Math extras

Extra arithmetic and bit manipulation functions. More...

Unsigned integer addition with overflow detection.
These functions compute a + b and store the result in *result, returning true if the operation overflowed.
static bool	u16_add_overflow (uint16_t a, uint16_t b, uint16_t *result)
	Add two unsigned 16-bit integers.
static bool	u32_add_overflow (uint32_t a, uint32_t b, uint32_t *result)
	Add two unsigned 32-bit integers.
static bool	u64_add_overflow (uint64_t a, uint64_t b, uint64_t *result)
	Add two unsigned 64-bit integers.
static bool	size_add_overflow (size_t a, size_t b, size_t *result)
	Add two size_t integers.

Unsigned integer multiplication with overflow detection.
These functions compute a * b and store the result in *result, returning true if the operation overflowed.
static bool	u16_mul_overflow (uint16_t a, uint16_t b, uint16_t *result)
	Multiply two unsigned 16-bit integers.
static bool	u32_mul_overflow (uint32_t a, uint32_t b, uint32_t *result)
	Multiply two unsigned 32-bit integers.
static bool	u64_mul_overflow (uint64_t a, uint64_t b, uint64_t *result)
	Multiply two unsigned 64-bit integers.
static bool	size_mul_overflow (size_t a, size_t b, size_t *result)
	Multiply two size_t integers.

Count leading zeros.
Count the number of leading zero bits in the bitwise representation of x. When x = 0, this is the size of x in bits.
static int	u32_count_leading_zeros (uint32_t x)
	Count the number of leading zero bits in a 32-bit integer.
static int	u64_count_leading_zeros (uint64_t x)
	Count the number of leading zero bits in a 64-bit integer.

Count trailing zeros.
Count the number of trailing zero bits in the bitwise representation of x. When x = 0, this is the size of x in bits.
static int	u32_count_trailing_zeros (uint32_t x)
	Count the number of trailing zero bits in a 32-bit integer.
static int	u64_count_trailing_zeros (uint64_t x)
	Count the number of trailing zero bits in a 64-bit integer.

Detailed Description

Extra arithmetic and bit manipulation functions.

Portable wrapper functions for a number of arithmetic and bit-counting functions that are often provided by compiler builtins. If the compiler does not have an appropriate builtin, a portable C implementation is used instead.

Function Documentation

size_add_overflow()

static bool size_add_overflow ( size_t a, size_t b, size_t * result )

static

#include <zephyr/sys/math_extras.h>

Add two size_t integers.

Parameters

a	First operand.
b	Second operand.
result	Pointer to the result.

Returns

true if the operation overflowed.

size_mul_overflow()

static bool size_mul_overflow ( size_t a, size_t b, size_t * result )

static

#include <zephyr/sys/math_extras.h>

Multiply two size_t integers.

Parameters

a	First operand.
b	Second operand.
result	Pointer to the result.

Returns

true if the operation overflowed.

u16_add_overflow()

static bool u16_add_overflow ( uint16_t a, uint16_t b, uint16_t * result )

static

#include <zephyr/sys/math_extras.h>

Add two unsigned 16-bit integers.

Parameters

a	First operand.
b	Second operand.
result	Pointer to the result.

Returns

true if the operation overflowed.

u16_mul_overflow()

static bool u16_mul_overflow ( uint16_t a, uint16_t b, uint16_t * result )

static

#include <zephyr/sys/math_extras.h>

Multiply two unsigned 16-bit integers.

Parameters

a	First operand.
b	Second operand.
result	Pointer to the result.

Returns

true if the operation overflowed.

u32_add_overflow()

static bool u32_add_overflow ( uint32_t a, uint32_t b, uint32_t * result )

static

#include <zephyr/sys/math_extras.h>

Add two unsigned 32-bit integers.

Parameters

a	First operand.
b	Second operand.
result	Pointer to the result.

Returns

true if the operation overflowed.

u32_count_leading_zeros()

static int u32_count_leading_zeros ( uint32_t x )

static

#include <zephyr/sys/math_extras.h>

Count the number of leading zero bits in a 32-bit integer.

Parameters

x	Integer to count leading zeros in.

Returns

Number of leading zero bits in x.

u32_count_trailing_zeros()

static int u32_count_trailing_zeros ( uint32_t x )

static

#include <zephyr/sys/math_extras.h>

Count the number of trailing zero bits in a 32-bit integer.

Parameters

x	Integer to count trailing zeros in.

Returns

Number of trailing zero bits in x.

u32_mul_overflow()

static bool u32_mul_overflow ( uint32_t a, uint32_t b, uint32_t * result )

static

#include <zephyr/sys/math_extras.h>

Multiply two unsigned 32-bit integers.

Parameters

a	First operand.
b	Second operand.
result	Pointer to the result.

Returns

true if the operation overflowed.

u64_add_overflow()

static bool u64_add_overflow ( uint64_t a, uint64_t b, uint64_t * result )

static

#include <zephyr/sys/math_extras.h>

Add two unsigned 64-bit integers.

Parameters

a	First operand.
b	Second operand.
result	Pointer to the result.

Returns

true if the operation overflowed.

u64_count_leading_zeros()

static int u64_count_leading_zeros ( uint64_t x )

static

#include <zephyr/sys/math_extras.h>

Count the number of leading zero bits in a 64-bit integer.

Parameters

x	Integer to count leading zeros in.

Returns

Number of leading zero bits in x.

u64_count_trailing_zeros()

static int u64_count_trailing_zeros ( uint64_t x )

static

#include <zephyr/sys/math_extras.h>

Count the number of trailing zero bits in a 64-bit integer.

Parameters

x	Integer to count trailing zeros in.

Returns

Number of trailing zero bits in x.

u64_mul_overflow()

static bool u64_mul_overflow ( uint64_t a, uint64_t b, uint64_t * result )

static

#include <zephyr/sys/math_extras.h>

Multiply two unsigned 64-bit integers.

Parameters

a	First operand.
b	Second operand.
result	Pointer to the result.

Returns

true if the operation overflowed.