llvm/lib/Analysis/MemDerefPrinter.cpp

   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
   9 #include "llvm/Analysis/MemDerefPrinter.h"
  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"
  17 #include "llvm/Support/raw_ostream.h"
  18
  19 using namespace llvm;
  20
  21 PreservedAnalyses MemDerefPrinterPass::run(Function &F,
  22                                            FunctionAnalysisManager &AM) {
  23   OS << "Memory Dereferencibility of pointers in function '" << F.getName()
  24      << "'\n";
  25
  26   SmallVector<Value *, 4> Deref;
  27   SmallPtrSet<Value *, 4> DerefAndAligned;
  28
  29   const DataLayout &DL = F.getDataLayout();
  30   for (auto &I : instructions(F)) {
  31     if (LoadInst *LI = dyn_cast<LoadInst>(&I)) {
  32       Value *PO = LI->getPointerOperand();
  33       if (isDereferenceablePointer(PO, LI->getType(), DL))
  34         Deref.push_back(PO);
  35       if (isDereferenceableAndAlignedPointer(PO, LI->getType(), LI->getAlign(),
  36                                              DL))
  37         DerefAndAligned.insert(PO);
  38     }
  39   }
  40
  41   OS << "The following are dereferenceable:\n";
  42   for (Value *V : Deref) {
  43     OS << "  ";
  44     V->print(OS);
  45     if (DerefAndAligned.count(V))
  46       OS << "\t(aligned)";
  47     else
  48       OS << "\t(unaligned)";
  49     OS << "\n";
  50   }
  51   return PreservedAnalyses::all();
  52 }