diff options
Diffstat (limited to 'arch/arc/lib/strchr-700.S')
| -rw-r--r-- | arch/arc/lib/strchr-700.S | 141 |
1 files changed, 141 insertions, 0 deletions
diff --git a/arch/arc/lib/strchr-700.S b/arch/arc/lib/strchr-700.S new file mode 100644 index 0000000..55fcc9f --- /dev/null +++ b/arch/arc/lib/strchr-700.S @@ -0,0 +1,141 @@ +/* + * 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__ */ |