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| /*
| * Copyright (C) 2004, 2007-2010, 2011-2014 Synopsys, Inc. All rights reserved.
| *
| * SPDX-License-Identifier: GPL-2.0+
| */
|
| /*
| * 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.
| */
|
| .global strchr
| .align 4
| 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 /* __BIG_ENDIAN__ */
| lsr %r7, %r3, %r7
| #endif /* _ENDIAN__ */
| 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
| /* For speed, we want this branch to be unaligned. */
| breq %r7, 0, .Loop
| /* Likewise this one */
| b .Lfound_char
| #else /* __BIG_ENDIAN__ */
| and %r12, %r12, %r4
| /* For speed, we want this branch to be unaligned. */
| breq %r12, 0, .Loop
| lsr_s %r12, %r12, 7
| bic %r2, %r7, %r6
| b.d .Lfound_char_b
| and_s %r2, %r2, %r12
| #endif /* _ENDIAN__ */
| /* 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.d [%blink]
| sub_s %r0, %r0, %r2
|
| .balign 4
| .Lfound0_ua:
| mov %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.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__ */
|
|
