__asm__ 在 C++ 错误

Question

我正在尝试使用以下 cod 读取 cpuid 信息，但它不起作用。我正在使用 Visual Studio 2010：

#include "stdafx.h"
#include <stdio.h>

int main()
{
  int a, b;

  for (a = 0; a < 5; a++)
  {
    __asm__("cpuid"
            :"=a"(b)                 // EAX into b (output)
            :"0"(a)                  // a into EAX (input)
            :"%ebx","%ecx","%edx");  // clobbered registers

    printf("The code %i gives %i\n", a, b);
  }

  return 0;
}

这就是它所说的：

'project_scs.exe': Loaded 'C:\Users\rares992\Documents\Visual Studio 2010\Projects\project_scs\Debug\project_scs.exe', Symbols loaded.
'project_scs.exe': Loaded 'C:\Windows\SysWOW64\ntdll.dll', Symbols loaded (source information stripped).
'project_scs.exe': Loaded 'C:\Windows\SysWOW64\kernel32.dll', Symbols loaded (source information stripped).
'project_scs.exe': Loaded 'C:\Windows\SysWOW64\KernelBase.dll', Symbols loaded (source information stripped).
'project_scs.exe': Loaded 'C:\Windows\SysWOW64\msvcp100d.dll', Symbols loaded.
'project_scs.exe': Loaded 'C:\Windows\SysWOW64\msvcr100d.dll', Symbols loaded.
The thread 'Win32 Thread' (0x2190) has exited with code -1073741510 (0xc000013a).
The program '[8828] project_scs.exe: Native' has exited with code -1073741510 (0xc000013a).

谁能告诉我该怎么做才能让它运行？谢谢

Answer 1

主要问题是：您使用了用于 GCC 的 AT&T 语法。但是，Visual Studio 需要 Intel 语法。看看我下面的例子并看看其中的链接：

#include <stdio.h>
#include <intrin.h>

#define EAX 0
#define EBX 1
#define ECX 2
#define EDX 3

int main ( void )
{
    int exx[4], a;

    // http://msdn.microsoft.com/en-us/library/4ks26t93%28v=vs.100%29.aspx
    puts ("Using VC inline assembler:");

    for (a = 0; a < 5; a++)
    {
        __asm
        {
            xor ecx, ecx            // needed for a=4
            mov eax, a
            cpuid
            mov exx[EAX], eax
        }
        printf("The code %i gives %08X\n", a, exx[EAX]);
    }

    // http://msdn.microsoft.com/en-us/library/vstudio/hskdteyh%28v=vs.100%29.aspx
    puts ("Using VC intrinsics:");

    for (a = 0; a < 5; a++)
    {
        __cpuid(exx, a);
         printf("The code %i gives %08X\n", a, exx[EAX]);
    }

    return 0;
}