mirror of
https://github.com/autc04/Retro68.git
synced 2024-11-30 19:53:46 +00:00
203 lines
5.1 KiB
ArmAsm
203 lines
5.1 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)
|
|
|
|
#include "asm.h"
|
|
|
|
/* In order to search for a zero in a W, we calculate
|
|
X := (W - 0x01010101) & ~W & 0x80808080;
|
|
In the little endian case:
|
|
If no byte in W is zero, X will be zero; otherwise, the least significant
|
|
byte of X which is nonzero indicates the least significant byte of W that
|
|
is zero.
|
|
In the big endian case:
|
|
X will be zero iff no byte in W is zero.
|
|
If X is nonzero, to find out which is the most significant zero byte
|
|
in W, we calculate:
|
|
Y := ~(((W | 0x80808080) - 0x01010101) | W) & 0x80808080;
|
|
Each byte in Y is 0x80 if the the corresponding byte in
|
|
W is zero, otherwise that byte of Y is 0. */
|
|
|
|
#if defined (__ARC_BARREL_SHIFTER__) && \
|
|
(defined (__ARC600__) || (!defined (__ARC_NORM__) && !defined (__ARC601__)))
|
|
|
|
ENTRY (strchr)
|
|
bmsk.f r2,r0,1
|
|
mov_s r3,0x01010101
|
|
extb_s r1,r1
|
|
asl r5,r1,8
|
|
or r5,r5,r1
|
|
beq.d .Laligned
|
|
asl r4,r5,16
|
|
sub_s r0,r0,r2
|
|
asl_s r2,r2,3
|
|
#ifdef __LITTLE_ENDIAN__
|
|
asl r7,r3,r2
|
|
#else
|
|
lsr r7,r3,r2
|
|
#endif
|
|
ld_s r2,[r0]
|
|
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.f r7,r12,r4
|
|
sub r12,r2,r3
|
|
bic_s r12,r12,r2
|
|
beq.d .Loop
|
|
and r12,r12,r4
|
|
b.d .Lfound_char_ua
|
|
btst r7,7
|
|
#else
|
|
and.f r8,r12,r4
|
|
sub r12,r2,r3
|
|
bic_s r12,r12,r2
|
|
beq.d .Loop
|
|
and r12,r12,r4
|
|
bic r12,r7,r6
|
|
asl_s r12,r12,7
|
|
and.f r2,r8,r12
|
|
b.d .Lfound_char_ua
|
|
sub_s r0,r0,4
|
|
#endif
|
|
|
|
.balign 4
|
|
.Laligned:
|
|
ld_s r2,[r0]
|
|
or r5,r5,r4
|
|
ror r4,r3
|
|
sub r12,r2,r3
|
|
bic_s r12,r12,r2
|
|
and r12,r12,r4
|
|
.Loop:
|
|
|
|
brne.d r12,0,.Lfound0
|
|
xor r6,r2,r5
|
|
ld.a r2,[r0,4]
|
|
sub r12,r6,r3
|
|
bic r12,r12,r6
|
|
and.f r7,r12,r4
|
|
sub r12,r2,r3
|
|
bic_s r12,r12,r2
|
|
beq.d .Loop
|
|
and r12,r12,r4
|
|
; 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:
|
|
btst r7,7
|
|
.Lfound_char_ua:
|
|
sub_s r0,r0,4
|
|
add.eq r0,r0,1
|
|
btst.eq r7,15
|
|
add.eq r0,r0,1
|
|
btst.eq r7,23
|
|
j_s.d [blink]
|
|
add.eq r0,r0,1
|
|
|
|
.balign 4
|
|
.Lfound0_ua:
|
|
mov_l r3,r7
|
|
.Lfound0:
|
|
sub r2,r6,r3
|
|
bic r2,r2,r6
|
|
and r2,r2,r4
|
|
or r3,r12,r2
|
|
sub_s r12,r3,1
|
|
xor_s r3,r3,r12
|
|
tst_s r2,r3
|
|
lsr r2,r3,31
|
|
lsr r12,r3,16
|
|
jeq.d [blink]
|
|
mov.eq r0,0
|
|
lsr r3,r3,8
|
|
sub_s r2,r2,r12
|
|
sub_s r2,r2,r3
|
|
bmsk_s r2,r2,1
|
|
j_s.d [blink]
|
|
add_s r0,r0,r2
|
|
#else /* BIG ENDIAN */
|
|
.Lfound_char:
|
|
asl r6,r6,7
|
|
sub_s r0,r0,4
|
|
bic.f r2,r7,r6
|
|
.Lfound_char_ua:
|
|
add.pl r0,r0,1
|
|
jmi.d [blink]
|
|
btst_s r2,23
|
|
add.eq r0,r0,1
|
|
btst.eq r2,15
|
|
j_s.d [blink]
|
|
add.eq r0,r0,1
|
|
|
|
; N.B. if we searched for a char zero and found it in the MSB,
|
|
; and ignored matches are identical, we will take the early exit
|
|
; like for an ordinary found zero - except for the extra stalls at jhi -
|
|
; but still compute the right result.
|
|
.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 r2,r4,r2
|
|
cmp r12,r2
|
|
mov.hi r0,0
|
|
btst.ls r2,31
|
|
jhi.d [blink]
|
|
add.eq r0,r0,1
|
|
btst.eq r2,23
|
|
add.eq r0,r0,1
|
|
btst.eq r2,15
|
|
j_s.d [blink]
|
|
add.eq r0,r0,1
|
|
#endif /* ENDIAN */
|
|
ENDFUNC (strchr)
|
|
#endif /* __ARC_BARREL_SHIFTER__ &&
|
|
(__ARC600__ || (!__ARC_NORM__ && !__ARC601__)) */
|
|
|
|
#endif /* !__OPTIMIZE_SIZE__ && !PREFER_SIZE_OVER_SPEED */
|