UefiCpuPkg: Move AsmRelocateApLoopStart from Mpfuncs.nasm to AmdSev.nasm

[mirror_edk2.git] / MdePkg / Library / BaseMemoryLib / SetMem.c

/** @file\r
  Implementation of the EfiSetMem routine. This function is broken\r
  out into its own source file so that it can be excluded from a\r
  build for a particular platform easily if an optimized version\r
  is desired.\r
\r
  Copyright (c) 2006 - 2010, Intel Corporation. All rights reserved.<BR>\r
  Copyright (c) 2012 - 2013, ARM Ltd. All rights reserved.<BR>\r
  Copyright (c) 2016, Linaro Ltd. All rights reserved.<BR>\r
\r
  SPDX-License-Identifier: BSD-2-Clause-Patent\r
\r
**/\r
\r
#include "MemLibInternals.h"\r
\r
/**\r
  Set Buffer to Value for Size bytes.\r
\r
  @param  Buffer   The memory to set.\r
  @param  Length   The number of bytes to set.\r
  @param  Value    The value of the set operation.\r
\r
  @return Buffer\r
\r
**/\r
VOID *\r
EFIAPI\r
InternalMemSetMem (\r
  OUT     VOID   *Buffer,\r
  IN      UINTN  Length,\r
  IN      UINT8  Value\r
  )\r
{\r
  //\r
  // Declare the local variables that actually move the data elements as\r
  // volatile to prevent the optimizer from replacing this function with\r
  // the intrinsic memset()\r
  //\r
  volatile UINT8   *Pointer8;\r
  volatile UINT32  *Pointer32;\r
  volatile UINT64  *Pointer64;\r
  UINT32           Value32;\r
  UINT64           Value64;\r
\r
  if ((((UINTN)Buffer & 0x7) == 0) && (Length >= 8)) {\r
    // Generate the 64bit value\r
    Value32 = (Value << 24) | (Value << 16) | (Value << 8) | Value;\r
    Value64 = LShiftU64 (Value32, 32) | Value32;\r
\r
    Pointer64 = (UINT64 *)Buffer;\r
    while (Length >= 8) {\r
      *(Pointer64++) = Value64;\r
      Length        -= 8;\r
    }\r
\r
    // Finish with bytes if needed\r
    Pointer8 = (UINT8 *)Pointer64;\r
  } else if ((((UINTN)Buffer & 0x3) == 0) && (Length >= 4)) {\r
    // Generate the 32bit value\r
    Value32 = (Value << 24) | (Value << 16) | (Value << 8) | Value;\r
\r
    Pointer32 = (UINT32 *)Buffer;\r
    while (Length >= 4) {\r
      *(Pointer32++) = Value32;\r
      Length        -= 4;\r
    }\r
\r
    // Finish with bytes if needed\r
    Pointer8 = (UINT8 *)Pointer32;\r
  } else {\r
    Pointer8 = (UINT8 *)Buffer;\r
  }\r
\r
  while (Length-- > 0) {\r
    *(Pointer8++) = Value;\r
  }\r
\r
  return Buffer;\r
}\r