arch/avr32/lib/io-readsw.S

   1 /*
   2  * Copyright (C) 2004-2006 Atmel Corporation
   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 .Lnot_word_aligned:
  10         /*
  11          * Bad alignment will cause a hardware exception, which is as
  12          * good as anything. No need for us to check for proper alignment.
  13          */
  14         ld.uh   r8, r12[0]
  15         sub     r10, 1
  16         st.h    r11++, r8
  17
  18         /* fall through */
  19
  20         .global __raw_readsw
  21         .type   __raw_readsw,@function
  22 __raw_readsw:
  23         cp.w    r10, 0
  24         reteq   r12
  25         mov     r9, 3
  26         tst     r11, r9
  27         brne    .Lnot_word_aligned
  28
  29         sub     r10, 2
  30         brlt    2f
  31
  32 1:      ldins.h r8:t, r12[0]
  33         ldins.h r8:b, r12[0]
  34         st.w    r11++, r8
  35         sub     r10, 2
  36         brge    1b
  37
  38 2:      sub     r10, -2
  39         reteq   r12
  40
  41         ld.uh   r8, r12[0]
  42         st.h    r11++, r8
  43         retal   r12