LLVM  15.0.0git
MemDerefPrinter.cpp
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1 //===- MemDerefPrinter.cpp - Printer for isDereferenceablePointer ---------===//
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 
10 #include "llvm/Analysis/Loads.h"
11 #include "llvm/Analysis/Passes.h"
12 #include "llvm/IR/InstIterator.h"
13 #include "llvm/IR/Instructions.h"
14 #include "llvm/IR/Module.h"
15 #include "llvm/InitializePasses.h"
16 #include "llvm/Pass.h"
18 
19 using namespace llvm;
20 
21 namespace {
22  struct MemDerefPrinter : public FunctionPass {
24  SmallPtrSet<Value *, 4> DerefAndAligned;
25 
26  static char ID; // Pass identification, replacement for typeid
27  MemDerefPrinter() : FunctionPass(ID) {
29  }
30  void getAnalysisUsage(AnalysisUsage &AU) const override {
31  AU.setPreservesAll();
32  }
33  bool runOnFunction(Function &F) override;
34  void print(raw_ostream &OS, const Module * = nullptr) const override;
35  void releaseMemory() override {
36  Deref.clear();
37  DerefAndAligned.clear();
38  }
39  };
40 }
41 
42 char MemDerefPrinter::ID = 0;
43 INITIALIZE_PASS_BEGIN(MemDerefPrinter, "print-memderefs",
44  "Memory Dereferenciblity of pointers in function", false, true)
45 INITIALIZE_PASS_END(MemDerefPrinter, "print-memderefs",
46  "Memory Dereferenciblity of pointers in function", false, true)
47 
49  return new MemDerefPrinter();
50 }
51 
53  const DataLayout &DL = F.getParent()->getDataLayout();
54  for (auto &I: instructions(F)) {
55  if (LoadInst *LI = dyn_cast<LoadInst>(&I)) {
56  Value *PO = LI->getPointerOperand();
57  if (isDereferenceablePointer(PO, LI->getType(), DL))
58  Deref.push_back(PO);
59  if (isDereferenceableAndAlignedPointer(PO, LI->getType(), LI->getAlign(),
60  DL))
61  DerefAndAligned.insert(PO);
62  }
63  }
64  return false;
65 }
66 
67 void MemDerefPrinter::print(raw_ostream &OS, const Module *M) const {
68  OS << "The following are dereferenceable:\n";
69  for (Value *V: Deref) {
70  OS << " ";
71  V->print(OS);
72  if (DerefAndAligned.count(V))
73  OS << "\t(aligned)";
74  else
75  OS << "\t(unaligned)";
76  OS << "\n";
77  }
78 }
79 
82  OS << "Memory Dereferencibility of pointers in function '" << F.getName()
83  << "'\n";
84 
86  SmallPtrSet<Value *, 4> DerefAndAligned;
87 
88  const DataLayout &DL = F.getParent()->getDataLayout();
89  for (auto &I : instructions(F)) {
90  if (LoadInst *LI = dyn_cast<LoadInst>(&I)) {
91  Value *PO = LI->getPointerOperand();
92  if (isDereferenceablePointer(PO, LI->getType(), DL))
93  Deref.push_back(PO);
94  if (isDereferenceableAndAlignedPointer(PO, LI->getType(), LI->getAlign(),
95  DL))
96  DerefAndAligned.insert(PO);
97  }
98  }
99 
100  OS << "The following are dereferenceable:\n";
101  for (Value *V : Deref) {
102  OS << " ";
103  V->print(OS);
104  if (DerefAndAligned.count(V))
105  OS << "\t(aligned)";
106  else
107  OS << "\t(unaligned)";
108  OS << "\n";
109  }
110  return PreservedAnalyses::all();
111 }
llvm::PreservedAnalyses
A set of analyses that are preserved following a run of a transformation pass.
Definition: PassManager.h:152
llvm
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:17
llvm::DataLayout
A parsed version of the target data layout string in and methods for querying it.
Definition: DataLayout.h:113
print
static void print(raw_ostream &Out, object::Archive::Kind Kind, T Val)
Definition: ArchiveWriter.cpp:152
InstIterator.h
Loads.h
llvm::Function
Definition: Function.h:60
Pass.h
llvm::SmallVector
This is a 'vector' (really, a variable-sized array), optimized for the case when the array is small.
Definition: SmallVector.h:1185
llvm::MemDerefPrinterPass::run
PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM)
Definition: MemDerefPrinter.cpp:80
true
basic Basic Alias true
Definition: BasicAliasAnalysis.cpp:1909
Module.h
llvm::SmallPtrSet< Value *, 4 >
F
#define F(x, y, z)
Definition: MD5.cpp:55
llvm::PassRegistry::getPassRegistry
static PassRegistry * getPassRegistry()
getPassRegistry - Access the global registry object, which is automatically initialized at applicatio...
