BLI_math_bits.h

Go to the documentation of this file.

/* SPDX-FileCopyrightText: 2023 Blender Authors
 *
 * SPDX-License-Identifier: GPL-2.0-or-later */
 
#pragma once
 
#include "BLI_build_config.h"
#include "BLI_math_inline.h"
#include "BLI_utildefines.h"
 
#ifdef __cplusplus
extern "C" {
#endif
 
/* Search the value from LSB to MSB for a set bit. Returns index of this bit. */
 
MINLINE int bitscan_forward_i(int a);
MINLINE unsigned int bitscan_forward_uint(unsigned int a);
MINLINE unsigned int bitscan_forward_uint64(unsigned long long a);
 
/* Similar to above, but also clears the bit. */
 
MINLINE int bitscan_forward_clear_i(int *a);
MINLINE unsigned int bitscan_forward_clear_uint(unsigned int *a);
 
/* Search the value from MSB to LSB for a set bit. Returns index of this bit. */
 
MINLINE int bitscan_reverse_i(int a);
MINLINE unsigned int bitscan_reverse_uint(unsigned int a);
MINLINE unsigned int bitscan_reverse_uint64(unsigned long long a);
 
/* Similar to above, but also clears the bit. */
 
MINLINE int bitscan_reverse_clear_i(int *a);
MINLINE unsigned int bitscan_reverse_clear_uint(unsigned int *a);
 
/* NOTE: Those functions returns 2 to the power of index of highest order bit. */
 
MINLINE unsigned int highest_order_bit_uint(unsigned int n);
MINLINE unsigned short highest_order_bit_s(unsigned short n);
 
#if COMPILER_GCC || COMPILER_CLANG
#  define count_bits_i(i) __builtin_popcount(i)
#  define count_bits_uint64(i) __builtin_popcountll(i)
#elif COMPILER_MSVC
#  define count_bits_i(i) __popcnt(i)
#  define count_bits_uint64(i) __popcnt64(i)
#else
MINLINE int count_bits_i(unsigned int n);
MINLINE int count_bits_uint64(uint64_t a);
#endif
 
MINLINE int float_as_int(float f);
MINLINE unsigned int float_as_uint(float f);
MINLINE float int_as_float(int i);
MINLINE float uint_as_float(unsigned int i);
MINLINE float xor_fl(float x, int y);
 
#if BLI_MATH_DO_INLINE
#  include "intern/math_bits_inline.c"
#endif
 
#ifdef __cplusplus
}
#endif