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rancid_rot
Asked:2020-03-12 14:53:30 +0800 CST2020-03-12 14:53:30 +0800 CST

寄存器和数据大小

  • 772

假设以 64 位模式编写的程序使用 dword 大小变量。假设我们需要在屏幕上显示它。如何在不损害健康的情况下将其转移到 rdx？下面的代码输出 0。我可以解决这个问题的唯一方法是用 qword 替换变量。

format PE64 console

include 'E:\Fresh\include\win64a.inc'

entry main1

section '.data' data readable writeable

        arg dd ?
        msg db '%lf',10,0

section '.text' code readable executable
main1:
        and rsp,-16

        mov [arg],1.0
        mov edx,[arg]
        mov rcx,msg
        call [printf]
        mov rcx,0
        call [ExitProcess]
ассемблер

1 个回答

  1. Best Answer

    从 float 到 double 的中间转换选项：

    format PE64 console

include 'include\win64a.inc'

entry main1

section '.data' data readable writeable

        arg dd ?
        buf dq ?
        msg db '%lf',10,0

section '.text' code readable executable
main1:
        and rsp,-16

        mov [arg], 1.0

        fld [arg]
        fst [buf]

        mov rdx, [buf]
        mov rcx, msg
        call [printf]
        mov rcx,0
        call [ExitProcess]

section '.idata' import data readable

library kernel, 'kernel32.dll', \
    msvcrt,'msvcrt.dll'

import kernel,\
    ExitProcess, 'ExitProcess'

import msvcrt,\
    printf,'printf'

    截屏

    • 2

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