1 //===- MemDerefPrinter.cpp - Printer for isDereferenceablePointer ---------===//
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 #include "llvm/Analysis/Passes.h"
11 #include "llvm/ADT/SetVector.h"
12 #include "llvm/Analysis/MemoryDependenceAnalysis.h"
13 #include "llvm/Analysis/ValueTracking.h"
14 #include "llvm/IR/CallSite.h"
15 #include "llvm/IR/DataLayout.h"
16 #include "llvm/IR/InstIterator.h"
17 #include "llvm/IR/LLVMContext.h"
18 #include "llvm/IR/Module.h"
19 #include "llvm/Support/ErrorHandling.h"
20 #include "llvm/Support/raw_ostream.h"
24 struct MemDerefPrinter : public FunctionPass {
25 SmallVector<Value *, 4> Deref;
26 SmallPtrSet<Value *, 4> DerefAndAligned;
28 static char ID; // Pass identification, replacement for typeid
29 MemDerefPrinter() : FunctionPass(ID) {
30 initializeMemDerefPrinterPass(*PassRegistry::getPassRegistry());
32 void getAnalysisUsage(AnalysisUsage &AU) const override {
35 bool runOnFunction(Function &F) override;
36 void print(raw_ostream &OS, const Module * = nullptr) const override;
37 void releaseMemory() override {
39 DerefAndAligned.clear();
44 char MemDerefPrinter::ID = 0;
45 INITIALIZE_PASS_BEGIN(MemDerefPrinter, "print-memderefs",
46 "Memory Dereferenciblity of pointers in function", false, true)
47 INITIALIZE_PASS_END(MemDerefPrinter, "print-memderefs",
48 "Memory Dereferenciblity of pointers in function", false, true)
50 FunctionPass *llvm::createMemDerefPrinter() {
51 return new MemDerefPrinter();
54 bool MemDerefPrinter::runOnFunction(Function &F) {
55 const DataLayout &DL = F.getParent()->getDataLayout();
56 for (auto &I: instructions(F)) {
57 if (LoadInst *LI = dyn_cast<LoadInst>(&I)) {
58 Value *PO = LI->getPointerOperand();
59 if (isDereferenceablePointer(PO, DL))
61 if (isDereferenceableAndAlignedPointer(PO, LI->getAlignment(), DL))
62 DerefAndAligned.insert(PO);
68 void MemDerefPrinter::print(raw_ostream &OS, const Module *M) const {
69 OS << "The following are dereferenceable:\n";
70 for (Value *V: Deref) {
72 if (DerefAndAligned.count(V))
75 OS << "\t(unaligned)";