关于repe stosd等命令。。。

[javawater]

近日在反汇编代码中发现

repe stosd
repe stosb
repe movsd
repe movsb
setnle al

等命令，四处搜索找不到对这些命令的详细解说，哪位大侠知道麻烦讲解一下，或者提供相关地址，谢谢

[W32API]

你是指 “repe” ？ REPE/REPZ

[W32API]

SETcc—Set Byte on Condition
0F 9F SETNLE r/m8 Set byte if not less or equal (ZF=0 and SF=OF)

[javawater]

非也，主要是stosd等，最重要的是和repe和起来用，我已经了解一点，不过不清楚

[csdsjkk]

repe stosd :
while ecx > 0
eax -> es:[edi]
add edi,4 (sub edi,4)
dec ecx
end while

[gad1star]

STOS - Store String (Byte, Word or Doubleword)
Usage: STOS dest
STOSB
STOSW
STOSD
Modifies flags: None
Stores value in accumulator to location at ES:(E)DI (even if operand
is given). (E)DI is incremented/decremented based on the size of
the operand (or instruction format) and the state of the Direction
Flag. Use with REP prefixes.

[W32API]

repe stosd
repe stosb

用 AL（(E)AX）初始化（填充）数据块

repe movsd
repe movsb

数据块复制

setnle al

SETcc—Set Byte on Condition
0F 9F SETNLE r/m8 Set byte if not less or equal (ZF=0 and SF=OF)

根据 EFLAGS register 标志状态信息设置 r/m8，符合置 1，否则置零。

[W32API]

repe stosd Fill (E)CX doublewords at ES:[(E)DI] with EAX
repe stosb Fill (E)CX bytes at ES:[(E)DI] with AL

[gad1star]

知道了他们是什么的缩写就简单多了。

LODS = Load String
LODSB = Load String by Byte
LODSW = Load String by word
LODSD = Load String by Doubleword

LODS - Load String (Byte, Word or Double)
Usage: LODS src
LODSB
LODSW
LODSD (386+)
Modifies flags: None
Transfers string element addressed by DS:SI (even if an operand is
supplied) to the accumulator. SI is incremented based on the size
of the operand or based on the instruction used. If the Direction
Flag is set SI is decremented, if the Direction Flag is clear SI

is incremented. Use with REP prefixes.


MOVS = Move String
MOVSB = Move String by Byte
MOVSW = Move String by word
MOVSD = Move String by Doubleword

MOVS - Move String (Byte or Word)
Usage: MOVS dest,src
MOVSB
MOVSW
MOVSD (386+)
Modifies flags: None
Copies data from addressed by DS:SI (even if operands are given) to
the location ES:DI destination and updates SI and DI based on the
size of the operand or instruction used. SI and DI are incremented
when the Direction Flag is cleared and decremented when the Direction

Flag is Set. Use with REP prefixes.