学 Win32 汇编[28] - 跳转指令: JMP、JECXZ、JA、JB、JG、JL、JE、JZ、JS、JC、JO、JP 等
跳转指令分三类:
一、无条件跳转: JMP;
二、根据 CX、ECX 寄存器的值跳转: JCXZ(CX 为 0 则跳转)、JECXZ(ECX 为 0 则跳转);
三、根据 EFLAGS 寄存器的标志位跳转, 这个太多了.
根据标志位跳转的指令:
JE ;等于则跳转 JNE ;不等于则跳转 JZ ;为 0 则跳转 JNZ ;不为 0 则跳转 JS ;为负则跳转 JNS ;不为负则跳转 JC ;进位则跳转 JNC ;不进位则跳转 JO ;溢出则跳转 JNO ;不溢出则跳转 JA ;无符号大于则跳转 JNA ;无符号不大于则跳转 JAE ;无符号大于等于则跳转 JNAE ;无符号不大于等于则跳转 JG ;有符号大于则跳转 JNG ;有符号不大于则跳转 JGE ;有符号大于等于则跳转 JNGE ;有符号不大于等于则跳转 JB ;无符号小于则跳转 JNB ;无符号不小于则跳转 JBE ;无符号小于等于则跳转 JNBE ;无符号不小于等于则跳转 JL ;有符号小于则跳转 JNL ;有符号不小于则跳转 JLE ;有符号小于等于则跳转 JNLE ;有符号不小于等于则跳转 JP ;奇偶位置位则跳转 JNP ;奇偶位清除则跳转 JPE ;奇偶位相等则跳转 JPO ;奇偶位不等则跳转
跳转相关的标志位:
| 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| OF | DF | IF | TF | SF | ZF | AF | PF | CF | |||
| 溢 出 |
符 号 |
零 | 未 用 |
辅 助 |
未 用 |
奇 偶 |
未 用 |
进 位 |
JMP 测试
; Test28_1.asm;
.386
.model flat, stdcall
include windows.inc
include kernel32.inc
include masm32.inc
include debug.inc
includelib kernel32.lib
includelib masm32.lib
includelib debug.lib
.code
main proc
PrintText '1'
jmp @F
PrintText '2'
PrintText '3'
@@: PrintText '4'
ret
main endp
end main
;测试结果应该是:
;1
;4
;以下都应该是这样.
JE 测试
; Test28_2.asm;
.386
.model flat, stdcall
include windows.inc
include kernel32.inc
include masm32.inc
include debug.inc
includelib kernel32.lib
includelib masm32.lib
includelib debug.lib
.code
main proc
PrintText '1'
mov eax, 123
cmp eax, 123
je @F
PrintText '2'
PrintText '3'
@@: PrintText '4'
ret
main endp
end main
JZ 测试
; Test28_3.asm;
.386
.model flat, stdcall
include windows.inc
include kernel32.inc
include masm32.inc
include debug.inc
includelib kernel32.lib
includelib masm32.lib
includelib debug.lib
.code
main proc
PrintText '1'
xor eax, eax
jz @F
PrintText '2'
PrintText '3'
@@: PrintText '4'
ret
main endp
end main
JS 测试
; Test28_4.asm;
.386
.model flat, stdcall
include windows.inc
include kernel32.inc
include masm32.inc
include debug.inc
includelib kernel32.lib
includelib masm32.lib
includelib debug.lib
.code
main proc
PrintText '1'
xor eax, eax
dec eax
js @F
PrintText '2'
PrintText '3'
@@: PrintText '4'
ret
main endp
end main
JC 测试
; Test28_5.asm;
.386
.model flat, stdcall
include windows.inc
include kernel32.inc
include masm32.inc
include debug.inc
includelib kernel32.lib
includelib masm32.lib
includelib debug.lib
.code
main proc
PrintText '1'
mov al, 0FFh
add al, 1
jc @F
PrintText '2'
PrintText '3'
@@: PrintText '4'
ret
main endp
end main
JO 测试
; Test28_6.asm;
.386
.model flat, stdcall
include windows.inc
include kernel32.inc
include masm32.inc
include debug.inc
includelib kernel32.lib
includelib masm32.lib
includelib debug.lib
.code
main proc
PrintText '1'
mov al, -128
sub al, 1
jo @F
PrintText '2'
PrintText '3'
@@: PrintText '4'
ret
main endp
end main
JA 测试
; Test28_7.asm;
.386
.model flat, stdcall
include windows.inc
include kernel32.inc
include masm32.inc
include debug.inc
includelib kernel32.lib
includelib masm32.lib
includelib debug.lib
.code
main proc
PrintText '1'
mov eax, 22
cmp eax, 11
ja @F
PrintText '2'
PrintText '3'
@@: PrintText '4'
ret
main endp
end main
JG 测试
; Test28_8.asm;
.386
.model flat, stdcall
include windows.inc
include kernel32.inc
include masm32.inc
include debug.inc
includelib kernel32.lib
includelib masm32.lib
includelib debug.lib
.code
main proc
PrintText '1'
mov eax, 1
cmp eax, -1
jg @F
PrintText '2'
PrintText '3'
@@: PrintText '4'
ret
main endp
end main
JP 测试
; Test28_9.asm;
.386
.model flat, stdcall
include windows.inc
include kernel32.inc
include masm32.inc
include debug.inc
includelib kernel32.lib
includelib masm32.lib
includelib debug.lib
.code
main proc
PrintText '1'
mov al, 00001110b
inc al
jp @F
PrintText '2'
PrintText '3'
@@: PrintText '4'
ret
main endp
end main
JECXZ 测试
; Test28_10.asm;
.386
.model flat, stdcall
include windows.inc
include kernel32.inc
include masm32.inc
include debug.inc
includelib kernel32.lib
includelib masm32.lib
includelib debug.lib
.code
main proc
PrintText '1'
xor ecx, ecx
jecxz @F
PrintText '2'
PrintText '3'
@@: PrintText '4'
ret
main endp
end main