将eax寄存器中的有符号数扩展为edx:eax中的有符号数。如果eax是正数,则edx会被设置为00000000h;如果eax是负数,则edx会被设置为FFFFFFFFH
.386 .model flat,stdcall option casemap:none .stack 4096 Include Irvine32.inc includelib Irvine32.lib ExitProcess PROTO,dwExitCode:DWORD .data packed_1 WORD 4536h packed_2 WORD 7207h sum DWORD ? .code main PROC mov eax,-5 ;edx=xxh eax=FFFFFFFBh CDQ ;EDX = FFFFFFFFh EAX = FFFFFFFB INVOKE ExitProcess,0 main ENDP END main
标签:四字,eax,符号,双字,CDQ,edx,main From: https://www.cnblogs.com/liming19680104/p/17937433