1/* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22/* 23 * Copyright 2008 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 .ident "%Z%%M% %I% %E% SMI" 28 29 .file "%M%" 30 31/* 32 * char *memset(sp, c, n) 33 * 34 * Set an array of n chars starting at sp to the character c. 35 * Return sp. 36 * 37 * Fast assembler language version of the following C-program for memset 38 * which represents the `standard' for the C-library. 39 * 40 * void * 41 * memset(void *sp1, int c, size_t n) 42 * { 43 * if (n != 0) { 44 * char *sp = sp1; 45 * do { 46 * *sp++ = (char)c; 47 * } while (--n != 0); 48 * } 49 * return (sp1); 50 * } 51 */ 52 53#include <sys/asm_linkage.h> 54 55 ANSI_PRAGMA_WEAK(memset,function) 56 57#include "synonyms.h" 58 59 ENTRY(memset) 60 mov %o0, %o5 ! copy sp before using it 61 cmp %o2, 7 ! if small counts, just write bytes 62 blu .wrchar 63 .empty ! following lable is ok in delay slot 64 65.walign:btst 3, %o5 ! if bigger, align to 4 bytes 66 bz .wrword 67 andn %o2, 3, %o3 ! create word sized count in %o3 68 dec %o2 ! decrement count 69 stb %o1, [%o5] ! clear a byte 70 b .walign 71 inc %o5 ! next byte 72 73.wrword:and %o1, 0xff, %o1 ! generate a word filled with c 74 sll %o1, 8, %o4 75 or %o1, %o4, %o1 76 sll %o1, 16, %o4 77 or %o1, %o4, %o1 781: st %o1, [%o5] ! word writing loop 79 subcc %o3, 4, %o3 80 bnz 1b 81 inc 4, %o5 82 83 and %o2, 3, %o2 ! leftover count, if any 84.wrchar:deccc %o2 ! byte clearing loop 85 inc %o5 86 bgeu,a .wrchar 87 stb %o1, [%o5 + -1] ! we've already incremented the address 88 89 retl 90 nop 91 92 SET_SIZE(memset) 93