30/// This pass computes, caches, and vends lazy value constraint information.
33 AssumptionCache *AC = nullptr;
34 const DataLayout *DL = nullptr;
35 class TargetLibraryInfo *TLI = nullptr;
36 void *PImpl = nullptr;
37 LazyValueInfo(const LazyValueInfo&) = delete;
38 void operator=(const LazyValueInfo&) = delete;
39public:
41 LazyValueInfo() = default;
44 : AC(AC_), DL(DL_), TLI(TLI_) {}
46 : AC(Arg.AC), DL(Arg.DL), TLI(Arg.TLI), PImpl(Arg.PImpl) {
47 Arg.PImpl = nullptr;
48 }
51 AC = Arg.AC;
52 DL = Arg.DL;
53 TLI = Arg.TLI;
54 PImpl = Arg.PImpl;
55 Arg.PImpl = nullptr;
56 return *this;
57 }
58
59 /// This is used to return true/false/dunno results.
60 enum Tristate {
61 Unknown = -1, False = 0, True = 1
62 };
63
64 // Public query interface.
65
66 /// Determine whether the specified value comparison with a constant is known
67 /// to be true or false on the specified CFG edge.
68 /// Pred is a CmpInst predicate.
69 Tristate getPredicateOnEdge(unsigned Pred, Value *V, Constant *C,
70 BasicBlock *FromBB, BasicBlock *ToBB,
71 Instruction *CxtI = nullptr);
72
73 /// Determine whether the specified value comparison with a constant is known
74 /// to be true or false at the specified instruction.
75 /// \p Pred is a CmpInst predicate. If \p UseBlockValue is true, the block
76 /// value is also taken into account.
77 Tristate getPredicateAt(unsigned Pred, Value *V, Constant *C,
78 Instruction *CxtI, bool UseBlockValue);
79
80 /// Determine whether the specified value comparison is known to be true
81 /// or false at the specified instruction. While this takes two Value's,
82 /// it still requires that one of them is a constant.
83 /// \p Pred is a CmpInst predicate.
84 /// If \p UseBlockValue is true, the block value is also taken into account.
85 Tristate getPredicateAt(unsigned Pred, Value *LHS, Value *RHS,
86 Instruction *CxtI, bool UseBlockValue);
87
88 /// Determine whether the specified value is known to be a constant at the
89 /// specified instruction. Return null if not.
91
92 /// Return the ConstantRange constraint that is known to hold for the
93 /// specified value at the specified instruction. This may only be called
94 /// on integer-typed Values.
96 bool UndefAllowed = true);
97
98 /// Return the ConstantRange constraint that is known to hold for the value
99 /// at a specific use-site.
100 ConstantRange getConstantRangeAtUse(const Use &U, bool UndefAllowed = true);
101
102 /// Determine whether the specified value is known to be a
103 /// constant on the specified edge. Return null if not.
105 Instruction *CxtI = nullptr);
106
107 /// Return the ConstantRage constraint that is known to hold for the
108 /// specified value on the specified edge. This may be only be called
109 /// on integer-typed Values.
111 BasicBlock *ToBB,
112 Instruction *CxtI = nullptr);
113
114 /// Inform the analysis cache that we have threaded an edge from
115 /// PredBB to OldSucc to be from PredBB to NewSucc instead.
116 void threadEdge(BasicBlock *PredBB, BasicBlock *OldSucc, BasicBlock *NewSucc);
117
118 /// Inform the analysis cache that we have erased a block.
119 void eraseBlock(BasicBlock *BB);
120
121 /// Complete flush all previously computed values
122 void clear(const Module *M);
123
124 /// Print the \LazyValueInfo Analysis.
125 /// We pass in the DTree that is required for identifying which basic blocks
126 /// we can solve/print for, in the LVIPrinter.
127 void printLVI(Function &F, DominatorTree &DTree, raw_ostream &OS);
128
129 // For old PM pass. Delete once LazyValueInfoWrapperPass is gone.
130 void releaseMemory();
131
132 /// Handle invalidation events in the new pass manager.
133 bool invalidate(Function &F, const PreservedAnalyses &PA,
135};
136
137/// Analysis to compute lazy value information.
138class LazyValueAnalysis : public AnalysisInfoMixin<LazyValueAnalysis> {
139public:
142
143private:
144 static AnalysisKey Key;
146};
147
148/// Wrapper around LazyValueInfo.
151 void operator=(const LazyValueInfoWrapperPass&) = delete;
152public:
153 static char ID;
156 assert(!Info.PImpl && "releaseMemory not called");
157 }
158
160
161 void getAnalysisUsage(AnalysisUsage &AU) const override;
162 void releaseMemory() override;
163 bool runOnFunction(Function &F) override;
164private:
165 LazyValueInfo Info;
166};
167
168} // end namespace llvm
169
170#endif
171
MachineBasicBlock MachineBasicBlock::iterator DebugLoc DL
amdgpu Simplify well known AMD library false FunctionCallee Value * Arg
#define F(x, y, z)
Definition: MD5.cpp:55
FunctionAnalysisManager FAM
This header defines various interfaces for pass management in LLVM.
