Ассемблер Для Процессоров Intel Pentium

32.973-018.1

004.43

12

. .

12 Intel Pentium. .: , 2006. 410 .: .

ISBN 5-469-00662-X

Intel

Pentium. ,

, MMX, SSE

SSE2.

Intel Pentium, Intel Pentium 4. -

. ,

.

32.973-018.1

004.43

.

.

, , , .

, ,

, .

ISBN 5-469-00662-X , 2006

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

1. Intel x86 . . . . . . . . . . . . . . . 14

2. . . . . . . . . . . 21

3. . . . . . . . . . . . . . . . . . . . . . . 26

4. . . . . . . . . . . . . . . 53

5. . . . . . . . . . . . . . . . . . 61

6. . . . . . . . . . . . . . . . . . . . . 93

7. . . . . . . . . . . . . . . . . . . 120

8. . . . . . . . . . . . . . . . 163

9. . . . . . . . . . . . . 206

10. . . . . . . . . . . . . . . . . 250

11. Intel Pentium . . . . . . . . . 266

12. MMX- Intel Pentium . . . . . . . . . . . . . 270

13. SSE- Intel Pentium . . . . . . . . . . . . . . 318

14. SSE2 Intel Pentium 4 . . . . . . . . . . . . 362

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 397

. 80x86 . . . . . . . . . . . . . 399

. 80x86 . . . . . . . . . . 406

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 409

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

1. Intel x86 . . . . . . . . . . . 14

2. . . . . . . . 21

2.1. . . . . . . . . . . . . . . . . . . . . . 23

2.2. . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

3. . . . . . . . . . . . . . . . . . . 26

3.1. . . . . . . . . . . . . . . . . . . . . 26

3.2. . . . . . . . . . . . . . . . . . . . 32

3.3. Intel Pentium . . . . . . . . . . . . . . . . 38

4. . . . . . . . . . . . 53

4.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

4.2.

MASM . . . . . . . . . . . . . . . . . . . . . . . . . . 54

4.3. MASM . . . . . . . . . . . . . . . . . . 57

5. . . . . . . . . . . . . . . 61

5.1. . . . . . . . . . . . . . . . . . . . . . . 63

5.2. jmp . . . . . . . . . . . . . . . . . . . . 66

5.3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

5.4. Intel Pentium . . . . . . . . . . . . . . . . 78

6. . . . . . . . . . . . . . . . . 93

6.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94

6.2. . . . . . . . . . . . . . . . . . . . 100

6.3. . . . . . . . . . . . . . . 110

6.4. . . . . . . . . . . . . . . 116

7. . . . . . . . . . . . . . . 120

7.1. . . . . . . . . . . . . . . . . . . . . . 124

7.2. . . . . . . . . . . . . . . . . . . . . . . . . 135

7.3. . . . . . . . . . . . . . . . . . . . . . . 145

7.4. lods stos . . . . . . . . . . . . . . . . . . . . . 150

7.5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154

7.6. . . . . . . . . . . . . . . . . . . . . . . . . . . . 157

7.7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160

8. . . . . . . . . . . . . 163

8.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163

8.2. . . . . . . . . . . . . . . . . . . . . . . . 166

8.3. . . . . . . . . . . . . . . . . . . . 168

8.4. . . . . . . . . . . . . . . . . . . . . . . . . . . 170

8.5. ASCII BCD . . . . . . . . . . . . . . . . . 189

8.6. ASCII- . . . . . . . . . . . . . . 197

8.7. ASCII . . . . . . . . . . . . . . 199

8.8. . . . . . . . . . . . . . . . . . . . . . 200

9. . . . . . . . . . 206

9.1. . . . . . . . . . . . . . . . . . . . . . . . . 207

9.2. . . . . . . . . . . . . . . . . . . . . . . . . . 209

9.3. . . . . . . . . . . . . . . 214

10. . . . . . . . . . . . . 250

10.1. . . . . . . . . . . . . . . . . . 250

10.2. Delphi 2005 . . . . . . . . . . . . . . 255

10.3. Visual C++ .NET 2005 . . . . . . . . . 261

11. Intel Pentium . . . . 266

11.1. Intel NetBurst . . . . . . . . . . . . . . . . . . . . . . 266

11.2. Intel Pentium 4 . . . . . . 268

12. MMX- Intel Pentium . . . . . . . . . 270

12.1. . . . . . . . . . . . . . . . . . . . . . . . . . 274

12.2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275

12.3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 285

12.4. . . . . . . . . . . . . . . . . . . 287

12.5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 302

12.6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 307

12.7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 311

12.8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 313

12.9. . . . . . . . . . . . . . . . . . . . . . . . . . 316

7

13. SSE- Intel Pentium . . . . . . . . . . 318

13.1. . . . . . . . . . . . . . . . . . . . . . . . . 322

13.2. . . . . . . . . . . . . . . . . . . . . . . . . 328

13.3. . . . . . . . . . . . . . . . . . . . . . . . . . . . 341

13.4. . . . . . . . . . . . . . . . . . . . . . . . . 347

13.5. . . . . . . . . . . . . . . . . . . . . . . . . . . . 354

13.6. . . . . . . . . . . . . . . . . . . . . . 356

13.7. . . . . . . . . . . . . . . . . . . . . . . . 356

13.8. . . . . . . . . . . . . . . . . . . . 360

14. SSE2 Intel Pentium 4 . . . . . . . . 362

14.1. 128- . . . . . 364

14.2. 128- . . . . . . . . 385

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 397

. 80x86 . . . . . . . . 399

. 80x86 . . . . . . 406

. . . . . . . . . . . . . . . . . . . . . . . . . . . 409

8

Intel Pentium. ,

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Intel Pentium.

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Intel Pentium 4 -

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12, MMX- Intel Pentium. -

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Intel. Intel ,

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Intel. 1979 . Intel

16- 8086,

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( 8086)

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Intel Pentium

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Intel Pentium P6,

1995 . -

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P6 Intel Pentium Pro.

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Intel Celeron, Intel Pentium III Intel Pentium III Xeon.

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(static) (Random Access

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4- 8- ,

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(advanced transfer cache).

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:

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Hyper Pipelined;

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assume CS:code, DS:datacode segmentstart:mov AX, datamov DS, AXmov , 09hmov DX, offset strint 21hmov AX, 4C00hint 21h

code endsdata segmentstr DB "Test string$"

data endsend start

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9 1001 9

10 1010 A (a)

11 1011 B (b)

12 1100 C (c)

13 1101 D (d)

14 1110 E (e)

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A B C D E F G H I J K L M N O P Q R S T U V W X Y Za b c d e f g h i j k l m n o p q r s t u v w x y z0 1 2 3 4 5 6 7 8 9? @ _ $ : . [ ] ( ) < > { }+ / * & % ! ' ~ | \ = # ^ ; , ` "

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3.2. 35

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.

EQU:

k EQU 1024adr EQU [BP]cle EQU XOR AX,AXd EQU BYTE PTRt EQU 'File'MASM EQU 5.1 + 0.9Msft EQU mat EQU 20*30

LABEL :

LABEL

LABEL - .

.

: BYTE, WORD, DWORD, QWORD,TBYTE, NEAR, FAR.

LABEL:

byte_array LABEL BYTEword_array DW 10 DUP(0)

byte_array word_array .

3.2. 37

3.3. Intel Pentium

,

, -

. -

Intel Pentium, :

8 , -

;

6 ;

EFLAGS, - ( )

;

- EIP ;

() ;

.

Intel Pentium.

Intel Pentium

. -

. 3.6.

. 3.6. Intel Pentium

38 3

. 32- (EAX, EBX,ECX, EDX, ESI, EDI, EBP, ESP), :

;

;

.

-

, -

ESP , . -

- -

. ECX, ESI EDI. , ,

, , ,

DS. -

:

EAX ;

EBX , , - DS;

ECX ;

EDX -;

ESI , , - DS ( -);

EDI , , ES ( --);

ESP , SS;

EBP , , - SS.

16 32- -

, 16- 8086 AX, BX,CX, DX, BP, SI, DI, SP. , 16- AX, BX, CX DX - 8- (AH, BH, CH, DH), (AL, BL, CL, DL). . 3.7.

