[mirror_edk2.git] / MdePkg / Library / BaseMemoryLibOptPei / Ia32 / CopyMem.S

#------------------------------------------------------------------------------
#
# 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:
#
#   CopyMem.Asm
#
# Abstract:
#
#   CopyMem function
#
# Notes:
#
#------------------------------------------------------------------------------

.globl ASM_PFX(InternalMemCopyMem)

#------------------------------------------------------------------------------
#  VOID *
#  EFIAPI
#  InternalMemCopyMem (
#    IN VOID   *Destination,
#    IN VOID   *Source,
#    IN UINTN  Count
#    );
#------------------------------------------------------------------------------
ASM_PFX(InternalMemCopyMem):
    push    %esi
    push    %edi
    movl    16(%esp), %esi              # esi <- Source
    movl    12(%esp), %edi              # edi <- Destination
    movl    20(%esp), %edx              # edx <- Count
    cmpl    %esi, %edi
    je      L_CopyDone
    cmpl    $0, %edx
    je      L_CopyDone
    leal    -1(%esi, %edx), %eax        # eax <- End of Source
    cmpl    %edi, %esi
    jae     L_CopyBytes
    cmpl    %edi, %eax
    jb      L_CopyBytes                 # Copy backward if overlapped
    movl    %eax, %esi                  # esi <- End of Source
    leal    -1(%edi, %edx), %edi        # edi <- End of Destination
    std
L_CopyBytes:
    movl    %edx, %ecx
    rep
    movsb                               # Copy bytes backward
    cld
L_CopyDone:
    movl    12(%esp), %eax              # eax <- Destination as return value
    pop     %edi
    pop     %esi
    ret
Commit	Line	Data
7b3b4b29	1	#------------------------------------------------------------------------------
	2	#
	3	# Copyright (c) 2006, Intel Corporation
	4	# All rights reserved. This program and the accompanying materials
	5	# are licensed and made available under the terms and conditions of the BSD License
	6	# which accompanies this distribution. The full text of the license may be found at
	7	# http://opensource.org/licenses/bsd-license.php
	8	#
	9	# THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
	10	# WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
	11	#
	12	# Module Name:
	13	#
	14	# CopyMem.Asm
	15	#
	16	# Abstract:
	17	#
	18	# CopyMem function
	19	#
	20	# Notes:
	21	#
	22	#------------------------------------------------------------------------------
	23
85c25283	24	.globl ASM_PFX(InternalMemCopyMem)
7b3b4b29	25
	26	#------------------------------------------------------------------------------
	27	# VOID *
	28	# EFIAPI
	29	# InternalMemCopyMem (
	30	# IN VOID *Destination,
	31	# IN VOID *Source,
	32	# IN UINTN Count
	33	# );
	34	#------------------------------------------------------------------------------
85c25283	35	ASM_PFX(InternalMemCopyMem):
7b3b4b29	36	push %esi
	37	push %edi
	38	movl 16(%esp), %esi # esi <- Source
	39	movl 12(%esp), %edi # edi <- Destination
	40	movl 20(%esp), %edx # edx <- Count
85c25283	41	cmpl %esi, %edi
85c25283	42	je L_CopyDone
5053cf7f	43	cmpl $0, %edx
85c25283	44	je L_CopyDone
7b3b4b29	45	leal -1(%esi, %edx), %eax # eax <- End of Source
85c25283	46	cmpl %edi, %esi
	47	jae L_CopyBytes
	48	cmpl %edi, %eax
	49	jb L_CopyBytes # Copy backward if overlapped
	50	movl %eax, %esi # esi <- End of Source
7b3b4b29	51	leal -1(%edi, %edx), %edi # edi <- End of Destination
85c25283	52	std
	53	L_CopyBytes:
	54	movl %edx, %ecx
7b3b4b29	55	rep
	56	movsb # Copy bytes backward
	57	cld
85c25283	58	L_CopyDone:
7b3b4b29	59	movl 12(%esp), %eax # eax <- Destination as return value
	60	pop %edi
	61	pop %esi
	62	ret