audk/ArmPkg/Library/BaseMemoryLibStm/AArch64/SetMem.c

85 lines
2.3 KiB
C

/** @file
Copyright (c) 2012-2013, ARM Ltd. All rights reserved.<BR>
This program and the accompanying materials
are licensed and made available under the terms and conditions of the BSD License
which accompanies this distribution. The full text of the license may be found at
http://opensource.org/licenses/bsd-license.php
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
**/
#include "MemLibInternals.h"
/**
Set Buffer to Value for Size bytes.
@param Buffer Memory to set.
@param Length Number of bytes to set
@param Value Value of the set operation.
@return Buffer
**/
VOID *
EFIAPI
InternalMemSetMem (
OUT VOID *Buffer,
IN UINTN Length,
IN UINT8 Value
)
{
//
// Declare the local variables that actually move the data elements as
// volatile to prevent the optimizer from replacing this function with
// the intrinsic memset()
//
volatile UINT8 *Pointer8;
volatile UINT32 *Pointer32;
volatile UINT64 *Pointer64;
UINT32 Value32;
UINT64 Value64;
if ((((UINTN)Buffer & 0x7) == 0) && (Length >= 8)) {
// Generate the 64bit value
Value32 = (Value << 24) | (Value << 16) | (Value << 8) | Value;
Value64 = (((UINT64)Value32) << 32) | Value32;
Pointer64 = (UINT64*)Buffer;
while (Length >= 8) {
*(Pointer64++) = Value64;
Length -= 8;
}
// Finish with bytes if needed
Pointer8 = (UINT8*)Pointer64;
while (Length-- > 0) {
*(Pointer8++) = Value;
}
} else if ((((UINTN)Buffer & 0x3) == 0) && (Length >= 4)) {
// Generate the 32bit value
Value32 = (Value << 24) | (Value << 16) | (Value << 8) | Value;
Pointer32 = (UINT32*)Buffer;
while (Length >= 4) {
*(Pointer32++) = Value32;
Length -= 4;
}
// Finish with bytes if needed
Pointer8 = (UINT8*)Pointer32;
while (Length-- > 0) {
*(Pointer8++) = Value;
}
} else {
Pointer8 = (UINT8*)Buffer;
while (Length-- > 0) {
*(Pointer8++) = Value;
}
}
return Buffer;
}