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
  38     INCLUDE AsmMacroExport.inc
  39
  40  RVCT_ASM_EXPORT InternalMemSetMem
  41   stmfd  sp!, {lr}
  42   tst    r0, #3
  43   movne  r3, #0
  44   moveq  r3, #1
  45   cmp    r1, #127
  46   movls lr, #0
  47   andhi  lr, r3, #1
  48   cmp    lr, #0
  49   mov    r12, r0
  50   bne    L31
  51 L32
  52   mov    r3, #0
  53   b      L43
  54 L31
  55   vdup.8  q0,r2
  56   vmov    q1,q0
  57   vmov    q2,q0
  58   vmov    q3,q0
  59   vmov    q4,q0
  60   vmov    q5,q0
  61   vmov    q6,q0
  62   vmov    q7,q0
  63   b        L32
  64 L34
  65   cmp      lr, #0
  66   streqb  r2, [r12], #1
  67   subeq    r1, r1, #1
  68   beq      L43
  69   sub      r1, r1, #128
  70   cmp      r1, #127
  71   movls    lr, r3
  72   vstm    r12!, {d0-d15}
  73 L43
  74   cmp      r1, #0
  75   bne      L34
  76   ldmfd    sp!, {pc}
  77
  78   END