ArmPkg/Library/BaseMemoryLibVstm/Arm/SetMem.S

   1 #------------------------------------------------------------------------------
   2 #
   3 # SemMem() 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 # All rights reserved. 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 /**
  21   Set Buffer to Value for Size bytes.
  22
  23   @param  Buffer   Memory to set.
  24   @param  Length   Number of bytes to set
  25   @param  Value    Value of the set operation.
  26
  27   @return Buffer
  28
  29 VOID *
  30 EFIAPI
  31 InternalMemSetMem (
  32   OUT     VOID                      *Buffer,
  33   IN      UINTN                     Length,
  34   IN      UINT8                     Value
  35   )
  36 **/
  37
  38 .text
  39 .align 2
  40 .globl ASM_PFX(InternalMemSetMem)
  41
  42 ASM_PFX(InternalMemSetMem):
  43         stmfd   sp!, {r4-r7, lr}
  44         tst       r0, #3
  45         movne   r3, #0
  46         moveq   r3, #1
  47         cmp       r1, #127
  48         movls lr, #0
  49         andhi   lr, r3, #1
  50         cmp       lr, #0
  51         mov       r12, r0
  52         bne       L31
  53 L32:
  54         mov       r3, #0
  55         b           L43
  56 L31:
  57   vdup.8  q0,r2
  58   vmov    q1,q0
  59   vmov    q2,q0
  60   vmov    q3,q0
  61   vmov    q4,q0
  62   vmov    q5,q0
  63   vmov    q6,q0
  64   vmov    q7,q0
  65         b             L32
  66 L34:
  67         cmp         lr, #0
  68         streqb  r2, [r12], #1
  69         subeq     r1, r1, #1
  70         beq         L43
  71         sub         r1, r1, #128
  72         cmp         r1, #127
  73         cmp         r1, #31
  74         movls     lr, r3
  75         vstm    r12!, {d0-d15}
  76 L43:
  77         cmp         r1, #0
  78         bne         L34
  79         ldmfd     sp!, {pc}
  80