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/*
* Copyright 2011-2015 Samy Al Bahra.
* Copyright 2011 David Joseph.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/*
* Several of these are from: http://graphics.stanford.edu/~seander/bithacks.html
*/
#define CK_INTERNAL_LOG_0 (0xAAAAAAAA)
#define CK_INTERNAL_LOG_1 (0xCCCCCCCC)
#define CK_INTERNAL_LOG_2 (0xF0F0F0F0)
#define CK_INTERNAL_LOG_3 (0xFF00FF00)
#define CK_INTERNAL_LOG_4 (0xFFFF0000)
CK_CC_INLINE static uint32_t
ck_internal_log(uint32_t v)
{
uint32_t r = (v & CK_INTERNAL_LOG_0) != 0;
r |= ((v & CK_INTERNAL_LOG_4) != 0) << 4;
r |= ((v & CK_INTERNAL_LOG_3) != 0) << 3;
r |= ((v & CK_INTERNAL_LOG_2) != 0) << 2;
r |= ((v & CK_INTERNAL_LOG_1) != 0) << 1;
return (r);
}
CK_CC_INLINE static uint32_t
ck_internal_power_2(uint32_t v)
{
--v;
v |= v >> 1;
v |= v >> 2;
v |= v >> 4;
v |= v >> 8;
v |= v >> 16;
return (++v);
}
CK_CC_INLINE static unsigned long
ck_internal_max(unsigned long x, unsigned long y)
{
return x ^ ((x ^ y) & -(x < y));
}
CK_CC_INLINE static uint64_t
ck_internal_max_64(uint64_t x, uint64_t y)
{
return x ^ ((x ^ y) & -(x < y));
}
CK_CC_INLINE static uint32_t
ck_internal_max_32(uint32_t x, uint32_t y)
{
return x ^ ((x ^ y) & -(x < y));
}
CK_CC_INLINE static unsigned long
ck_internal_bsf(unsigned long v)
{
#if defined(__GNUC__)
return __builtin_ffs(v);
#else
unsigned int i;
const unsigned int s = sizeof(unsigned long) * 8 - 1;
for (i = 0; i < s; i++) {
if (v & (1UL << (s - i)))
return sizeof(unsigned long) * 8 - i;
}
return 1;
#endif /* !__GNUC__ */
}
CK_CC_INLINE static uint64_t
ck_internal_bsf_64(uint64_t v)
{
#if defined(__GNUC__)
return __builtin_ffs(v);
#else
unsigned int i;
const unsigned int s = sizeof(unsigned long) * 8 - 1;
for (i = 0; i < s; i++) {
if (v & (1ULL << (63U - i)))
return i;
}
#endif /* !__GNUC__ */
return 1;
}
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