[mirror_edk2.git] / MdePkg / Library / BaseMemoryLibMmx / 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:
#
#------------------------------------------------------------------------------

.global _InternalMemCopyMem

#------------------------------------------------------------------------------
#  VOID *
#  EFIAPI
#  InternalMemCopyMem (
#    IN VOID   *Destination,
#    IN VOID   *Source,
#    IN UINTN  Count
#    );
#------------------------------------------------------------------------------
_InternalMemCopyMem:
    push    %esi
    push    %edi
    movl    16(%esp), %esi              # esi <- Source
    movl    12(%esp), %edi              # edi <- Destination
    movl    20(%esp), %edx              # edx <- Count
    leal    -1(%esi,%edx,), %eax        # eax <- End of Source
    cmpl    %edi, %esi
    jae     L0
    cmpl    %edi, %eax                  # Overlapped?
    jae     @CopyBackward               # Copy backward if overlapped
L0:
    xorl    %ecx, %ecx
    subl    %esi, %ecx
    andl    $7, %ecx                    # ecx + esi aligns on 8-byte boundary
    jz      L1
    cmpl    %edx, %ecx
    cmova   %edx, %ecx
    subl    %ecx, %edx                  # edx <- remaining bytes to copy
    rep
    movsb
L1:
    movl    %edx, %ecx
    andl    $7, %edx
    shrl    $3, %ecx                    # ecx <- # of Qwords to copy
    jz      @CopyBytes
    pushl   %eax
    pushl   %eax
    movq    %mm0, (%esp)                # save mm0
L2:
    movq    (%esi), %mm0
    movq    %mm0, (%edi)
    addl    $8, %esi
    addl    $8, %edi
    loop    L2
    movq    (%esp), %mm0                # restore mm0
    popl    %ecx                        # stack cleanup
    popl    %ecx                        # stack cleanup
    jmp     @CopyBytes
@CopyBackward:
    movl    %eax, %esi                  # esi <- Last byte in Source
    leal    -1(%edi,%edx,), %edi        # edi <- Last byte in Destination
    std
@CopyBytes:
    movl    %edx, %ecx
    rep
    movsb
    cld
    movl    12(%esp), %eax
    pop     %edi
    pop     %esi
    ret
Commit	Line	Data
	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
	24	.global _InternalMemCopyMem
	25
	26	#------------------------------------------------------------------------------
	27	# VOID *
	28	# EFIAPI
	29	# InternalMemCopyMem (
	30	# IN VOID *Destination,
	31	# IN VOID *Source,
	32	# IN UINTN Count
	33	# );
	34	#------------------------------------------------------------------------------
	35	_InternalMemCopyMem:
	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
	41	leal -1(%esi,%edx,), %eax # eax <- End of Source
	42	cmpl %edi, %esi
	43	jae L0
	44	cmpl %edi, %eax # Overlapped?
	45	jae @CopyBackward # Copy backward if overlapped
	46	L0:
	47	xorl %ecx, %ecx
	48	subl %esi, %ecx
	49	andl $7, %ecx # ecx + esi aligns on 8-byte boundary
	50	jz L1
	51	cmpl %edx, %ecx
	52	cmova %edx, %ecx
	53	subl %ecx, %edx # edx <- remaining bytes to copy
	54	rep
	55	movsb
	56	L1:
	57	movl %edx, %ecx
	58	andl $7, %edx
	59	shrl $3, %ecx # ecx <- # of Qwords to copy
	60	jz @CopyBytes
	61	pushl %eax
	62	pushl %eax
	63	movq %mm0, (%esp) # save mm0
	64	L2:
	65	movq (%esi), %mm0
	66	movq %mm0, (%edi)
	67	addl $8, %esi
	68	addl $8, %edi
	69	loop L2
	70	movq (%esp), %mm0 # restore mm0
	71	popl %ecx # stack cleanup
	72	popl %ecx # stack cleanup
	73	jmp @CopyBytes
	74	@CopyBackward:
	75	movl %eax, %esi # esi <- Last byte in Source
	76	leal -1(%edi,%edx,), %edi # edi <- Last byte in Destination
	77	std
	78	@CopyBytes:
	79	movl %edx, %ecx
	80	rep
	81	movsb
	82	cld
	83	movl 12(%esp), %eax
	84	pop %edi
	85	pop %esi
	86	ret