bzero.S revision 1.1.16.2
1 /* $NetBSD: bzero.S,v 1.1.16.2 2020/04/21 19:37:43 martin Exp $ */ 2 3 /*- 4 * Copyright (c) 2000 Doug Rabson 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 * 28 * __FBSDID("$FreeBSD: releng/10.1/lib/libc/ia64/string/bzero.S 125669 2004-02-10 20:45:28Z cperciva $"); 29 */ 30 31 #include <machine/asm.h> 32 33 /* 34 * void 35 * bzero(void *b, size_t len); 36 */ 37 ENTRY(bzero, 2) 38 39 cmp.le p6,p0=in1,r0 // bail if len <= 0 40 (p6) br.ret.spnt.few rp 41 ;; 42 mov r14=ar.lc // save ar.lc 43 44 cmp.ltu p6,p0=17,in1 // check for small 45 (p6) br.dptk.few 3f 46 47 1: add r15=-1,in1 ;; 48 mov ar.lc=r15 ;; 49 2: st1 [in0]=r0,1 // zero one byte 50 br.cloop.sptk.few 2b // loop 51 52 ;; 53 mov ar.lc=r14 // done 54 br.ret.sptk.few rp 55 56 // Zero up to 8byte alignment 57 58 3: tbit.nz p6,p0=in0,0 ;; 59 (p6) st1 [in0]=r0,1 60 (p6) add in1=-1,in1 ;; 61 62 tbit.nz p6,p0=in0,1 ;; 63 (p6) st2 [in0]=r0,2 64 (p6) add in1=-2,in1 ;; 65 66 tbit.nz p6,p0=in0,2 ;; 67 (p6) st4 [in0]=r0,4 68 (p6) add in1=-4,in1 69 70 ;; 71 shr.u r15=in1,3 // word count 72 extr.u in1=in1,0,3 ;; // trailing bytes 73 cmp.eq p6,p0=r15,r0 // check for zero 74 cmp.ne p7,p0=in1,r0 75 (p6) br.dpnt.few 1b // zero last bytes 76 77 add r15=-1,r15 ;; 78 mov ar.lc=r15 ;; 79 4: st8 [in0]=r0,8 80 br.cloop.sptk.few 4b 81 82 (p7) br.dpnt.few 1b // zero last bytes 83 84 ;; 85 mov ar.lc=r14 // done 86 br.ret.sptk.few rp 87 88 END(bzero) 89
Indexes created Tue Sep 23 14:10:03 GMT 2025