cosmopolitan/libc/math/hypotf.c

35 lines
575 B
C

#include "libc/math/math.h"
float hypotf(float x, float y)
{
union {float f; uint32_t i;} ux = {x}, uy = {y}, ut;
float_t z;
ux.i &= -1U>>1;
uy.i &= -1U>>1;
if (ux.i < uy.i) {
ut = ux;
ux = uy;
uy = ut;
}
x = ux.f;
y = uy.f;
if (uy.i == 0xff<<23)
return y;
if (ux.i >= 0xff<<23 || uy.i == 0 || ux.i - uy.i >= 25<<23)
return x + y;
z = 1;
if (ux.i >= (0x7f+60)<<23) {
z = 0x1p90f;
x *= 0x1p-90f;
y *= 0x1p-90f;
} else if (uy.i < (0x7f-60)<<23) {
z = 0x1p-90f;
x *= 0x1p90f;
y *= 0x1p90f;
}
return z*sqrtf((double)x*x + (double)y*y);
}