Orange Pi5 kernel

// SPDX-License-Identifier: GPL-2.0-only
/* IEEE754 floating point arithmetic
 * double precision: common utilities
 */
/*
 * MIPS floating point support
 * Copyright (C) 1994-2000 Algorithmics Ltd.
 */
 
#include "ieee754dp.h"
 
union ieee754dp ieee754dp_mul(union ieee754dp x, union ieee754dp y)
{
<------>int re;
<------>int rs;
<------>u64 rm;
<------>unsigned int lxm;
<------>unsigned int hxm;
<------>unsigned int lym;
<------>unsigned int hym;
<------>u64 lrm;
<------>u64 hrm;
<------>u64 t;
<------>u64 at;
 
<------>COMPXDP;
<------>COMPYDP;
 
<------>EXPLODEXDP;
<------>EXPLODEYDP;
 
<------>ieee754_clearcx();
 
<------>FLUSHXDP;
<------>FLUSHYDP;
 
<------>switch (CLPAIR(xc, yc)) {
<------>case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_SNAN):
<------>case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_SNAN):
<------>case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_SNAN):
<------>case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_SNAN):
<------>case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_SNAN):
<------><------>return ieee754dp_nanxcpt(y);
 
<------>case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_SNAN):
<------>case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_QNAN):
<------>case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_ZERO):
<------>case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_NORM):
<------>case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_DNORM):
<------>case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_INF):
<------><------>return ieee754dp_nanxcpt(x);
 
<------>case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_QNAN):
<------>case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_QNAN):
<------>case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_QNAN):
<------>case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_QNAN):
<------><------>return y;
 
<------>case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_QNAN):
<------>case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_ZERO):
<------>case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_NORM):
<------>case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_DNORM):
<------>case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_INF):
<------><------>return x;
 
 
<------>/*
<------> * Infinity handling
<------> */
<------>case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_ZERO):
<------>case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_INF):
<------><------>ieee754_setcx(IEEE754_INVALID_OPERATION);
<------><------>return ieee754dp_indef();
 
<------>case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_INF):
<------>case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_INF):
<------>case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_NORM):
<------>case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_DNORM):
<------>case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_INF):
<------><------>return ieee754dp_inf(xs ^ ys);
 
<------>case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_ZERO):
<------>case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_NORM):
<------>case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_DNORM):
<------>case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_ZERO):
<------>case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_ZERO):
<------><------>return ieee754dp_zero(xs ^ ys);
 
 
<------>case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM):
<------><------>DPDNORMX;
<------><------>fallthrough;
<------>case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_DNORM):
<------><------>DPDNORMY;
<------><------>break;
 
<------>case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_NORM):
<------><------>DPDNORMX;
<------><------>break;
 
<------>case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_NORM):
<------><------>break;
<------>}
<------>/* rm = xm * ym, re = xe+ye basically */
<------>assert(xm & DP_HIDDEN_BIT);
<------>assert(ym & DP_HIDDEN_BIT);
 
<------>re = xe + ye;
<------>rs = xs ^ ys;
 
<------>/* shunt to top of word */
<------>xm <<= 64 - (DP_FBITS + 1);
<------>ym <<= 64 - (DP_FBITS + 1);
 
<------>/*
<------> * Multiply 64 bits xm, ym to give high 64 bits rm with stickness.
<------> */
 
<------>lxm = xm;
<------>hxm = xm >> 32;
<------>lym = ym;
<------>hym = ym >> 32;
 
<------>lrm = DPXMULT(lxm, lym);
<------>hrm = DPXMULT(hxm, hym);
 
<------>t = DPXMULT(lxm, hym);
 
<------>at = lrm + (t << 32);
<------>hrm += at < lrm;
<------>lrm = at;
 
<------>hrm = hrm + (t >> 32);
 
<------>t = DPXMULT(hxm, lym);
 
<------>at = lrm + (t << 32);
<------>hrm += at < lrm;
<------>lrm = at;
 
<------>hrm = hrm + (t >> 32);
 
<------>rm = hrm | (lrm != 0);
 
<------>/*
<------> * Sticky shift down to normal rounding precision.
<------> */
<------>if ((s64) rm < 0) {
<------><------>rm = (rm >> (64 - (DP_FBITS + 1 + 3))) |
<------><------>     ((rm << (DP_FBITS + 1 + 3)) != 0);
<------><------>re++;
<------>} else {
<------><------>rm = (rm >> (64 - (DP_FBITS + 1 + 3 + 1))) |
<------><------>     ((rm << (DP_FBITS + 1 + 3 + 1)) != 0);
<------>}
<------>assert(rm & (DP_HIDDEN_BIT << 3));
 
<------>return ieee754dp_format(rs, re, rm);
}