MdePkg/Library/BaseMemoryLibMmx/X64/CopyMem.S

   1 #
   2 # ConvertAsm.py: Automatically generated from CopyMem.asm
   3 #
   4 #------------------------------------------------------------------------------
   5 #
   6 # Copyright (c) 2006 - 2008, Intel Corporation
   7 # All rights reserved. This program and the accompanying materials
   8 # are licensed and made available under the terms and conditions of the BSD License
   9 # which accompanies this distribution.  The full text of the license may be found at
  10 # http://opensource.org/licenses/bsd-license.php
  11 #
  12 # THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  13 # WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  14 #
  15 # Module Name:
  16 #
  17 #   CopyMem.S
  18 #
  19 # Abstract:
  20 #
  21 #   CopyMem function
  22 #
  23 # Notes:
  24 #
  25 #------------------------------------------------------------------------------
  26
  27
  28 #------------------------------------------------------------------------------
  29 #  VOID *
  30 #  EFIAPI
  31 #  InternalMemCopyMem (
  32 #    IN VOID   *Destination,
  33 #    IN VOID   *Source,
  34 #    IN UINTN  Count
  35 #    )
  36 #------------------------------------------------------------------------------
  37 .intel_syntax noprefix
  38 .globl ASM_PFX(InternalMemCopyMem)
  39 ASM_PFX(InternalMemCopyMem):
  40     push    rsi
  41     push    rdi
  42     mov     rsi, rdx                    # rsi <- Source
  43     mov     rdi, rcx                    # rdi <- Destination
  44     lea     r9, [rsi + r8 - 1]          # r9 <- End of Source
  45     cmp     rsi, rdi
  46     mov     rax, rdi                    # rax <- Destination as return value
  47     jae     L0
  48     cmp     r9, rdi
  49     jae     L_CopyBackward              # Copy backward if overlapped
  50 L0:
  51     mov     rcx, r8
  52     and     r8, 7
  53     shr     rcx, 3                      # rcx <- # of Qwords to copy
  54     jz      L_CopyBytes
  55     movd    r10, mm0                    # (Save mm0 in r10)
  56 L1:
  57     movq    mm0, [rsi]
  58     movntq  [rdi], mm0
  59     add     rsi, 8
  60     add     rdi, 8
  61     loop    L1
  62     mfence
  63     movd    mm0, r10                    # (Restore mm0)
  64     jmp     L_CopyBytes
  65 L_CopyBackward:
  66     mov     rsi, r9                     # rsi <- End of Source
  67     lea     rdi, [rdi + r8 - 1]         # rdi <- End of Destination
  68     std                                 # set direction flag
  69 L_CopyBytes:
  70     mov     rcx, r8
  71     rep     movsb                       # Copy bytes backward
  72     cld
  73     pop     rdi
  74     pop     rsi
  75     ret