(CS, DS, SS, ES, FS GS) 16- - . ,

3.3. Intel Pentium 39

.

4.

. 3.7.

, ,

: /

EFLAGS - EIP. .

EFLAFS, , 32 - , , ,

. . 3.8

.

. 3.8. /

40 3

. 3.8 -

:

OF ( ) ,

;

DF ( ) . DF = 0, , . DF = 1, ;

SF ( ) , SF = 1;

ZF ( ) 1, 0;

AF ( ) - - .

( 3);

PF ( ) 1, ;

CF ( ) , .

CF stc, clc cmc. , ,

bt, bts, btr btc. ,

, -

(BCD) .

, CF 1 ( ) . -

( ), -

1 OF.

BCD, AF . SF , . ZF .

-

CF adc ( ) sbb( ) , -

.

jCC (CC : eq, le, lt, ne . .), setCC, loopCC cmovCC.

-

pushf, pushfd, popf, popfd. , AX - lahf sahf.


EIP . -

jCC, call, ret iret, EIP - -

, . -

- , -

, call, , .

EIP , - , , - . ,

call.

, ,

.

. 32- Intel Pentium

:

, , (flat memory model) -

. -

. , , -

.

, 232.

. 3.9;

. 3.9.

(segmented memory model)

, -

42 3

. , -

. ,

,

( ) . , 32--

, 16 383 ,

232 . -

. 3.10.

. 3.10.

: , ,

, -

. -

.

.

. ,

,

;

(real-address mode memory model)

, 8086. -

, -

16- .

, -

64 . ,

, 220 .


32- -

, , . 32- -

, ,

. 32-

16- 32- . 16--

16-

16- .

, -

. - -

.

, -

.

,

, .

, .

- , , -

. - -

, -.

, , -

.

:.

16 : 16 16 : 32.

(Effective

Address, EA).

. -

, -

, . 3.2.

3.2.

CS

SS

,

,

ESP EBP

DS

, ,

-

- ES ,

ES

-

44 3

, -

. 3.2.

DS, - , .

, , EAX , ES , EBX.

mov ES:[EBX], EAX

, -

.

-

, ,

. :

-

CS;

-

ES;

-

SS.

. 16--

, , , :

mov DS, BX

, BX, - DS. - 48- , .

32- , 16- -

.

, , -

.

-

, . -

,

, , -

.

, , -

. -

:

, 8-, 16- 32- ;

, -

;


,

;

, 2, 4 8.

, , ,

, -

. , . 3.11.

. 3.11. (EA)

,

-

:

ESP ;

ESP EBP, SS. DS.

, ,

, .

.

.

1.

. . -

. -

,

mov AX, mem1

mem1 . -, - , -

. , , mem1 -. , , , -

PTR:

mov AX, word ptr mem1

, mem1 . - AX 1D7Fh (. 3.12).

46 3

. 3.12. mem1

AX mem1,

mov AX, word ptr mem1+2

AX mem1(. . 3.12), AX 0EC34h ( - !).

PTR.

PTR

PTR , , .

, . 3.3.

3.3. PTR

BYTE 1

WORD 2

DWORD 4

QWORD 8

TBYTE 10

NEAR 0FFFFh

FAR 0FFFEh

. BYTE, WORD, DWORD,QWORD TWORD , NEAR FAR . PTR , . , PTR ,

(, WORD). 2. -

(). -

, .

.

lea BX, mem1mov AX, [BX]

mem1 . - BX, AX


, , BX. - . 3.13.

. 3.13.

, mem1 1A9Fh 1CD6h ( ) 1CD7 (-

). BX mem1, . AX mem1.

3.

( + ). -

:

, 2. -

, -

;

. -

, -

, . ,

EBP, . - .

, , -

. MASM

:

[ + ][][]

48 3

, , -

, . :

. . .s1 DB "String 1". . .lea EBX, s1mov AL, byte ptr [EBX][5]. . .

(lea EBX, s1) EBX , - ( 0).

EBX 5, 6- s1 ( g), AL. , - AL g. - . 3.14.

. 3.14.

4. -

+ .

,

. ,

AL s1 10 (11- , +):

. . .s1 DB "!@#$%^&*()+][". . .mov EBX, 10mov AL, byte ptr s1[EBX]. . .


5. -

( ) + .

, , 2, ,

. . -

, .

, :

. . .s1 DB "0123456789ABCDEF". . .mov EBX, 7mov AL, byte ptr s1[EBX*2]. . .

EBX AL E, 14 (7 2) s1.

6. -

+ + .

-

, .

, :

. . .s1 DB "ABCD EFGH IJKLM"s2 DB "abcd efgh ijklm"s3 DB "0123 4567 89"sarray label dword

DD s1DD s2DD s3

. . .mov EBX, sarray+4mov ESI, 10mov AL, byte ptr [EBX][ESI][2]. . .

sarray, s1 s3. , - . , k, - s2. EBX , ESI . EBX s2, (- mov EBX, sarray+4), ESI , k ( 10).

mov ESI, 10

k 2 ijklm, - AL:

mov AL, byte ptr [EBX][ESI][2]

7.

+ ( ) + . -

50 3

, -

, .

, :

. . .a1 DD 45, -87, 23, -11, 83, -442, 56, -340a2 DD 92, -31, 9, -598, 361, 406, -172, 7a3 DD 234, 8, -177, 921, 380, -12, 0, -51iarray label dword

DD a1DD a2DD a3

. . .mov EBX, iarray+8mov ESI, 4mov EAX, [EBX][ESI*2][8]

(a1 a3), - . , 380 ( -

) EAX. , .

EBX a3 ( mov EBX, iarray+8), - . , EBX . ESI , - 4 ( )

mov ESI, 4

, a3 (380) EAX:

mov EAX, [EBX][ESI*2][8]

[ESI*2], 8, a3c 2 ( 177), [8] 8. (EBX, ESI, 8) (EA) .

, - -

,

.

:

MASM 7.10 Windows XP DDK.

, -

. -

. , -

20 EAX:

sub EAX, 20

, div idiv, . -

, -

, (232).


, ,

. -

, .

, .

:

mov EAX, EDXadd EAX, ECX

.

:

mov EAX, BL

EAX BL , .

Intel Pentium.

,

. (general-purpose instructions) -

:

(, ) ;

(, ,

);

;

( , -

);

( ,

, ).

- (, -

, -

. .).

,

, , (EAX,EBX, ECX, EDX, ESI, EDI, EBP, ESP) (CS, DS, SS, ES, FS, GS).

MASM 6.14 -

Intel Pentium, MMX-,

SSE- SSE2-,

. .

52 3

-

.

, , -

. , -

MASM Microsoft,

. -

. 3, -

.

4.1.

, ,

.

Intel Pentium :

. 16--

-

64 , 32- 4 .

, -

, .

, 16, ,

, .

. -

, , -

. -

. ,

64 ,

, .

4

, ,

, -

. , ,

, -

. :.

32- -

. , ( )

32-

.

:

, . MASM -

,

CS, DS SS .

4.2.

MASM

MASM , -

, , , -

Microsoft. -

,

.

,

:

.DATA (.data) _DATA . .MODEL. , - .DATA, , , :

.dataval1 DW 11string1 DB "Text string"byte1 DB ?

.DATA? (.data?) , - .

.

.DATA? ?. .DATA? , - , , -

. .MODEL. .DATA?:

.data?DB 5 DUP (?)

54 4

.CONST (.const) , - . -

.

, -

. , .CONST, . .MODEL.

.STACK (.stack) [] , .

, 1 . -

. -

.MODEL.

.CODE (.code) [] , .

_TEXT, . , _TEXT tiny, small,compact flat __TEXT medium, large huge. .MODEL, , .

.MODEL (.model) _ [,__] [,_] [,-_] , .

-

. -

, tiny, small, compact, medium, large, huge flat. _ .

,

, , -

. ,

() .

, .386,.486, .586, .686. , (near far). , . . 4.1 .

4.1.

