align.h File Reference

Align memory. More...

#include <assert.h>
#include <stdint.h>
#include <stdlib.h>
#include "is_pow2.h"

Go to the source code of this file.

Macros
#define	CALC_ALIGNMENT_PADDING(alignment, ptr)
	compile time calc_alignment_padding.

Functions
static void *	align (const size_t alignment, const size_t size, void **ptr_ptr, size_t *space_ptr)
	Align pointer to the next alignment boundary.
static uintptr_t	calc_alignment_padding (const size_t alignment, const uintptr_t ptr)
	Calculate the alignment padding required to align a pointer.

Detailed Description

Align memory.

This is a direct translation of the std::align implementation in libstdc++.

See:

• https://en.cppreference.com/w/cpp/memory/align

Macro Definition Documentation

CALC_ALIGNMENT_PADDING

#define CALC_ALIGNMENT_PADDING	(		alignment,
			ptr )

Value:

((((ptr) - 1u + (alignment)) & -(alignment)) - (ptr))

compile time calc_alignment_padding.

Function Documentation

align()

static void * align ( const size_t alignment, const size_t size, void ** ptr_ptr, size_t * space_ptr )

inlinestatic

Align pointer to the next alignment boundary.

Parameters

[in]	alignment	The desired alignment.
[in]	size	The size of the storage to be aligned.
[in,out]	ptr_ptr	Pointer to contiguous storage (a buffer) of at least space bytes. Given it's pointer.
[in,out]	space_ptr	The size of the buffer in which to operate. Given it's pointer.

Returns

The adjusted value of *ptr_ptr.

Return values

NULL	If the space provided is too small.

calc_alignment_padding()

static uintptr_t calc_alignment_padding ( const size_t alignment, const uintptr_t ptr )

inlinestatic

Calculate the alignment padding required to align a pointer.

Parameters

[in]	alignment	The desired alignment.
[in]	ptr	Pointer to a buffer as uintptr_t.

Returns

The padding to be added to ptr to align ptr.