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/IR/InstIterator.h"
  12 #include "llvm/IR/Instructions.h"
  13 #include "llvm/Pass.h"
  14 #include "llvm/Support/raw_ostream.h"
  15
  16 using namespace llvm;
  17
  18 PreservedAnalyses MemDerefPrinterPass::run(Function &F,
  19                                            FunctionAnalysisManager &AM) {
  20   OS << "Memory Dereferencibility of pointers in function '" << F.getName()
  21      << "'\n";
  22
  23   SmallVector<Value *, 4> Deref;
  24   SmallPtrSet<Value *, 4> DerefAndAligned;
  25
  26   const DataLayout &DL = F.getDataLayout();
  27   for (auto &I : instructions(F)) {
  28     if (LoadInst *LI = dyn_cast<LoadInst>(&I)) {
  29       Value *PO = LI->getPointerOperand();
  30       if (isDereferenceablePointer(PO, LI->getType(), DL, LI))
  31         Deref.push_back(PO);
  32       if (isDereferenceableAndAlignedPointer(PO, LI->getType(), LI->getAlign(),
  33                                              DL, LI))
  34         DerefAndAligned.insert(PO);
  35     }
  36   }
  37
  38   OS << "The following are dereferenceable:\n";
  39   for (Value *V : Deref) {
  40     OS << "  ";
  41     V->print(OS);
  42     if (DerefAndAligned.count(V))
  43       OS << "\t(aligned)";
  44     else
  45       OS << "\t(unaligned)";
  46     OS << "\n";
  47   }
  48   return PreservedAnalyses::all();
  49 }