lib/Analysis/PtrUseVisitor.cpp

   1 //===- PtrUseVisitor.cpp - InstVisitors over a pointers uses --------------===//
   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 /// \file
  10 /// Implementation of the pointer use visitors.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "llvm/Analysis/PtrUseVisitor.h"
  15 #include "llvm/IR/Instruction.h"
  16 #include "llvm/IR/Instructions.h"
  17 #include <algorithm>
  18
  19 using namespace llvm;
  20
  21 void detail::PtrUseVisitorBase::enqueueUsers(Instruction &I) {
  22   for (Use &U : I.uses()) {
  23     if (VisitedUses.insert(&U).second) {
  24       UseToVisit NewU = {
  25         UseToVisit::UseAndIsOffsetKnownPair(&U, IsOffsetKnown),
  26         Offset
  27       };
  28       Worklist.push_back(std::move(NewU));
  29     }
  30   }
  31 }
  32
  33 bool detail::PtrUseVisitorBase::adjustOffsetForGEP(GetElementPtrInst &GEPI) {
  34   if (!IsOffsetKnown)
  35     return false;
  36
  37   APInt TmpOffset(DL.getIndexTypeSizeInBits(GEPI.getType()), 0);
  38   if (GEPI.accumulateConstantOffset(DL, TmpOffset)) {
  39     Offset += TmpOffset.sextOrTrunc(Offset.getBitWidth());
  40     return true;
  41   }
  42
  43   return false;
  44 }