某群有个人提出一个奇怪的问题,这段代码的循环不正常

;MASMPlus 代码模板 - 控制台程序

.386
.model flat, stdcall
option casemap :none

include windows.inc
include user32.inc
include kernel32.inc
include masm32.inc
include gdi32.inc

includelib gdi32.lib
includelib user32.lib
includelib kernel32.lib
includelib masm32.lib
include macro.asm
.data
 lpMsg  db "Hello World!",0
 
.data?
 buffer db MAX_PATH dup(?)
 
.CODE
START:
  
 mov ecx,5
@@:
  
   invoke MessageBoxA,NULL,CTEXT("13"),CTEXT("13"),MB_OK
  
 loop @B
 
 invoke ExitProcess,0
 
end START

按道理Loop等于ECX-1,然后查看ECX==0,如果相当则不循环,如果不等于则进行循环,但是这个ECX却不是5

在调用Api前后加入pushad popad则正常了

;MASMPlus 代码模板 - 控制台程序.386.model flat, stdcalloption casemap :noneinclude windows.incinclude user32.incinclude kernel32.incinclude masm32.incinclude gdi32.incincludelib gdi32.libincludelib user32.libincludelib kernel32.libincludelib masm32.libinclude macro.asm.data    lpMsg        db "Hello World!",0    .data?    buffer    db MAX_PATH dup(?)    .CODESTART:       mov ecx,5@@:   pushad   invoke MessageBoxA,NULL,CTEXT("13"),CTEXT("13"),MB_OK   popad    loop @B        invoke ExitProcess,0    end START

汇编中如果汇编和调用API混合用的话要注意Pushad popad