minix/lib/nbsd_libc/arch/sparc64/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

196 lines
5.4 KiB
ArmAsm

/* $NetBSD: memset.S,v 1.4 2001/08/02 01:17:28 eeh Exp $ */
/*
* Copyright (c) 2001, Eduardo E. Horvath
*
* This software was developed by the Computer Systems Engineering group
* at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
* contributed to Berkeley.
*
* 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 the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
*
* from: Header: bzero.s,v 1.1 92/06/25 12:52:46 torek Exp
*/
#include <machine/asm.h>
#ifndef _LOCORE
#define _LOCORE
#endif
#include <machine/ctlreg.h>
#include <machine/frame.h>
#include <machine/psl.h>
#if defined(LIBC_SCCS) && !defined(lint)
RCSID("$NetBSD: memset.S,v 1.4 2001/08/02 01:17:28 eeh Exp $")
#endif /* LIBC_SCCS and not lint */
/*
* bzero(addr, len)
*
* We want to use VIS instructions if we're clearing out more than
* 256 bytes, but to do that we need to properly save and restore the
* FP registers. Unfortunately the code to do that in the kernel needs
* to keep track of the current owner of the FPU, hence the different
* code.
*
* XXXXX To produce more efficient code, we do not allow lengths
* greater than 0x80000000000000000, which are negative numbers.
* This should not really be an issue since the VA hole should
* cause any such ranges to fail anyway.
*/
ENTRY(bzero)
! %o0 = addr, %o1 = len
mov %o1, %o2
clr %o1 ! Initialize our pattern
/*
* memset(addr, c, len)
*
*/
ENTRY(memset)
! %o0 = addr, %o1 = pattern, %o2 = len
mov %o0, %o4 ! Save original pointer
Lbzero_internal:
btst 7, %o0 ! Word aligned?
bz,pn %xcc, 0f
nop
inc %o0
deccc %o2 ! Store up to 7 bytes
bge,a,pt %xcc, Lbzero_internal
stb %o1, [%o0 - 1]
retl ! Duplicate Lbzero_done
mov %o4, %o0
0:
/*
* Duplicate the pattern so it fills 64-bits.
*/
andcc %o1, 0x0ff, %o1 ! No need to extend zero
bz,pt %icc, 1f
sllx %o1, 8, %o3 ! sigh. all dependent insns.
or %o1, %o3, %o1
sllx %o1, 16, %o3
or %o1, %o3, %o1
sllx %o1, 32, %o3
or %o1, %o3, %o1
1:
#if 1
!! Now we are 64-bit aligned
cmp %o2, 256 ! Use block clear if len > 256
bge,pt %xcc, Lbzero_block ! use block store insns
#endif
deccc 8, %o2
Lbzero_longs:
bl,pn %xcc, Lbzero_cleanup ! Less than 8 bytes left
nop
3:
inc 8, %o0
deccc 8, %o2
bge,pt %xcc, 3b
stx %o1, [%o0 - 8] ! Do 1 longword at a time
/*
* Len is in [-8..-1] where -8 => done, -7 => 1 byte to zero,
* -6 => two bytes, etc. Mop up this remainder, if any.
*/
Lbzero_cleanup:
btst 4, %o2
bz,pt %xcc, 5f ! if (len & 4) {
nop
stw %o1, [%o0] ! *(int *)addr = 0;
inc 4, %o0 ! addr += 4;
5:
btst 2, %o2
bz,pt %xcc, 7f ! if (len & 2) {
nop
sth %o1, [%o0] ! *(short *)addr = 0;
inc 2, %o0 ! addr += 2;
7:
btst 1, %o2
bnz,a %icc, Lbzero_done ! if (len & 1)
stb %o1, [%o0] ! *addr = 0;
Lbzero_done:
retl
mov %o4, %o0 ! Restore ponter for memset (ugh)
#if 1
Lbzero_block:
/*
* Userland:
*
* Floating point registers are volatile. What luck.
*
* See locore.s for the kernel version.
*
*/
! wr %g0, FPRS_FEF, %fprs ! Enable FPU
!! We are now 8-byte aligned. We need to become 64-byte aligned.
btst 63, %o0
bz,pt %xcc, 2f
nop
1:
stx %o1, [%o0]
inc 8, %o0
btst 63, %o0
bnz,pt %xcc, 1b
dec 8, %o2
2:
brz %o1, 3f ! Skip the memory op
fzero %f0 ! for bzero
stx %o1, [%o0] ! Flush this puppy to RAM
membar #StoreLoad
ldd [%o0], %f0
3:
fmovd %f0, %f2 ! Duplicate the pattern
fmovd %f0, %f4
fmovd %f0, %f6
fmovd %f0, %f8
fmovd %f0, %f10
fmovd %f0, %f12
fmovd %f0, %f14
!! Remember: we were 8 bytes too far
dec 56, %o2 ! Go one iteration too far
5:
stda %f0, [%o0] ASI_BLK_P ! Store 64 bytes
deccc 64, %o2
bg,pn %xcc, 5b
inc 64, %o0
membar #Sync
/*
* Now we're done we need to load the FPU state from where
* we put it.
*/
ba,pt %xcc, Lbzero_longs ! Finish up the remainder
inccc 56, %o2 ! Restore the count
#endif