arch/arc/lib/strcmp-archs.S

   1 /*
   2  * Copyright (C) 2014-15 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 <linux/linkage.h>
  10
  11 ENTRY_CFI(strcmp)
  12         or      r2, r0, r1
  13         bmsk_s  r2, r2, 1
  14         brne    r2, 0, @.Lcharloop
  15
  16 ;;; s1 and s2 are word aligned
  17         ld.ab   r2, [r0, 4]
  18
  19         mov_s   r12, 0x01010101
  20         ror     r11, r12
  21         .align  4
  22 .LwordLoop:
  23         ld.ab   r3, [r1, 4]
  24         ;; Detect NULL char in str1
  25         sub     r4, r2, r12
  26         ld.ab   r5, [r0, 4]
  27         bic     r4, r4, r2
  28         and     r4, r4, r11
  29         brne.d.nt       r4, 0, .LfoundNULL
  30         ;; Check if the read locations are the same
  31         cmp     r2, r3
  32         beq.d   .LwordLoop
  33         mov.eq  r2, r5
  34
  35         ;; A match is found, spot it out
  36 #ifdef __LITTLE_ENDIAN__
  37         swape   r3, r3
  38         mov_s   r0, 1
  39         swape   r2, r2
  40 #else
  41         mov_s   r0, 1
  42 #endif
  43         cmp_s   r2, r3
  44         j_s.d   [blink]
  45         bset.lo r0, r0, 31
  46
  47         .align 4
  48 .LfoundNULL:
  49 #ifdef __BIG_ENDIAN__
  50         swape   r4, r4
  51         swape   r2, r2
  52         swape   r3, r3
  53 #endif
  54         ;; Find null byte
  55         ffs     r0, r4
  56         bmsk    r2, r2, r0
  57         bmsk    r3, r3, r0
  58         swape   r2, r2
  59         swape   r3, r3
  60         ;; make the return value
  61         sub.f   r0, r2, r3
  62         mov.hi  r0, 1
  63         j_s.d   [blink]
  64         bset.lo r0, r0, 31
  65
  66         .align 4
  67 .Lcharloop:
  68         ldb.ab  r2, [r0, 1]
  69         ldb.ab  r3, [r1, 1]
  70         nop
  71         breq    r2, 0, .Lcmpend
  72         breq    r2, r3, .Lcharloop
  73
  74         .align 4
  75 .Lcmpend:
  76         j_s.d   [blink]
  77         sub     r0, r2, r3
  78 END_CFI(strcmp)