[mirror_edk2.git] / MdePkg / Library / BaseMemoryLibRepStr / Ia32 / CopyMem.asm

//\r
// Include common header file for this module.\r
//\r
\r
\r
;------------------------------------------------------------------------------\r
;\r
; Copyright (c) 2006, Intel Corporation\r
; All rights reserved. This program and the accompanying materials\r
; are licensed and made available under the terms and conditions of the BSD License\r
; which accompanies this distribution.  The full text of the license may be found at\r
; http://opensource.org/licenses/bsd-license.php\r
;\r
; THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
; WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
;\r
; Module Name:\r
;\r
;   CopyMem.Asm\r
;\r
; Abstract:\r
;\r
;   CopyMem function\r
;\r
; Notes:\r
;\r
;------------------------------------------------------------------------------\r
\r
    .386\r
    .model  flat,C\r
    .code\r
\r
;------------------------------------------------------------------------------\r
;  VOID *\r
;  InternalMemCopyMem (\r
;    IN VOID   *Destination,\r
;    IN VOID   *Source,\r
;    IN UINTN  Count\r
;    )\r
;------------------------------------------------------------------------------\r
InternalMemCopyMem  PROC    USES    esi edi\r
    mov     esi, [esp + 16]             ; esi <- Source\r
    mov     edi, [esp + 12]             ; edi <- Destination\r
    mov     edx, [esp + 20]             ; edx <- Count\r
    lea     eax, [esi + edx - 1]        ; eax <- End of Source\r
    cmp     esi, edi\r
    jae     @F\r
    cmp     eax, edi\r
    jae     @CopyBackward               ; Copy backward if overlapped\r
@@:\r
    mov     ecx, edx\r
    and     edx, 3\r
    shr     ecx, 2\r
    rep     movsd                       ; Copy as many Dwords as possible\r
    jmp     @CopyBytes\r
@CopyBackward:\r
    mov     esi, eax                    ; esi <- End of Source\r
    lea     edi, [edi + edx - 1]        ; edi <- End of Destination\r
    std\r
@CopyBytes:\r
    mov     ecx, edx\r
    rep     movsb                       ; Copy bytes backward\r
    cld\r
    mov     eax, [esp + 12]             ; eax <- Destination as return value\r
    ret\r
InternalMemCopyMem  ENDP\r
\r
    END\r
Commit	Line	Data
e1f414b6	1	//\r
	2	// Include common header file for this module.\r
	3	//\r
f734a10a	4	\r
e1f414b6	5	\r
	6	;------------------------------------------------------------------------------\r
	7	;\r
	8	; Copyright (c) 2006, Intel Corporation\r
	9	; All rights reserved. This program and the accompanying materials\r
	10	; are licensed and made available under the terms and conditions of the BSD License\r
	11	; which accompanies this distribution. The full text of the license may be found at\r
	12	; http://opensource.org/licenses/bsd-license.php\r
	13	;\r
	14	; THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
	15	; WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
	16	;\r
	17	; Module Name:\r
	18	;\r
	19	; CopyMem.Asm\r
	20	;\r
	21	; Abstract:\r
	22	;\r
	23	; CopyMem function\r
	24	;\r
	25	; Notes:\r
	26	;\r
	27	;------------------------------------------------------------------------------\r
	28	\r
	29	.386\r
	30	.model flat,C\r
	31	.code\r
	32	\r
	33	;------------------------------------------------------------------------------\r
	34	; VOID *\r
	35	; InternalMemCopyMem (\r
	36	; IN VOID *Destination,\r
	37	; IN VOID *Source,\r
	38	; IN UINTN Count\r
	39	; )\r
	40	;------------------------------------------------------------------------------\r
	41	InternalMemCopyMem PROC USES esi edi\r
	42	mov esi, [esp + 16] ; esi <- Source\r
	43	mov edi, [esp + 12] ; edi <- Destination\r
	44	mov edx, [esp + 20] ; edx <- Count\r
	45	lea eax, [esi + edx - 1] ; eax <- End of Source\r
	46	cmp esi, edi\r
	47	jae @F\r
	48	cmp eax, edi\r
	49	jae @CopyBackward ; Copy backward if overlapped\r
	50	@@:\r
	51	mov ecx, edx\r
	52	and edx, 3\r
	53	shr ecx, 2\r
	54	rep movsd ; Copy as many Dwords as possible\r
	55	jmp @CopyBytes\r
	56	@CopyBackward:\r
	57	mov esi, eax ; esi <- End of Source\r
	58	lea edi, [edi + edx - 1] ; edi <- End of Destination\r
	59	std\r
	60	@CopyBytes:\r
	61	mov ecx, edx\r
	62	rep movsb ; Copy bytes backward\r
	63	cld\r
	64	mov eax, [esp + 12] ; eax <- Destination as return value\r
	65	ret\r
	66	InternalMemCopyMem ENDP\r
	67	\r
	68	END\r