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blender-archive/source/blender/blenlib/intern/math_bits_inline.c
Campbell Barton 65ec7ec524 Cleanup: remove redundant, invalid info from headers
BF-admins agree to remove header information that isn't useful,
to reduce noise.

- BEGIN/END license blocks

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  No need for separator text.

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  This is often invalid, outdated or misleading
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See P901 for script to perform these edits.
2019-02-02 01:36:28 +11:00

151 lines
3.1 KiB
C

/*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* */
/** \file blender/blenlib/intern/math_bits_inline.c
* \ingroup bli
*/
#ifndef __MATH_BITS_INLINE_C__
#define __MATH_BITS_INLINE_C__
#ifdef _MSC_VER
# include <intrin.h>
#endif
#include "BLI_math_bits.h"
MINLINE int bitscan_forward_i(int a)
{
BLI_assert(a != 0);
#ifdef _MSC_VER
unsigned long ctz;
_BitScanForward(&ctz, a);
return ctz;
#else
return __builtin_ctz((unsigned int)a);
#endif
}
MINLINE unsigned int bitscan_forward_uint(unsigned int a)
{
return (unsigned int)bitscan_forward_i((int)a);
}
MINLINE int bitscan_forward_clear_i(int *a)
{
int i = bitscan_forward_i(*a);
*a &= (*a) - 1;
return i;
}
MINLINE unsigned int bitscan_forward_clear_uint(unsigned int *a)
{
return (unsigned int)bitscan_forward_clear_i((int *)a);
}
MINLINE int bitscan_reverse_i(int a)
{
BLI_assert(a != 0);
#ifdef _MSC_VER
unsigned long clz;
_BitScanReverse(&clz, a);
return clz;
#else
return __builtin_clz((unsigned int)a);
#endif
}
MINLINE unsigned int bitscan_reverse_uint(unsigned int a)
{
return (unsigned int)bitscan_reverse_i((int)a);
}
MINLINE int bitscan_reverse_clear_i(int *a)
{
int i = bitscan_reverse_i(*a);
/* TODO(sergey): This could probably be optimized. */
*a &= ~(1 << (sizeof(int) * 8 - i - 1));
return i;
}
MINLINE unsigned int bitscan_reverse_clear_uint(unsigned int *a)
{
return (unsigned int)bitscan_reverse_clear_i((int *)a);
}
MINLINE unsigned int highest_order_bit_uint(unsigned int n)
{
if (n == 0) {
return 0;
}
return 1 << (sizeof(unsigned int) * 8 - bitscan_reverse_uint(n));
}
MINLINE unsigned short highest_order_bit_s(unsigned short n)
{
n |= (n >> 1);
n |= (n >> 2);
n |= (n >> 4);
n |= (n >> 8);
return (unsigned short)(n - (n >> 1));
}
#ifndef __GNUC__
MINLINE int count_bits_i(unsigned int i)
{
/* variable-precision SWAR algorithm. */
i = i - ((i >> 1) & 0x55555555);
i = (i & 0x33333333) + ((i >> 2) & 0x33333333);
return (((i + (i >> 4)) & 0x0F0F0F0F) * 0x01010101) >> 24;
}
#endif
MINLINE int float_as_int(float f)
{
union { int i; float f; } u;
u.f = f;
return u.i;
}
MINLINE unsigned int float_as_uint(float f)
{
union { unsigned int i; float f; } u;
u.f = f;
return u.i;
}
MINLINE float int_as_float(int i)
{
union { int i; float f; } u;
u.i = i;
return u.f;
}
MINLINE float uint_as_float(unsigned int i)
{
union { unsigned int i; float f; } u;
u.i = i;
return u.f;
}
MINLINE float xor_fl(float x, int y)
{
return int_as_float(float_as_int(x) ^ y);
}
#endif /* __MATH_BITS_INLINE_C__ */