newlib-cygwin/newlib/libc/machine/arc/memset.S

111 lines
3.3 KiB
ArmAsm

/*
Copyright (c) 2015, Synopsys, Inc. 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) Neither the name of the Synopsys, Inc., 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 COPYRIGHT HOLDERS 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 COPYRIGHT HOLDER 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.
*/
/* This implementation is optimized for performance. For code size a generic
implementation of this function from newlib/libc/string/memset.c will be
used. */
#if !defined (__OPTIMIZE_SIZE__) && !defined (PREFER_SIZE_OVER_SPEED)
#include "asm.h"
#if defined (__ARC601__) \
|| (!defined (__ARC_BARREL_SHIFTER__) && !defined (__ARCHS__))
/* To deal with alignment/loop issues, SMALL must be at least 2. */
#define SMALL 8 /* Even faster if aligned. */
.global __strncpy_bzero
.hidden __strncpy_bzero
/* __strncpy_bzero provides the following interface to strncpy:
r0: return value
r2: zeroing length
r3: zeroing start address
No attempt is made here for __strncpy_memset to speed up aligned
cases, because the copying of a string presumably leaves start address
and length alignment for the zeroing randomly distributed. */
ENTRY (memset)
brls.d r2,SMALL,.Ltiny
mov_s r3,r0
or r12,r0,r2
bmsk.f r12,r12,1
breq_s r1,0,.Lbzero
mov r4,0
stb.a r1,[sp,-4]
stb r1,[sp,1]
stb r1,[sp,2]
stb r1,[sp,3]
ld.ab r1,[sp,4]
.Lbzero:
beq.d .Laligned
.Lbzero2:
add r6,r2,r3
.Lnot_tiny:
stb r1,[r6,-1]
bclr r12,r6,0
stw r1,[r12,-2]
stb.ab r1,[r3,1]
bclr_s r3,r3,0
stw.ab r1,[r3,2]
bclr_s r3,r3,1
.Laligned: ; This code address should be aligned for speed.
sub r6,r6,8
brlo.d r6,r3,.Loop_end
sub r6,r6,8
3:
st_l r1,[r3,4]
brhs.d r6,r3,3b
st.ab r1,[r3,8]
.Loop_end:
bic r12,r6,3
j_s.d [blink]
st_s r1,[r12,12]
.balign 4
__strncpy_bzero:
brhi.d r2,8,.Lbzero2
mov_s r1,0
.Ltiny:
sub_s r2,r2,11
sub1 r12,pcl,r2
j_s [r12]
stb_s r1,[r3,7]
stb_s r1,[r3,6]
stb_s r1,[r3,5]
stb_s r1,[r3,4]
stb_s r1,[r3,3]
stb_s r1,[r3,2]
stb_s r1,[r3,1]
stb_s r1,[r3]
j_s [blink]
ENDFUNC (memset)
#endif /* __ARC601__ || (!__ARC_BARREL_SHIFTER__ && !__ARCHS__) */
#endif /* !__OPTIMIZE_SIZE__ && !PREFER_SIZE_OVER_SPEED */