1 //===- ReplaceConstant.h - Replacing LLVM constant expressions --*- 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 declares the utility function for replacing LLVM constant
10 // expressions by instructions.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_IR_REPLACECONSTANT_H
15 #define LLVM_IR_REPLACECONSTANT_H
16 
17 #include <map>
18 #include <vector>
19 
20 namespace llvm {
21 
22 class ConstantExpr;
23 class Instruction;
24 class Use;
25 template <typename PtrType> class SmallPtrSetImpl;
26 
27 /// The given instruction \p I contains given constant expression \p CE as one
28 /// of its operands, possibly nested within constant expression trees. Convert
29 /// all reachable paths from contant expression operands of \p I to \p CE into
30 /// corresponding instructions, insert them before \p I, update operands of \p I
31 /// accordingly, and if required, return all such converted instructions at
32 /// \p Insts.
33 void convertConstantExprsToInstructions(
34     Instruction *I, ConstantExpr *CE,
35     SmallPtrSetImpl<Instruction *> *Insts = nullptr);
36 
37 /// The given instruction \p I contains constant expression CE within the
38 /// constant expression trees of it`s constant expression operands, and
39 /// \p CEPaths holds all the reachable paths (to CE) from such constant
40 /// expression trees of \p I. Convert constant expressions within these paths
41 /// into corresponding instructions, insert them before \p I, update operands of
42 /// \p I accordingly, and if required, return all such converted instructions at
43 /// \p Insts.
44 void convertConstantExprsToInstructions(
45     Instruction *I,
46     std::map<Use *, std::vector<std::vector<ConstantExpr *>>> &CEPaths,
47     SmallPtrSetImpl<Instruction *> *Insts = nullptr);
48 
49 /// Given an instruction \p I which uses given constant expression \p CE as
50 /// operand, either directly or nested within other constant expressions, return
51 /// all reachable paths from the constant expression operands of \p I to \p CE,
52 /// and return collected paths at \p CEPaths.
53 void collectConstantExprPaths(
54     Instruction *I, ConstantExpr *CE,
55     std::map<Use *, std::vector<std::vector<ConstantExpr *>>> &CEPaths);
56 
57 } // end namespace llvm
58 
59 #endif // LLVM_IR_REPLACECONSTANT_H
60