arch/sparc64/lib/strlen_user.S

   1 /* strlen_user.S: Sparc64 optimized strlen_user code
   2  *
   3  * Return length of string in userspace including terminating 0
   4  * or 0 for error
   5  *
   6  * Copyright (C) 1991,1996 Free Software Foundation
   7  * Copyright (C) 1996,1999 David S. Miller (davem@redhat.com)
   8  * Copyright (C) 1996,1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
   9  */
  10
  11 #include <asm/asi.h>
  12
  13 #define LO_MAGIC 0x01010101
  14 #define HI_MAGIC 0x80808080
  15
  16         .align 4
  17         .global __strlen_user, __strnlen_user
  18 __strlen_user:
  19         sethi   %hi(32768), %o1
  20 __strnlen_user:
  21         mov     %o1, %g1
  22         mov     %o0, %o1
  23         andcc   %o0, 3, %g0
  24         be,pt   %icc, 9f
  25          sethi  %hi(HI_MAGIC), %o4
  26 10:     lduba   [%o0] %asi, %o5
  27         brz,pn  %o5, 21f
  28          add    %o0, 1, %o0
  29         andcc   %o0, 3, %g0
  30         be,pn   %icc, 4f
  31          or     %o4, %lo(HI_MAGIC), %o3
  32 11:     lduba   [%o0] %asi, %o5
  33         brz,pn  %o5, 22f
  34          add    %o0, 1, %o0
  35         andcc   %o0, 3, %g0
  36         be,pt   %icc, 13f
  37          srl    %o3, 7, %o2
  38 12:     lduba   [%o0] %asi, %o5
  39         brz,pn  %o5, 23f
  40          add    %o0, 1, %o0
  41         ba,pt   %icc, 2f
  42 15:      lda    [%o0] %asi, %o5
  43 9:      or      %o4, %lo(HI_MAGIC), %o3
  44 4:      srl     %o3, 7, %o2
  45 13:     lda     [%o0] %asi, %o5
  46 2:      sub     %o5, %o2, %o4
  47         andcc   %o4, %o3, %g0
  48         bne,pn  %icc, 82f
  49          add    %o0, 4, %o0
  50         sub     %o0, %o1, %g2
  51 81:     cmp     %g2, %g1
  52         blu,pt  %icc, 13b
  53          mov    %o0, %o4
  54         ba,a,pt %xcc, 1f
  55
  56         /* Check every byte. */
  57 82:     srl     %o5, 24, %g7
  58         andcc   %g7, 0xff, %g0
  59         be,pn   %icc, 1f
  60          add    %o0, -3, %o4
  61         srl     %o5, 16, %g7
  62         andcc   %g7, 0xff, %g0
  63         be,pn   %icc, 1f
  64          add    %o4, 1, %o4
  65         srl     %o5, 8, %g7
  66         andcc   %g7, 0xff, %g0
  67         be,pn   %icc, 1f
  68          add    %o4, 1, %o4
  69         andcc   %o5, 0xff, %g0
  70         bne,pt  %icc, 81b
  71          sub    %o0, %o1, %g2
  72         add     %o4, 1, %o4
  73 1:      retl
  74          sub    %o4, %o1, %o0
  75 21:     retl
  76          mov    1, %o0
  77 22:     retl
  78          mov    2, %o0
  79 23:     retl
  80          mov    3, %o0
  81
  82         .section .fixup,#alloc,#execinstr
  83         .align  4
  84 30:
  85         retl
  86          clr    %o0
  87
  88         .section __ex_table,#alloc
  89         .align  4
  90
  91         .word   10b, 30b
  92         .word   11b, 30b
  93         .word   12b, 30b
  94         .word   15b, 30b
  95         .word   13b, 30b