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
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
|
; Copyright (C) 2000 MySQL AB
;
; This library is free software; you can redistribute it and/or
; modify it under the terms of the GNU Library General Public
; License as published by the Free Software Foundation; version 2
; of the License.
;
; This library is distributed in the hope that it will be useful,
; but WITHOUT ANY WARRANTY; without even the implied warranty of
; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
; Library General Public License for more details.
;
; You should have received a copy of the GNU Library General Public
; License along with this library; if not, write to the Free
; Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
; MA 02111-1307, USA
TITLE Optimized cmp of pointer to strings of unsigned chars
ifndef M_I386
.8087
DOSSEG
.MODEL LARGE
.DATA
compare_length dw 0
.CODE STRINGS
PUBLIC _get_ptr_compare
_get_ptr_compare PROC
mov bx,sp
mov cx,ss:[BX+4]
mov compare_length,cx
mov dx,seg strings:_ptr_cmp
mov ax,offset _ptr_cmp_0
jcxz @F
mov ax,offset _ptr_cmp_1
dec cx
jz @F
mov ax,offset _ptr_cmp
@@: ret
_get_ptr_compare ENDP
_ptr_cmp_0 PROC
mov AX,0 ; Emptyt strings are always equal
ret
_ptr_cmp_0 ENDP
_ptr_cmp_1 PROC
mov bx,sp
mov dx,si ; Save si and ds
mov cx,ds
lds si,DWORD PTR ss:[bx+4] ; s1
lds si,DWORD PTR ds:[si]
mov al,ds:[si]
xor ah,ah
lds si,DWORD PTR ss:[bx+8] ; s2
lds si,DWORD PTR ds:[si]
mov bl,ds:[si]
mov bh,ah
sub ax,bx
mov ds,cx ; restore si and ds
mov si,dx
ret
_ptr_cmp_1 ENDP
_ptr_cmp PROC
mov bx,bp ; Save bp
mov dx,di ; Save di
mov bp,sp
push ds
push si
mov cx,compare_length ; Length of memory-area
lds si,DWORD PTR [bp+4] ; s1
lds si,DWORD PTR ds:[si]
les di,DWORD PTR [bp+8] ; s2
les di,DWORD PTR es:[di]
; cld ; Work uppward
xor ax,ax
repe cmpsb ; Compare strings
je @F ; Strings are equal
sbb ax,ax
cmc
adc ax,0
@@: pop si
pop ds
mov di,dx
mov bp,bx
ret
_ptr_cmp ENDP
else
include macros.asm
fix_es MACRO fix_cld ; Load ES if neaded
ife ESeqDS
mov ax,ds
mov es,ax
endif
ifnb <fix_cld>
cld
endif
ENDM
begdata
compare_length dd 0 ; Length of strings
enddata
begcode get_ptr_compare
public _get_ptr_compare
_get_ptr_compare proc near
mov ecx,P-SIZEPTR[esp]
mov compare_length,ecx
mov eax,offset _TEXT:_ptr_cmp_0
jecxz @F
mov eax,offset _TEXT:_ptr_cmp_1
dec ecx
jz @F
mov eax,offset _TEXT:_ptr_cmp
@@: ret
_get_ptr_compare endp
endcode _get_ptr_compare
begcode ptr_cmp_0
_ptr_cmp_0 PROC
mov EAX,0 ; Emptyt strings are always equal
ret
_ptr_cmp_0 ENDP
endcode ptr_cmp_0
begcode ptr_cmp_1
_ptr_cmp_1 proc near
mov edx,esi ; Save esi
mov esi,P-SIZEPTR[esp] ; *s1
mov esi,[esi]
movzx eax,[esi]
mov esi,P[esp] ; *s2
mov esi,[esi]
movzx ecx,[esi]
sub eax,ecx
mov esi,edx ; Restore esi
ret
_ptr_cmp_1 ENDP
endcode ptr_cmp_1
begcode ptr_cmp
_ptr_cmp proc near
fix_es 1
push ebp
mov ebp,esp
mov edx,edi ; Save esi
push esi
mov esi,P[ebp] ; *s1
mov esi,[esi]
mov edi,P+SIZEPTR[ebp] ; *s2
mov edi,[edi]
mov ecx,compare_length ; Length of memory-area
xor eax,eax
repe cmpsb ; Compare strings
je @F ; Strings are equal
sbb eax,eax
cmc
adc eax,0
@@: pop esi
mov edi,edx
pop ebp
ret
_ptr_cmp ENDP
endcode ptr_cmp
endif
END
|