diff options
Diffstat (limited to 'EdkCompatibilityPkg/Foundation/Library/CompilerStub/Ia32/memcpy.asm')
-rw-r--r-- | EdkCompatibilityPkg/Foundation/Library/CompilerStub/Ia32/memcpy.asm | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/EdkCompatibilityPkg/Foundation/Library/CompilerStub/Ia32/memcpy.asm b/EdkCompatibilityPkg/Foundation/Library/CompilerStub/Ia32/memcpy.asm new file mode 100644 index 0000000000..37b505678a --- /dev/null +++ b/EdkCompatibilityPkg/Foundation/Library/CompilerStub/Ia32/memcpy.asm @@ -0,0 +1,81 @@ +;------------------------------------------------------------------------------
+;
+; Copyright (c) 2007, 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:
+;
+; memcpy function
+;
+; Notes:
+;
+;------------------------------------------------------------------------------
+
+ .686
+ .model flat,C
+ .mmx
+ .code
+
+;------------------------------------------------------------------------------
+; VOID *
+; memcpy (
+; IN VOID *Destination,
+; IN VOID *Source,
+; IN UINTN Count
+; );
+;------------------------------------------------------------------------------
+memcpy PROC USES esi edi
+ mov esi, [esp + 16] ; esi <- Source
+ mov edi, [esp + 12] ; edi <- Destination
+ mov edx, [esp + 20] ; edx <- Count
+ lea eax, [esi + edx - 1] ; eax <- End of Source
+ cmp esi, edi
+ je @CopyMemDone
+ cmp edx, 0
+ je @CopyMemDone
+ cmp esi, edi
+ jae @F
+ cmp eax, edi ; Overlapped?
+ jae @CopyBackward ; Copy backward if overlapped
+@@:
+ mov ecx, edx
+ and edx, 7
+ shr ecx, 3 ; ecx <- # of Qwords to copy
+ jz @CopyBytes
+ push eax
+ push eax
+ movq [esp], mm0 ; save mm0
+@@:
+ movq mm0, [esi]
+ movq [edi], mm0
+ add esi, 8
+ add edi, 8
+ loop @B
+ movq mm0, [esp] ; restore mm0
+ pop ecx ; stack cleanup
+ pop ecx ; stack cleanup
+ jmp @CopyBytes
+@CopyBackward:
+ mov esi, eax ; esi <- Last byte in Source
+ lea edi, [edi + edx - 1] ; edi <- Last byte in Destination
+ std
+@CopyBytes:
+ mov ecx, edx
+ rep movsb
+ cld
+@CopyMemDone:
+ mov eax, [esp + 12]
+ ret
+memcpy ENDP
+
+ END
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