Gabor Greif | 697e94c | 2008-05-15 10:04:30 +0000 | [diff] [blame] | 1 | //===-- Use.cpp - Implement the Use class ---------------------------------===// |
Gabor Greif | f6caff66 | 2008-05-10 08:32:32 +0000 | [diff] [blame] | 2 | // |
| 3 | // The LLVM Compiler Infrastructure |
| 4 | // |
| 5 | // This file is distributed under the University of Illinois Open Source |
| 6 | // License. See LICENSE.TXT for details. |
| 7 | // |
| 8 | //===----------------------------------------------------------------------===// |
| 9 | // |
| 10 | // This file implements the algorithm for finding the User of a Use. |
| 11 | // |
| 12 | //===----------------------------------------------------------------------===// |
| 13 | |
Jay Foad | 59809c7 | 2011-01-16 08:10:57 +0000 | [diff] [blame] | 14 | #include "llvm/Value.h" |
Gabor Greif | f6caff66 | 2008-05-10 08:32:32 +0000 | [diff] [blame] | 15 | |
| 16 | namespace llvm { |
| 17 | |
| 18 | //===----------------------------------------------------------------------===// |
Gabor Greif | 5ef7404 | 2008-05-13 22:51:52 +0000 | [diff] [blame] | 19 | // Use swap Implementation |
| 20 | //===----------------------------------------------------------------------===// |
| 21 | |
| 22 | void Use::swap(Use &RHS) { |
Gabor Greif | 715b9d2 | 2008-09-19 15:13:20 +0000 | [diff] [blame] | 23 | Value *V1(Val); |
| 24 | Value *V2(RHS.Val); |
Gabor Greif | 5ef7404 | 2008-05-13 22:51:52 +0000 | [diff] [blame] | 25 | if (V1 != V2) { |
| 26 | if (V1) { |
| 27 | removeFromList(); |
| 28 | } |
| 29 | |
| 30 | if (V2) { |
| 31 | RHS.removeFromList(); |
Gabor Greif | 715b9d2 | 2008-09-19 15:13:20 +0000 | [diff] [blame] | 32 | Val = V2; |
Gabor Greif | 5ef7404 | 2008-05-13 22:51:52 +0000 | [diff] [blame] | 33 | V2->addUse(*this); |
| 34 | } else { |
Gabor Greif | 715b9d2 | 2008-09-19 15:13:20 +0000 | [diff] [blame] | 35 | Val = 0; |
Gabor Greif | 5ef7404 | 2008-05-13 22:51:52 +0000 | [diff] [blame] | 36 | } |
| 37 | |
| 38 | if (V1) { |
Gabor Greif | 715b9d2 | 2008-09-19 15:13:20 +0000 | [diff] [blame] | 39 | RHS.Val = V1; |
Gabor Greif | 5ef7404 | 2008-05-13 22:51:52 +0000 | [diff] [blame] | 40 | V1->addUse(RHS); |
| 41 | } else { |
Gabor Greif | 715b9d2 | 2008-09-19 15:13:20 +0000 | [diff] [blame] | 42 | RHS.Val = 0; |
Gabor Greif | 5ef7404 | 2008-05-13 22:51:52 +0000 | [diff] [blame] | 43 | } |
| 44 | } |
| 45 | } |
| 46 | |
| 47 | //===----------------------------------------------------------------------===// |
Gabor Greif | f6caff66 | 2008-05-10 08:32:32 +0000 | [diff] [blame] | 48 | // Use getImpliedUser Implementation |
| 49 | //===----------------------------------------------------------------------===// |
| 50 | |
| 51 | const Use *Use::getImpliedUser() const { |
| 52 | const Use *Current = this; |
| 53 | |
| 54 | while (true) { |
Gabor Greif | 2231c2c | 2009-01-05 16:05:32 +0000 | [diff] [blame] | 55 | unsigned Tag = (Current++)->Prev.getInt(); |
Gabor Greif | f6caff66 | 2008-05-10 08:32:32 +0000 | [diff] [blame] | 56 | switch (Tag) { |
| 57 | case zeroDigitTag: |
| 58 | case oneDigitTag: |
| 59 | continue; |
| 60 | |
| 61 | case stopTag: { |
| 62 | ++Current; |
| 63 | ptrdiff_t Offset = 1; |
| 64 | while (true) { |
Gabor Greif | 2231c2c | 2009-01-05 16:05:32 +0000 | [diff] [blame] | 65 | unsigned Tag = Current->Prev.getInt(); |
Gabor Greif | f6caff66 | 2008-05-10 08:32:32 +0000 | [diff] [blame] | 66 | switch (Tag) { |
| 67 | case zeroDigitTag: |
| 68 | case oneDigitTag: |
| 69 | ++Current; |
