gfx/graphite2/src/inc/bits.h@6474c204b198 (annotated)
gfx/graphite2/src/inc/bits.h
Wed, 31 Dec 2014 06:09:35 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Wed, 31 Dec 2014 06:09:35 +0100
- changeset 0
- 6474c204b198
- permissions
- -rw-r--r--
Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.
| michael@0 | 1 | /* GRAPHITE2 LICENSING |
| michael@0 | 2 | |
| michael@0 | 3 | Copyright 2012, SIL International |
| michael@0 | 4 | All rights reserved. |
| michael@0 | 5 | |
| michael@0 | 6 | This library is free software; you can redistribute it and/or modify |
| michael@0 | 7 | it under the terms of the GNU Lesser General Public License as published |
| michael@0 | 8 | by the Free Software Foundation; either version 2.1 of License, or |
| michael@0 | 9 | (at your option) any later version. |
| michael@0 | 10 | |
| michael@0 | 11 | This program is distributed in the hope that it will be useful, |
| michael@0 | 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| michael@0 | 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| michael@0 | 14 | Lesser General Public License for more details. |
| michael@0 | 15 | |
| michael@0 | 16 | You should also have received a copy of the GNU Lesser General Public |
| michael@0 | 17 | License along with this library in the file named "LICENSE". |
| michael@0 | 18 | If not, write to the Free Software Foundation, 51 Franklin Street, |
| michael@0 | 19 | Suite 500, Boston, MA 02110-1335, USA or visit their web page on the |
| michael@0 | 20 | internet at http://www.fsf.org/licenses/lgpl.html. |
| michael@0 | 21 | |
| michael@0 | 22 | Alternatively, the contents of this file may be used under the terms of the |
| michael@0 | 23 | Mozilla Public License (http://mozilla.org/MPL) or the GNU General Public |
| michael@0 | 24 | License, as published by the Free Software Foundation, either version 2 |
| michael@0 | 25 | of the License or (at your option) any later version. |
| michael@0 | 26 | */ |
| michael@0 | 27 | #pragma once |
| michael@0 | 28 | |
| michael@0 | 29 | namespace graphite2 |
| michael@0 | 30 | { |
| michael@0 | 31 | |
| michael@0 | 32 | template<typename T> |
| michael@0 | 33 | inline unsigned int bit_set_count(T v) |
| michael@0 | 34 | { |
| michael@0 | 35 | v = v - ((v >> 1) & T(~T(0)/3)); // temp |
| michael@0 | 36 | v = (v & T(~T(0)/15*3)) + ((v >> 2) & T(~T(0)/15*3)); // temp |
| michael@0 | 37 | v = (v + (v >> 4)) & T(~T(0)/255*15); // temp |
| michael@0 | 38 | return (T)(v * T(~T(0)/255)) >> (sizeof(T)-1)*8; // count |
| michael@0 | 39 | } |
| michael@0 | 40 | |
| michael@0 | 41 | |
| michael@0 | 42 | template<int S> |
| michael@0 | 43 | inline unsigned long _mask_over_val(unsigned long v) |
| michael@0 | 44 | { |
| michael@0 | 45 | v = _mask_over_val<S/2>(v); |
| michael@0 | 46 | v |= v >> S*4; |
| michael@0 | 47 | return v; |
| michael@0 | 48 | } |
| michael@0 | 49 | |
| michael@0 | 50 | template<> |
| michael@0 | 51 | inline unsigned long _mask_over_val<1>(unsigned long v) |
| michael@0 | 52 | { |
| michael@0 | 53 | v |= v >> 1; |
| michael@0 | 54 | v |= v >> 2; |
| michael@0 | 55 | v |= v >> 4; |
| michael@0 | 56 | return v; |
| michael@0 | 57 | } |
| michael@0 | 58 | |
| michael@0 | 59 | template<typename T> |
| michael@0 | 60 | inline T mask_over_val(T v) |
| michael@0 | 61 | { |
| michael@0 | 62 | return _mask_over_val<sizeof(T)>(v); |
| michael@0 | 63 | } |
| michael@0 | 64 | |
| michael@0 | 65 | template<typename T> |
| michael@0 | 66 | inline unsigned long next_highest_power2(T v) |
| michael@0 | 67 | { |
| michael@0 | 68 | return _mask_over_val<sizeof(T)>(v-1)+1; |
| michael@0 | 69 | } |
| michael@0 | 70 | |
| michael@0 | 71 | template<typename T> |
| michael@0 | 72 | inline unsigned int log_binary(T v) |
| michael@0 | 73 | { |
| michael@0 | 74 | return bit_set_count(mask_over_val(v))-1; |
| michael@0 | 75 | } |
| michael@0 | 76 | |
| michael@0 | 77 | template<typename T> |
| michael@0 | 78 | inline T has_zero(const T x) |
| michael@0 | 79 | { |
| michael@0 | 80 | return (x - T(~T(0)/255)) & ~x & T(~T(0)/255*128); |
| michael@0 | 81 | } |
| michael@0 | 82 | |
| michael@0 | 83 | template<typename T> |
| michael@0 | 84 | inline T zero_bytes(const T x, unsigned char n) |
| michael@0 | 85 | { |
| michael@0 | 86 | const T t = T(~T(0)/255*n); |
| michael@0 | 87 | return T((has_zero(x^t) >> 7)*n); |
| michael@0 | 88 | } |
| michael@0 | 89 | |
| michael@0 | 90 | } |
