1*1fb62fb0SOlivier Houchard /*
2*1fb62fb0SOlivier Houchard * Copyright 2011-2015 Samy Al Bahra.
3*1fb62fb0SOlivier Houchard * Copyright 2011 David Joseph.
4*1fb62fb0SOlivier Houchard * All rights reserved.
5*1fb62fb0SOlivier Houchard *
6*1fb62fb0SOlivier Houchard * Redistribution and use in source and binary forms, with or without
7*1fb62fb0SOlivier Houchard * modification, are permitted provided that the following conditions
8*1fb62fb0SOlivier Houchard * are met:
9*1fb62fb0SOlivier Houchard * 1. Redistributions of source code must retain the above copyright
10*1fb62fb0SOlivier Houchard * notice, this list of conditions and the following disclaimer.
11*1fb62fb0SOlivier Houchard * 2. Redistributions in binary form must reproduce the above copyright
12*1fb62fb0SOlivier Houchard * notice, this list of conditions and the following disclaimer in the
13*1fb62fb0SOlivier Houchard * documentation and/or other materials provided with the distribution.
14*1fb62fb0SOlivier Houchard *
15*1fb62fb0SOlivier Houchard * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16*1fb62fb0SOlivier Houchard * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17*1fb62fb0SOlivier Houchard * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18*1fb62fb0SOlivier Houchard * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19*1fb62fb0SOlivier Houchard * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20*1fb62fb0SOlivier Houchard * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21*1fb62fb0SOlivier Houchard * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22*1fb62fb0SOlivier Houchard * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23*1fb62fb0SOlivier Houchard * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24*1fb62fb0SOlivier Houchard * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25*1fb62fb0SOlivier Houchard * SUCH DAMAGE.
26*1fb62fb0SOlivier Houchard */
27*1fb62fb0SOlivier Houchard
28*1fb62fb0SOlivier Houchard /*
29*1fb62fb0SOlivier Houchard * Several of these are from: http://graphics.stanford.edu/~seander/bithacks.html
30*1fb62fb0SOlivier Houchard */
31*1fb62fb0SOlivier Houchard
32*1fb62fb0SOlivier Houchard #define CK_INTERNAL_LOG_0 (0xAAAAAAAA)
33*1fb62fb0SOlivier Houchard #define CK_INTERNAL_LOG_1 (0xCCCCCCCC)
34*1fb62fb0SOlivier Houchard #define CK_INTERNAL_LOG_2 (0xF0F0F0F0)
35*1fb62fb0SOlivier Houchard #define CK_INTERNAL_LOG_3 (0xFF00FF00)
36*1fb62fb0SOlivier Houchard #define CK_INTERNAL_LOG_4 (0xFFFF0000)
37*1fb62fb0SOlivier Houchard
38*1fb62fb0SOlivier Houchard CK_CC_INLINE static uint32_t
ck_internal_log(uint32_t v)39*1fb62fb0SOlivier Houchard ck_internal_log(uint32_t v)
40*1fb62fb0SOlivier Houchard {
41*1fb62fb0SOlivier Houchard uint32_t r = (v & CK_INTERNAL_LOG_0) != 0;
42*1fb62fb0SOlivier Houchard
43*1fb62fb0SOlivier Houchard r |= ((v & CK_INTERNAL_LOG_4) != 0) << 4;
44*1fb62fb0SOlivier Houchard r |= ((v & CK_INTERNAL_LOG_3) != 0) << 3;
45*1fb62fb0SOlivier Houchard r |= ((v & CK_INTERNAL_LOG_2) != 0) << 2;
46*1fb62fb0SOlivier Houchard r |= ((v & CK_INTERNAL_LOG_1) != 0) << 1;
47*1fb62fb0SOlivier Houchard return (r);
48*1fb62fb0SOlivier Houchard }
49*1fb62fb0SOlivier Houchard
50*1fb62fb0SOlivier Houchard CK_CC_INLINE static uint32_t
ck_internal_power_2(uint32_t v)51*1fb62fb0SOlivier Houchard ck_internal_power_2(uint32_t v)
52*1fb62fb0SOlivier Houchard {
53*1fb62fb0SOlivier Houchard
54*1fb62fb0SOlivier Houchard --v;
55*1fb62fb0SOlivier Houchard v |= v >> 1;
56*1fb62fb0SOlivier Houchard v |= v >> 2;
57*1fb62fb0SOlivier Houchard v |= v >> 4;
58*1fb62fb0SOlivier Houchard v |= v >> 8;
59*1fb62fb0SOlivier Houchard v |= v >> 16;
60*1fb62fb0SOlivier Houchard return (++v);
61*1fb62fb0SOlivier Houchard }
62*1fb62fb0SOlivier Houchard
63*1fb62fb0SOlivier Houchard CK_CC_INLINE static unsigned long
ck_internal_max(unsigned long x,unsigned long y)64*1fb62fb0SOlivier Houchard ck_internal_max(unsigned long x, unsigned long y)
65*1fb62fb0SOlivier Houchard {
66*1fb62fb0SOlivier Houchard
67*1fb62fb0SOlivier Houchard return x ^ ((x ^ y) & -(x < y));
68*1fb62fb0SOlivier Houchard }
69*1fb62fb0SOlivier Houchard
70*1fb62fb0SOlivier Houchard CK_CC_INLINE static uint64_t
ck_internal_max_64(uint64_t x,uint64_t y)71*1fb62fb0SOlivier Houchard ck_internal_max_64(uint64_t x, uint64_t y)
72*1fb62fb0SOlivier Houchard {
73*1fb62fb0SOlivier Houchard
74*1fb62fb0SOlivier Houchard return x ^ ((x ^ y) & -(x < y));
75*1fb62fb0SOlivier Houchard }
76*1fb62fb0SOlivier Houchard
77*1fb62fb0SOlivier Houchard CK_CC_INLINE static uint32_t
ck_internal_max_32(uint32_t x,uint32_t y)78*1fb62fb0SOlivier Houchard ck_internal_max_32(uint32_t x, uint32_t y)
79*1fb62fb0SOlivier Houchard {
80*1fb62fb0SOlivier Houchard
81*1fb62fb0SOlivier Houchard return x ^ ((x ^ y) & -(x < y));
82*1fb62fb0SOlivier Houchard }
83