/* $NetBSD: bcopy.S,v 1.1 2016/08/05 15:06:02 scole Exp $ */ /*- * Copyright (c) 2000 Doug Rabson * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * __FBSDID("$FreeBSD: releng/10.1/lib/libc/ia64/string/bcopy.S 125669 2004-02-10 20:45:28Z cperciva $"); */ #include <machine/asm.h> /* * void * bcopy(const void *src, void *dst, size_t len); */ /* * Not the fastest bcopy in the world. */ ENTRY(bcopy, 3) cmp.le p6,p0=in2,r0 // bail if len <= 0 (p6) br.ret.spnt.few rp sub r14=in1,in0 ;; // check for overlap cmp.ltu p6,p0=r14,in2 // dst-src < len (p6) br.cond.spnt.few 5f extr.u r14=in0,0,3 // src & 7 extr.u r15=in1,0,3 ;; // dst & 7 cmp.eq p6,p0=r14,r15 // different alignment? (p6) br.cond.spnt.few 2f // branch if same alignment 1: ld1 r14=[in0],1 ;; // copy bytewise st1 [in1]=r14,1 add in2=-1,in2 ;; // len-- cmp.ne p6,p0=r0,in2 (p6) br.cond.dptk.few 1b // loop br.ret.sptk.few rp // done 2: cmp.eq p6,p0=r14,r0 // aligned? (p6) br.cond.sptk.few 4f 3: ld1 r14=[in0],1 ;; // copy bytewise st1 [in1]=r14,1 extr.u r15=in0,0,3 // src & 7 add in2=-1,in2 ;; // len-- cmp.eq p6,p0=r0,in2 // done? cmp.eq p7,p0=r0,r15 ;; // aligned now? (p6) br.ret.spnt.few rp // return if done (p7) br.cond.spnt.few 4f // go to main copy br.cond.sptk.few 3b // more bytes to copy // At this point, in2 is non-zero 4: mov r14=8 ;; cmp.ltu p6,p0=in2,r14 ;; // len < 8? (p6) br.cond.spnt.few 1b // byte copy the end ld8 r15=[in0],8 ;; // copy word st8 [in1]=r15,8 add in2=-8,in2 ;; // len -= 8 cmp.ne p6,p0=r0,in2 // done? (p6) br.cond.spnt.few 4b // again br.ret.sptk.few rp // return // Don't bother optimising overlap case 5: add in0=in0,in2 add in1=in1,in2 ;; add in0=-1,in0 add in1=-1,in1 ;; 6: ld1 r14=[in0],-1 ;; st1 [in1]=r14,-1 add in2=-1,in2 ;; cmp.ne p6,p0=r0,in2 (p6) br.cond.spnt.few 6b br.ret.sptk.few rp END(bcopy) |