1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
|
/*++
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:
}
}
|