| 70 | Offset = (Offset << 1) + Tag; |
| 71 | continue; |
| 72 | default: |
| 73 | return Current + Offset; |
| 74 | } |
| 75 | } |
| 76 | } |
| 77 | |
| 78 | case fullStopTag: |
| 79 | return Current; |
| 80 | } |
| 81 | } |
| 82 | } |
| 83 | |
| 84 | //===----------------------------------------------------------------------===// |
| 85 | // Use initTags Implementation |
| 86 | //===----------------------------------------------------------------------===// |
| 87 | |
Jay Foad | bbb91f2 | 2011-01-16 15:30:52 +0000 | [diff] [blame] | 88 | Use *Use::initTags(Use * const Start, Use *Stop) { |
| 89 | ptrdiff_t Done = 0; |
Gabor Greif | 39c06b3 | 2010-07-19 14:48:15 +0000 | [diff] [blame] | 90 | while (Done < 20) { |
Gabor Greif | fee4daf | 2010-07-16 20:35:19 +0000 | [diff] [blame] | 91 | if (Start == Stop--) |
| 92 | return Start; |
Gabor Greif | 39c06b3 | 2010-07-19 14:48:15 +0000 | [diff] [blame] | 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, |
| 99 | oneDigitTag, stopTag |
| 100 | }; |
Jay Foad | bbb91f2 | 2011-01-16 15:30:52 +0000 | [diff] [blame] | 101 | new(Stop) Use(tags[Done++]); |
Gabor Greif | fee4daf | 2010-07-16 20:35:19 +0000 | [diff] [blame] | 102 | } |
| 103 | |
Gabor Greif | f6caff66 | 2008-05-10 08:32:32 +0000 | [diff] [blame] | 104 | ptrdiff_t Count = Done; |
| 105 | while (Start != Stop) { |
| 106 | --Stop; |
Gabor Greif | f6caff66 | 2008-05-10 08:32:32 +0000 | [diff] [blame] | 107 | if (!Count) { |
Jay Foad | bbb91f2 | 2011-01-16 15:30:52 +0000 | [diff] [blame] | 108 | new(Stop) Use(stopTag); |
Gabor Greif | f6caff66 | 2008-05-10 08:32:32 +0000 | [diff] [blame] | 109 | ++Done; |
| 110 | Count = Done; |
| 111 | } else { |
Jay Foad | bbb91f2 | 2011-01-16 15:30:52 +0000 | [diff] [blame] | 112 | new(Stop) Use(PrevPtrTag(Count & 1)); |
Gabor Greif | f6caff66 | 2008-05-10 08:32:32 +0000 | [diff] [blame] | 113 | Count >>= 1; |
| 114 | ++Done; |
| 115 | } |
| 116 | } |
| 117 | |
| 118 | return Start; |
| 119 | } |
| 120 | |
| 121 | //===----------------------------------------------------------------------===// |
| 122 | // Use zap Implementation |
| 123 | //===----------------------------------------------------------------------===// |
| 124 | |
| 125 | void Use::zap(Use *Start, const Use *Stop, bool del) { |
Jay Foad | bbb91f2 | 2011-01-16 15:30:52 +0000 | [diff] [blame] | 126 | while (Start != Stop) |
| 127 | (--Stop)->~Use(); |
| 128 | if (del) |
Gabor Greif | f6caff66 | 2008-05-10 08:32:32 +0000 | [diff] [blame] | 129 | ::operator delete(Start); |
Gabor Greif | f6caff66 | 2008-05-10 08:32:32 +0000 | [diff] [blame] | 130 | } |
| 131 | |
| 132 | //===----------------------------------------------------------------------===// |
Gabor Greif | f6caff66 | 2008-05-10 08:32:32 +0000 | [diff] [blame] | 133 | // Use getUser Implementation |
| 134 | //===----------------------------------------------------------------------===// |
| 135 | |
| 136 | User *Use::getUser() const { |
| 137 | const Use *End = getImpliedUser(); |
Jay Foad | 5c54d75 | 2011-06-20 14:12:33 +0000 | [diff] [blame^] | 138 | const UserRef *ref = reinterpret_cast<const UserRef*>(End); |
| 139 | return ref->getInt() |
| 140 | ? ref->getPointer() |
Gabor Greif | 6265ab8 | 2009-01-05 16:28:14 +0000 | [diff] [blame] | 141 | : (User*)End; |
Gabor Greif | f6caff66 | 2008-05-10 08:32:32 +0000 | [diff] [blame] | 142 | } |
| 143 | |
Gabor Greif | f6caff66 | 2008-05-10 08:32:32 +0000 | [diff] [blame] | 144 | } // End llvm namespace |