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Based on 1 normalized pattern(s): this program is free software you can distribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is distributed in the hope it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 51 franklin st fifth floor boston ma 02110 1301 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 33 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Richard Fontana <rfontana@redhat.com> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190531081038.563233189@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
156 lines
3.9 KiB
C
156 lines
3.9 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/* IEEE754 floating point arithmetic
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* single precision
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*/
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/*
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* MIPS floating point support
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* Copyright (C) 1994-2000 Algorithmics Ltd.
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*/
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#include "ieee754sp.h"
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union ieee754sp ieee754sp_mul(union ieee754sp x, union ieee754sp y)
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{
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int re;
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int rs;
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unsigned int rm;
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unsigned short lxm;
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unsigned short hxm;
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unsigned short lym;
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unsigned short hym;
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unsigned int lrm;
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unsigned int hrm;
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unsigned int t;
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unsigned int at;
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COMPXSP;
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COMPYSP;
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EXPLODEXSP;
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EXPLODEYSP;
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ieee754_clearcx();
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FLUSHXSP;
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FLUSHYSP;
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switch (CLPAIR(xc, yc)) {
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case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_SNAN):
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case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_SNAN):
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case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_SNAN):
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case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_SNAN):
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case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_SNAN):
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return ieee754sp_nanxcpt(y);
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case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_SNAN):
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case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_QNAN):
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case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_ZERO):
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case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_NORM):
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case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_DNORM):
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case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_INF):
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return ieee754sp_nanxcpt(x);
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case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_QNAN):
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case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_QNAN):
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case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_QNAN):
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case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_QNAN):
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return y;
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case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_QNAN):
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case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_ZERO):
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case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_NORM):
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case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_DNORM):
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case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_INF):
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return x;
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/*
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* Infinity handling
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*/
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case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_ZERO):
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case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_INF):
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ieee754_setcx(IEEE754_INVALID_OPERATION);
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return ieee754sp_indef();
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case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_INF):
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case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_INF):
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case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_NORM):
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case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_DNORM):
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case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_INF):
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return ieee754sp_inf(xs ^ ys);
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case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_ZERO):
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case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_NORM):
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case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_DNORM):
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case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_ZERO):
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case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_ZERO):
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return ieee754sp_zero(xs ^ ys);
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case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM):
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SPDNORMX;
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/* fall through */
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case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_DNORM):
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SPDNORMY;
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break;
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case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_NORM):
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SPDNORMX;
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break;
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case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_NORM):
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break;
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}
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/* rm = xm * ym, re = xe+ye basically */
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assert(xm & SP_HIDDEN_BIT);
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assert(ym & SP_HIDDEN_BIT);
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re = xe + ye;
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rs = xs ^ ys;
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/* shunt to top of word */
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xm <<= 32 - (SP_FBITS + 1);
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ym <<= 32 - (SP_FBITS + 1);
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/*
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* Multiply 32 bits xm, ym to give high 32 bits rm with stickness.
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*/
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lxm = xm & 0xffff;
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hxm = xm >> 16;
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lym = ym & 0xffff;
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hym = ym >> 16;
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lrm = lxm * lym; /* 16 * 16 => 32 */
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hrm = hxm * hym; /* 16 * 16 => 32 */
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t = lxm * hym; /* 16 * 16 => 32 */
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at = lrm + (t << 16);
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hrm += at < lrm;
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lrm = at;
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hrm = hrm + (t >> 16);
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t = hxm * lym; /* 16 * 16 => 32 */
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at = lrm + (t << 16);
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hrm += at < lrm;
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lrm = at;
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hrm = hrm + (t >> 16);
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rm = hrm | (lrm != 0);
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/*
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* Sticky shift down to normal rounding precision.
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*/
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if ((int) rm < 0) {
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rm = (rm >> (32 - (SP_FBITS + 1 + 3))) |
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((rm << (SP_FBITS + 1 + 3)) != 0);
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re++;
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} else {
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rm = (rm >> (32 - (SP_FBITS + 1 + 3 + 1))) |
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((rm << (SP_FBITS + 1 + 3 + 1)) != 0);
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}
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assert(rm & (SP_HIDDEN_BIT << 3));
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return ieee754sp_format(rs, re, rm);
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}
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