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 # 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 INTERWORK_FUNC(InternalMemSetMem)
  42
  43 ASM_PFX(InternalMemSetMem):
  44         stmfd   sp!, {r4-r7, lr}
  45         tst       r0, #3
  46         movne   r3, #0
  47         moveq   r3, #1
  48         cmp       r1, #127
  49         movls lr, #0
  50         andhi   lr, r3, #1
  51         cmp       lr, #0
  52         mov       r12, r0
  53         bne       L31
  54 L32:
  55         mov       r3, #0
  56         b           L43
  57 L31:
  58   vdup.8  q0,r2
  59   vmov    q1,q0
  60   vmov    q2,q0
  61   vmov    q3,q0
  62   vmov    q4,q0
  63   vmov    q5,q0
  64   vmov    q6,q0
  65   vmov    q7,q0
  66         b             L32
  67 L34:
  68         cmp         lr, #0
  69         streqb  r2, [r12], #1
  70         subeq     r1, r1, #1
  71         beq         L43
  72         sub         r1, r1, #128
  73         cmp         r1, #127
  74         cmp         r1, #31
  75         movls     lr, r3
  76         vstm    r12!, {d0-d15}
  77 L43:
  78         cmp         r1, #0
  79         bne         L34
  80         ldmfd     sp!, {pc}
  81