ArmPkg/Library/CompilerIntrinsicsLib/Arm/memmove.asm

   1 //------------------------------------------------------------------------------
   2 //
   3 // Copyright (c) 2011-2014, ARM Limited. All rights reserved.
   4 //
   5 // This program and the accompanying materials
   6 // are licensed and made available under the terms and conditions of the BSD License
   7 // which accompanies this distribution.  The full text of the license may be found at
   8 // http://opensource.org/licenses/bsd-license.php
   9 //
  10 // THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  11 // WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  12 //
  13 //------------------------------------------------------------------------------
  14
  15
  16
  17     INCLUDE AsmMacroExport.inc
  18
  19 ;
  20 ;VOID
  21 ;EFIAPI
  22 ;__aeabi_memmove (
  23 ; IN  VOID          *Destination,
  24 ; IN  CONST VOID    *Source,
  25 ; IN  UINT32        Size
  26 ; );
  27 ;
  28  RVCT_ASM_EXPORT __aeabi_memmove
  29   CMP     r2, #0
  30   BXEQ    lr
  31   CMP     r0, r1
  32   BXEQ    lr
  33   BHI     memmove_backward
  34
  35 memmove_forward
  36   LDRB    r3, [r1], #1
  37   STRB    r3, [r0], #1
  38   SUBS    r2, r2, #1
  39   BNE     memmove_forward
  40   BX      lr
  41
  42 memmove_backward
  43   add     r0, r2
  44   add     r1, r2
  45 memmove_backward_loop
  46   LDRB    r3, [r1, #-1]!
  47   STRB    r3, [r0, #-1]!
  48   SUBS    r2, r2, #1
  49   BNE     memmove_backward_loop
  50   BX      lr
  51
  52   END