FPU 的典型示例: 基本运算:直接使用浮点变量进行加减乘除,如: float a = 5.5f; float b = 3.25f; float c = a + b; 标准库函数:使用数学库函数,如 sinf...例如,计算正弦值: float angle = 0.0f; float sine = sinf(angle); 一个实际应用是控制 LED 亮度,通过正弦波生成呼吸效果: #include "stm32f4xx.h...CR1 |= TIM_CR1_CEN; // 启用定时器 float angle = 0.0f; while (1) { float brightness = (sinf...)); // 测量 FPU 性能 start = DWT->CYCCNT; for (int i = 0; i < 1000; i++) { result = sinf...// 这里假设已切换编译器设置 start = DWT->CYCCNT; for (int i = 0; i < 1000; i++) { result = sinf
* (numSlices + 1) + j) * 3; if (vertices) { (*vertices)[vertex + 0] = radius * sinf...(angleStep * (float)i) * sinf(angleStep * (float)j); (*vertices)[vertex + 1]...= radius * cosf(angleStep * (float)i); (*vertices)[vertex + 2] = radius * sinf(angleStep
tmp; tmp = tp; float factor_w = -flag * M_PI / l; cmplx w = {cosf(factor_w), sinf...np, flag); float wexp0 = -2 * (float) M_PI * (flag) / (float) (n); cmplx wt = {cosf(wexp0), sinf...np, flag); float wexp0 = -2 * (float) M_PI * (flag) / (float) (n); cmplx wt = {cosf(wexp0), sinf...np, flag); float wexp0 = -2 * (float) M_PI * (flag) / (float) (n); cmplx wt = {cosf(wexp0), sinf...np, flag); float wexp0 = -2 * (float) M_PI * (flag) / (float) (n); cmplx wt = {cosf(wexp0), sinf
lines; int a = 10; for (float t = 0; t < 2 * M_PI; t += 0.001) { float x = 16 * pow(sinf
另一种则是使用这些函数代替: __expf(x) 代替 expf(x); __logf(x) 代替 logf(x); __sinf(x) 代替 sinf(x); 以此类推,在函数名前面加两个下划线,可以将原数学函数替换为允许在精度上妥协而提升计算性能的数学函数
QVector lines; for (float t = 0; t < 2 * M_PI; t += 0.001) { float x = 16 * pow(sinf
(2)单精度测试 使用函数sinf 测试100次求平均是69.8个时钟周期一次: ?
.:-=+*#%@"); for (float t = 0.0f;; t += 0.1f) { int sy = 0; float s = sinf(t); float a = s
.:-=+*#%@"); for (float t = 0.0f;; t += 0.1f) { int sy = 0; float s = sinf(t);
分解成尾数和阶 using ::pow; //计算幂 using ::powf; //计算幂 using ::powl; //计算幂 using ::sin; //正弦 using ::sinf
basic_point; basic_point.x = 0.5 * std::cos(pcl::deg2rad(angle)); basic_point.y = sinf
double sin(double x);用于计算一个角度(以弧度为单位)的正弦值(double)float sinf(float x);用于计算一个角度(以弧度为单位)的正弦值(float)long...16. sin,sinf,sinl16.1 函数说明函数声明函数功能 double sin(double x);用于计算一个角度(以弧度为单位)的正弦值(double)float sinf(float...= M_PI / 4.0L; long double z = M_PI / 3.0L; printf("sin(%lf) = %lf\n", x, sin(x)); printf("sinf...(%f) = %f\n", y, sinf(y)); printf("sinl(%Lf) = %Lf\n", z, sinl(z)); return 0;}16.3 运行结果17. sincos
不难看出,这里使用了C++中的cmath库,因此其中的sinf、cosf和sqrtf都来自这个库。 ? ?
time) { return std::powf(number::e, r_ * time) * (c1_ * std::cosf(w_ * time) + c2_ * std::sinf...power = std::powf(number::e, r_ * time); float cosine = std::cosf(w_ * time); float sine = std::sinf
if(is%2==0)system("color d"); else system("color c"); int sy = 0; float s = sinf
自身的半径大小 float x = center.x+cosf(2*M_PI/_itemCount*i)*(radius-25); float y = center.y+sinf
static float transY = 0.0; glMatrixMode(GL_MODELVIEW); glLoadIdentity(); glTranslatef(0.0, (GLfloat)(sinf
acosf() asinf() atanf() atan2f() ceilf() cosf() expf() fabsf() floorf() fmodf() logf() log10f() powf() sinf
static GLfloat z=-2.0; //1 static GLfloat spinX=0; static GLfloat spinY=0; glTranslatef(0.0, (GLfloat)(sinf
生成正弦波数据 for (int i = 0; i < numFrames; ++i) { float sampleValue = kAmplitude * sinf