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

#include "mathF.h"

#define FLOAT_SPECIALIZATION
#include "ep.h"

extern CONSTATTR float2 MATH_PRIVATE(epexpep)(float2 x);

CONSTATTR float
MATH_MANGLE(expm1)(float x)
{
#if defined EXTRA_ACCURACY
    float2 e = sub(MATH_PRIVATE(epexpep)(con(x, 0.0f)), 1.0f);
    float z = e.hi;
#else
    float fn = BUILTIN_RINT_F32(x * 0x1.715476p+0f);
    float t = BUILTIN_FMA_F32(-fn, -0x1.05c610p-29f, BUILTIN_FMA_F32(-fn, 0x1.62e430p-1f, x));
    float p = MATH_MAD(t, MATH_MAD(t, MATH_MAD(t, MATH_MAD(t, MATH_MAD(t,
                  0x1.a26762p-13f, 0x1.6d2e00p-10f), 0x1.110ff2p-7f), 0x1.555502p-5f),
                  0x1.555556p-3f), 0x1.000000p-1f);
    p = BUILTIN_FMA_F32(t, t*p, t);
    int e = fn == 128.0f ? 127 : (int)fn;
    float s = BUILTIN_FLDEXP_F32(1.0f, e);
    float z = BUILTIN_FMA_F32(s, p, s - 1.0f);
    z = fn == 128.0 ? 2.0f*z : z;
#endif
    
    if (!FINITE_ONLY_OPT()) {
        z = x > 0x1.62e42ep+6f ? AS_FLOAT(PINFBITPATT_SP32) : z;
    }

    z = x < -17.0f ? -1.0f : z;

    return z;
}