我现在正在研究Vertorization性能测试,但遇到以下错误


  1> ConsoleApplication2.obj:错误LNK2001:无法解析的外部符号“专用:静态联合_LARGE_INTEGER Timer :: m_freq”(?m_freq @ Timer @@ 0T_LARGE_INTEGER @@ A)
  1> ConsoleApplication2.obj:错误LNK2001:无法解析的外部符号“私有:静态__int64 Timer :: m_overhead”(?m_overhead @ Timer @@ 0_JA)
  1> c:\ users \ lara feodorovna \ documents \ Visual Studio 2012 \ Projects \ ConsoleApplication2 \ Debug \ ConsoleApplication2.exe:致命错误LNK1120:2无法解析的外部


--------------- timer.h(我手动添加了)---------------

#pragma once
#include <windows.h>

struct Timer
{
     void Start()
     {
         QueryPerformanceCounter(&m_start);
     }

     void Stop()
     {
         QueryPerformanceCounter(&m_stop);
     }

     // Returns elapsed time in milliseconds (ms)
     double Elapsed()
     {
         return (m_stop.QuadPart - m_start.QuadPart - m_overhead) \
                                           * 1000.0 / m_freq.QuadPart;
     }

 private:

     // Returns the overhead of the timer in ticks
     static LONGLONG GetOverhead()
     {
         Timer t;
         t.Start();
         t.Stop();
         return t.m_stop.QuadPart - t.m_start.QuadPart;
     }

     LARGE_INTEGER m_start;
     LARGE_INTEGER m_stop;
     static LARGE_INTEGER m_freq;
     static LONGLONG m_overhead;
};


--------------------- ConsolApplication2.cpp -----------------------

#include "stdafx.h"
#include "timer.h"

const int MAXNUM = 100000;

int a[MAXNUM];
int b[MAXNUM];
int c[MAXNUM];

int _tmain(int argc, _TCHAR* argv[])
{
    Timer timer;
    double time_NoVector;
    double time_Vector;

    //No Vectorization
    timer.Start();
    #pragma loop(no_vector)
    for (int j=0; j<MAXNUM; j++)
    {
        c[j]=a[j]+b[j];
    }
    timer.Stop();
    time_NoVector=timer.Elapsed();

    //Vectorization
    timer.Start();
    for(int j=0; j <MAXNUM; j++)
    {
        c[j] = a[j] + b[j];
    }
    timer.Stop();
    time_Vector=timer.Elapsed();

    printf("---------------------------------------------\n");
    printf("%-14s %10s %10s\n", "Version", "Times(s)", "Speedup");
    printf("---------------------------------------------\n");
    printf("%-14s %10.4f %10.4f\n", "NoVector", time_NoVector, 1.0);
    printf("%-14s %10.4f %10.4f\n\n", "Vector", time_Vector, time_NoVector / time_Vector);

    return 0;

}


请帮我

最佳答案

如果static中有class个成员,则必须在翻译单元中对其进行定义。

在标题中:

struct Timer
{
    // ...

    // Declaration of your static members
    static LARGE_INTEGER m_freq;
    static LONGLONG m_overhead;
};


在.cpp文件中:

// Definitions
LARGE_INTEGER Timer::m_freq;
LONGLONG Timer::m_overhead;


尊重One Definition Rule

关于c++ - VS 2012错误LNK2001:无法解析的外部符号,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/18671454/

10-11 23:13
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