/*===--------------------------------------------------------------------------
 *                   ROCm Device Libraries
 *
 * This file is distributed under the University of Illinois Open Source
 * License. See LICENSE.TXT for details.
 *===------------------------------------------------------------------------*/

#include "mathD.h"

CONSTATTR double
MATH_MANGLE(rhypot)(double x, double y)
{
    double a = BUILTIN_ABS_F64(x);
    double b = BUILTIN_ABS_F64(y);
    double t = BUILTIN_MAX_F64(a, b);
    int e = BUILTIN_FREXP_EXP_F64(t);
    a = BUILTIN_FLDEXP_F64(a, -e);
    b = BUILTIN_FLDEXP_F64(b, -e);
    double d2 = MATH_MAD(a, a, b*b);
    double z = BUILTIN_RSQRT_F64(d2);
    double u = MATH_MAD(-d2*z, z, 1.0);
    z = MATH_MAD(z*u, MATH_MAD(u, 0.375, 0.5), z);
    double ret = BUILTIN_FLDEXP_F64(z, -e);

    if (!FINITE_ONLY_OPT()) {
        ret = t == 0.0 ? AS_DOUBLE(PINFBITPATT_DP64) : ret;

        ret = BUILTIN_ISNAN_F64(x) |
              BUILTIN_ISNAN_F64(y) ?  AS_DOUBLE(QNANBITPATT_DP64) : ret;

        ret = BUILTIN_ISINF_F64(x) | BUILTIN_ISINF_F64(y) ?  0.0 : ret;
    }

    return ret;
}