80 строки
1.5 KiB
C
80 строки
1.5 KiB
C
/*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file COPYING in the main directory of this archive
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* for more details.
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*/
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#include <linux/module.h>
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#include <linux/string.h>
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void *memcpy(void *to, const void *from, size_t n)
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{
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void *xto = to;
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size_t temp, temp1;
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if (!n)
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return xto;
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if ((long)to & 1) {
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char *cto = to;
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const char *cfrom = from;
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*cto++ = *cfrom++;
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to = cto;
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from = cfrom;
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n--;
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}
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if (n > 2 && (long)to & 2) {
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short *sto = to;
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const short *sfrom = from;
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*sto++ = *sfrom++;
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to = sto;
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from = sfrom;
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n -= 2;
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}
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temp = n >> 2;
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if (temp) {
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long *lto = to;
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const long *lfrom = from;
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#if defined(CONFIG_M68000) || defined(CONFIG_COLDFIRE)
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for (; temp; temp--)
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*lto++ = *lfrom++;
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#else
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asm volatile (
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" movel %2,%3\n"
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" andw #7,%3\n"
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" lsrl #3,%2\n"
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" negw %3\n"
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" jmp %%pc@(1f,%3:w:2)\n"
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"4: movel %0@+,%1@+\n"
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" movel %0@+,%1@+\n"
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" movel %0@+,%1@+\n"
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" movel %0@+,%1@+\n"
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" movel %0@+,%1@+\n"
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" movel %0@+,%1@+\n"
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" movel %0@+,%1@+\n"
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" movel %0@+,%1@+\n"
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"1: dbra %2,4b\n"
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" clrw %2\n"
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" subql #1,%2\n"
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" jpl 4b"
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: "=a" (lfrom), "=a" (lto), "=d" (temp), "=&d" (temp1)
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: "0" (lfrom), "1" (lto), "2" (temp));
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#endif
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to = lto;
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from = lfrom;
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}
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if (n & 2) {
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short *sto = to;
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const short *sfrom = from;
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*sto++ = *sfrom++;
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to = sto;
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from = sfrom;
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}
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if (n & 1) {
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char *cto = to;
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const char *cfrom = from;
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*cto = *cfrom;
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}
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return xto;
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}
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EXPORT_SYMBOL(memcpy);
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