diff options
Diffstat (limited to 'EdkCompatibilityPkg/Foundation/Library/EfiCommonLib/Ia32/EfiZeroMem.S')
| -rw-r--r-- | EdkCompatibilityPkg/Foundation/Library/EfiCommonLib/Ia32/EfiZeroMem.S | 278 |
1 files changed, 139 insertions, 139 deletions
diff --git a/EdkCompatibilityPkg/Foundation/Library/EfiCommonLib/Ia32/EfiZeroMem.S b/EdkCompatibilityPkg/Foundation/Library/EfiCommonLib/Ia32/EfiZeroMem.S index e279335499..c72f12295c 100644 --- a/EdkCompatibilityPkg/Foundation/Library/EfiCommonLib/Ia32/EfiZeroMem.S +++ b/EdkCompatibilityPkg/Foundation/Library/EfiCommonLib/Ia32/EfiZeroMem.S @@ -1,139 +1,139 @@ -#/*++ -# -#Copyright (c) 2006, Intel Corporation -#All rights reserved. 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. -# -#Module Name: -# -# EfiZeroMem.c -# -#Abstract: -# -# This is the code that supports IA32-optimized ZeroMem service -# -#--*/ -#include "EfiBind.h" -#--------------------------------------------------------------------------- - .686: - #.MODEL flat,C - .mmx: - .code: - -#--------------------------------------------------------------------------- -.globl ASM_PFX(EfiCommonLibZeroMem) -#VOID -#EfiCommonLibZeroMem ( -# IN VOID *Buffer, -# IN UINTN Count -# ) -#/*++ -# -#Input: VOID *Buffer - Pointer to buffer to clear -# UINTN Count - Number of bytes to clear -# -#Output: None. -# -#Saves: -# -#Modifies: -# -#Description: This function is an optimized zero-memory function. -# -#Notes: This function tries to zero memory 8 bytes at a time. As a result, -# it first picks up any misaligned bytes, then words, before getting -# in the main loop that does the 8-byte clears. -# -#--*/ -ASM_PFX(EfiCommonLibZeroMem): -# UINT64 MmxSave; - pushl %ebp - movl %esp, %ebp - pushl %ecx # Reserve space for local variable MmxSave - pushl %ecx - pushl %edi - - movl 0xC(%ebp), %ecx # Count - movl 8(%ebp), %edi # Buffer - - # Pick up misaligned start bytes (get pointer 4-byte aligned) -_StartByteZero: - movl %edi, %eax - andb $3, %al # check lower 2 bits of address - testb %al, %al - je _ZeroBlocks # already aligned? - cmpl $0, %ecx - je _ZeroMemDone - - # Clear the byte memory location - movb $0, (%edi) - incl %edi - - # Decrement our count - decl %ecx - jmp _StartByteZero # back to top of loop - -_ZeroBlocks: - - # Compute how many 64-byte blocks we can clear - movl %ecx, %edx - shrl $6, %ecx # convert to 64-byte count - shll $6, %ecx # convert back to bytes - subl %ecx, %edx # subtract from the original count - shrl $6, %ecx # and this is how many 64-byte blocks - - # If no 64-byte blocks, then skip - cmpl $0, %ecx - je _ZeroRemaining - - # Save mm0 - movq %mm0, -8(%ebp) # Save mm0 to MmxSave - - pxor %mm0, %mm0 # Clear mm0 - -_B: - movq %mm0, %ds:(%edi) - movq %mm0, %ds:8(%edi) - movq %mm0, %ds:16(%edi) - movq %mm0, %ds:24(%edi) - movq %mm0, %ds:32(%edi) - movq %mm0, %ds:40(%edi) - movq %mm0, %ds:48(%edi) - movq %mm0, %ds:56(%edi) - - addl $64, %edi - decl %ecx - jnz _B - -# Restore mm0 - movq -8(%ebp), %mm0 # Restore mm0 from MmxSave - emms # Exit MMX Instruction - -_ZeroRemaining: - # Zero out as many DWORDS as possible - movl %edx, %ecx - shrl $2, %ecx - xorl %eax, %eax - - rep - stosl - - # Zero out remaining as bytes - movl %edx, %ecx - andl $03, %ecx - - rep - stosb - -_ZeroMemDone: - - popl %edi - leave - ret -#EfiCommonLibZeroMem ENDP - +#/*++
+#
+#Copyright (c) 2006, Intel Corporation
+#All rights reserved. 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.
