/*
 * Copyright (c) 2018, NVIDIA CORPORATION.  All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

#ifndef COMMON_H_H63T0LSL
#define COMMON_H_H63T0LSL

#include <stdint.h>

/* Constants for Cody-Waite argument reduction */
#define _1_OVER_PI_F 3.18309870e-01f
#define PI_HI_F      3.14159203e+00f
#define PI_MI_F      6.27832947e-07f
#define PI_LO_F      1.07728259e-14f
#define THRESHOLD_F  3.90000000e+04f

/* Coefficents of approximate sine on [-PI/2,+PI/2] */
#define A_F  2.71998335e-08f
#define B_F  2.41072144e-06f
#define C_F -1.97597357e-04f
#define D_F  8.33254773e-03f
#define E_F -1.66666433e-01f

/* 192 bits of 1/PI for Payne-Hanek argument reduction. */
static uint32_t i1opi_f [] = {
    0x9e21c820,
    0x6db14acc,
    0xfa9a6ee0,
    0xfe13abe8,
    0x27220a94,
    0x517cc1b7,
};

#define PI_2_M63 3.406121580086555e-19

/* -fno-strict-aliasing */
static int32_t __attribute__((always_inline)) inline
float_as_int(float f)
{
    return *(int32_t*)&f;
}

/* -fno-strict-aliasing */
static float __attribute__((always_inline)) inline
int_as_float(int32_t i)
{
    return *(float*)&i;
}

typedef struct {
    uint32_t x;
    uint32_t y;
} uint2;

/* -fno-strict-aliasing */
static uint2 __attribute__((always_inline)) inline
umad32wide(uint32_t a, uint32_t b, uint32_t c)
{
    union {
        uint2 ui2;
        uint64_t ull;
    } res;
    res.ull = (uint64_t)a * b + c;
    return res.ui2;
}

#endif