Retro68/gcc/newlib/libc/machine/i960/memset.S
Wolfgang Thaller ec13cc9ce7 fix newlib
2018-12-29 09:59:36 +01:00

122 lines
3.9 KiB
ArmAsm

/*******************************************************************************
*
* Copyright (c) 1993 Intel Corporation
*
* Intel hereby grants you permission to copy, modify, and distribute this
* software and its documentation. Intel grants this permission provided
* that the above copyright notice appears in all copies and that both the
* copyright notice and this permission notice appear in supporting
* documentation. In addition, Intel grants this permission provided that
* you prominently mark as "not part of the original" any modifications
* made to this software or documentation, and that the name of Intel
* Corporation not be used in advertising or publicity pertaining to
* distribution of the software or the documentation without specific,
* written prior permission.
*
* Intel Corporation provides this AS IS, WITHOUT ANY WARRANTY, EXPRESS OR
* IMPLIED, INCLUDING, WITHOUT LIMITATION, ANY WARRANTY OF MERCHANTABILITY
* OR FITNESS FOR A PARTICULAR PURPOSE. Intel makes no guarantee or
* representations regarding the use of, or the results of the use of,
* the software and documentation in terms of correctness, accuracy,
* reliability, currentness, or otherwise; and you rely on the software,
* documentation and results solely at your own risk.
*
* IN NO EVENT SHALL INTEL BE LIABLE FOR ANY LOSS OF USE, LOSS OF BUSINESS,
* LOSS OF PROFITS, INDIRECT, INCIDENTAL, SPECIAL OR CONSEQUENTIAL DAMAGES
* OF ANY KIND. IN NO EVENT SHALL INTEL'S TOTAL LIABILITY EXCEED THE SUM
* PAID TO INTEL FOR THE PRODUCT LICENSED HEREUNDER.
*
******************************************************************************/
.file "memset.s"
#ifdef __PIC
.pic
#endif
#ifdef __PID
.pid
#endif
/*
* (c) copyright 1989,1993 Intel Corp., all rights reserved
*/
/*
procedure memset (optimized assembler version: 80960K series, 80960CA)
dest_addr = memset (dest_addr, char, len)
Fill len bytes pointed to by dest_addr with the value of char.
Return the original address of dest_addr.
This program avoids performing unaligned accesses. It stores
from zero to seven bytes, and then stores aligned longwords,
and then stores from zero to seven bytes, as necessary to
store len bytes starting at dest_addr.
At the time of this writing, only g0 thru g7 and g13 are available
for use in this leafproc; other registers would have to be saved and
restored. These nine registers, plus tricky use of g14 are sufficient
to implement the routine.
*/
.globl _memset
.globl __memset
.leafproc _memset, __memset
.align 2
_memset:
#ifndef __PIC
lda Lrett,g14
#else
lda Lrett-(.+8)(ip),g14
#endif
__memset:
cmpo 7,g2 # are there fewer than seven characters to move?
lda (g14),g13 # save return address
notand g0,7,g3 # test for non-aligned dest_ptr
lda 0,g14 # conform to register conventions
shlo 24,g1,g4 # prepare word of char
lda (g0),g6 # preserve dest_ptr for return
shro 8,g4,g5
bge.f Lcloop_setup
cmpo g3,g0 # is dest longword aligned
lda 7(g3),g3 # bump dest_ptr to next longword boundary
or g4,g5,g4
be.t Lwloop_setup
Lbgn_cloop:
cmpo g6,g3 # Have we reached longword boundary?
stob g1,(g6) # store one byte of char
subo 1,g2,g2 # decrement len
lda 1(g6),g6 # increment dest_ptr
bne.t Lbgn_cloop # loop if more bytes to store before longword
cmpobge.f 7,g2,Lcloop
Lwloop_setup:
shro 16,g4,g5
or g4,g5,g4
mov g4,g5 # now have a longword of char
Lwloop:
cmpo 15,g2 # Do we have to store more longwords?
stl g4,(g6) # Store longword of char
subo 8,g2,g2 # Decrement len
lda 8(g6),g6 # Increment dest_ptr
bl.t Lwloop # loop if more longwords to store
Lcloop_setup:
cmpobge.t 0,g2,Lexit
Lcloop:
cmpo 1,g2 # Is len exhausted?
stob g1,(g6) # Store byte
subo 1,g2,g2 # Decrement len
lda 1(g6),g6 # Increment dest_ptr
bne.t Lcloop # loop if more bytes to store
Lexit:
bx (g13)
Lrett:
ret
/* end of memset */