TINY NEAR NEAR MS-DOS

SMALL NEAR NEAR MS-DOS, Windows

MEDIUM FAR NEAR MS-DOS, Windows

COMPACT NEAR FAR MS-DOS, Windows

LARGE FAR FAR MS-DOS, Windows

HUGE FAR FAR MS-DOS, Windows

FLAT NEAR NEAR Windows NT, Windows 2000,

Windows XP, Windows 2003

4.2. 55

MASM, -

6.1.

small . near (). large . (far).

medium , -

(far), (near). compact , - (far), (near). huge large.

, -

. , -

large (near). , - .

tiny 16- MS-DOS. .

64 . ,

flat - 32- .

tiny , , 32-. ,

flat. flat .model flat

: .386, .486, .586 .686. - , ,

Intel Pentium .386 .486. ,

,

16- 32- .

(near), 32-. __ -

,

(C++, Pascal). :

C, BASIC, FORTRAN, PASCAL, SYSCALL, STDCALL. , , -

, ,

.

-

.

_ OS_DOS, - .

56 4

, _

NEARSTACK ( SS DS, ) FARSTACK ( SS DS, ). -

NEARSTACK. .MODEL:

.model flat, c

flat , 32- . c , (, -

) , C.

:

.model large, c, farstack

large, C ( SS DS).

.model medium, pascal

medium, - Pascal ,

.

4.3. MASM

, MASM,

, ,

, .

, (main), , -

. -

, ,

. ,

.MODEL. - 32-,

, 16-

, . 16- .

16- , -

MASM:

.model small, c ; ;

.stack 100h ; 256

.data ;

. . .; . . ..code ; main:. . .

4.3. MASM 57

; . . .end mainend

end main main . end . 16- MS-DOS

, -

. 4.1 .

4.1. MS-DOS

.model large

.datas1 DB "TEST STRING$"

.codemov AX, @datamov DS, AXlea DX, s1mov AH, 9hint 21hmov ax, 4c00hint 21h

end

s1. DS , - .data:

mov AX, @datamov DS, AX

s1, DS:DX, - 9h 21h MS-DOS.

.

32- :

.model flat

.stack

.data; .codemain:. . .; . . .end mainend

(flat), 32- near.

, 32- -

( .data), (- .stack) ( .code).

58 4

, 32- -

/ .

SEGMENT. SEGMENT - :

SEGMENT . . . ENDS

, SEGMENT , flat. SEGMENT - ,

flat. ASSUME:

ASSUME CS:FLAT, DS:FLAT, SS:FLAT, ES:FLAT, FS:ERROR, GS:ERROR

FS GS , ERROR.

32- -

( _seg_ex), . src, data1, dst data2 (code segment).

, ( -

):

_seg_ex (, _seg_ex proc _seg_ex endp). _seg_ex 4.2.

4.2. 32-

.586

.model flatoption casemap:none

data1 segmentsrc DB "Test STRING To Copy"len EQU $-src

data1 endsdata2 segment publicdst DB len+1 DUP('+')

data2 endscode segment_seg_ex procassume CS:FLAT,DS:FLAT, SS:FLAT, ES:FLAT, FS:ERROR, GS:ERRORmov ESI, offset data1mov EDI, offset data2cldmov CX, lenrep movsbmov EAX, offset data2ret

_seg_ex endpcode endsend

4.3. MASM 59

flat 32-- , , -

( src dst) ESI EDI,, :

mov ESI, offset data1mov EDI, offset data2

src dst, CX :

cldmov CX, lenrep movsb

EAX - dst. , ,

.model flat. -: , flat, , , .

,

Visual C++ .NET (

). 4.3.

4.3. , seg_ex

#include extern "C" char* seg_ex(void);int main(void){printf("EXTERNAL MODULE EXAMPLE: %s\n", seg_ex());return 0;

}

seg_ex , extern.

EXTERNAL MODULE EXAMPLE: Test STRING To Copy+

60 4

, , , -

.

, , , C++ Pascal, -

, ,

.

-

. , ,

:

, - -

.

A, B,

C. if else. , if else, - switch case.

, .

, -

. -

while, do while, for, repeat until . .

. ,

? ,

,

, , ,

.

5

:

, , .IF .WHILE, ( MASM).

, if else, , . -

, , -

, . ,

, -

, .

-

.

,

. -

, , ,

if else, while , :

;

( )

.

-

,

. , -

, -

.

-

; .

, -

EFLAGS . 16

.

. -

:

CF (Carry Flag ) (0 1) -

;

PF (Parity Flag ) 8 . -

0, 1.

;

AF (Auxiliary Carry Flag ) - 1, -

( 3) .

ASCII--

, ;

62 5

ZF (Zero Flag ) - . -

0, 1.

je jz;

SF (Sign Flag ) - ( ) -

: 0, -

1.

jg jl;

TF (Trap Flag ) - 1, ,

;

IF (Interrupt Flag ) , ;

DF (Direction Flag ) - . -

SI (ESI) DI (EDI), ;

OF (Overflow Flag ) -, () -

.

CF, SF, ZF, PF, DF, - OF AF. , - , TF IF.

,

.

5.1.

.

next ECX. - ECX cmp, - AF, CF, OF, PF, SF ZF:

. . .cmp ECX, 0jz next , ECX 0

next: , ECX 0

. . .

5.1. 63

ECX , cmp ZF . jz ZF , 1, - , , next. if, - ECX = 0.

-

cmp. ZF, - ECX. jz next, .

Intel , -

.

-

(cmp, test), (add, sub .) (and, or, xor). , test SF, ZF PF. OF CF , AF . , test . ,

:

. . .test AX, 1jne bit1_set. . .

AX. 1, ZF 0 bit1_test.

, -

. -

.

, .

, -

, : . -

, ,

. -

, .

, AX 11000110B, BX 00010110B, - AX BX, . - . 5.1.

5.1.

JE/JZ , / ZF

JNE/JNZ , / ZF

64 5

JA/JNBE , / ZF, CF

JAE/JNB , / CF

JB/JNAE , / CF

JBE/JNA , / CF, AF

-

. , jb jnae , jb , jnae.

. 5.2.

5.2.

JE/JZ , / ZF

JNE/JNZ , / ZF

JG/JNLE , / ZF, SF, OF

JGE/JNL , / SF, OF

JL/JNGE , / SF, OF

JLE/JNG , / ZF, SF, OF

,

(je/jz) (jne/jnz) - . / .

- ,

. . 5.3.

5.3.

JS , SF

JNS , SF

JC , CF

JNC , CF

JO , OF

JNO , OF

JP/JPE , PF

JNP/JP , PF

-

CX . - . jcxz - , CX.

5.1. 65

5.2. jmp

jmp, , .

- EIP .

, -

, ,

. , -

- EIP. , -

CS. : - jmp:

jmp short _jmp near ptr _jmp far ptr _

_ , -

. jmp:

jmp label1 ; , ; ,

jmp near ptr label1 ; ;

jmp short label1 ; , ; , ; -128 - +127

jmp far ptr label1 ; , ; , ;

, . short , 128 +127,

.

EIP 8- . near ptr ,

EIP 16- . , far ptr , . CS, - EIP.

jmp 16- MS-DOS,

64 ,

.

32- -

4 .

, 3, flat,

66 5

, , -

. 32--

.

32- -

. ,

DOS, 32- Windows- COM-, -

. 32-

(near ptr) 4 .

jmp - , .

, :

jmp reg16jmp reg32jmp word ptr [reg16]jmp dword ptr [reg32]

reg16 (reg32) 16- 32- .

, , -

.

32- (reg32), , -

, 32-. -

jmp 32- Windows-. jmp -

, , -

, . :

. . .

.code. . .

L1:xor EDX, EDX. . .lea ESI, L1jmp ESI. . .

ESI L1, - jmp ESI .

. . .

.datalabel_offset DD L1

.code. . .

L1:xor EDX, EDX. . .lea ESI, label_offsetjmp dword ptr [ESI]. . .

5.2. jmp 67

ESI label_offset, label_offset L1. jmpdword ptr [ESI] L1.

,

,

,

. .

16- , -

5.1, s1, s2 s3.

5.1.