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
Value * RHS
Value * LHS
API to communicate dependencies between analyses during invalidation.
Definition: PassManager.h:661
A container for analyses that lazily runs them and caches their results.
Definition: PassManager.h:620
Represent the analysis usage information of a pass.
A cache of @llvm.assume calls within a function.
LLVM Basic Block Representation.
Definition: BasicBlock.h:56
This class represents a range of values.
Definition: ConstantRange.h:47
This is an important base class in LLVM.
Definition: Constant.h:41
A parsed version of the target data layout string in and methods for querying it.
Definition: DataLayout.h:114
Concrete subclass of DominatorTreeBase that is used to compute a normal dominator tree.
Definition: Dominators.h:166
FunctionPass class - This class is used to implement most global optimizations.
Definition: Pass.h:308
Analysis to compute lazy value information.
Result run(Function &F, FunctionAnalysisManager &FAM)
Wrapper around LazyValueInfo.
bool runOnFunction(Function &F) override
runOnFunction - Virtual method overriden by subclasses to do the per-function processing of the pass.
void releaseMemory() override
releaseMemory() - This member can be implemented by a pass if it wants to be able to release its memo...
void getAnalysisUsage(AnalysisUsage &AU) const override
getAnalysisUsage - This function should be overriden by passes that need analysis information to do t...
This pass computes, caches, and vends lazy value constraint information.
Definition: LazyValueInfo.h:31
LazyValueInfo & operator=(LazyValueInfo &&Arg)
Definition: LazyValueInfo.h:49
ConstantRange getConstantRangeAtUse(const Use &U, bool UndefAllowed=true)
Return the ConstantRange constraint that is known to hold for the value at a specific use-site.
void eraseBlock(BasicBlock *BB)
Inform the analysis cache that we have erased a block.
LazyValueInfo(LazyValueInfo &&Arg)
Definition: LazyValueInfo.h:45
void threadEdge(BasicBlock *PredBB, BasicBlock *OldSucc, BasicBlock *NewSucc)
Inform the analysis cache that we have threaded an edge from PredBB to OldSucc to be from PredBB to N...
Tristate
This is used to return true/false/dunno results.
Definition: LazyValueInfo.h:60
Constant * getConstantOnEdge(Value *V, BasicBlock *FromBB, BasicBlock *ToBB, Instruction *CxtI=nullptr)
Determine whether the specified value is known to be a constant on the specified edge.
ConstantRange getConstantRangeOnEdge(Value *V, BasicBlock *FromBB, BasicBlock *ToBB, Instruction *CxtI=nullptr)
Return the ConstantRage constraint that is known to hold for the specified value on the specified edg...
Tristate getPredicateOnEdge(unsigned Pred, Value *V, Constant *C, BasicBlock *FromBB, BasicBlock *ToBB, Instruction *CxtI=nullptr)
Determine whether the specified value comparison with a constant is known to be true or false on the ...
void clear(const Module *M)
Complete flush all previously computed values.
Tristate getPredicateAt(unsigned Pred, Value *V, Constant *C, Instruction *CxtI, bool UseBlockValue)
Determine whether the specified value comparison with a constant is known to be true or false at the ...
Constant * getConstant(Value *V, Instruction *CxtI)
Determine whether the specified value is known to be a constant at the specified instruction.
void printLVI(Function &F, DominatorTree &DTree, raw_ostream &OS)
Print the \LazyValueInfo Analysis.
LazyValueInfo()=default
LazyValueInfo(AssumptionCache *AC_, const DataLayout *DL_, TargetLibraryInfo *TLI_)
Definition: LazyValueInfo.h:42
bool invalidate(Function &F, const PreservedAnalyses &PA, FunctionAnalysisManager::Invalidator &Inv)
Handle invalidation events in the new pass manager.
ConstantRange getConstantRange(Value *V, Instruction *CxtI, bool UndefAllowed=true)
Return the ConstantRange constraint that is known to hold for the specified value at the specified in...
A Module instance is used to store all the information related to an LLVM module.
Definition: Module.h:65
A set of analyses that are preserved following a run of a transformation pass.
Definition: PassManager.h:152
Provides information about what library functions are available for the current target.
A Use represents the edge between a Value definition and its users.
Definition: Use.h:43
LLVM Value Representation.
Definition: Value.h:74
This class implements an extremely fast bulk output stream that can only output to a stream.
Definition: raw_ostream.h:52
@ C
The default llvm calling convention, compatible with C.
Definition: CallingConv.h:34
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:18
A CRTP mix-in that provides informational APIs needed for analysis passes.
Definition: PassManager.h:394
A special type used by analysis passes to provide an address that identifies that particular analysis...
Definition: PassManager.h:69