root/arch/mips/math-emu/dp_2008class.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * IEEE754 floating point arithmetic
 * double precision: CLASS.f
 * FPR[fd] = class(FPR[fs])
 *
 * MIPS floating point support
 * Copyright (C) 2015 Imagination Technologies, Ltd.
 * Author: Markos Chandras <markos.chandras@imgtec.com>
 */

#include "ieee754dp.h"

int ieee754dp_2008class(union ieee754dp x)
{
        COMPXDP;

        EXPLODEXDP;

        /*
         * 10 bit mask as follows:
         *
         * bit0 = SNAN
         * bit1 = QNAN
         * bit2 = -INF
         * bit3 = -NORM
         * bit4 = -DNORM
         * bit5 = -ZERO
         * bit6 = INF
         * bit7 = NORM
         * bit8 = DNORM
         * bit9 = ZERO
         */

        switch(xc) {
        case IEEE754_CLASS_SNAN:
                return 0x01;
        case IEEE754_CLASS_QNAN:
                return 0x02;
        case IEEE754_CLASS_INF:
                return 0x04 << (xs ? 0 : 4);
        case IEEE754_CLASS_NORM:
                return 0x08 << (xs ? 0 : 4);
        case IEEE754_CLASS_DNORM:
                return 0x10 << (xs ? 0 : 4);
        case IEEE754_CLASS_ZERO:
                return 0x20 << (xs ? 0 : 4);
        default:
                pr_err("Unknown class: %d\n", xc);
                return 0;
        }
}