mirror of
https://github.com/autc04/Retro68.git
synced 2024-11-19 03:05:15 +00:00
167 lines
4.4 KiB
ArmAsm
167 lines
4.4 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/strchr.c will be
|
|
used. */
|
|
#if !defined (__OPTIMIZE_SIZE__) && !defined (PREFER_SIZE_OVER_SPEED)
|
|
|
|
/* ARC700 has a relatively long pipeline and branch prediction, so we want
|
|
to avoid branches that are hard to predict. On the other hand, the
|
|
presence of the norm instruction makes it easier to operate on whole
|
|
words branch-free. */
|
|
#include "asm.h"
|
|
|
|
#if (defined (__ARC700__) || defined (__ARCEM__) || defined (__ARCHS__)) \
|
|
&& defined (__ARC_NORM__) && defined (__ARC_BARREL_SHIFTER__)
|
|
|
|
ENTRY (strchr)
|
|
extb_s r1,r1
|
|
asl r5,r1,8
|
|
bmsk r2,r0,1
|
|
or r5,r5,r1
|
|
mov_s r3,0x01010101
|
|
breq.d r2,r0,.Laligned
|
|
asl r4,r5,16
|
|
sub_s r0,r0,r2
|
|
asl r7,r2,3
|
|
ld_s r2,[r0]
|
|
#ifdef __LITTLE_ENDIAN__
|
|
asl r7,r3,r7
|
|
#else
|
|
lsr r7,r3,r7
|
|
#endif
|
|
or r5,r5,r4
|
|
ror r4,r3
|
|
sub r12,r2,r7
|
|
bic_s r12,r12,r2
|
|
and r12,r12,r4
|
|
brne.d r12,0,.Lfound0_ua
|
|
xor r6,r2,r5
|
|
ld.a r2,[r0,4]
|
|
sub r12,r6,r7
|
|
bic r12,r12,r6
|
|
#ifdef __LITTLE_ENDIAN__
|
|
and r7,r12,r4
|
|
breq r7,0,.Loop ; For speed, we want this branch to be unaligned.
|
|
b_l .Lfound_char ; Likewise this one.
|
|
#else
|
|
and r12,r12,r4
|
|
breq_l r12,0,.Loop ; For speed, we want this branch to be unaligned.
|
|
lsr_s r12,r12,7
|
|
bic r2,r7,r6
|
|
b.d .Lfound_char_b
|
|
and_s r2,r2,r12
|
|
#endif
|
|
; /* We require this code address to be unaligned for speed... */
|
|
.Laligned:
|
|
ld_s r2,[r0]
|
|
or r5,r5,r4
|
|
ror r4,r3
|
|
; /* ... so that this code address is aligned, for itself and ... */
|
|
.Loop:
|
|
sub r12,r2,r3
|
|
bic_s r12,r12,r2
|
|
and r12,r12,r4
|
|
brne.d r12,0,.Lfound0
|
|
xor r6,r2,r5
|
|
ld.a r2,[r0,4]
|
|
sub r12,r6,r3
|
|
bic r12,r12,r6
|
|
and r7,r12,r4
|
|
breq r7,0,.Loop /* ... so that this branch is unaligned. */
|
|
; Found searched-for character. r0 has already advanced to next word.
|
|
#ifdef __LITTLE_ENDIAN__
|
|
/* We only need the information about the first matching byte
|
|
(i.e. the least significant matching byte) to be exact,
|
|
hence there is no problem with carry effects. */
|
|
.Lfound_char:
|
|
sub r3,r7,1
|
|
bic r3,r3,r7
|
|
norm r2,r3
|
|
sub_s r0,r0,1
|
|
asr_s r2,r2,3
|
|
j_l.d [blink]
|
|
sub_s r0,r0,r2
|
|
|
|
.balign 4
|
|
.Lfound0_ua:
|
|
mov_l r3,r7
|
|
.Lfound0:
|
|
sub r3,r6,r3
|
|
bic r3,r3,r6
|
|
and r2,r3,r4
|
|
or_s r12,r12,r2
|
|
sub_s r3,r12,1
|
|
bic_s r3,r3,r12
|
|
norm r3,r3
|
|
add_s r0,r0,3
|
|
asr_s r12,r3,3
|
|
asl.f 0,r2,r3
|
|
sub_s r0,r0,r12
|
|
j_s.d [blink]
|
|
mov.pl r0,0
|
|
#else /* BIG ENDIAN */
|
|
.Lfound_char:
|
|
lsr r7,r7,7
|
|
|
|
bic r2,r7,r6
|
|
.Lfound_char_b:
|
|
norm r2,r2
|
|
sub_s r0,r0,4
|
|
asr_s r2,r2,3
|
|
j_l.d [blink]
|
|
add_s r0,r0,r2
|
|
|
|
.Lfound0_ua:
|
|
mov_s r3,r7
|
|
.Lfound0:
|
|
asl_s r2,r2,7
|
|
or r7,r6,r4
|
|
bic_s r12,r12,r2
|
|
sub r2,r7,r3
|
|
or r2,r2,r6
|
|
bic r12,r2,r12
|
|
bic.f r3,r4,r12
|
|
norm r3,r3
|
|
|
|
add.pl r3,r3,1
|
|
asr_s r12,r3,3
|
|
asl.f 0,r2,r3
|
|
add_s r0,r0,r12
|
|
j_s.d [blink]
|
|
mov.mi r0,0
|
|
#endif /* ENDIAN */
|
|
ENDFUNC (strchr)
|
|
#endif /* (__ARC700__ || __ARCEM__ || __ARCHS__) && __ARC_NORM__
|
|
&& __ARC_BARREL_SHIFTER__ */
|
|
|
|
#endif /* !__OPTIMIZE_SIZE__ && !PREFER_SIZE_OVER_SPEED */
|