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/* $OpenBSD: memcpy.S,v 1.6 2015/08/31 02:53:56 guenther Exp $ */
/* $NetBSD: bcopy.S,v 1.3 1996/10/17 03:08:11 cgd Exp $ */
/*
* Copyright (c) 1995 Carnegie-Mellon University.
* All rights reserved.
*
* Author: Trevor Blackwell. Support for use as memcpy() and memmove()
* added by Chris Demetriou.
*
* Permission to use, copy, modify and distribute this software and
* its documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
* FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie the
* rights to redistribute these changes.
*/
#include "SYS.h"
#define SRCREG a1
#define DSTREG a0
#define SIZEREG a2
/*
* Copy bytes.
*
* char *memcpy(void *to, const void *from, size_t len);
*
* No matter how invoked, the source and destination registers
* for calculation. There's no point in copying them to "working"
* registers, since the code uses their values "in place," and
* copying them would be slower.
*/
LEAF(memcpy,3)
/* set up return value, while we still can */
mov DSTREG,v0
/* Check for zero length */
beq SIZEREG,bcopy_done
/* a3 = end address */
addq SRCREG,SIZEREG,a3
/* Get the first word */
ldq_u t2,0(SRCREG)
/* Do they have the same alignment? */
xor SRCREG,DSTREG,t0
and t0,7,t0
and DSTREG,7,t1
bne t0,bcopy_different_alignment
/* src & dst have same alignment */
beq t1,bcopy_all_aligned
ldq_u t3,0(DSTREG)
addq SIZEREG,t1,SIZEREG
mskqh t2,SRCREG,t2
mskql t3,SRCREG,t3
or t2,t3,t2
/* Dst is 8-byte aligned */
bcopy_all_aligned:
/* If less than 8 bytes,skip loop */
subq SIZEREG,1,t0
and SIZEREG,7,SIZEREG
bic t0,7,t0
beq t0,bcopy_samealign_lp_end
bcopy_samealign_lp:
stq_u t2,0(DSTREG)
addq DSTREG,8,DSTREG
ldq_u t2,8(SRCREG)
subq t0,8,t0
addq SRCREG,8,SRCREG
bne t0,bcopy_samealign_lp
bcopy_samealign_lp_end:
/* If we're done, exit */
bne SIZEREG,bcopy_small_left
stq_u t2,0(DSTREG)
RET
bcopy_small_left:
mskql t2,SIZEREG,t4
ldq_u t3,0(DSTREG)
mskqh t3,SIZEREG,t3
or t4,t3,t4
stq_u t4,0(DSTREG)
RET
bcopy_different_alignment:
/*
* this is the fun part
*/
addq SRCREG,SIZEREG,a3
cmpule SIZEREG,8,t0
bne t0,bcopy_da_finish
beq t1,bcopy_da_noentry
/* Do the initial partial word */
subq zero,DSTREG,t0
and t0,7,t0
ldq_u t3,7(SRCREG)
extql t2,SRCREG,t2
extqh t3,SRCREG,t3
or t2,t3,t5
insql t5,DSTREG,t5
ldq_u t6,0(DSTREG)
mskql t6,DSTREG,t6
or t5,t6,t5
stq_u t5,0(DSTREG)
addq SRCREG,t0,SRCREG
addq DSTREG,t0,DSTREG
subq SIZEREG,t0,SIZEREG
ldq_u t2,0(SRCREG)
bcopy_da_noentry:
subq SIZEREG,1,t0
bic t0,7,t0
and SIZEREG,7,SIZEREG
beq t0,bcopy_da_finish2
bcopy_da_lp:
ldq_u t3,7(SRCREG)
addq SRCREG,8,SRCREG
extql t2,SRCREG,t4
extqh t3,SRCREG,t5
subq t0,8,t0
or t4,t5,t5
stq t5,0(DSTREG)
addq DSTREG,8,DSTREG
beq t0,bcopy_da_finish1
ldq_u t2,7(SRCREG)
addq SRCREG,8,SRCREG
extql t3,SRCREG,t4
extqh t2,SRCREG,t5
subq t0,8,t0
or t4,t5,t5
stq t5,0(DSTREG)
addq DSTREG,8,DSTREG
bne t0,bcopy_da_lp
bcopy_da_finish2:
/* Do the last new word */
mov t2,t3
bcopy_da_finish1:
/* Do the last partial word */
ldq_u t2,-1(a3)
extql t3,SRCREG,t3
extqh t2,SRCREG,t2
or t2,t3,t2
br zero,bcopy_samealign_lp_end
bcopy_da_finish:
/* Do the last word in the next source word */
ldq_u t3,-1(a3)
extql t2,SRCREG,t2
extqh t3,SRCREG,t3
or t2,t3,t2
insqh t2,DSTREG,t3
insql t2,DSTREG,t2
lda t4,-1(zero)
mskql t4,SIZEREG,t5
cmovne t5,t5,t4
insqh t4,DSTREG,t5
insql t4,DSTREG,t4
addq DSTREG,SIZEREG,a4
ldq_u t6,0(DSTREG)
ldq_u t7,-1(a4)
bic t6,t4,t6
bic t7,t5,t7
and t2,t4,t2
and t3,t5,t3
or t2,t6,t2
or t3,t7,t3
stq_u t3,-1(a4)
stq_u t2,0(DSTREG)
bcopy_done:
RET
END_STRONG(memcpy)
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