LLVM 17.0.0git
PHITransAddr.h
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1//===- PHITransAddr.h - PHI Translation for Addresses -----------*- 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 PHITransAddr class.
10//
11//===----------------------------------------------------------------------===//
12
13#ifndef LLVM_ANALYSIS_PHITRANSADDR_H
14#define LLVM_ANALYSIS_PHITRANSADDR_H
15
17#include "llvm/IR/Instruction.h"
18
19namespace llvm {
20class AssumptionCache;
21class DominatorTree;
22class DataLayout;
23class TargetLibraryInfo;
24
25/// PHITransAddr - An address value which tracks and handles phi translation.
26/// As we walk "up" the CFG through predecessors, we need to ensure that the
27/// address we're tracking is kept up to date. For example, if we're analyzing
28/// an address of "&A[i]" and walk through the definition of 'i' which is a PHI
29/// node, we *must* phi translate i to get "&A[j]" or else we will analyze an
30/// incorrect pointer in the predecessor block.
31///
32/// This is designed to be a relatively small object that lives on the stack and
33/// is copyable.
34///
36 /// Addr - The actual address we're analyzing.
37 Value *Addr;
38
39 /// The DataLayout we are playing with.
40 const DataLayout &DL;
41
42 /// TLI - The target library info if known, otherwise null.
43 const TargetLibraryInfo *TLI = nullptr;
44
45 /// A cache of \@llvm.assume calls used by SimplifyInstruction.
47
48 /// InstInputs - The inputs for our symbolic address.
50
51public:
53 : Addr(Addr), DL(DL), AC(AC) {
54 // If the address is an instruction, the whole thing is considered an input.
55 addAsInput(Addr);
56 }
57
58 Value *getAddr() const { return Addr; }
59
60 /// needsPHITranslationFromBlock - Return true if moving from the specified
61 /// BasicBlock to its predecessors requires PHI translation.
63 // We do need translation if one of our input instructions is defined in
64 // this block.
65 return any_of(InstInputs, [BB](const auto &InstInput) {
66 return InstInput->getParent() == BB;
67 });
68 }
69
70 /// isPotentiallyPHITranslatable - If this needs PHI translation, return true
71 /// if we have some hope of doing it. This should be used as a filter to
72 /// avoid calling PHITranslateValue in hopeless situations.
74
75 /// translateValue - PHI translate the current address up the CFG from
76 /// CurBB to Pred, updating our state to reflect any needed changes. If
77 /// 'MustDominate' is true, the translated value must dominate PredBB.
79 const DominatorTree *DT, bool MustDominate);
80
81 /// translateWithInsertion - PHI translate this value into the specified
82 /// predecessor block, inserting a computation of the value if it is
83 /// unavailable.
84 ///
85 /// All newly created instructions are added to the NewInsts list. This
86 /// returns null on failure.
87 ///
89 const DominatorTree &DT,
91
92 void dump() const;
93
94 /// verify - Check internal consistency of this data structure. If the
95 /// structure is valid, it returns true. If invalid, it prints errors and
96 /// returns false.
97 bool verify() const;
98
99private:
100 Value *translateSubExpr(Value *V, BasicBlock *CurBB, BasicBlock *PredBB,
101 const DominatorTree *DT);
102
103 /// insertTranslatedSubExpr - Insert a computation of the PHI translated
104 /// version of 'V' for the edge PredBB->CurBB into the end of the PredBB
105 /// block. All newly created instructions are added to the NewInsts list.
106 /// This returns null on failure.
107 ///
108 Value *insertTranslatedSubExpr(Value *InVal, BasicBlock *CurBB,
109 BasicBlock *PredBB, const DominatorTree &DT,
111
112 /// addAsInput - If the specified value is an instruction, add it as an input.
113 Value *addAsInput(Value *V) {
114 // If V is an instruction, it is now an input.
115 if (Instruction *VI = dyn_cast<Instruction>(V))
116 InstInputs.push_back(VI);
117 return V;
118 }
119};
120
121} // end namespace llvm
122
123#endif
MachineBasicBlock MachineBasicBlock::iterator DebugLoc DL
uint64_t Addr
@ VI
This file defines the SmallVector class.
A cache of @llvm.assume calls within a function.
LLVM Basic Block Representation.
Definition: BasicBlock.h:56
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
PHITransAddr - An address value which tracks and handles phi translation.
Definition: PHITransAddr.h:35
Value * translateValue(BasicBlock *CurBB, BasicBlock *PredBB, const DominatorTree *DT, bool MustDominate)
translateValue - PHI translate the current address up the CFG from CurBB to Pred, updating our state ...
void dump() const
PHITransAddr(Value *Addr, const DataLayout &DL, AssumptionCache *AC)
Definition: PHITransAddr.h:52
bool isPotentiallyPHITranslatable() const
isPotentiallyPHITranslatable - If this needs PHI translation, return true if we have some hope of doi...
bool verify() const
verify - Check internal consistency of this data structure.
Value * translateWithInsertion(BasicBlock *CurBB, BasicBlock *PredBB, const DominatorTree &DT, SmallVectorImpl< Instruction * > &NewInsts)
translateWithInsertion - PHI translate this value into the specified predecessor block,...
bool needsPHITranslationFromBlock(BasicBlock *BB) const
needsPHITranslationFromBlock - Return true if moving from the specified BasicBlock to its predecessor...
Definition: PHITransAddr.h:62
Value * getAddr() const
Definition: PHITransAddr.h:58
This class consists of common code factored out of the SmallVector class to reduce code duplication b...
Definition: SmallVector.h:577
void push_back(const T &Elt)
Definition: SmallVector.h:416
This is a 'vector' (really, a variable-sized array), optimized for the case when the array is small.
Definition: SmallVector.h:1200
Provides information about what library functions are available for the current target.
LLVM Value Representation.
Definition: Value.h:74
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:18
bool any_of(R &&range, UnaryPredicate P)
Provide wrappers to std::any_of which take ranges instead of having to pass begin/end explicitly.
Definition: STLExtras.h:1742