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https://github.com/edk2-porting/linux-next.git
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29507663df
Our internal process shares memcpy, memset, etc., with libc, and we did some minor tweaking as part of moving from uclibc to glibc, which is now reflected in the kernel versions of these files. There are no semantic changes in this commit, just whitespace (memcpy_32.S now properly uses tabs), naming (memmove.c instead of memmove_32.c, since TILE-Gx shares the file with TILEPro), and a couple of other minor tweaks. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
64 lines
1.4 KiB
C
64 lines
1.4 KiB
C
/*
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* Copyright 2010 Tilera Corporation. All Rights Reserved.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation, version 2.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
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* NON INFRINGEMENT. See the GNU General Public License for
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* more details.
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*/
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#include <linux/types.h>
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#include <linux/string.h>
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#include <linux/module.h>
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void *memmove(void *dest, const void *src, size_t n)
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{
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if ((const char *)src >= (char *)dest + n
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|| (char *)dest >= (const char *)src + n) {
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/* We found no overlap, so let memcpy do all the heavy
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* lifting (prefetching, etc.)
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*/
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return memcpy(dest, src, n);
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}
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if (n != 0) {
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const uint8_t *in;
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uint8_t x;
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uint8_t *out;
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int stride;
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if (src < dest) {
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/* copy backwards */
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in = (const uint8_t *)src + n - 1;
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out = (uint8_t *)dest + n - 1;
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stride = -1;
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} else {
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/* copy forwards */
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in = (const uint8_t *)src;
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out = (uint8_t *)dest;
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stride = 1;
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}
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/* Manually software-pipeline this loop. */
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x = *in;
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in += stride;
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while (--n != 0) {
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*out = x;
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out += stride;
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x = *in;
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in += stride;
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}
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*out = x;
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}
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return dest;
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}
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EXPORT_SYMBOL(memmove);
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