.model small

.stack 100h

.datas1 DB 0dh, 0ah, "String 1$"s2 DB 0dh, 0ah, "String 2$"s3 DB 0dh, 0ah, "String 3$"

sarray label word ; , DW s1 ; s1 s2DW s2DW s3

num DW 0 ; jmplabel_array label word ;

DW L1 ; L1DW L2 ; L2DW L3 ; L3

.codestart:mov AX, @datamov DS, AXmov ES, AX;mov CX, 3 ; -> CXlea DI, label_array ;

next:mov SI, DImov BX, num ; -> BXshl BX, 1 ; 2

; label_arrayadd SI, BX ;

; jmpjmp word ptr [SI] ; ,

; SI (L1 L2)wedge:inc num ; loop next ; ;

L1: ; L1lea DX, s1mov AH, 9hint 21h

68 5

jmp wedge ; L2: ; L2lea DX, s2mov AH, 9hint 21hjmp wedge

L3: ; L3lea DX, s3mov AH, 9hint 21h;mov AH, 1h ; int 21h;mov AX, 4c00h ; int 21hend startend

-

jmp , - L1, L2 L3. jmp SI : SI label_array, , ( L1 L3 ).

-

. , L2 label_array 2 ( num = 1). :

String 1String 2String 3

, jmp -

. , , -

jmp - switch case C++ ( case Pascal), .

,

, ,

jmp. 32- ( _case_1).

02, EAX , -. ,

_case_1, .

5.2. jmp 69

EBP, - EBX. - 5.2.

5.2. case

.686

.model flatoption casemap: none.datas1 DB "String 1", 0s2 DB "String 2", 0s3 DB "String 3", 0err DB "Incorrect parameter!", 0label_array label dword ; ,

; ; L1, L2 L3

DD 3 DUP (?).code_case_1 procpush EBPmov EBP, ESPmov EBX, dword ptr [EBP+8] ; ( )

; EBXlea ESI, label_array ; -> ESImov [ESI], offset L1 ; mov [ESI+4], offset L2 ; L1, L2 L3mov [ESI+8], offset L3lea EAX, err_exit ; EAX

; ;

shl EBX, 2 ; ; ,; 4

cmp EBX, 8 ; ; 8 ( ; 02)

jle next1 ; 8? ; ,

jmp EAX ; , 2,;

next1:cmp EBX, 0 ;

; ? jge get_string ; ,

; jmp EAX ; , ,

; get_string: ;

; , ; ;

cmovge EAX, [ESI][EBX]jmp EAX

L1: ; ; ,; 0

70 5

lea EAX, s1 ; s1 -> EAXjmp exit ;

L2: ; ; ,; 1


L3: ; ; ,; 2


err_exit: ; ;

lea EAX, err ; -> EAXexit:pop EBPret

_case_1 endpend

lea ESI, label_arraymov [ESI], offset L1mov [ESI+4], offset L2mov [ESI+8], offset L3

,

. 32- -

, , label_array , L1, L2 L3. , .

EAX , - :

lea EAX, err_exit

jmp EAX

( EAX), - , .

(L1, L2 L3), - :

shl EBX, 2

,

02, , .

,

cmovge EAX, [ESI][EBX]

5.2. jmp 71

. -

, cmovge, -, :

( SF);

SF = 1, EAX (L1, L2 L3). , - label_array ( ESI) ( EBX).

.

5.3.

, , . -

() -

, .

:

;

, .

:

. , , -

. ,

:

. . .

.datas1 DB "ABCDFEG", 0

.code. . .mov AL, 0lea SI, s1

next:cmp byte ptr [SI], 0je exitinc SIinc ALjmp next

exit:. . .

. -

AL, 0. - ,

, . SI. , , -

DS : SI. -

cmp byte ptr [SI], 0

72 5

, .

0, AL 1, SI

inc SI

. , -

( ).

,

. -

A s1. - len, - :

. . ..datas1 DB "ABCAEFGAGEBA"len EQU $-s1

.code. . .mov DX, lenmov AL, 'A'xor BL, BLlea SI, s1

next:cmp byte ptr [SI], ALje inc_counter

continue:dec DXjz exitinc SIjmp next

inc_counter:inc BLjmp continue. . .

exit:. . .

, .

len, DX DX 1. DX, 0. A - , BL (- 0).

-

AL. , - A, BL :

cmp byte ptr [SI], ALje inc_counter. . .

inc_counter:inc BL

5.3. 73

BL. - -

loop, .

loop CX (ECX), ,

128 +127 . CX (ECX) . loop CX (ECX) . loop : ,

.

loop:

. . .

.datacounter DW 5

.code. . .xor AX, AXmov CX, counter ; -> CX

next:inc AX ; AXloop next ;

. . .

AX 5. loop , ,

:

. . .

.datacounter DW 5

.code. . .xor AX, AXmov CX, counter ; -> CX

next:inc AX ; AXdec CX ; CXjcxz skip ; CX = 0, jmp next ;

. . .skip:. . .

jcxz jz, :

. . ..datacounter DW 5

.code

74 5

. . .xor AX, AXmov CX, counter ; -> CX

next:inc AX ; AXdec CX ; CXjnz next ; CX = 0, ,

; . . .

loop loope/loopz loopne/loopnz. loope/loopz. loope loopz - .

. -

CX (ECX), 0 ZF 1, .

loope. 16-,

( 5.3).

5.3.

.model small

.datas1 DB " String with leading blanks !$"len EQU $-s1msg DB "Blank string!$"

.codestart:mov AX, @datamov DS, AXlea SI, s1 ; -> SIdec SI ; mov CX, len ; -> CXmov AL, ' ' ; -> AL

next:inc SI ; cmp byte ptr [SI], AL ; loope next ; , ,

; ,; ;

cmp CX, 0 ; ?je fail ; , ,

; mov DX, SI ; , ,

; ,; , DX

show:mov AH, 9h ; int 21hmov AH, 1hint 21h

5.3. 75

mov AX, 4C00hint 21h

fail:lea DX, msgjmp showend startend

loopne/loopnz. loope/loopz , , ZF = 0. - loopne loopnz . loopne 5.4. - , 16- , -

, + ( String 2).

5.4. +

.model small

.datas1 DB "String 1+String 2$"len EQU $-s1msg DB "Char + not found!$"

.codestart:mov AX, @datamov DS, AXlea SI, s1dec SImov CX, lenmov AL, '+'

next:inc SIcmp byte ptr [SI], ALloopne nextcmp CX, 0je failmov DX, SI

show:mov AH, 9hint 21hmov AH, 1hint 21hmov AX, 4C00hint 21h


, loop - ,

.

76 5

5.3 ()

, ,

loop, . 32- , -

.

loopd, loop - , ECX, 4. , -

4 , ECX - . -

4 ,

. loopd , loop. , loopd Intel.

loopd - 32- , -

, 100.

EAX, 0 . ( _loopd_ex) 5.5.

5.5. , 100

.586

.model flatoption casemap: none.dataa1 DD 312, -45, 91, -16, -377 ; len EQU $-a1 ;

.code_loopd_ex procmov ECX, len ; -> ECXshr ECX, 2 ; lea ESI, a1 ; -> ESImov EAX, -100 ; -> EAX

next:cmp EAX, [ESI] ;

; EAXjge found ; -100,

; add ESI, 4 ; -100,

; loopd next ; jmp not_found ; , -100

found:mov EAX, [ESI] ; -> EAXjmp exit ;

not_found:mov EAX, 0 ; EAX

; 0exit:ret

_loopd_ex endpend

5.3. 77

, , ,

4 .

5.4. Intel Pentium

-

, -

.

, -

,

.

-

, Intel Pentium,

, . -

, .

, . ,

-

, .

, .

Intel Pentium -

, , -

.

--

, , , -

. Intel

Pentium ,

.

.

Intel

, Pentium II, , -

.

setCC, cmovCC fcmovCC, CC (e, ne, le . .). setCC.

:

setCC reg8setCC mem8

setCC : sete/setz, setl/setnge . ., reg8/mem8 , 8-

, AL, AH, BL . ., . , 1, 0. -

78 5

setCC , .

:

cmp AL, 0sete BL

cmp - AL, ZF 1. sete - BL 1. AL - , , BL 0.

setCC . 5.4.

