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79 lines
1.5 KiB
79 lines
1.5 KiB
// 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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* Copyright (C) 2017 Imagination Technologies, Ltd. |
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* Author: Aleksandar Markovic <[email protected]> |
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*/ |
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#include "ieee754sp.h" |
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union ieee754sp ieee754sp_rint(union ieee754sp x) |
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{ |
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union ieee754sp ret; |
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u32 residue; |
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int sticky; |
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int round; |
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int odd; |
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COMPXDP; /* <-- DP needed for 64-bit mantissa tmp */ |
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ieee754_clearcx(); |
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EXPLODEXSP; |
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FLUSHXSP; |
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if (xc == IEEE754_CLASS_SNAN) |
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return ieee754sp_nanxcpt(x); |
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if ((xc == IEEE754_CLASS_QNAN) || |
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(xc == IEEE754_CLASS_INF) || |
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(xc == IEEE754_CLASS_ZERO)) |
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return x; |
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if (xe >= SP_FBITS) |
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return x; |
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if (xe < -1) { |
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residue = xm; |
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round = 0; |
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sticky = residue != 0; |
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xm = 0; |
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} else { |
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residue = xm << (xe + 1); |
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residue <<= 31 - SP_FBITS; |
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round = (residue >> 31) != 0; |
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sticky = (residue << 1) != 0; |
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xm >>= SP_FBITS - xe; |
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} |
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odd = (xm & 0x1) != 0x0; |
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switch (ieee754_csr.rm) { |
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case FPU_CSR_RN: /* toward nearest */ |
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if (round && (sticky || odd)) |
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xm++; |
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break; |
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case FPU_CSR_RZ: /* toward zero */ |
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break; |
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case FPU_CSR_RU: /* toward +infinity */ |
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if ((round || sticky) && !xs) |
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xm++; |
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break; |
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case FPU_CSR_RD: /* toward -infinity */ |
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if ((round || sticky) && xs) |
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xm++; |
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break; |
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} |
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if (round || sticky) |
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ieee754_setcx(IEEE754_INEXACT); |
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ret = ieee754sp_flong(xm); |
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SPSIGN(ret) = xs; |
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return ret; |
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}
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