memset.c (1323B)
1/* 2 * This file is subject to the terms and conditions of the GNU General Public 3 * License. See the file COPYING in the main directory of this archive 4 * for more details. 5 */ 6 7#include <linux/module.h> 8#include <linux/string.h> 9 10void *memset(void *s, int c, size_t count) 11{ 12 void *xs = s; 13 size_t temp; 14 15 if (!count) 16 return xs; 17 c &= 0xff; 18 c |= c << 8; 19 c |= c << 16; 20 if ((long)s & 1) { 21 char *cs = s; 22 *cs++ = c; 23 s = cs; 24 count--; 25 } 26 if (count > 2 && (long)s & 2) { 27 short *ss = s; 28 *ss++ = c; 29 s = ss; 30 count -= 2; 31 } 32 temp = count >> 2; 33 if (temp) { 34 long *ls = s; 35#if defined(CONFIG_M68000) || defined(CONFIG_COLDFIRE) 36 for (; temp; temp--) 37 *ls++ = c; 38#else 39 size_t temp1; 40 asm volatile ( 41 " movel %1,%2\n" 42 " andw #7,%2\n" 43 " lsrl #3,%1\n" 44 " negw %2\n" 45 " jmp %%pc@(2f,%2:w:2)\n" 46 "1: movel %3,%0@+\n" 47 " movel %3,%0@+\n" 48 " movel %3,%0@+\n" 49 " movel %3,%0@+\n" 50 " movel %3,%0@+\n" 51 " movel %3,%0@+\n" 52 " movel %3,%0@+\n" 53 " movel %3,%0@+\n" 54 "2: dbra %1,1b\n" 55 " clrw %1\n" 56 " subql #1,%1\n" 57 " jpl 1b" 58 : "=a" (ls), "=d" (temp), "=&d" (temp1) 59 : "d" (c), "0" (ls), "1" (temp)); 60#endif 61 s = ls; 62 } 63 if (count & 2) { 64 short *ss = s; 65 *ss++ = c; 66 s = ss; 67 } 68 if (count & 1) { 69 char *cs = s; 70 *cs = c; 71 } 72 return xs; 73} 74EXPORT_SYMBOL(memset);