5.4. setCC

SETAE/SETNB , / CF

SETE/SETZ , / ZF

SETNE/SETNZ , / ZF

SETB/SETNAE , / CF

SETBE/SETNA , / CF, ZF

SETL/SETNGE , / SF, OF

SETGE/SETNL , / SF, OF

SETG/SETNLE , / ZF, SF, OF

SETS , SF = 1 SF

SETNS , SF = 0 SF

SETC , CF = 1 CF

SETNC , CF = 0 CF

SETO , OF = 1 OF

SETNO , OF = 0 OF

SETP/SETPE , PF = 1 PF

SETNP/SETPO , PF = 0 PF

setCC . , -

. . -

, 50 100. -

find_num, 5.6. a1, -

ESI. -, :

100 ( cmp dword ptr [ESI], 100 jle next1), 50 ( cmp dword ptr [ESI], 50 jge found). setCC .


5.6. , 50100

.686

.model flatoption casemap: none.dataa1 DD 34, -53, 88, 13, 67len EQU $-a1

.codefind_num proclea ESI, a1 ; -> ESImov ECX, len ; -> ECXshr ECX, 2 ;

next:cmp dword ptr [ESI], 100 ; 100?jle next1 ; , jmp next_addr ; 100,

; next1:cmp dword ptr [ESI], 50 ; 50?jge found ; , ,

; EAX next_addr: ; add ESI, 4dec ECX ; jnz next ; ECX 0,

; mov EAX, 0 ; ,

; , EAX 0jmp exit

found:mov EAX, [ESI] ; -> EAX

exit:ret

find_num endpend

5.7 ,

setCC.

5.7. setCC 5.6

.686

.model flatoption casemap: none.dataa1 DD 34, -53, 88, 13, 67len EQU $-a1g50 DB ? ; l100 DB ?

.codefind_num proclea ESI, a1 ; -> ESImov ECX, len ; -> ECXshr ECX, 2 ;

80 5

next:cmp dword ptr [ESI], 50 ; 50?setge g50 ; , g50 1,

; g50 0cmp dword ptr [ESI], 100 ; 100?setle l100 ; , l100 1,

; l100 0mov AL, g50 ; g50 l100cmp AL, l100je found ; ,

; add ESI, 4 ; , g50 l100, dec ECXjnz nextmov EAX, 0 ; , ,

; EAX 0jmp exit

found:mov EAX, [ESI] ; -> EAX

exit:ret

find_num endpend

.

, ,

. -

EAX 88.

, , cmovCC. :

cmovCC src, dst

CC (e, ne, nz, le . .), src 16- 32-- , dst 16- 32- .

, , dst

src. , src . -

cmovCC:

.dataop1 DW ?

.code

. . .cmp AX, op1cmovge AX, op1. . .

AX op1, op1 - AX. AX op1, -.

cmovCC - . cmovCC , , cpuid.


, -

, .

.

, -

:

. . .

.datanum1 DD 12num2 DD 11

.code

. . .clcmov EAX, num1mov EDX, num2cmp EAX, EDXjg num1_g_num2mov EBX, EDXjmp exit

num1_g_num2:mov EBX, EAX

exit:. . .

num1 num2, EBX. jg, , num1 num2. - cmovl. - :

. . .

.datanum1 DD 12num2 DD 11

.code. . .mov EAX, num1mov EDX, num2cmp EAX, EDXcmovl EAX, EDXmov EBX, EAX. . .

. EAX (num1), EDX (num2). - :

cmp EAX, EDX

EAX EDX, EDX EAX, EAX , EAX EDX:

cmovl EAX, EDX

, EAX EBX. - , .

82 5

cmovCC , -. cpuid.

. (

) . jge, :

.datanum1 DD -18

.code. . .mov EAX, num1cmp EAX, 0jge exitneg EAX

exit:. . .

, cmp -. , cmovl. - :

. . .

.datanum1 DD 18

.code. . .mov EAX, num1mov EDX, EAXneg EDXcmp EAX, 0cmovl EAX, EDX. . .

find_num, setCC cmovCC ( 5.8).

find_num, ( - ). , g50 l100 cmove EAX, [ESI] EAX. je exit ( ZF = 1), ( add ESI, 4). cmove EAX, [ESI] , je exit, , - , cmp AL, l100. , - .

- , ,

.

, ,

, -

. -

, .

, -

.


5.8. , 50100

( )

.686

.model flatoption casemap: none.dataa1 DD 34, -93, 95, 13, 7, 1len EQU $-a1g50 DB ?l100 DB ?

.codefind_num proclea ESI, a1mov ECX, lenshr ECX, 2

next:cmp dword ptr [ESI], 50setge g50cmp dword ptr [ESI], 100setle l100mov AL, g50cmp AL, l100cmove EAX, [ESI]je exitadd ESI, 4dec ECXjnz nextmov EAX, 0

exit:ret

find_num endpend

.

, -

-

. :

:

jmp

, -

:

xor EBX, EBXLl:

inc EBXcmp EBX, 100000je exitjmp Ll

exit:

EBX 0 100 000, exit.

84 5

.

,

.

,

:

. . .mov EDX, 100000

L1:. . .

. . .dec EDXjnz L1

exit:. . .

, -

EDX. , . - ZF, 0, , . -

.

-

,

. ( 5.9).

.

32- ( _set0).

5.9.

.686

.model flatoption casemap:none.dataiarray DD -73, 931, -89, 92, -5, 67, 30len EQU $-iarray

.code_set0 proclea ESI, iarray ; -> ESImov EDX, len ; ( ) -> EDXshr EDX, 2 ;

next:cmp dword ptr [ESI], 0 ; jge no_change ; , mov dword ptr [ESI], 0 ; , 0

no_change:add ESI, 4 ; dec EDX ; 1jnz next ; lea EAX, iarray ; -> EAXret

_set0 endpend


, -

next jnz next . jge no_change, - .

,

. setge., (-

5.10).

5.10. 5.9,

setge

.686

.model flatoption casemap:none.dataiarray DD 273, 417, -31, -92, 5, -67, 360len EQU $-iarray

.code_set0 procpush EBXlea ESI, iarraymov EDX, lenshr EDX, 2

next:xor EBX, EBXcmp dword ptr [ESI], 0setge BLimul EBX, dword ptr [ESI]mov dword ptr [ESI], EBXadd ESI, 4dec EDXjnz nextlea EAX, iarraypop EBXret

_set0 endpend

,

, . -

(unrolling) .

,

.

, ,

.

() , -

, -

( src) (dst). - 5.11.

86 5

5.11.

. . .

.datasrc DD 345, -65, 12, 99, 369, 267len EQU $-srcdst DD 6 DUP (?)

.code

. . .mov ESI, src ; src> ESImov EDI, dst ; dst -> EDImov ECX, len ; -> ECXshr ECX, 2 ;

; L1:mov EAX, [ESI]add ESI, 4mov [EDI], EAXadd EDI, 4dec ECXjnz L1

. . .

-

. -

5.12 ( ).

5.12. 5.11

. . .

.datasrc DD 345, -65, 12, 99, 369, 267len EQU $-srcdst DD 6 DUP (?)

.code

. . .mov ESI, src ; src> ESImov EDI, dst ; dst -> EDImov ECX, len ; -> ECXshr ECX, 3 ;

; (; )

L1:mov EAX, [ESI] ;

; EAXmov EBX, [ESI + 4] ; EBXmov [EDI], EAX ; EDImov [EDI + 4], EBX ;

; EDI 4 add ESI, 8 ; , add EDI, 8 ; dec ECXjnz label ;

; . . .


-

, .

, , .

.

10

0, 1. -

, -

, 5.13.

5.13.

. . .

.dataiarray DD 10 dup (0)len EQU $-iarray

.code

. . .mov ECX, len ; ( ) -> ECXlea ESI, i1 ; -> ESImov EBX, 2 ; 2 EBX

; , next:mov EAX, ECX ; -> EAXdiv EBX ; ,

; cmp EDX, 0jne store_1 ; ,

; 1mov DWORD PTR [ESI], 0 ; , 0jmp next_addr

store_1:mov DWORD PTR [ESI], 1

next_addr: ; add ESI, 4loop next. . .

