MdePkg/Library/BaseMemoryLibOptDxe/X64/CopyMem.S

   1 #
   2 # ConvertAsm.py: Automatically generated from CopyMem.asm
   3 #
   4 #------------------------------------------------------------------------------
   5 #
   6 # Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>
   7 # 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 #  VOID *
  29 #  EFIAPI
  30 #  InternalMemCopyMem (
  31 #    IN VOID   *Destination,
  32 #    IN VOID   *Source,
  33 #    IN UINTN  Count
  34 #    )
  35 #------------------------------------------------------------------------------
  36 ASM_GLOBAL ASM_PFX(InternalMemCopyMem)
  37 ASM_PFX(InternalMemCopyMem):
  38     pushq   %rsi
  39     pushq   %rdi
  40     movq    %rdx, %rsi                  # rsi <- Source
  41     movq    %rcx, %rdi                  # rdi <- Destination
  42     leaq    -1(%rsi,%r8,), %r9          # r9 <- Last byte of Source
  43     cmpq    %rdi, %rsi
  44     movq    %rdi, %rax                  # rax <- Destination as return value
  45     jae     L0                          # Copy forward if Source > Destination
  46     cmpq    %rdi, %r9                   # Overlapped?
  47     jae     L_CopyBackward              # Copy backward if overlapped
  48 L0:
  49     xorq    %rcx, %rcx
  50     subq    %rdi, %rcx                  # rcx <- -rdi
  51     andq    $15, %rcx                   # rcx + rsi should be 16 bytes aligned
  52     jz      L1                          # skip if rcx == 0
  53     cmpq    %r8, %rcx
  54     cmova   %r8, %rcx
  55     subq    %rcx, %r8
  56     rep     movsb
  57 L1:
  58     movq    %r8,  %rcx
  59     andq    $15, %r8
  60     shrq    $4, %rcx                    # rcx <- # of DQwords to copy
  61     jz      L_CopyBytes
  62     movdqu  %xmm0, 0x18(%rsp)           # save xmm0 on stack
  63 L2:
  64     movdqu  (%rsi), %xmm0               # rsi may not be 16-byte aligned
  65     movntdq %xmm0, (%rdi)               # rdi should be 16-byte aligned
  66     addq    $16, %rsi
  67     addq    $16, %rdi
  68     loop    L2
  69     mfence
  70     movdqa  0x18(%rsp), %xmm0            # restore xmm0
  71     jmp     L_CopyBytes                  # copy remaining bytes
  72 L_CopyBackward:
  73     movq    %r9, %rsi                   # rsi <- Last byte of Source
  74     leaq     -1(%rdi, %r8,), %rdi       # rdi <- Last byte of Destination
  75     std
  76 L_CopyBytes:
  77     movq    %r8, %rcx
  78     rep     movsb
  79     cld
  80     popq    %rdi
  81     popq    %rsi
  82     ret