EdkCompatibilityPkg/Foundation/Library/EfiCommonLib/Ia32/EfiSetMemSSE2.c

   1 /*++
   2
   3 Copyright (c) 2006, Intel Corporation
   4 All rights reserved. This program and the accompanying materials
   5 are licensed and made available under the terms and conditions of the BSD License
   6 which accompanies this distribution.  The full text of the license may be found at
   7 http://opensource.org/licenses/bsd-license.php
   8
   9 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  10 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  11
  12 Module Name:
  13
  14   EfiSetMemSSE2.c
  15
  16 Abstract:
  17
  18   This is the code that supports IA32-optimized SetMem service
  19
  20 --*/
  21
  22 #include "Tiano.h"
  23
  24 VOID
  25 EfiCommonLibSetMem (
  26   IN VOID   *Buffer,
  27   IN UINTN  Count,
  28   IN UINT8  Value
  29   )
  30 /*++
  31
  32 Input:  VOID   *Buffer - Pointer to buffer to write
  33         UINTN  Count   - Number of bytes to write
  34         UINT8  Value   - Value to write
  35
  36 Output: None.
  37
  38 Saves:
  39
  40 Modifies:
  41
  42 Description:  This function is an optimized set-memory function.
  43
  44 Notes:  This function tries to set memory 8 bytes at a time. As a result,
  45         it first picks up any misaligned bytes, then words, before getting
  46         in the main loop that does the 8-byte clears.
  47
  48 --*/
  49 {
  50   UINT64 QWordValue;
  51   UINT64 MmxSave;
  52   __asm {
  53     mov edx, Count
  54     test edx, edx
  55     je _SetMemDone
  56
  57     push ebx
  58
  59     mov eax, Buffer
  60     mov bl, Value
  61     mov edi, eax
  62     mov  bh, bl
  63
  64     cmp edx, 256
  65     jb _SetRemindingByte
  66
  67     and al, 0fh
  68     test al, al
  69     je _SetBlock
  70
  71     mov eax, edi
  72     shr eax, 4
  73     inc eax
  74     shl eax, 4
  75     sub eax, edi
  76     cmp eax, edx
  77     jnb _SetRemindingByte
  78
  79     sub edx, eax
  80     mov ecx, eax
  81
  82     mov al, bl
  83     rep stosb
  84
  85 _SetBlock:
  86     mov eax, edx
  87     shr eax, 7
  88     test eax, eax
  89     je _SetRemindingByte
  90
  91     shl eax, 7
  92     sub edx, eax
  93     shr eax, 7
  94
  95     mov  WORD PTR QWordValue[0], bx
  96     mov  WORD PTR QWordValue[2], bx
  97     mov  WORD PTR QWordValue[4], bx
  98     mov  WORD PTR QWordValue[6], bx
  99
 100
 101     movq  MmxSave, mm0
 102     movq  mm0, QWordValue
 103
 104     movq2dq  xmm1, mm0
 105     pshufd   xmm1, xmm1, 0
 106
 107 _Loop:
 108     movdqa  OWORD PTR ds:[edi], xmm1
 109     movdqa  OWORD PTR ds:[edi+16], xmm1
 110     movdqa  OWORD PTR ds:[edi+32], xmm1
 111     movdqa  OWORD PTR ds:[edi+48], xmm1
 112     movdqa  OWORD PTR ds:[edi+64], xmm1
 113     movdqa  OWORD PTR ds:[edi+80], xmm1
 114     movdqa  OWORD PTR ds:[edi+96], xmm1
 115     movdqa  OWORD PTR ds:[edi+112], xmm1
 116     add edi, 128
 117     dec eax
 118     jnz _Loop
 119
 120 ; Restore mm0
 121     movq  mm0, MmxSave
 122     emms                                 ; Exit MMX Instruction
 123
 124 _SetRemindingByte:
 125     mov ecx, edx
 126
 127     mov eax, ebx
 128     shl eax, 16
 129     mov ax, bx
 130     shr ecx, 2
 131     rep stosd
 132
 133     mov ecx, edx
 134     and ecx, 3
 135     rep stosb
 136
 137     pop ebx
 138
 139 _SetMemDone:
 140   }
 141 }