Definition: PassRegistry.cpp:31
llvm::AnalysisUsage
Represent the analysis usage information of a pass.
Definition: PassAnalysisSupport.h:47
llvm::initializeMemDerefPrinterPass
void initializeMemDerefPrinterPass(PassRegistry &)
false
Definition: StackSlotColoring.cpp:141
in
The object format emitted by the WebAssembly backed is documented in
Definition: README.txt:11
llvm::isDereferenceablePointer
bool isDereferenceablePointer(const Value *V, Type *Ty, const DataLayout &DL, const Instruction *CtxI=nullptr, const DominatorTree *DT=nullptr, const TargetLibraryInfo *TLI=nullptr)
Return true if this is always a dereferenceable pointer.
Definition: Loads.cpp:227
llvm::raw_ostream
This class implements an extremely fast bulk output stream that can only output to a stream.
Definition: raw_ostream.h:54
llvm::CallingConv::ID
unsigned ID
LLVM IR allows to use arbitrary numbers as calling convention identifiers.
Definition: CallingConv.h:24
INITIALIZE_PASS_END
#define INITIALIZE_PASS_END(passName, arg, name, cfg, analysis)
Definition: PassSupport.h:58
llvm::instructions
inst_range instructions(Function *F)
Definition: InstIterator.h:133
I
#define I(x, y, z)
Definition: MD5.cpp:58
memderefs
print memderefs
Definition: MemDerefPrinter.cpp:45
MemDerefPrinter.h
llvm::Module
A Module instance is used to store all the information related to an LLVM module.
Definition: Module.h:65
llvm::SmallPtrSetImpl::count
size_type count(ConstPtrType Ptr) const
count - Return 1 if the specified pointer is in the set, 0 otherwise.
Definition: SmallPtrSet.h:383
INITIALIZE_PASS_BEGIN
INITIALIZE_PASS_BEGIN(MemDerefPrinter, "print-memderefs", "Memory Dereferenciblity of pointers in function", false, true) INITIALIZE_PASS_END(MemDerefPrinter
llvm::SmallPtrSetImplBase::clear
void clear()
Definition: SmallPtrSet.h:95
llvm::sys::Memory
This class provides various memory handling functions that manipulate MemoryBlock instances.
Definition: Memory.h:52
llvm::Value::getType
Type * getType() const
All values are typed, get the type of this value.
Definition: Value.h:255
DL
MachineBasicBlock MachineBasicBlock::iterator DebugLoc DL
Definition: AArch64SLSHardening.cpp:76
llvm::LoadInst
An instruction for reading from memory.
Definition: Instructions.h:176
llvm::createMemDerefPrinter
FunctionPass * createMemDerefPrinter()
Definition: MemDerefPrinter.cpp:48
runOnFunction
static bool runOnFunction(Function &F, bool PostInlining)
Definition: EntryExitInstrumenter.cpp:69
llvm::AnalysisUsage::setPreservesAll
void setPreservesAll()
Set by analyses that do not transform their input at all.
Definition: PassAnalysisSupport.h:130
llvm::PreservedAnalyses::all
static PreservedAnalyses all()
Construct a special preserved set that preserves all passes.
Definition: PassManager.h:158
llvm::SmallVectorImpl::clear
void clear()
Definition: SmallVector.h:591
Instructions.h
llvm::AnalysisManager
A container for analyses that lazily runs them and caches their results.
Definition: InstructionSimplify.h:42
llvm::FunctionPass
FunctionPass class - This class is used to implement most global optimizations.
Definition: Pass.h:308
function
print Memory Dereferenciblity of pointers in function
Definition: MemDerefPrinter.cpp:46
raw_ostream.h
InitializePasses.h
llvm::Value
LLVM Value Representation.
Definition: Value.h:74
of
Add support for conditional and other related patterns Instead of
Definition: README.txt:134
llvm::isDereferenceableAndAlignedPointer
bool isDereferenceableAndAlignedPointer(const Value *V, Type *Ty, Align Alignment, const DataLayout &DL, const Instruction *CtxI=nullptr, const DominatorTree *DT=nullptr, const TargetLibraryInfo *TLI=nullptr)
Returns true if V is always a dereferenceable pointer with alignment greater or equal than requested.
Definition: Loads.cpp:205
Passes.h
llvm::SmallPtrSetImpl::insert
std::pair< iterator, bool > insert(PtrType Ptr)
Inserts Ptr if and only if there is no element in the container equal to Ptr.
Definition: SmallPtrSet.h:365
llvm::Intrinsic::ID
unsigned ID
Definition: TargetTransformInfo.h:37