下面代码的惊人输出结果显示,使用双精度进行算术运算比使用长整型快了近100%:
测试除法运算符浮点算术耗时:15974.5024毫秒。
测试除法运算符整数算术耗时:28548.183毫秒。
所用构建设置为.Net4.5 C# 5.0(平台目标:x64)。
所用硬件为英特尔Core i5-2520M(运行Windows7 64位)。 注意:所使用的运算符(这里是除法)会影响结果,除法最大化了这一观察结果。
测试除法运算符浮点算术耗时:15974.5024毫秒。
测试除法运算符整数算术耗时:28548.183毫秒。
所用构建设置为.Net4.5 C# 5.0(平台目标:x64)。
所用硬件为英特尔Core i5-2520M(运行Windows7 64位)。 注意:所使用的运算符(这里是除法)会影响结果,除法最大化了这一观察结果。
const int numOfIterations = 1; //this value takes memory access out of the game
const int numOfRepetitions = 500000000; //CPU bound application
Random rand = new Random();
double[] Operand1 = new double[numOfIterations];
double[] Operand2 = new double[numOfIterations];
double[] Operand3 = new double[numOfIterations];
long[] Int64Operand1 = new long[numOfIterations];
long[] Int64Operand2 = new long[numOfIterations];
long[] Int64Operand3 = new long[numOfIterations];
for (int i = 0; i < numOfIterations; i++)
{
Operand1[i]=(rand.NextDouble() * 100);
Operand2[i]=(rand.NextDouble() * 80);
Operand3[i]=(rand.NextDouble() * 17);
Int64Operand1[i] = (long)Operand1[i];
Int64Operand2[i] = (long)Operand2[i]+1;
Int64Operand3[i] = (long)Operand3[i]+1;
}
double[] StdResult = new double[numOfIterations];
long[] NewResult = new long[numOfIterations];
TimeSpan begin = Process.GetCurrentProcess().TotalProcessorTime;
for (int j = 0; j < numOfRepetitions; j++)
{
for (int i = 0; i < numOfIterations; i++)
{
double result = Operand1[i] / Operand2[i];
result = result / Operand3[i];
StdResult[i]=(result);
}
}
TimeSpan end = Process.GetCurrentProcess().TotalProcessorTime;
Console.WriteLine("Test_DivOperator Float arithmetic measured time: " + (end - begin).TotalMilliseconds + " ms.");
begin = Process.GetCurrentProcess().TotalProcessorTime;
for (int j = 0; j < numOfRepetitions; j++)
{
for (int i = 0; i < numOfIterations; i++)
{
long result = Int64Operand1[i] / Int64Operand2[i];
result = result / Int64Operand3[i];
NewResult[i]=(result);
}
}
end = Process.GetCurrentProcess().TotalProcessorTime;
Console.WriteLine("Test_DivOperator Integer arithmetic measured time: " + (end - begin).TotalMilliseconds + " ms.");