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/*
* Copyright (C) 2011 Tobias Klauser <tklauser@distanz.ch>
* Copyright (C) 2004 Microtronix Datacom Ltd
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#include <linux/types.h>
#include <linux/string.h>
#ifdef __HAVE_ARCH_MEMSET
void *memset(void *s, int c, size_t count)
{
int destptr, charcnt, dwordcnt, fill8reg, wrkrega;
if (!count)
return s;
c &= 0xFF;
if (count <= 8) {
char *xs = (char *) s;
while (count--)
*xs++ = c;
return s;
}
__asm__ __volatile__ (
/* fill8 %3, %5 (c & 0xff) */
" slli %4, %5, 8\n"
" or %4, %4, %5\n"
" slli %3, %4, 16\n"
" or %3, %3, %4\n"
/* Word-align %0 (s) if necessary */
" andi %4, %0, 0x01\n"
" beq %4, zero, 1f\n"
" addi %1, %1, -1\n"
" stb %3, 0(%0)\n"
" addi %0, %0, 1\n"
"1: mov %2, %1\n"
/* Dword-align %0 (s) if necessary */
" andi %4, %0, 0x02\n"
" beq %4, zero, 2f\n"
" addi %1, %1, -2\n"
" sth %3, 0(%0)\n"
" addi %0, %0, 2\n"
" mov %2, %1\n"
/* %1 and %2 are how many more bytes to set */
"2: srli %2, %2, 2\n"
/* %2 is how many dwords to set */
"3: stw %3, 0(%0)\n"
" addi %0, %0, 4\n"
" addi %2, %2, -1\n"
" bne %2, zero, 3b\n"
/* store residual word and/or byte if necessary */
" andi %4, %1, 0x02\n"
" beq %4, zero, 4f\n"
" sth %3, 0(%0)\n"
" addi %0, %0, 2\n"
/* store residual byte if necessary */
"4: andi %4, %1, 0x01\n"
" beq %4, zero, 5f\n"
" stb %3, 0(%0)\n"
"5:\n"
: "=r" (destptr), /* %0 Output */
"=r" (charcnt), /* %1 Output */
"=r" (dwordcnt), /* %2 Output */
"=r" (fill8reg), /* %3 Output */
"=r" (wrkrega) /* %4 Output */
: "r" (c), /* %5 Input */
"0" (s), /* %0 Input/Output */
"1" (count) /* %1 Input/Output */
: "memory" /* clobbered */
);
return s;
}
#endif /* __HAVE_ARCH_MEMSET */
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