/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * IEEE754 floating point
 * double precision internal header file
 */
/*
 * MIPS floating point support
 * Copyright (C) 1994-2000 Algorithmics Ltd.
 */

#include <linux/compiler.h>

#include "ieee754int.h"

#define assert(expr) ((void)0)

#define DP_EBIAS        1023
#define DP_EMIN         (-1022)
#define DP_EMAX         1023
#define DP_FBITS        52
#define DP_MBITS        52

#define DP_MBIT(x)      ((u64)1 << (x))
#define DP_HIDDEN_BIT   DP_MBIT(DP_FBITS)
#define DP_SIGN_BIT     DP_MBIT(63)

#define DPSIGN(dp)      (dp.sign)
#define DPBEXP(dp)      (dp.bexp)
#define DPMANT(dp)      (dp.mant)

static inline int ieee754dp_finite(union ieee754dp x)
{
        return DPBEXP(x) != DP_EMAX + 1 + DP_EBIAS;
}

/* 3bit extended double precision sticky right shift */
#define XDPSRS(v,rs)    \
        ((rs > (DP_FBITS+3))?1:((v) >> (rs)) | ((v) << (64-(rs)) != 0))

#define XDPSRSX1() \
        (xe++, (xm = (xm >> 1) | (xm & 1)))

#define XDPSRS1(v)      \
        (((v) >> 1) | ((v) & 1))

/* 32bit * 32bit => 64bit unsigned integer multiplication */
#define DPXMULT(x, y)   ((u64)(x) * (u64)y)

/* convert denormal to normalized with extended exponent */
#define DPDNORMx(m,e) \
        while ((m >> DP_FBITS) == 0) { m <<= 1; e--; }
#define DPDNORMX        DPDNORMx(xm, xe)
#define DPDNORMY        DPDNORMx(ym, ye)
#define DPDNORMZ        DPDNORMx(zm, ze)

static inline union ieee754dp builddp(int s, int bx, u64 m)
{
        union ieee754dp r;

        assert((s) == 0 || (s) == 1);
        assert((bx) >= DP_EMIN - 1 + DP_EBIAS
               && (bx) <= DP_EMAX + 1 + DP_EBIAS);
        assert(((m) >> DP_FBITS) == 0);

        r.sign = s;
        r.bexp = bx;
        r.mant = m;

        return r;
}

extern union ieee754dp __cold ieee754dp_nanxcpt(union ieee754dp);
extern union ieee754dp ieee754dp_format(int, int, u64);