, -

. -

, unr_1. 5.14.

5.14. 5.13

.686

.model flatoption casemap: none.dataiarray DD 10 dup (7)len EQU $-iarray

.code_unr_1 proclea ESI, iarraymov EBX, len

88 5

shr EBX, 2dec EBXxor EDX, EDX

next:mov DWORD PTR [ESI], 0mov DWORD PTR [ESI+4], 1add EDX, 2cmp EDX, EBXjae exitadd ESI, 8jmp next

exit:lea EAX, iarrayret

_unr_1 endpend

,

. -

; ,

.

-

mov DWORD PTR [ESI], 0mov DWORD PTR [ESI+4],1

ESI 8 - add ESI,8, . - EBX:

mov EBX, lenshr EBX, 2dec EBX

.

10 , EBX 9 - . , -

. -

,

, . -

, 1589 , , -

397 -

.

,

.

-

loop . . ,

.

loop, , , loope loopne, - .


, loop . -

, loop , . -

loop . , , , Intel Pentium, -

loop - .

loop :

dest:. . .dec cxjnz dest. . .

loope loopne, -, ,

Intel Pentium. loopCC (CC = e, ne,z, nz) . , -

.

loope 16- (. 5.3)., -

. 5.15 -

.

5.15. 5.3

.model small

.datas1 DB " String with leading blanks !$"len EQU $-s1msg DB "Blank string!$"

.codestart:mov AX, @datamov DS, AXlea SI, s1dec SImov CX, lenmov AL, ' '

next:inc SIcmp byte ptr [SI], ALjne $+7dec CXjnz nextjmp failmov DX, SI

show:mov AH, 9h

90 5

int 21hmov AH, 1hint 21hmov AX, 4C00hint 21h


loope (- ):

. . .jne $+7dec CXjnz next. . .

?

cmp byte ptr [SI], AL

, , . -

cmp ZF 0. jne $+7 ZF , +7 .

.

mov DX, SI

DX -. 7 .

, jne $+7

mov DX, SI

,

CX, 0, . - ,

jmp fail

loopne, , +(. 5.4).

5.16.

, loopne, - .

, , jne je, , (8 7). , ,


dec CX dec CL, - 1 .

5.16. loopne 5.4

.model small

.datas1 DB "String 1+String 2$"len EQU $-s1msg DB "Char + not found!$"

.codestart:mov AX, @datamov DS, AXlea SI, s1dec SImov CL, lenmov AL, '+'

next:inc SIcmp byte ptr [SI], ALje $+8dec CLjnz nextjmp failmov DX, SIinc DX

show:mov AH, 9hint 21hmov AH, 1hint 21hmov AX, 4C00hint 21h


loopCC. , ,

.

92 5

,

, , -

. -

, ,

, .

. -

(

).

, -

, proc endp. , ,

. -

() .

-

, , -

. ,

ASM

, OBJ.

, -

32- Windows:

(Dynamic Link Library, DLL),

.

, DLL. -

DLL

Windows, , -

-

.

6

, -

.

6.1.

, -

.

SS:SP (16- ) SS:ESP (32- ). SP(ESP) 16- 32- - , . , ,

. LIFO (Last In, First Out

, ). ,

, , .

x86 ,

, -

, (2 ).

, . , -

SP (ESP) 2, 4 . .

, .

- ,

push. 16- 32- . -

SP (ESP) 2 ( ) 4 ( ). :

push reg16/reg32push mem16/mem32push segregpush immed

reg16/reg32 16- 32- , mem16/mem32

(16 32 ), segreg

(CS, DS, ES), immed . push c - (immed) Intel Pentium .

push. , , - 16- -

pushf, 32- pushfd. - , 80386. ,

push, - :

pusha 16- (AX, BX, CX, DX, SP, BP, SI, DI);

pushad 32- (EAX, EBX, ECX, EDX, ESP,EBP, ESI, EDI).

push .

94 6

, , 7EE3h

(. 6.1).

. 6.1.

mov BX, 2CE9hpush BX

push - BX , SP 2 - , . 6.2.

. 6.2. push BX

, , ,

16 , SP (ESP) 1. ,

1 . () 2

4 ( ). , -

,

. 6.3:

mov EBX, 4FE91A77hpush EBX

. 6.3.

6.1. 95

4, -

.

pop. ( ) .

16- 32-

. SP (ESP) - 2 ( ) 4 ( ).

pop push - , push. , - popf ( 16- ) popfd ( 32-). - , popa ( 16-- ) popad ( 32-). , , ,

EDX:

pop EDX

EDX 4FE91A77h, 4 (. 6.4).

. 6.4. pop EDX

,

. , push pop , -

. -

:

mov EAX, 11223344hpush EAXpop BXpop CX

push EAX 11223344h. pop BX , 3344h, BX. ESP 2. - pop CX , 1122h, - CX. ESP 2.

. . .

.dataop DW 7777h

.code

96 6

. . .push DS:oppop AX. . .

16- op (- push DS:op), , ( DS). SP 2. pop AX - AX , SP 2. , - AX 7777h.

16--

. 6.1.

6.1. (16- )

.model small

.datanum1 DW '91's1 DB "STRING 1 $"s2 DB "STRING 2 $"

.codestart:

mov AX, @datamov DS, AXpush DS:num1lea SI, s2push SIlea DX, s1mov AH, 9hint 21hpop DXint 21hpop DXxchg DH, DLmov AH, 2hint 21hxchg DH, DLint 21hmov AX, 4c00hint 21hend startend

-

num1 s1 s2, - s1, s2 num1. num1 ( push DS:num1), s2:

push DS:num1lea SI, s2push s2

6.1. 97

4,

, . 6.5.

. 6.5.

s1:

lea DX, s1mov AH, 9hint 21h

s2 DX. s2 :

pop DXint 21h

num1, SP 2. pop DX num1 DX, 2. DX :

pop DXxchg DH, DLmov AH, 2hint 21hxchg DH, DLint 21h

: , -

, , -

, . ( )

. , s1 - S.

, . -

- ,

-

- . ,

, . , -

, .

98 6

-

, -

.

push pop. , , -

, BP(EBP). SP (ESP) BP (EBP), . ( 6.2).

6.2. EBP (16- )

. . .

.dataop1 DW 1149hop2 DW 0E37h

.code

. . .mov AX, @datamov DS, AXpush DS:op1push DS:op2mov BP, SPmov AX, word ptr [BP+2]mov BX, word ptr [BP]. . .

op1 op2 , op1 [SP+2], op2 [SP] (. 6.6).

. 6.6. op1 op2

mov BP, SP BP - SP, op1 [BP+2], op2 [BP]. AX 1149h, BX 0E37h.

32- Intel Pentium

EBP ESP. ,

6.1. 99

op2 op1, EAX:

.686

.model flatoption casemap: none.dataop1 DD 145op2 DD 98

.code. . .push op1push op2mov EAX, dword ptr [ESP] ; op1 -> EAXsub EAX, dword ptr [ESP+4] ; op2 - op1 > EAX. . .

-

, pop .

add:

add ESP, n

n , -

SP (ESP). , (12 ):

.code

. . .push EAXpush EBXpush ECX. . .add ESP, 12. . .

push 12 ( ), -

, add. , .

6.2.

, ,

,

-

.

. (-

) , :

. . .mov AX, 0mov BX, 0

100 6

jmp startadd1 proc ; add1inc AXret ;

add1 endpsub1 proc ; sub1dec BXret ;

sub1 endpstart:call add1 ; add1call sub1 ; sub1jmp start

, ( -

) proc, - endp. - ret. ASM .

proc. proc ,

. ,

.

proc : near far. - near , , far , . , ,

near ( near ). (near) -

, , (far) -, , . 32-

.

, , -

,

.

, ,

.

, -

, -

:

mov AX, 0mov BX, 0

next:call add1call sub1jmp next

add1: ; , inc AXret

sub1: ; , dec BXret

6.2. 101

proc endp , () .

,

. ,

proc endp, . - call, , - . -

ret, , call.

call ret. - .

, ,

, ret - , .

