1 //===-- Use.cpp - Implement the Use class ---------------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements the algorithm for finding the User of a Use.
12 //===----------------------------------------------------------------------===//
14 #include "llvm/Value.h"
18 //===----------------------------------------------------------------------===//
19 // Use swap Implementation
20 //===----------------------------------------------------------------------===//
22 void Use::swap(Use &RHS) {
47 //===----------------------------------------------------------------------===//
48 // Use getImpliedUser Implementation
49 //===----------------------------------------------------------------------===//
51 const Use *Use::getImpliedUser() const {
52 const Use *Current = this;
55 unsigned Tag = (Current++)->Prev.getInt();
65 unsigned Tag = Current->Prev.getInt();
70 Offset = (Offset << 1) + Tag;
73 return Current + Offset;
84 //===----------------------------------------------------------------------===//
85 // Use initTags Implementation
86 //===----------------------------------------------------------------------===//
88 Use *Use::initTags(Use * const Start, Use *Stop) {
93 static const PrevPtrTag tags[20] = { fullStopTag, oneDigitTag, stopTag,
94 oneDigitTag, oneDigitTag, stopTag,
95 zeroDigitTag, oneDigitTag, oneDigitTag,
96 stopTag, zeroDigitTag, oneDigitTag,
97 zeroDigitTag, oneDigitTag, stopTag,
98 oneDigitTag, oneDigitTag, oneDigitTag,
101 new(Stop) Use(tags[Done++]);
104 ptrdiff_t Count = Done;
105 while (Start != Stop) {
108 new(Stop) Use(stopTag);
112 new(Stop) Use(PrevPtrTag(Count & 1));
121 //===----------------------------------------------------------------------===//
122 // Use zap Implementation
123 //===----------------------------------------------------------------------===//
125 void Use::zap(Use *Start, const Use *Stop, bool del) {
126 while (Start != Stop)
129 ::operator delete(Start);
132 //===----------------------------------------------------------------------===//
133 // Use getUser Implementation
134 //===----------------------------------------------------------------------===//
136 User *Use::getUser() const {
137 const Use *End = getImpliedUser();
138 const UserRef *ref = reinterpret_cast<const UserRef*>(End);
144 } // End llvm namespace