mirror of
https://github.com/espressif/esp-idf.git
synced 2026-06-04 20:26:38 +03:00
ec68cb3300
This option replaces implementations of functions from ROM: - memcpy - memcmp - memmove - str[n]cpy - str[n]cmp The functions used in the firmware will be better optimized for misaligned memory. Here are some measurements in CPU cycles for 4096-byte buffers: memcpy: 28676 -> 4128 memcmp: 49147 -> 14259 memmove: 33896 -> 8086 strcpy: 32771 -> 17313 strcmp: 32775 -> 13191
89 lines
2.5 KiB
C
89 lines
2.5 KiB
C
/*
|
|
* SPDX-FileCopyrightText: 1994-2009 Red Hat, Inc.
|
|
*
|
|
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD AND Apache-2.0
|
|
*
|
|
* SPDX-FileContributor: 2025 Espressif Systems (Shanghai) CO LTD
|
|
*/
|
|
#include <string.h>
|
|
#include <_ansi.h>
|
|
#include <stddef.h>
|
|
#include <limits.h>
|
|
#include "local.h"
|
|
|
|
__attribute__((optimize("-Os")))
|
|
void *
|
|
__inhibit_loop_to_libcall
|
|
memmove(void *dst_void,
|
|
const void *src_void,
|
|
size_t length)
|
|
{
|
|
char *dst = dst_void;
|
|
const char *src = src_void;
|
|
long *aligned_dst;
|
|
const long *aligned_src;
|
|
|
|
if (src < dst && dst < src + length) {
|
|
/* Destructive overlap...have to copy backwards */
|
|
src += length;
|
|
dst += length;
|
|
|
|
if (!TOO_SMALL_LITTLE_BLOCK(length) && !UNALIGNED_X_Y(src, dst)) {
|
|
aligned_dst = (long*)dst;
|
|
aligned_src = (long*)src;
|
|
|
|
/* Copy one long word at a time if possible. */
|
|
while (!TOO_SMALL_LITTLE_BLOCK(length)) {
|
|
*--aligned_dst = *--aligned_src;
|
|
length -= LITTLE_BLOCK_SIZE;
|
|
}
|
|
|
|
/* Pick up any residual with a byte copier. */
|
|
dst = (char*)aligned_dst;
|
|
src = (char*)aligned_src;
|
|
}
|
|
|
|
while (length--) {
|
|
*--dst = *--src;
|
|
}
|
|
} else {
|
|
/* Use optimizing algorithm for a non-destructive copy to closely
|
|
match memcpy. If the size is small or either SRC or DST is unaligned,
|
|
then punt into the byte copy loop. This should be rare. */
|
|
if (!TOO_SMALL_LITTLE_BLOCK(length) && !UNALIGNED_X_Y(src, dst)) {
|
|
aligned_dst = (long*)dst;
|
|
aligned_src = (long*)src;
|
|
|
|
/* Copy 4X long words at a time if possible. */
|
|
while (!TOO_SMALL_BIG_BLOCK(length)) {
|
|
*aligned_dst++ = *aligned_src++;
|
|
*aligned_dst++ = *aligned_src++;
|
|
*aligned_dst++ = *aligned_src++;
|
|
*aligned_dst++ = *aligned_src++;
|
|
length -= BIG_BLOCK_SIZE;
|
|
}
|
|
|
|
/* Copy one long word at a time if possible. */
|
|
while (!TOO_SMALL_LITTLE_BLOCK(length)) {
|
|
*aligned_dst++ = *aligned_src++;
|
|
length -= LITTLE_BLOCK_SIZE;
|
|
}
|
|
|
|
/* Pick up any residual with a byte copier. */
|
|
dst = (char*)aligned_dst;
|
|
src = (char*)aligned_src;
|
|
}
|
|
|
|
while (length--) {
|
|
*dst++ = *src++;
|
|
}
|
|
}
|
|
|
|
return dst_void;
|
|
}
|
|
|
|
// Hook to force the linker to include this file
|
|
void esp_libc_include_memmove_impl(void)
|
|
{
|
|
}
|