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| | #include "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
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