arch/arc/lib/strlen.S

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