kopia lustrzana https://github.com/micropython/micropython
71 wiersze
1.6 KiB
C
71 wiersze
1.6 KiB
C
/*
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* This file is part of the MicroPython project, http://micropython.org/
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*
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* These math functions are taken from newlib-nano-2, the newlib/libm/math
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* directory, available from https://github.com/32bitmicro/newlib-nano-2.
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*
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* Appropriate copyright headers are reproduced below.
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*/
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/* sf_frexp.c -- float version of s_frexp.c.
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* Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
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*/
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/*
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* ====================================================
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* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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*
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* Developed at SunPro, a Sun Microsystems, Inc. business.
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* Permission to use, copy, modify, and distribute this
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* software is freely granted, provided that this notice
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* is preserved.
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* ====================================================
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*/
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#include "fdlibm.h"
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#ifdef __STDC__
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static const float
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#else
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static float
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#endif
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two25 = 3.3554432000e+07f; /* 0x4c000000 */
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#ifdef __STDC__
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float frexpf(float x, int *eptr)
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#else
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float frexpf(x, eptr)
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float x; int *eptr;
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#endif
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{
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__int32_t hx, ix;
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GET_FLOAT_WORD(hx,x);
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ix = 0x7fffffff&hx;
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*eptr = 0;
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if(!FLT_UWORD_IS_FINITE(ix)||FLT_UWORD_IS_ZERO(ix)) return x; /* 0,inf,nan */
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if (FLT_UWORD_IS_SUBNORMAL(ix)) { /* subnormal */
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x *= two25;
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GET_FLOAT_WORD(hx,x);
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ix = hx&0x7fffffff;
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*eptr = -25;
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}
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*eptr += (ix>>23)-126;
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hx = (hx&0x807fffff)|0x3f000000;
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SET_FLOAT_WORD(x,hx);
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return x;
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}
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#ifdef _DOUBLE_IS_32BITS
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#ifdef __STDC__
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double frexp(double x, int *eptr)
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#else
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double frexp(x, eptr)
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double x; int *eptr;
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#endif
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{
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return (double) frexpf((float) x, eptr);
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}
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#endif /* defined(_DOUBLE_IS_32BITS) */
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