LLVM  7.0.0svn
MemDerefPrinter.cpp
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1 //===- MemDerefPrinter.cpp - Printer for isDereferenceablePointer ---------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "llvm/Analysis/Loads.h"
11 #include "llvm/Analysis/Passes.h"
12 #include "llvm/IR/CallSite.h"
13 #include "llvm/IR/DataLayout.h"
14 #include "llvm/IR/InstIterator.h"
15 #include "llvm/IR/LLVMContext.h"
16 #include "llvm/IR/Module.h"
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, DL))
58  Deref.push_back(PO);
59  if (isDereferenceableAndAlignedPointer(PO, LI->getAlignment(), DL))
60  DerefAndAligned.insert(PO);
61  }
62  }
63  return false;
64 }
65 
66 void MemDerefPrinter::print(raw_ostream &OS, const Module *M) const {
67  OS << "The following are dereferenceable:\n";
68  for (Value *V: Deref) {
69  V->print(OS);
70  if (DerefAndAligned.count(V))
71  OS << "\t(aligned)";
72  else
73  OS << "\t(unaligned)";
74  OS << "\n\n";
75  }
76 }
A parsed version of the target data layout string in and methods for querying it. ...
Definition: DataLayout.h:111
static PassRegistry * getPassRegistry()
getPassRegistry - Access the global registry object, which is automatically initialized at applicatio...
Compute iterated dominance frontiers using a linear time algorithm.
Definition: AllocatorList.h:24
A Module instance is used to store all the information related to an LLVM module. ...
Definition: Module.h:63
This class provides various memory handling functions that manipulate MemoryBlock instances...
Definition: Memory.h:46
F(f)
An instruction for reading from memory.
Definition: Instructions.h:164
print Memory Dereferenciblity of pointers in function
const DataLayout & getDataLayout() const
Get the data layout for the module&#39;s target platform.
Definition: Module.cpp:361
static bool runOnFunction(Function &F, bool PostInlining)
void initializeMemDerefPrinterPass(PassRegistry &)
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:371
Represent the analysis usage information of a pass.
FunctionPass class - This class is used to implement most global optimizations.
Definition: Pass.h:285
static void print(raw_ostream &Out, object::Archive::Kind Kind, T Val)
size_type count(ConstPtrType Ptr) const
count - Return 1 if the specified pointer is in the set, 0 otherwise.
Definition: SmallPtrSet.h:382
INITIALIZE_PASS_END(RegBankSelect, DEBUG_TYPE, "Assign register bank of generic virtual registers", false, false) RegBankSelect
SmallPtrSet - This class implements a set which is optimized for holding SmallSize or less elements...
Definition: SmallPtrSet.h:418
This is a &#39;vector&#39; (really, a variable-sized array), optimized for the case when the array is small...
Definition: SmallVector.h:861
Module.h This file contains the declarations for the Module class.
void setPreservesAll()
Set by analyses that do not transform their input at all.
INITIALIZE_PASS_BEGIN(MemDerefPrinter, "print-memderefs", "Memory Dereferenciblity of pointers in function", false, true) INITIALIZE_PASS_END(MemDerefPrinter
bool isDereferenceablePointer(const Value *V, const DataLayout &DL, const Instruction *CtxI=nullptr, const DominatorTree *DT=nullptr)
Return true if this is always a dereferenceable pointer.
Definition: Loads.cpp:153
Basic Alias true
#define I(x, y, z)
Definition: MD5.cpp:58
print memderefs
Module * getParent()
Get the module that this global value is contained inside of...
Definition: GlobalValue.h:565
LLVM Value Representation.
Definition: Value.h:73
This class implements an extremely fast bulk output stream that can only output to a stream...
Definition: raw_ostream.h:46
inst_range instructions(Function *F)
Definition: InstIterator.h:134
bool isDereferenceableAndAlignedPointer(const Value *V, unsigned Align, const DataLayout &DL, const Instruction *CtxI=nullptr, const DominatorTree *DT=nullptr)
Returns true if V is always a dereferenceable pointer with alignment greater or equal than requested...
Definition: Loads.cpp:129
FunctionPass * createMemDerefPrinter()