arch/arc/lib/strlen.S

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
   4  */
   5
   6 #include <linux/linkage.h>
   7
   8 ENTRY_CFI(strlen)
   9         or      r3,r0,7
  10         ld      r2,[r3,-7]
  11         ld.a    r6,[r3,-3]
  12         mov     r4,0x01010101
  13         ; uses long immediate
  14 #ifdef __LITTLE_ENDIAN__
  15         asl_s   r1,r0,3
  16         btst_s  r0,2
  17         asl     r7,r4,r1
  18         ror     r5,r4
  19         sub     r1,r2,r7
  20         bic_s   r1,r1,r2
  21         mov.eq  r7,r4
  22         sub     r12,r6,r7
  23         bic     r12,r12,r6
  24         or.eq   r12,r12,r1
  25         and     r12,r12,r5
  26         brne    r12,0,.Learly_end
  27 #else /* BIG ENDIAN */
  28         ror     r5,r4
  29         btst_s  r0,2
  30         mov_s   r1,31
  31         sub3    r7,r1,r0
  32         sub     r1,r2,r4
  33         bic_s   r1,r1,r2
  34         bmsk    r1,r1,r7
  35         sub     r12,r6,r4
  36         bic     r12,r12,r6
  37         bmsk.ne r12,r12,r7
  38         or.eq   r12,r12,r1
  39         and     r12,r12,r5
  40         brne    r12,0,.Learly_end
  41 #endif /* ENDIAN */
  42
  43 .Loop:
  44         ld_s    r2,[r3,4]
  45         ld.a    r6,[r3,8]
  46         ; stall for load result
  47         sub     r1,r2,r4
  48         bic_s   r1,r1,r2
  49         sub     r12,r6,r4
  50         bic     r12,r12,r6
  51         or      r12,r12,r1
  52         and     r12,r12,r5
  53         breq r12,0,.Loop
  54 .Lend:
  55         and.f   r1,r1,r5
  56         sub.ne  r3,r3,4
  57         mov.eq  r1,r12
  58 #ifdef __LITTLE_ENDIAN__
  59         sub_s   r2,r1,1
  60         bic_s   r2,r2,r1
  61         norm    r1,r2
  62         sub_s   r0,r0,3
  63         lsr_s   r1,r1,3
  64         sub         r0,r3,r0
  65         j_s.d   [blink]
  66         sub         r0,r0,r1
  67 #else /* BIG ENDIAN */
  68         lsr_s   r1,r1,7
  69         mov.eq  r2,r6
  70         bic_s   r1,r1,r2
  71         norm    r1,r1
  72         sub         r0,r3,r0
  73         lsr_s   r1,r1,3
  74         j_s.d   [blink]
  75         add         r0,r0,r1
  76 #endif /* ENDIAN */
  77 .Learly_end:
  78         b.d     .Lend
  79         sub_s.ne r1,r1,r1
  80 END_CFI(strlen)