minix/common/lib/libc/arch/arm/string/memset.S
Gianluca Guida b6cbf7203b Import unmodified NetBSD libc in trunk
This patch imports the unmodified current version of NetBSD libc.
The NetBSD includes are in /nbsd_include, while the libc code itself is 
split between lib/nbsd_libc and common/lib/libc.
2011-02-14 19:36:03 +00:00

235 lines
7.3 KiB
ArmAsm

/* $NetBSD: memset.S,v 1.1 2005/12/20 19:28:49 christos Exp $ */
/*
* Copyright 2003 Wasabi Systems, Inc.
* All rights reserved.
*
* Written by Steve C. Woodford for Wasabi Systems, Inc.
*
* 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed for the NetBSD Project by
* Wasabi Systems, Inc.
* 4. The name of Wasabi Systems, Inc. may not be used to endorse
* or promote products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``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 WASABI SYSTEMS, INC
* 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.
*/
/*
* Copyright (c) 1995 Mark Brinicombe.
* 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Mark Brinicombe.
* 4. The name of the company nor the name of the author may be used to
* endorse or promote products derived from this software without specific
* prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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.
*/
#include <machine/asm.h>
/*
* memset: Sets a block of memory to the specified value
*
* On entry:
* r0 - dest address
* r1 - byte to write
* r2 - number of bytes to write
*
* On exit:
* r0 - dest address
*/
#ifdef _BZERO
/* LINTSTUB: Func: void bzero(void *, size_t) */
ENTRY(bzero)
mov r3, #0x00
#else
/* LINTSTUB: Func: void *memset(void *, int, size_t) */
ENTRY(memset)
and r3, r1, #0xff /* We deal with bytes */
mov r1, r2
#endif
cmp r1, #0x04 /* Do we have less than 4 bytes */
mov ip, r0
blt .Lmemset_lessthanfour
/* Ok first we will word align the address */
ands r2, ip, #0x03 /* Get the bottom two bits */
bne .Lmemset_wordunaligned /* The address is not word aligned */
/* We are now word aligned */
.Lmemset_wordaligned:
#ifndef _BZERO
orr r3, r3, r3, lsl #8 /* Extend value to 16-bits */
#endif
#ifdef __XSCALE__
tst ip, #0x04 /* Quad-align for Xscale */
#else
cmp r1, #0x10
#endif
#ifndef _BZERO
orr r3, r3, r3, lsl #16 /* Extend value to 32-bits */
#endif
#ifdef __XSCALE__
subne r1, r1, #0x04 /* Quad-align if necessary */
strne r3, [ip], #0x04
cmp r1, #0x10
#endif
blt .Lmemset_loop4 /* If less than 16 then use words */
mov r2, r3 /* Duplicate data */
cmp r1, #0x80 /* If < 128 then skip the big loop */
blt .Lmemset_loop32
/* Do 128 bytes at a time */
.Lmemset_loop128:
subs r1, r1, #0x80
#ifdef __XSCALE__
strged r2, [ip], #0x08
strged r2, [ip], #0x08
strged r2, [ip], #0x08
strged r2, [ip], #0x08
strged r2, [ip], #0x08
strged r2, [ip], #0x08
strged r2, [ip], #0x08
strged r2, [ip], #0x08
strged r2, [ip], #0x08
strged r2, [ip], #0x08
strged r2, [ip], #0x08
strged r2, [ip], #0x08
strged r2, [ip], #0x08
strged r2, [ip], #0x08
strged r2, [ip], #0x08
strged r2, [ip], #0x08
#else
stmgeia ip!, {r2-r3}
stmgeia ip!, {r2-r3}
stmgeia ip!, {r2-r3}
stmgeia ip!, {r2-r3}
stmgeia ip!, {r2-r3}
stmgeia ip!, {r2-r3}
stmgeia ip!, {r2-r3}
stmgeia ip!, {r2-r3}
stmgeia ip!, {r2-r3}
stmgeia ip!, {r2-r3}
stmgeia ip!, {r2-r3}
stmgeia ip!, {r2-r3}
stmgeia ip!, {r2-r3}
stmgeia ip!, {r2-r3}
stmgeia ip!, {r2-r3}
stmgeia ip!, {r2-r3}
#endif
bgt .Lmemset_loop128
RETc(eq) /* Zero length so just exit */
add r1, r1, #0x80 /* Adjust for extra sub */
/* Do 32 bytes at a time */
.Lmemset_loop32:
subs r1, r1, #0x20
#ifdef __XSCALE__
strged r2, [ip], #0x08
strged r2, [ip], #0x08
strged r2, [ip], #0x08
strged r2, [ip], #0x08
#else
stmgeia ip!, {r2-r3}
stmgeia ip!, {r2-r3}
stmgeia ip!, {r2-r3}
stmgeia ip!, {r2-r3}
#endif
bgt .Lmemset_loop32
RETc(eq) /* Zero length so just exit */
adds r1, r1, #0x10 /* Partially adjust for extra sub */
/* Deal with 16 bytes or more */
#ifdef __XSCALE__
strged r2, [ip], #0x08
strged r2, [ip], #0x08
#else
stmgeia ip!, {r2-r3}
stmgeia ip!, {r2-r3}
#endif
RETc(eq) /* Zero length so just exit */
addlt r1, r1, #0x10 /* Possibly adjust for extra sub */
/* We have at least 4 bytes so copy as words */
.Lmemset_loop4:
subs r1, r1, #0x04
strge r3, [ip], #0x04
bgt .Lmemset_loop4
RETc(eq) /* Zero length so just exit */
#ifdef __XSCALE__
/* Compensate for 64-bit alignment check */
adds r1, r1, #0x04
RETc(eq)
cmp r1, #2
#else
cmp r1, #-2
#endif
strb r3, [ip], #0x01 /* Set 1 byte */
strgeb r3, [ip], #0x01 /* Set another byte */
strgtb r3, [ip] /* and a third */
RET /* Exit */
.Lmemset_wordunaligned:
rsb r2, r2, #0x004
strb r3, [ip], #0x01 /* Set 1 byte */
cmp r2, #0x02
strgeb r3, [ip], #0x01 /* Set another byte */
sub r1, r1, r2
strgtb r3, [ip], #0x01 /* and a third */
cmp r1, #0x04 /* More than 4 bytes left? */
bge .Lmemset_wordaligned /* Yup */
.Lmemset_lessthanfour:
cmp r1, #0x00
RETc(eq) /* Zero length so exit */
strb r3, [ip], #0x01 /* Set 1 byte */
cmp r1, #0x02
strgeb r3, [ip], #0x01 /* Set another byte */
strgtb r3, [ip] /* and a third */
RET /* Exit */