LLVM  15.0.0git
SetOperations.h
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1 //===-- llvm/ADT/SetOperations.h - Generic Set Operations -------*- 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 /// \file
10 /// This file defines generic set operations that may be used on set's of
11 /// different types, and different element types.
12 ///
13 //===----------------------------------------------------------------------===//
14 
15 #ifndef LLVM_ADT_SETOPERATIONS_H
16 #define LLVM_ADT_SETOPERATIONS_H
17 
18 namespace llvm {
19 
20 /// set_union(A, B) - Compute A := A u B, return whether A changed.
21 ///
22 template <class S1Ty, class S2Ty>
23 bool set_union(S1Ty &S1, const S2Ty &S2) {
24  bool Changed = false;
25 
26  for (typename S2Ty::const_iterator SI = S2.begin(), SE = S2.end();
27  SI != SE; ++SI)
28  if (S1.insert(*SI).second)
29  Changed = true;
30 
31  return Changed;
32 }
33 
34 /// set_intersect(A, B) - Compute A := A ^ B
35 /// Identical to set_intersection, except that it works on set<>'s and
36 /// is nicer to use. Functionally, this iterates through S1, removing
37 /// elements that are not contained in S2.
38 ///
39 template <class S1Ty, class S2Ty>
40 void set_intersect(S1Ty &S1, const S2Ty &S2) {
41  for (typename S1Ty::iterator I = S1.begin(); I != S1.end();) {
42  const auto &E = *I;
43  ++I;
44  if (!S2.count(E)) S1.erase(E); // Erase element if not in S2
45  }
46 }
47 
48 /// set_difference(A, B) - Return A - B
49 ///
50 template <class S1Ty, class S2Ty>
51 S1Ty set_difference(const S1Ty &S1, const S2Ty &S2) {
52  S1Ty Result;
53  for (typename S1Ty::const_iterator SI = S1.begin(), SE = S1.end();
54  SI != SE; ++SI)
55  if (!S2.count(*SI)) // if the element is not in set2
56  Result.insert(*SI);
57  return Result;
58 }
59 
60 /// set_subtract(A, B) - Compute A := A - B
61 ///
62 template <class S1Ty, class S2Ty>
63 void set_subtract(S1Ty &S1, const S2Ty &S2) {
64  for (typename S2Ty::const_iterator SI = S2.begin(), SE = S2.end();
65  SI != SE; ++SI)
66  S1.erase(*SI);
67 }
68 
69 /// set_is_subset(A, B) - Return true iff A in B
70 ///
71 template <class S1Ty, class S2Ty>
72 bool set_is_subset(const S1Ty &S1, const S2Ty &S2) {
73  if (S1.size() > S2.size())
74  return false;
75  for (const auto It : S1)
76  if (!S2.count(It))
77  return false;
78  return true;
79 }
80 
81 } // End llvm namespace
82 
83 #endif
llvm
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:17
llvm::set_is_subset
bool set_is_subset(const S1Ty &S1, const S2Ty &S2)
set_is_subset(A, B) - Return true iff A in B
Definition: SetOperations.h:72
llvm::set_union
bool set_union(S1Ty &S1, const S2Ty &S2)
set_union(A, B) - Compute A := A u B, return whether A changed.
Definition: SetOperations.h:23
E
static GCRegistry::Add< CoreCLRGC > E("coreclr", "CoreCLR-compatible GC")
llvm::set_subtract
void set_subtract(S1Ty &S1, const S2Ty &S2)
set_subtract(A, B) - Compute A := A - B
Definition: SetOperations.h:63
I
#define I(x, y, z)
Definition: MD5.cpp:58
SI
StandardInstrumentations SI(Debug, VerifyEach)
llvm::set_difference
S1Ty set_difference(const S1Ty &S1, const S2Ty &S2)
set_difference(A, B) - Return A - B
Definition: SetOperations.h:51
llvm::set_intersect
void set_intersect(S1Ty &S1, const S2Ty &S2)
set_intersect(A, B) - Compute A := A ^ B Identical to set_intersection, except that it works on set<>...
Definition: SetOperations.h:40