mirror of
https://github.com/brain-hackers/u-boot-brain
synced 2024-08-30 22:08:52 +09:00
![Masahiro Yamada](/assets/img/avatar_default.png)
Including <linux/compiler.h> is enough for general use. Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
133 lines
3.3 KiB
C
133 lines
3.3 KiB
C
/*
|
|
* Copyright (C) 1991,1992,1993,1997,1998,2003, 2005 Free Software Foundation, Inc.
|
|
* This file is part of the GNU C Library.
|
|
* Copyright (c) 2011 The Chromium OS Authors.
|
|
*
|
|
* SPDX-License-Identifier: GPL-2.0+
|
|
*/
|
|
|
|
/* From glibc-2.14, sysdeps/i386/memset.c */
|
|
|
|
#include <linux/types.h>
|
|
#include <linux/compiler.h>
|
|
#include <asm/string.h>
|
|
|
|
typedef uint32_t op_t;
|
|
|
|
void *memset(void *dstpp, int c, size_t len)
|
|
{
|
|
int d0;
|
|
unsigned long int dstp = (unsigned long int) dstpp;
|
|
|
|
/* This explicit register allocation improves code very much indeed. */
|
|
register op_t x asm("ax");
|
|
|
|
x = (unsigned char) c;
|
|
|
|
/* Clear the direction flag, so filling will move forward. */
|
|
asm volatile("cld");
|
|
|
|
/* This threshold value is optimal. */
|
|
if (len >= 12) {
|
|
/* Fill X with four copies of the char we want to fill with. */
|
|
x |= (x << 8);
|
|
x |= (x << 16);
|
|
|
|
/* Adjust LEN for the bytes handled in the first loop. */
|
|
len -= (-dstp) % sizeof(op_t);
|
|
|
|
/*
|
|
* There are at least some bytes to set. No need to test for
|
|
* LEN == 0 in this alignment loop.
|
|
*/
|
|
|
|
/* Fill bytes until DSTP is aligned on a longword boundary. */
|
|
asm volatile(
|
|
"rep\n"
|
|
"stosb" /* %0, %2, %3 */ :
|
|
"=D" (dstp), "=c" (d0) :
|
|
"0" (dstp), "1" ((-dstp) % sizeof(op_t)), "a" (x) :
|
|
"memory");
|
|
|
|
/* Fill longwords. */
|
|
asm volatile(
|
|
"rep\n"
|
|
"stosl" /* %0, %2, %3 */ :
|
|
"=D" (dstp), "=c" (d0) :
|
|
"0" (dstp), "1" (len / sizeof(op_t)), "a" (x) :
|
|
"memory");
|
|
len %= sizeof(op_t);
|
|
}
|
|
|
|
/* Write the last few bytes. */
|
|
asm volatile(
|
|
"rep\n"
|
|
"stosb" /* %0, %2, %3 */ :
|
|
"=D" (dstp), "=c" (d0) :
|
|
"0" (dstp), "1" (len), "a" (x) :
|
|
"memory");
|
|
|
|
return dstpp;
|
|
}
|
|
|
|
#define OP_T_THRES 8
|
|
#define OPSIZ (sizeof(op_t))
|
|
|
|
#define BYTE_COPY_FWD(dst_bp, src_bp, nbytes) \
|
|
do { \
|
|
int __d0; \
|
|
asm volatile( \
|
|
/* Clear the direction flag, so copying goes forward. */ \
|
|
"cld\n" \
|
|
/* Copy bytes. */ \
|
|
"rep\n" \
|
|
"movsb" : \
|
|
"=D" (dst_bp), "=S" (src_bp), "=c" (__d0) : \
|
|
"0" (dst_bp), "1" (src_bp), "2" (nbytes) : \
|
|
"memory"); \
|
|
} while (0)
|
|
|
|
#define WORD_COPY_FWD(dst_bp, src_bp, nbytes_left, nbytes) \
|
|
do { \
|
|
int __d0; \
|
|
asm volatile( \
|
|
/* Clear the direction flag, so copying goes forward. */ \
|
|
"cld\n" \
|
|
/* Copy longwords. */ \
|
|
"rep\n" \
|
|
"movsl" : \
|
|
"=D" (dst_bp), "=S" (src_bp), "=c" (__d0) : \
|
|
"0" (dst_bp), "1" (src_bp), "2" ((nbytes) / 4) : \
|
|
"memory"); \
|
|
(nbytes_left) = (nbytes) % 4; \
|
|
} while (0)
|
|
|
|
void *memcpy(void *dstpp, const void *srcpp, size_t len)
|
|
{
|
|
unsigned long int dstp = (long int)dstpp;
|
|
unsigned long int srcp = (long int)srcpp;
|
|
|
|
/* Copy from the beginning to the end. */
|
|
|
|
/* If there not too few bytes to copy, use word copy. */
|
|
if (len >= OP_T_THRES) {
|
|
/* Copy just a few bytes to make DSTP aligned. */
|
|
len -= (-dstp) % OPSIZ;
|
|
BYTE_COPY_FWD(dstp, srcp, (-dstp) % OPSIZ);
|
|
|
|
/* Copy from SRCP to DSTP taking advantage of the known
|
|
* alignment of DSTP. Number of bytes remaining is put
|
|
* in the third argument, i.e. in LEN. This number may
|
|
* vary from machine to machine.
|
|
*/
|
|
WORD_COPY_FWD(dstp, srcp, len, len);
|
|
|
|
/* Fall out and copy the tail. */
|
|
}
|
|
|
|
/* There are just a few bytes to copy. Use byte memory operations. */
|
|
BYTE_COPY_FWD(dstp, srcp, len);
|
|
|
|
return dstpp;
|
|
}
|