freebsd-skq/lib/libc/ia64/string/bcopy.S
2000-10-14 17:01:12 +00:00

97 lines
2.9 KiB
ArmAsm

/*-
* 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.
*
* $FreeBSD$
*/
#include <machine/asm.h>
/*
* 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)