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Diffstat (limited to 'EDK/Foundation/Library/EfiCommonLib/Ia32/EfiSetMem.asm')
| -rw-r--r-- | EDK/Foundation/Library/EfiCommonLib/Ia32/EfiSetMem.asm | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/EDK/Foundation/Library/EfiCommonLib/Ia32/EfiSetMem.asm b/EDK/Foundation/Library/EfiCommonLib/Ia32/EfiSetMem.asm new file mode 100644 index 0000000..3b08c37 --- /dev/null +++ b/EDK/Foundation/Library/EfiCommonLib/Ia32/EfiSetMem.asm @@ -0,0 +1,154 @@ + TITLE EfiSetMem.asm: Optimized setmemory routine + +;------------------------------------------------------------------------------ +; +; Copyright (c) 2004, 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: +; +; EfiSetMem.asm +; +; Abstract: +; +; This is the code that supports IA32-optimized SetMem service +; +;------------------------------------------------------------------------------ + +; PROC:PRIVATE + .686P + .MMX + .MODEL SMALL + .CODE + +EfiCommonLibSetMem PROTO C Buffer:PTR DWORD, Count:DWORD, Value:BYTE + +;------------------------------------------------------------------------------ +; Procedure: EfiCommonLibSetMem +; +; VOID +; EfiCommonLibSetMem ( +; IN VOID *Buffer, +; IN UINTN Count, +; IN UINT8 Value +; ) +; +; Input: VOID *Buffer - Pointer to buffer to write +; UINTN Count - Number of bytes to write +; UINT8 Value - Value to write +; +; Output: None. +; +; Saves: +; +; Modifies: +; +; Description: This function is an optimized zero-memory function. +; +; Notes: This function tries to zero memory 8 bytes at a time. As a result, +; it first picks up any misaligned bytes, then words, before getting +; in the main loop that does the 8-byte clears. +; +;------------------------------------------------------------------------------ +EfiCommonLibSetMem PROC C Buffer:PTR DWORD, Count:DWORD, Value:BYTE + LOCAL QWordValue:QWORD + LOCAL MmxSave:QWORD + + + mov edx, Count + test edx, edx + je _SetMemDone + + push edi + push ebx + + mov eax, Buffer + mov bl, Value + mov edi, eax + mov bh, bl + + cmp edx, 256 + jb _SetRemindingByte + + and al, 07h + test al, al + je _SetBlock + + mov eax, edi + shr eax, 3 + inc eax + shl eax, 3 + sub eax, edi + cmp eax, edx + jnb _SetRemindingByte + + sub edx, eax + mov ecx, eax + + mov al, bl + rep stosb + +_SetBlock: + mov eax, edx + shr eax, 6 + test eax, eax + je _SetRemindingByte + + shl eax, 6 + sub edx, eax + shr eax, 6 + + mov WORD PTR QWordValue[0], bx + mov WORD PTR QWordValue[2], bx + mov WORD PTR QWordValue[4], bx + mov WORD PTR QWordValue[6], bx + + + movq MmxSave, mm0 + movq mm0, QWordValue + +@@: + movq QWORD PTR ds:[edi], mm0 + movq QWORD PTR ds:[edi+8], mm0 + movq QWORD PTR ds:[edi+16], mm0 + movq QWORD PTR ds:[edi+24], mm0 + movq QWORD PTR ds:[edi+32], mm0 + movq QWORD PTR ds:[edi+40], mm0 + movq QWORD PTR ds:[edi+48], mm0 + movq QWORD PTR ds:[edi+56], mm0 + add edi, 64 + dec eax + jnz @B + +; Restore mm0 + movq mm0, MmxSave + emms ; Exit MMX Instruction + +_SetRemindingByte: + mov ecx, edx + + mov eax, ebx + shl eax, 16 + mov ax, bx + shr ecx, 2 + rep stosd + + mov ecx, edx + and ecx, 3 + rep stosb + + pop ebx + pop edi + +_SetMemDone: + ret 0 + +EfiCommonLibSetMem ENDP + END +
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