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 
enqueueUsers(Instruction & I)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 
adjustOffsetForGEP(GetElementPtrInst & GEPI)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 }
45