, , , .

call , call, SP (ESP). ret - , -

.

(near far) ret call . call - . ., ,

.

, ret . ,

, , ,

. ret , -

,

.

call :

( );

( ,

);

( -

, );

( , -

, , -

).

-

. .model near far

102 6

, tiny, small compact - near, medium, large huge far. far- medium, large huge . 32-, flat, - (near).

call. - , call -

EIP , .

-

, 3

( E8h ).

call : ,

. -

EIP CS: EIP , , CS .

, 5 (

9Ah, ).

far ptr, , .

6.3 , -

.

6.3. (16- )

.model largedata segments1 DB 0dh, 0ah, "Direct far call of subr1 demo !$"s2 DB 0dh, 0ah, "Direct far call of subr2 demo !$"

data endscode1 segmentassume CS:code1main proc ; mov AX, @datamov DS, AXcall far ptr subr1 ; subr1call far ptr subr2 ; subr2

; call ; : 9

mov AH, 1hint 21hmov Ax, 4C00hint 21h

main endpcode1 ends

6.2. 103

. . .code2 segmentassume CS:code2subr1 proc far ; subr1

lea DX, s1mov AH, 9hint 21hret ; ret 0h (

; )subr1 endpsubr2 proc far ; subr2

lea DX, s2mov AH, 9hint 21hret ; ret 0h (

; )subr2 endpcode2 ends. . .

subr1 subr2 - s1 s2. call ,

, . 6.7.

. 6.7.

( far), ret 0CBh, -

(0C3h), -:

EIP CS, . -

retf. . -

, . ,

, , -

. -

16-

( 6.4).

104 6

6.3. ()

6.4. (16- )

.model small

.datas1 DB 0dh, 0ah, "Near indirect call of subr1 !$"s2 DB 0dh, 0ah, "Near indirect call of subr2 !$"addr1 DW subr1addr2 DW subr2

.codestart:mov AX, @datamov DS, AXcall DS:addr1 ; subr1 ,

; addr1call DS:addr2 ; subr2 ,

; addr2mov AH, 1hint 21hmov AX, 4C00hint 21h

subr1 proclea DX, s1mov AH, 9hint 21hret

subr1 endpsubr2 proclea DX, s2mov AH, 9hint 21hret

subr2 endpend startend

subr1 subr2 near , , addr1 addr2 .

( s1 s2) .

:

call BX ; BXcall[BX] ; ,

; BXcall[BX][SI] ; ,

; SI tbl[SI] ; tbl ,

; SI

6.5 16- , -

.

( )

6.2. 105

SI BX, SI tbl , BX .

6.5. (16- )

.model smalldata segmenttbl label word

DW subr1 ; subr1DW subr2 ; subr2DW subr3 ; subr3

s1 DB 0dh, 0ah, "Near indirect call subr1 demo 2 !$"s2 DB 0dh, 0ah, "Near indirect call subr2 demo 2 !$"s3 DB 0dh, 0ah, "Near indirect call subr3 demo 2 !$"

data endscode segmentassume CS:code, DS:datamain procmov AX, datamov DS, AXlea SI, tbl ; -> SIxor BX, BX ; -> BXmov CX, 3 ; -> CX

next:call word ptr [BX][SI] ; add BX, 2 ;

; dec CX ; 1jnz next ; mov Ax, 4C00hint 21hmain endp

subr1 proc ; subr1lea DX, s1mov AH, 9hint 21hret

subr1 endpsubr2 proc ; subr2lea DX, s2mov AH, 9hint 21hret

subr2 endpsubr3 proc ; subr3lea DX, s3mov AH, 9hint 21hret

subr3 endpend maincode endsend

106 6

, -

add BX, 2

next:call word ptr [BX][SI] ; add BX, 2

. . .jnz next

tbl , - BX 2.

:

Near indirect call subr1 demo 2 !Near indirect call subr2 demo 2 !Near indirect call subr3 demo 2 !

. -

,

, ,

.

6.6. 16-

, .

6.6. (16- )

.model largedata segmenttbl label dword

DD subr1 ; subr1DD subr2 ; subr2DD subr3 ; subr3

s1 DB 0dh, 0ah, "FAR INDIRECT CALL subr1 DEMO !$"s2 DB 0dh, 0ah, "FAR INDIRECT CALL subr2 DEMO !$"s3 DB 0dh, 0ah, "FAR INDIRECT CALL subr3 DEMO !$"

data endscode0 segmentassume CS:code0, DS:datamain procmov AX, datamov DS, AXlea SI, tbl ; -> SIpush SI ;

; ; subr1, subr2 subr3

mov word ptr [SI], offset subr1 ; subr1 > ;

mov AX, code1 ; , ; subr1 > AX

mov word ptr [SI+2], AX ; AX -> ; ; ; subr2

add SI, 4

6.2. 107

mov word ptr [SI], offset subr2mov AX, code2mov word ptr [SI+2], AX

; ; ; subr3

add SI, 4mov word ptr [SI], offset subr3mov AX, code3mov word ptr [SI+2], AXpop SI ;

; tblxor BX, BX ; BX,

; ;

mov CX, 3 ; -> CXnext:call dword ptr [BX][SI] ;

; subr1, subr2 subr3add BX, 4 ;

; tbldec CX ; 1jnz next ; ,

; CX 0mov AX, 4C00hint 21h

main endpcode1 segmentassume CS:code1subr1 proc far ; subr1lea DX, s1mov AH, 9hint 21hret

subr1 endpcode1 endscode2 segmentassume CS:code2subr2 proc far ; subr2lea DX, s2mov AH, 9hint 21hret

subr2 endpcode2 endscode3 segmentassume CS:code3subr3 proc far ; subr3lea DX, s3mov AH, 9hint 21hret

subr3 endpcode3 endsend mainend

108 6

6.6 ()

, .

tbl. (subr1, subr2 subr3), (code1, code2 code3). - .

( ) , ,

. , tbl - 12 .

4-

, , , subr2:

mov word ptr [SI], offset subr2mov AX, code2mov word ptr [SI+2], AX

(-

code0) next, -, :

next:call dword ptr [BX][SI]add BX, 4dec CXjnz next

:

FAR INDIRECT CALL subr1 DEMO !FAR INDIRECT CALL subr2 DEMO !FAR INDIRECT CALL subr3 DEMO !

, -

. 32- ( -

.model flat), .

4 , , -

.

( near ptr). , 16- ( -

), 32- .

32- -

,

. 6.7.

_far_demo32 - sub1 sub2. sub1 i1 i2, res. sub2 -

res. _far_demo32 , - ESI. ESI tbl, - .

6.2. 109

6.7. (32- )

.686

.model flatoption casemap: none.datatbl label dword

DD sub1DD sub2

i1 DD -39i2 DD 41res DD 2 DUP(0)

.code_far_demo32 proclea ESI, tblmov [ESI], offset sub1mov [ESI+4], offset sub2call dword ptr [ESI]call dword ptr [ESI+4]lea EAX, resret

_far_demo32 endpsub1 procclcmov EAX, i1adc EAX, i2mov res, EAXret

sub1 endpsub2 procclcmov EAX, i1sbb EAX, i2mov res+4, EAXret

sub2 endpend

_far_demo32 res, - .

, 32- ,

,

.

6.3.

. -

,

. -

,

110 6

,

, .

, -

. , ,

. -

, -

, .

,

, -

- .

-

.

? , -

, .

EAX, EBX, ECX, EDX, - EBP, ESI, EDI. EBP - ESP , , - . ESI EDI , .

.

32-

. , -

() . -

: minint - minabs .

minint -, minabs .

minint EAX, - EBX. , , - i1 i2. , min_val abs_val . -

EAX. minint - minabs.

-

, 6.8.

6.8.

(32- )

. . .

.datai1 DD 34i2 DD 17min_val DD ?abs_val DD ?

. . .

6.3. 111

.code

. . .mov EAX, i1mov E, i2call minint

; i1 i2 EAX.; min_val;

mov min_val, EAXcall minabs

; abs_valmov abs_val, EAX. . .

