STM32的FPU问题

Taven

               我用STM32F301做实验，就计算浮点数的加减乘除，为什么启用FPU反而比不启用FPU计算慢？。下面是我实验的代码，很简单。通过观察小灯的闪烁快慢来看计算速度。

#include "LED.h"
#include "system_tick.h"
#include "math.h"
//#include "arm_math.h"
int i=0;
float c=1.3f,sin_vlu=0.0f,cos_vlu=0.0f;
int main(void)
{
SystemTick_init();
LED_Init();
while(1)
{
  LED0_ON;
/*************************FPU运算************************/
for(i=0;i<65536;i++)
  {
//  arm_sin_cos_f32(30.0f,&sin_vlu,&cos_vlu);
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
      c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
      c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
      c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
      c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
      c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
      c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
      c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
      c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
      c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
      c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
      c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
  }
///*************************CPU运算**************************/
// for(i=0;i<65536;i++)
//  {
//    c = cos(1.3f);
//  }
  LED0_OFF;

/*************************FPU运算************************/
for(i=0;i<65536;i++)
  {
//  arm_sin_cos_f32(30.0f,&sin_vlu,&cos_vlu);
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
      c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
      c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
      c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
      c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
      c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
      c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
      c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
      c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
      c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
      c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
      c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
  }
///*************************CPU运算**************************/
// for(i=0;i<65536;i++)
//  {
//    c = cos(1.3f);
//  }
}
}

augustedward

两种要用同一种算法进行比较才行。你这个两种计算量就不一样

Taven

augustedward 发表于 2017-10-24 19:07
两种要用同一种算法进行比较才行。你这个两种计算量就不一样

这里不就是浮点数的加减乘除么，计算量不一样嘛

augustedward

Taven 发表于 2017-10-25 00:23
这里不就是浮点数的加减乘除么，计算量不一样嘛

你不用FPU时用的是 for(i=0;i<65536;i++)
//  {
//    c = cos(1.3f);
//  }


用FPU时，用的是 c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
      c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
      c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
      c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f*2.5623f/3.00543f+6.00435f-4.56234f;
   c=3.1f*2.5623f/3.00543f+6

这两种公式都不一样。能放到一起比吗？

Taven

augustedward 发表于 2017-10-25 18:44
你不用FPU时用的是 for(i=0;i

屏蔽了，一直不用啊。只是编译时开起浮点或者不开启。我都说了只计算加减乘除。无语