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![Liangliang Huang](/assets/img/avatar_default.png)
Convert the various /* fallthrough */ comments to the pseudo-keyword fallthrough; Done via script: https://lore.kernel.org/lkml/b56602fcf79f849e733e7b521bb0e17895d390fa.1582230379.git.joe@perches.com/ Signed-off-by: Liangliang Huang <huangll@lemote.com> Reviewed-by: Huacai Chen <chenhc@lemote.com> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
164 lines
3.7 KiB
C
164 lines
3.7 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_add(union ieee754sp x, union ieee754sp y)
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{
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int s;
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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_INF):
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if (xs == ys)
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return x;
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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_ZERO, IEEE754_CLASS_INF):
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case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_INF):
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return y;
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case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_ZERO):
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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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return x;
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/*
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* Zero handling
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*/
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case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_ZERO):
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if (xs == ys)
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return x;
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else
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return ieee754sp_zero(ieee754_csr.rm == FPU_CSR_RD);
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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 x;
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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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return y;
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case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM):
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SPDNORMX;
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fallthrough;
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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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assert(xm & SP_HIDDEN_BIT);
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assert(ym & SP_HIDDEN_BIT);
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/*
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* Provide guard, round and stick bit space.
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*/
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xm <<= 3;
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ym <<= 3;
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if (xe > ye) {
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/*
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* Have to shift y fraction right to align.
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*/
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s = xe - ye;
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ym = XSPSRS(ym, s);
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ye += s;
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} else if (ye > xe) {
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/*
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* Have to shift x fraction right to align.
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*/
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s = ye - xe;
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xm = XSPSRS(xm, s);
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xe += s;
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}
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assert(xe == ye);
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assert(xe <= SP_EMAX);
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if (xs == ys) {
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/*
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* Generate 28 bit result of adding two 27 bit numbers
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* leaving result in xm, xs and xe.
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*/
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xm = xm + ym;
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if (xm >> (SP_FBITS + 1 + 3)) { /* carry out */
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SPXSRSX1();
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}
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} else {
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if (xm >= ym) {
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xm = xm - ym;
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} else {
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xm = ym - xm;
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xs = ys;
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}
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if (xm == 0)
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return ieee754sp_zero(ieee754_csr.rm == FPU_CSR_RD);
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/*
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* Normalize in extended single precision
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*/
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while ((xm >> (SP_FBITS + 3)) == 0) {
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xm <<= 1;
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xe--;
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}
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}
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return ieee754sp_format(xs, xe, xm);
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}
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