diff options
Diffstat (limited to 'EdkCompatibilityPkg/Foundation/Library/CompilerStub/x64/memcpy.asm')
-rw-r--r-- | EdkCompatibilityPkg/Foundation/Library/CompilerStub/x64/memcpy.asm | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/EdkCompatibilityPkg/Foundation/Library/CompilerStub/x64/memcpy.asm b/EdkCompatibilityPkg/Foundation/Library/CompilerStub/x64/memcpy.asm new file mode 100644 index 0000000000..7e04431459 --- /dev/null +++ b/EdkCompatibilityPkg/Foundation/Library/CompilerStub/x64/memcpy.asm @@ -0,0 +1,73 @@ +;------------------------------------------------------------------------------
+;
+; 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:
+;
+;------------------------------------------------------------------------------
+
+ .code
+
+;------------------------------------------------------------------------------
+; VOID *
+; memcpy (
+; OUT VOID *DestinationBuffer,
+; IN CONST VOID *SourceBuffer,
+; IN UINTN Length
+; );
+;------------------------------------------------------------------------------
+memcpy PROC USES rsi rdi
+ mov rax, rcx ; rax <- Destination as return value
+ cmp rdx, rcx ; if Source == Destination, do nothing
+ je @CopyMemDone
+ cmp r8, 0 ; if Count == 0, do nothing
+ je @CopyMemDone
+ mov rsi, rdx ; rsi <- Source
+ mov rdi, rcx ; rdi <- Destination
+ lea r9, [rsi + r8 - 1] ; r9 <- End of Source
+ cmp rsi, rdi
+ jae @F
+ cmp r9, rdi
+ jae @CopyBackward ; Copy backward if overlapped
+@@:
+ mov rcx, r8
+ and r8, 7
+ shr rcx, 3 ; rcx <- # of Qwords to copy
+ jz @CopyBytes
+ DB 49h, 0fh, 7eh, 0c2h ; movd r10, mm0 (Save mm0 in r10)
+@@:
+ DB 0fh, 6fh, 06h ; movd mm0, [rsi]
+ DB 48h, 0fh, 7eh, 07h ; movd [rdi], mm0
+ add rsi, 8
+ add rdi, 8
+ loop @B
+ DB 49h, 0fh, 6eh, 0c2h ; movd mm0, r10 (Restore mm0)
+ jmp @CopyBytes
+@CopyBackward:
+ mov rsi, r9 ; rsi <- End of Source
+ lea rdi, [rdi + r8 - 1] ; rdi <- End of Destination
+ std ; set direction flag
+@CopyBytes:
+ mov rcx, r8
+ rep movsb ; Copy bytes backward
+ cld
+@CopyMemDone:
+ ret
+memcpy ENDP
+
+ END
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