/*++ 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: EfiSetMemSSE2.c Abstract: This is the code that supports IA32-optimized SetMem service --*/ #include "Tiano.h" 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 set-memory function. Notes: This function tries to set 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. --*/ { UINT64 QWordValue; UINT64 MmxSave; __asm { mov edx, Count test edx, edx je _SetMemDone push ebx mov eax, Buffer mov bl, Value mov edi, eax mov bh, bl cmp edx, 256 jb _SetRemindingByte and al, 0fh test al, al je _SetBlock mov eax, edi shr eax, 4 inc eax shl eax, 4 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, 7 test eax, eax je _SetRemindingByte shl eax, 7 sub edx, eax shr eax, 7 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 movq2dq xmm1, mm0 pshufd xmm1, xmm1, 0 _Loop: movdqa OWORD PTR ds:[edi], xmm1 movdqa OWORD PTR ds:[edi+16], xmm1 movdqa OWORD PTR ds:[edi+32], xmm1 movdqa OWORD PTR ds:[edi+48], xmm1 movdqa OWORD PTR ds:[edi+64], xmm1 movdqa OWORD PTR ds:[edi+80], xmm1 movdqa OWORD PTR ds:[edi+96], xmm1 movdqa OWORD PTR ds:[edi+112], xmm1 add edi, 128 dec eax jnz _Loop ; 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 _SetMemDone: } }