1 //===- LazyValueInfo.h - Value constraint analysis --------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines the interface for lazy computation of value constraint
13 //===----------------------------------------------------------------------===//
15 #ifndef LLVM_ANALYSIS_LAZYVALUEINFO_H
16 #define LLVM_ANALYSIS_LAZYVALUEINFO_H
18 #include "llvm/IR/PassManager.h"
19 #include "llvm/Pass.h"
22 class AssumptionCache;
28 class TargetLibraryInfo;
31 /// This pass computes, caches, and vends lazy value constraint information.
33 friend class LazyValueInfoWrapperPass;
34 AssumptionCache *AC = nullptr;
35 const DataLayout *DL = nullptr;
36 class TargetLibraryInfo *TLI = nullptr;
37 DominatorTree *DT = nullptr;
38 void *PImpl = nullptr;
39 LazyValueInfo(const LazyValueInfo&) = delete;
40 void operator=(const LazyValueInfo&) = delete;
44 LazyValueInfo(AssumptionCache *AC_, const DataLayout *DL_, TargetLibraryInfo *TLI_,
46 : AC(AC_), DL(DL_), TLI(TLI_), DT(DT_) {}
47 LazyValueInfo(LazyValueInfo &&Arg)
48 : AC(Arg.AC), DL(Arg.DL), TLI(Arg.TLI), DT(Arg.DT), PImpl(Arg.PImpl) {
51 LazyValueInfo &operator=(LazyValueInfo &&Arg) {
62 /// This is used to return true/false/dunno results.
64 Unknown = -1, False = 0, True = 1
67 // Public query interface.
69 /// Determine whether the specified value comparison with a constant is known
70 /// to be true or false on the specified CFG edge.
71 /// Pred is a CmpInst predicate.
72 Tristate getPredicateOnEdge(unsigned Pred, Value *V, Constant *C,
73 BasicBlock *FromBB, BasicBlock *ToBB,
74 Instruction *CxtI = nullptr);
76 /// Determine whether the specified value comparison with a constant is known
77 /// to be true or false at the specified instruction
78 /// (from an assume intrinsic). Pred is a CmpInst predicate.
79 Tristate getPredicateAt(unsigned Pred, Value *V, Constant *C,
82 /// Determine whether the specified value is known to be a
83 /// constant at the end of the specified block. Return null if not.
84 Constant *getConstant(Value *V, BasicBlock *BB, Instruction *CxtI = nullptr);
86 /// Return the ConstantRange constraint that is known to hold for the
87 /// specified value at the end of the specified block. This may only be called
88 /// on integer-typed Values.
89 ConstantRange getConstantRange(Value *V, BasicBlock *BB, Instruction *CxtI = nullptr);
91 /// Determine whether the specified value is known to be a
92 /// constant on the specified edge. Return null if not.
93 Constant *getConstantOnEdge(Value *V, BasicBlock *FromBB, BasicBlock *ToBB,
94 Instruction *CxtI = nullptr);
96 /// Return the ConstantRage constraint that is known to hold for the
97 /// specified value on the specified edge. This may be only be called
98 /// on integer-typed Values.
99 ConstantRange getConstantRangeOnEdge(Value *V, BasicBlock *FromBB,
101 Instruction *CxtI = nullptr);
103 /// Inform the analysis cache that we have threaded an edge from
104 /// PredBB to OldSucc to be from PredBB to NewSucc instead.
105 void threadEdge(BasicBlock *PredBB, BasicBlock *OldSucc, BasicBlock *NewSucc);
107 /// Inform the analysis cache that we have erased a block.
108 void eraseBlock(BasicBlock *BB);
110 /// Print the \LazyValueInfo Analysis.
111 /// We pass in the DTree that is required for identifying which basic blocks
112 /// we can solve/print for, in the LVIPrinter. The DT is optional
113 /// in LVI, so we need to pass it here as an argument.
114 void printLVI(Function &F, DominatorTree &DTree, raw_ostream &OS);
116 // For old PM pass. Delete once LazyValueInfoWrapperPass is gone.
117 void releaseMemory();
119 /// Handle invalidation events in the new pass manager.
120 bool invalidate(Function &F, const PreservedAnalyses &PA,
121 FunctionAnalysisManager::Invalidator &Inv);
124 /// \brief Analysis to compute lazy value information.
125 class LazyValueAnalysis : public AnalysisInfoMixin<LazyValueAnalysis> {
127 typedef LazyValueInfo Result;
128 Result run(Function &F, FunctionAnalysisManager &FAM);
131 static AnalysisKey Key;
132 friend struct AnalysisInfoMixin<LazyValueAnalysis>;
135 /// Wrapper around LazyValueInfo.
136 class LazyValueInfoWrapperPass : public FunctionPass {
137 LazyValueInfoWrapperPass(const LazyValueInfoWrapperPass&) = delete;
138 void operator=(const LazyValueInfoWrapperPass&) = delete;
141 LazyValueInfoWrapperPass() : FunctionPass(ID) {
142 initializeLazyValueInfoWrapperPassPass(*PassRegistry::getPassRegistry());
144 ~LazyValueInfoWrapperPass() override {
145 assert(!Info.PImpl && "releaseMemory not called");
148 LazyValueInfo &getLVI();
150 void getAnalysisUsage(AnalysisUsage &AU) const override;
151 void releaseMemory() override;
152 bool runOnFunction(Function &F) override;
157 } // end namespace llvm