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82 lines
2.0 KiB
82 lines
2.0 KiB
/* 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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* This program is free software; you can distribute it and/or modify it |
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* under the terms of the GNU General Public License (Version 2) as |
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* published by the Free Software Foundation. |
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* |
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* This program is distributed in the hope it will be useful, but WITHOUT |
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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* for more details. |
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* |
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* You should have received a copy of the GNU General Public License along |
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* with this program; if not, write to the Free Software Foundation, Inc., |
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* 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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*/ |
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#include "ieee754sp.h" |
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#include "ieee754dp.h" |
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static inline union ieee754sp ieee754sp_nan_fdp(int xs, u64 xm) |
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{ |
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return buildsp(xs, SP_EMAX + 1 + SP_EBIAS, |
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xm >> (DP_FBITS - SP_FBITS)); |
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} |
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union ieee754sp ieee754sp_fdp(union ieee754dp x) |
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{ |
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union ieee754sp y; |
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u32 rm; |
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COMPXDP; |
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COMPYSP; |
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EXPLODEXDP; |
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ieee754_clearcx(); |
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FLUSHXDP; |
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switch (xc) { |
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case IEEE754_CLASS_SNAN: |
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return ieee754sp_nanxcpt(ieee754sp_nan_fdp(xs, xm)); |
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case IEEE754_CLASS_QNAN: |
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y = ieee754sp_nan_fdp(xs, xm); |
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EXPLODEYSP; |
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if (!ieee754_class_nan(yc)) |
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y = ieee754sp_indef(); |
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return y; |
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case IEEE754_CLASS_INF: |
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return ieee754sp_inf(xs); |
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case IEEE754_CLASS_ZERO: |
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return ieee754sp_zero(xs); |
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case IEEE754_CLASS_DNORM: |
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/* can't possibly be sp representable */ |
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ieee754_setcx(IEEE754_UNDERFLOW); |
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ieee754_setcx(IEEE754_INEXACT); |
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if ((ieee754_csr.rm == FPU_CSR_RU && !xs) || |
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(ieee754_csr.rm == FPU_CSR_RD && xs)) |
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return ieee754sp_mind(xs); |
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return ieee754sp_zero(xs); |
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case IEEE754_CLASS_NORM: |
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break; |
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} |
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/* |
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* Convert from DP_FBITS to SP_FBITS+3 with sticky right shift. |
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*/ |
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rm = (xm >> (DP_FBITS - (SP_FBITS + 3))) | |
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((xm << (64 - (DP_FBITS - (SP_FBITS + 3)))) != 0); |
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return ieee754sp_format(xs, xe, rm); |
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}
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