mirror of https://gitee.com/openkylin/linux.git
82 lines
1.9 KiB
C
82 lines
1.9 KiB
C
/*
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* Copyright (C) 2002 Mark Debbage (Mark.Debbage@superh.com)
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*
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* May be copied or modified under the terms of the GNU General Public
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* License. See linux/COPYING for more information.
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*
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*/
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#include <linux/types.h>
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#include <asm/string.h>
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// This is a simplistic optimization of memcpy to increase the
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// granularity of access beyond one byte using aligned
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// loads and stores. This is not an optimal implementation
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// for SH-5 (especially with regard to prefetching and the cache),
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// and a better version should be provided later ...
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void *memcpy(void *dest, const void *src, size_t count)
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{
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char *d = (char *) dest, *s = (char *) src;
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if (count >= 32) {
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int i = 8 - (((unsigned long) d) & 0x7);
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if (i != 8)
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while (i-- && count--) {
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*d++ = *s++;
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}
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if (((((unsigned long) d) & 0x7) == 0) &&
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((((unsigned long) s) & 0x7) == 0)) {
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while (count >= 32) {
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unsigned long long t1, t2, t3, t4;
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t1 = *(unsigned long long *) (s);
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t2 = *(unsigned long long *) (s + 8);
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t3 = *(unsigned long long *) (s + 16);
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t4 = *(unsigned long long *) (s + 24);
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*(unsigned long long *) (d) = t1;
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*(unsigned long long *) (d + 8) = t2;
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*(unsigned long long *) (d + 16) = t3;
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*(unsigned long long *) (d + 24) = t4;
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d += 32;
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s += 32;
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count -= 32;
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}
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while (count >= 8) {
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*(unsigned long long *) d =
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*(unsigned long long *) s;
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d += 8;
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s += 8;
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count -= 8;
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}
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}
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if (((((unsigned long) d) & 0x3) == 0) &&
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((((unsigned long) s) & 0x3) == 0)) {
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while (count >= 4) {
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*(unsigned long *) d = *(unsigned long *) s;
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d += 4;
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s += 4;
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count -= 4;
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}
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}
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if (((((unsigned long) d) & 0x1) == 0) &&
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((((unsigned long) s) & 0x1) == 0)) {
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while (count >= 2) {
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*(unsigned short *) d = *(unsigned short *) s;
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d += 2;
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s += 2;
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count -= 2;
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}
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}
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}
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while (count--) {
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*d++ = *s++;
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}
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return d;
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}
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