The Tor Browser / file comparison
comparison: gfx/graphite2/src/inc/bits.h
gfx/graphite2/src/inc/bits.h
- branch
- TOR_BUG_9701
- changeset 15
- b8a032363ba2
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| -1:000000000000 | 0:17b149d4e87c |
|---|---|
| 1 /* GRAPHITE2 LICENSING | |
| 2 | |
| 3 Copyright 2012, SIL International | |
| 4 All rights reserved. | |
| 5 | |
| 6 This library is free software; you can redistribute it and/or modify | |
| 7 it under the terms of the GNU Lesser General Public License as published | |
| 8 by the Free Software Foundation; either version 2.1 of License, or | |
| 9 (at your option) any later version. | |
| 10 | |
| 11 This program is distributed in the hope that it will be useful, | |
| 12 but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| 14 Lesser General Public License for more details. | |
| 15 | |
| 16 You should also have received a copy of the GNU Lesser General Public | |
| 17 License along with this library in the file named "LICENSE". | |
| 18 If not, write to the Free Software Foundation, 51 Franklin Street, | |
| 19 Suite 500, Boston, MA 02110-1335, USA or visit their web page on the | |
| 20 internet at http://www.fsf.org/licenses/lgpl.html. | |
| 21 | |
| 22 Alternatively, the contents of this file may be used under the terms of the | |
| 23 Mozilla Public License (http://mozilla.org/MPL) or the GNU General Public | |
| 24 License, as published by the Free Software Foundation, either version 2 | |
| 25 of the License or (at your option) any later version. | |
| 26 */ | |
| 27 #pragma once | |
| 28 | |
| 29 namespace graphite2 | |
| 30 { | |
| 31 | |
| 32 template<typename T> | |
| 33 inline unsigned int bit_set_count(T v) | |
| 34 { | |
| 35 v = v - ((v >> 1) & T(~T(0)/3)); // temp | |
| 36 v = (v & T(~T(0)/15*3)) + ((v >> 2) & T(~T(0)/15*3)); // temp | |
| 37 v = (v + (v >> 4)) & T(~T(0)/255*15); // temp | |
| 38 return (T)(v * T(~T(0)/255)) >> (sizeof(T)-1)*8; // count | |
| 39 } | |
| 40 | |
| 41 | |
| 42 template<int S> | |
| 43 inline unsigned long _mask_over_val(unsigned long v) | |
| 44 { | |
| 45 v = _mask_over_val<S/2>(v); | |
| 46 v |= v >> S*4; | |
| 47 return v; | |
| 48 } | |
| 49 | |
| 50 template<> | |
| 51 inline unsigned long _mask_over_val<1>(unsigned long v) | |
| 52 { | |
| 53 v |= v >> 1; | |
| 54 v |= v >> 2; | |
| 55 v |= v >> 4; | |
| 56 return v; | |
| 57 } | |
| 58 | |
| 59 template<typename T> | |
| 60 inline T mask_over_val(T v) | |
| 61 { | |
| 62 return _mask_over_val<sizeof(T)>(v); | |
| 63 } | |
| 64 | |
| 65 template<typename T> | |
| 66 inline unsigned long next_highest_power2(T v) | |
| 67 { | |
| 68 return _mask_over_val<sizeof(T)>(v-1)+1; | |
| 69 } | |
| 70 | |
| 71 template<typename T> | |
| 72 inline unsigned int log_binary(T v) | |
| 73 { | |
| 74 return bit_set_count(mask_over_val(v))-1; | |
| 75 } | |
| 76 | |
| 77 template<typename T> | |
| 78 inline T has_zero(const T x) | |
| 79 { | |
| 80 return (x - T(~T(0)/255)) & ~x & T(~T(0)/255*128); | |
| 81 } | |
| 82 | |
| 83 template<typename T> | |
| 84 inline T zero_bytes(const T x, unsigned char n) | |
| 85 { | |
| 86 const T t = T(~T(0)/255*n); | |
| 87 return T((has_zero(x^t) >> 7)*n); | |
| 88 } | |
| 89 | |
| 90 } |
