github.com/afumu/libc@v0.0.6/musl/src/math/hypotf.c (about)

     1  #include <math.h>
     2  #include <stdint.h>
     3  
     4  float hypotf(float x, float y)
     5  {
     6  	union {float f; uint32_t i;} ux = {x}, uy = {y}, ut;
     7  	float_t z;
     8  
     9  	ux.i &= -1U>>1;
    10  	uy.i &= -1U>>1;
    11  	if (ux.i < uy.i) {
    12  		ut = ux;
    13  		ux = uy;
    14  		uy = ut;
    15  	}
    16  
    17  	x = ux.f;
    18  	y = uy.f;
    19  	if (uy.i == 0xff<<23)
    20  		return y;
    21  	if (ux.i >= 0xff<<23 || uy.i == 0 || ux.i - uy.i >= 25<<23)
    22  		return x + y;
    23  
    24  	z = 1;
    25  	if (ux.i >= (0x7f+60)<<23) {
    26  		z = 0x1p90f;
    27  		x *= 0x1p-90f;
    28  		y *= 0x1p-90f;
    29  	} else if (uy.i < (0x7f-60)<<23) {
    30  		z = 0x1p-90f;
    31  		x *= 0x1p90f;
    32  		y *= 0x1p90f;
    33  	}
    34  	return z*sqrtf((double)x*x + (double)y*y);
    35  }