1 //===- TypeMetadataUtils.h - Utilities related to type metadata --*- C++ -*-==//
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 // This file contains functions that make it easier to manipulate type metadata
10 // for devirtualization.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_ANALYSIS_TYPEMETADATAUTILS_H
15 #define LLVM_ANALYSIS_TYPEMETADATAUTILS_H
16 
17 #include "llvm/ADT/SmallVector.h"
18 #include <cstdint>
19 
20 namespace llvm {
21 
22 class CallBase;
23 class CallInst;
24 class Constant;
25 class DominatorTree;
26 class Instruction;
27 class Module;
28 
29 /// The type of CFI jumptable needed for a function.
30 enum CfiFunctionLinkage {
31   CFL_Definition = 0,
32   CFL_Declaration = 1,
33   CFL_WeakDeclaration = 2
34 };
35 
36 /// A call site that could be devirtualized.
37 struct DevirtCallSite {
38   /// The offset from the address point to the virtual function.
39   uint64_t Offset;
40   /// The call site itself.
41   CallBase &CB;
42 };
43 
44 /// Given a call to the intrinsic \@llvm.type.test, find all devirtualizable
45 /// call sites based on the call and return them in DevirtCalls.
46 void findDevirtualizableCallsForTypeTest(
47     SmallVectorImpl<DevirtCallSite> &DevirtCalls,
48     SmallVectorImpl<CallInst *> &Assumes, const CallInst *CI,
49     DominatorTree &DT);
50 
51 /// Given a call to the intrinsic \@llvm.type.checked.load, find all
52 /// devirtualizable call sites based on the call and return them in DevirtCalls.
53 void findDevirtualizableCallsForTypeCheckedLoad(
54     SmallVectorImpl<DevirtCallSite> &DevirtCalls,
55     SmallVectorImpl<Instruction *> &LoadedPtrs,
56     SmallVectorImpl<Instruction *> &Preds, bool &HasNonCallUses,
57     const CallInst *CI, DominatorTree &DT);
58 
59 Constant *getPointerAtOffset(Constant *I, uint64_t Offset, Module &M);
60 }
61 
62 #endif
63