; minint minabsminint proccmp E,Ejl exitmov E,E

exit:ret

minint endpminabs procmov EAX, min_valcmp EAX, 0jge quitneg EAX

quit:ret

minabs endp. . .

. -

minint EBX, .

, EBX :

mov EAX, i1push EBXmov E, i2call minintpop EBX

, -

, , .

( -

), , -

. ,

pusha, pushad, popa popad., ,

( AX EAX), , .

112 6

6.8 ()

. , ; -

, . -

: -

( ) ,

. , -

.

?

EBP. ( ESP), [EBP+n] . n -

2 (2, 4, 6, 8 . .).

EBP, . (sub2),

, . -

, EAX. , -

i1 i2, i1 i2., , -

. .

:

. . ..model flat.datai1 DD 34i2 DD 190

.code. . .push i2push i1call sub2pop i1pop i2. . .

sub2 procpush EBPmov EBP, ESPmov EAX, dword ptr [EBP+8]sub EAX, dword ptr [EBP+12]pop EBPret

sub2 endp. . .

. -

i1 i2 :

push i2push i1call sub2

6.3. 113

sub2. , . 6.8.

. 6.8. push i2 push i1

,

push 8. call sub2 , .

sub2 push EBP - EBP, i1 i2 . , . 6.9.

. 6.9. call sub2 push EBP

, , i1, - [EBP+8], i2 [EBP+12]. , , . -

i2 i1, i1 i2:

mov EAX, dword ptr [EBP+8]sub EAX, dword ptr [EBP+12]

EAX . pop EBP - EBP, ret , call, EIP.

, sub2 - i1 i2. , ,

, . -

,

114 6

. , -,

, .

, .

sub2 pop - , :

pop i1pop i2

,

, .

, call

add ESP, 8

ESP , . -

push i2push i1call sub2add ESP, 8

sub2 . ret n, n , . sub2 :

sub2 procpush EBPmov EBP, ESPmov EAX, dword ptr [EBP+8]sub EAX, dword ptr [EBP+12]pop EBPret 8

sub2 endp

ret ret n n = 0. n , -

ret . ,

. , -

add , - ret n. : -

, , , -

. .

. ,

,

. , -

, ,

6.3. 115

. ,

. , -

EAX.

6.4.

, ,

, -

.

.

: -

, -

.

. -

.

:

. , -

, -

.

- .

, ,

-

.

,

-

.

-

, , .

, , , -

, -

. ,

.

-

.

public extern. public , extern ,

. -

-

.

116 6

:

, ,

public;

, -

, extern.

. -

a1 + a2 b3, a1, a2 b3 . -

: _add2, a1 + a2, _sub1, b3.

(

_add_sub). ASM, -

OBJ. (link ) -

32- .

_add_sub a1, a2 b3 , .

, -

, public. , _add2 _sub2, _add_sub, extern. _add_sub 6.9.

6.9. (32- )

.686

.model flat

.stack 100hoption casemap: noneextern _add2:procextern _sub1:procpublic a1, a2, b3

.dataa1 DD 12a2 DD 17b3 DD 34

.code_add_sub procclc ; call _add2 ; a1 + a2push EAX ; ,

; ; _sub1

call _sub1 ; (a1 + a2); b3. ; EAX

ret_add_sub endpend

6.4. 117

, .

(extern), , - , . public, ASM- , -

, .

_add2:

.686

.model flatoption casemap: nonepublic _add2extern a1: DWORDextern a2: DWORD

.code_add2 procmov EAX, a1adc EAX, a2ret

_add2 endpend

_add2 _add_sub, - (public) . , _add2 -, (

_add_sub), (extern). - .

,

. , , ,

EAX. _sub2.

:

.686

.model flatoption casemap: noneextern b3: DWORDpublic _sub1

.code_sub1 procpush EBPmov EBP, ESPmov EAX, dword ptr [EBP+8]sub EAX, b3pop EBPret 4

_sub1 endpend

b3 , - _add_sub, . _sub2

118 6

,

_add_sub. . _sub2 . -

, _add_sub :

push EAXcall _sub1

( a1 a2). - _sub2 EBP ( - ).

, ,

ret . 4 , ret 4. , EAX.

, _add_sub EAX. EAX 5. ,

.

6.4. 119

, .

-

, . , -

,

.

, .

-

. :

;

- -;

;

;

;

;

().

.

-

,

.

, ,

.

, , .

, , .

.

7

( , ), -

.

0, ,

, -

. Pascal -

Delphi. (short strings), -

255 .

,

(0). -

(null-terminated strings). -

C Windows.

:

String_0 DB "NULL-TERMINATED STRING",0

-

. , . -

:

. . .

.datas1 DB "STRING"len EQU $-s1

. . .

s1, len - . , -

len . len ( CX ECX, ).

, -

. -

, :

. . .

.datas1 DB "TEST STRING",0

.code

. . .lea ESI, s1 ; . . .cmp byte ptr [ESI],0 ; . . .

( Pascal), -

, :

. . .

.datas1 DB 7, "STRING1"

.code

. . .

121

lea ESI, s1mov CL, byte ptr [ESI]inc ESI. . .

1,

[ESI+1]. CL s1, - 7 ( mov CL, byte ptr [ESI]). .

, , -

, -

. .

,

,

, .

. , -

. -

CX (ECX) - , :

. . .

.datanum_array DD 34, 456, -768, 12len EQU $-num_array

.code

. . .lea ESI, dword ptr num_array ; -> ESImov ECX, len ; -> ECXshr ECX, 2 ;

; . . .add ESI, 4 ; . . .

-

. -

4 , 2 .

Intel

. -

Intel , -

. .

, .

rep. rep - :

rep , CX 0;

repz, repe , , ( ZF 0). , ZF 1 ECX (CX) ;

122 7

repne, repnz , , - ( ZF 1). - ZF 0 0 ECX (CX).

Intel, , -

, , -

.

,

. -

ESI(SI) EDI (DI). ESI (SI), (-

) EDI (DI). . , -

. () ()

. -

DF . 1, , 0, -

. -

. , ,

1 , 1 .

, 4 ,

4.

ESI (SI) EDI (DI) . .

. :

movs ;

lods - EAX (AX, AL) , ESI (SI);

stos EAX (AX, AL) , EDI (DI);

cmps , , - ESI (SI) EDI (DI);

scas , - EAX (AX, AL) , EDI (DI).

. ,

movs : movsb, movsw movsd. movsb , movsw - , movsd . b, w d - ESI (SI) EDI (DI). ,

.

ESI (SI) / EDI (DI) .

123

, -

.

.

-

16- 32- . -

32- ,

, . -

EAX () -, .

7.1.

movs. - , , rep - ECX (CX) . EDI (DI) - , , -

ESI (SI). , movs

ESI (SI) EDI (DI) . DF movs - 1 ( ), 2 ( ) 4 (

) EDI (DI) ESI (SI). 16- --

DS:SI, - ES:DI, CX. 32- ESI EDI, ECX. ,

.

movsb, movsw movsd -

. movs - . , STRING_A STRING_B DB, - , CX, STRING_B STRING_A:

rep movs STRING_A, STRING_B

:

rep movs ES:BYTE PTR[DI], DS:[SI]

DI SI STRING_A STRING_B.

124 7

rep , . rep - CX, - ( movs) CX . DF :

cld - DF 0;

std - DF 1.

-

, .

rep movsb ( 16- ):

. . .mov CX, counter

next:mov AL,[SI]mov DI],ALinc SI | dec SI ; inc DI | dec DI ; loop next

. . .

16- MS-DOS, -

movsb. 7.1.

7.1. movsb

(16- )

.model small

.datasrc DB "COPIED TEST STRING"len EQU $-srcdst DB len DUP (' ')

DB '$'.codestart:

mov AX, @data ; mov DS, AXmov ES, AXcld ; DF lea SI, src ; -> DS:SIlea DI, dst ; -> ES:DImov CX, len ; -> CXrep movsb ; lea DX, dst ; mov AH, 9hint 21hmov AX, 4c00hint 21hend startend

7.1. 125

-

DF , . 0 cld. - SI, - DI. -

9h 21h.

32-

( _cp_strings), 7.2.

7.2. movsb

(32- )

.586

.model flatop

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