1/* 2 * Copyright 2011-2015 Samy Al Bahra. 3 * Copyright 2011 David Joseph. 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28/* 29 * Several of these are from: http://graphics.stanford.edu/~seander/bithacks.html 30 */ 31 32#define CK_INTERNAL_LOG_0 (0xAAAAAAAA) 33#define CK_INTERNAL_LOG_1 (0xCCCCCCCC) 34#define CK_INTERNAL_LOG_2 (0xF0F0F0F0) 35#define CK_INTERNAL_LOG_3 (0xFF00FF00) 36#define CK_INTERNAL_LOG_4 (0xFFFF0000) 37 38CK_CC_INLINE static uint32_t 39ck_internal_log(uint32_t v) 40{ 41 uint32_t r = (v & CK_INTERNAL_LOG_0) != 0; 42 43 r |= ((v & CK_INTERNAL_LOG_4) != 0) << 4; 44 r |= ((v & CK_INTERNAL_LOG_3) != 0) << 3; 45 r |= ((v & CK_INTERNAL_LOG_2) != 0) << 2; 46 r |= ((v & CK_INTERNAL_LOG_1) != 0) << 1; 47 return (r); 48} 49 50CK_CC_INLINE static uint32_t 51ck_internal_power_2(uint32_t v) 52{ 53 54 --v; 55 v |= v >> 1; 56 v |= v >> 2; 57 v |= v >> 4; 58 v |= v >> 8; 59 v |= v >> 16; 60 return (++v); 61} 62 63CK_CC_INLINE static unsigned long 64ck_internal_max(unsigned long x, unsigned long y) 65{ 66 67 return x ^ ((x ^ y) & -(x < y)); 68} 69 70CK_CC_INLINE static uint64_t 71ck_internal_max_64(uint64_t x, uint64_t y) 72{ 73 74 return x ^ ((x ^ y) & -(x < y)); 75} 76 77CK_CC_INLINE static uint32_t 78ck_internal_max_32(uint32_t x, uint32_t y) 79{ 80 81 return x ^ ((x ^ y) & -(x < y)); 82} 83