+#
+#Module Name:
+#
+# EfiZeroMem.c
+#
+#Abstract:
+#
+# This is the code that supports IA32-optimized ZeroMem service
+#
+#--*/
+#include "EfiBind.h"
+#---------------------------------------------------------------------------
+ .686:
+ #.MODEL flat,C
+ .mmx:
+ .code:
+
+#---------------------------------------------------------------------------
+.globl ASM_PFX(EfiCommonLibZeroMem)
+#VOID
+#EfiCommonLibZeroMem (
+# IN VOID *Buffer,
+# IN UINTN Count
+# )
+#/*++
+#
+#Input: VOID *Buffer - Pointer to buffer to clear
+# UINTN Count - Number of bytes to clear
+#
+#Output: None.
+#
+#Saves:
+#
+#Modifies:
+#
+#Description: This function is an optimized zero-memory function.
+#
+#Notes: This function tries to zero memory 8 bytes at a time. As a result,
+# it first picks up any misaligned bytes, then words, before getting
+# in the main loop that does the 8-byte clears.
+#
+#--*/
+ASM_PFX(EfiCommonLibZeroMem):
+# UINT64 MmxSave;
+ pushl %ebp
+ movl %esp, %ebp
+ pushl %ecx # Reserve space for local variable MmxSave
+ pushl %ecx
+ pushl %edi
+
+ movl 0xC(%ebp), %ecx # Count
+ movl 8(%ebp), %edi # Buffer
+
+ # Pick up misaligned start bytes (get pointer 4-byte aligned)
+_StartByteZero:
+ movl %edi, %eax
+ andb $3, %al # check lower 2 bits of address
+ testb %al, %al
+ je _ZeroBlocks # already aligned?
+ cmpl $0, %ecx
+ je _ZeroMemDone
+
+ # Clear the byte memory location
+ movb $0, (%edi)
+ incl %edi
+
+ # Decrement our count
+ decl %ecx
+ jmp _StartByteZero # back to top of loop
+
+_ZeroBlocks:
+
+ # Compute how many 64-byte blocks we can clear
+ movl %ecx, %edx
+ shrl $6, %ecx # convert to 64-byte count
+ shll $6, %ecx # convert back to bytes
+ subl %ecx, %edx # subtract from the original count
+ shrl $6, %ecx # and this is how many 64-byte blocks
+
+ # If no 64-byte blocks, then skip
+ cmpl $0, %ecx
+ je _ZeroRemaining
+
+ # Save mm0
+ movq %mm0, -8(%ebp) # Save mm0 to MmxSave
+
+ pxor %mm0, %mm0 # Clear mm0
+
+_B:
+ movq %mm0, %ds:(%edi)
+ movq %mm0, %ds:8(%edi)
+ movq %mm0, %ds:16(%edi)
+ movq %mm0, %ds:24(%edi)
+ movq %mm0, %ds:32(%edi)
+ movq %mm0, %ds:40(%edi)
+ movq %mm0, %ds:48(%edi)
+ movq %mm0, %ds:56(%edi)
+
+ addl $64, %edi
+ decl %ecx
+ jnz _B
+
+# Restore mm0
+ movq -8(%ebp), %mm0 # Restore mm0 from MmxSave
+ emms # Exit MMX Instruction
+
+_ZeroRemaining:
+ # Zero out as many DWORDS as possible
+ movl %edx, %ecx
+ shrl $2, %ecx
+ xorl %eax, %eax
+
+ rep
+ stosl
+
+ # Zero out remaining as bytes
+ movl %edx, %ecx
+ andl $03, %ecx
+
+ rep
+ stosb
+
+_ZeroMemDone:
+
+ popl %edi
+ leave
+ ret
+#EfiCommonLibZeroMem ENDP
+
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