text: #include "libc/math/libm.h"
  
  #if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
  long double hypotl(long double x, long double y)
  {
  	return hypot(x, y);
  }
  #elif (LDBL_MANT_DIG == 64 || LDBL_MANT_DIG == 113) && LDBL_MAX_EXP == 16384
  #if LDBL_MANT_DIG == 64
  #define SPLIT (0x1p32L+1)
  #elif LDBL_MANT_DIG == 113
  #define SPLIT (0x1p57L+1)
  #endif
  
  static void sq(long double *hi, long double *lo, long double x)
  {
  	long double xh, xl, xc;
  	xc = x*SPLIT;
  	xh = x - xc + xc;
  	xl = x - xh;
  	*hi = x*x;
  	*lo = xh*xh - *hi + 2*xh*xl + xl*xl;
  }
  
  long double hypotl(long double x, long double y)
  {
  	union ldshape ux = {x}, uy = {y};
  	int ex, ey;
  	long double hx, lx, hy, ly, z;
  
  	ux.i.se &= 0x7fff;
  	uy.i.se &= 0x7fff;
  	if (ux.i.se < uy.i.se) {
  		ex = uy.i.se;
  		ey = ux.i.se;
  		x = uy.f;
  		y = ux.f;
  	} else {
  		ex = ux.i.se;
  		ey = uy.i.se;
  		x = ux.f;
  		y = uy.f;
  	}
  
  	if (ex == 0x7fff && isinf(y))
  		return y;
  	if (ex == 0x7fff || y == 0)
  		return x;
  	if (ex - ey > LDBL_MANT_DIG)
  		return x + y;
  
  	z = 1;
  	if (ex > 0x3fff+8000) {
  		z = 0x1p10000L;
  		x *= 0x1p-10000L;
  		y *= 0x1p-10000L;
  	} else if (ey < 0x3fff-8000) {
  		z = 0x1p-10000L;
  		x *= 0x1p10000L;
  		y *= 0x1p10000L;
  	}
  	sq(&hx, &lx, x);
  	sq(&hy, &ly, y);
  	return z*sqrtl(ly+lx+hy+hx);
  }
  #endif
  