aml/aml_memset.c

/*
 * Copyright (c) 2021-2022 Amlogic, Inc. All rights reserved.
 *
 * SPDX-License-Identifier: MIT
 */

#include "aml_memset.h"

void *memset(void *dest, int c, size_t len)
{
	char *d = (char *)dest;
	uint32_t cccc;
	uint32_t *dw;
	char *head;
	char *const tail = (char *)dest + len;
	/* Set 'body' to the last word boundary */
	uint32_t *const body = (uint32_t *)((uintptr_t)tail & ~3);

	c &= 0xff; /* Clear upper bits before ORing below */
	cccc = c | (c << 8) | (c << 16) | (c << 24);

	if ((uintptr_t)tail < (((uintptr_t)d + 3) & ~3))
		/* len is shorter than the first word boundary */
		head = tail;
	else
		/* Set 'head' to the first word boundary */
		head = (char *)(((uintptr_t)d + 3) & ~3);

	/* Copy head */
	while (d < head)
		*(d++) = c;

	/* Copy body */
	dw = (uint32_t *)d;
	while (dw < body)
		*(dw++) = cccc;

	/* Copy tail */
	d = (char *)dw;
	while (d < tail)
		*(d++) = c;

	return dest;
}