ArmPkg/Library/BaseMemoryLibVstm/Arm/SetMem.asm

   1 ;------------------------------------------------------------------------------
   2 ;
   3 ; SetMem() worker for ARM
   4 ;
   5 ; This file started out as C code that did 64 bit moves if the buffer was
   6 ; 32-bit aligned, else it does a byte copy. It also does a byte copy for
   7 ; any trailing bytes. Update to use VSTM/VLDM to do 128 byte writes.
   8 ;
   9 ; Copyright (c) 2008 - 2010, Apple Inc. All rights reserved.<BR>
  10 ; This program and the accompanying materials
  11 ; are licensed and made available under the terms and conditions of the BSD License
  12 ; which accompanies this distribution.  The full text of the license may be found at
  13 ; http://opensource.org/licenses/bsd-license.php
  14 ;
  15 ; THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  16 ; WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  17 ;
  18
  19 /**
  20   Set Buffer to Value for Size bytes.
  21
  22   @param  Buffer   Memory to set.
  23   @param  Length   Number of bytes to set
  24   @param  Value    Value of the set operation.
  25
  26   @return Buffer
  27
  28 VOID *
  29 EFIAPI
  30 InternalMemSetMem (
  31   OUT     VOID                      *Buffer,
  32   IN      UINTN                     Length,
  33   IN      UINT8                     Value
  34   )
  35 **/
  36
  37         EXPORT InternalMemSetMem
  38
  39         AREA AsmMemStuff, CODE, READONLY
  40
  41 InternalMemSetMem
  42         stmfd   sp!, {lr}
  43         tst       r0, #3
  44         movne   r3, #0
  45         moveq   r3, #1
  46         cmp       r1, #127
  47         movls lr, #0
  48         andhi   lr, r3, #1
  49         cmp       lr, #0
  50         mov       r12, r0
  51         bne       L31
  52 L32
  53         mov       r3, #0
  54         b           L43
  55 L31
  56   vdup.8  q0,r2
  57   vmov    q1,q0
  58   vmov    q2,q0
  59   vmov    q3,q0
  60   vmov    q4,q0
  61   vmov    q5,q0
  62   vmov    q6,q0
  63   vmov    q7,q0
  64         b             L32
  65 L34
  66         cmp         lr, #0
  67         streqb  r2, [r12], #1
  68         subeq     r1, r1, #1
  69         beq         L43
  70         sub         r1, r1, #128
  71         cmp         r1, #127
  72         movls     lr, r3
  73         vstm    r12!, {d0-d15}
  74 L43
  75         cmp         r1, #0
  76         bne         L34
  77         ldmfd     sp!, {pc}
  78
  79   END
  80