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62 lines
1.5 KiB
C
62 lines
1.5 KiB
C
/* s_frexpl.c -- long double version of s_frexp.c.
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* Conversion to long double by Ulrich Drepper,
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* Cygnus Support, drepper@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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#if defined(LIBM_SCCS) && !defined(lint)
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static char rcsid[] = "$NetBSD: $";
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#endif
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/*
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* for non-zero x
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* x = frexpl(arg,&exp);
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* return a long double fp quantity x such that 0.5 <= |x| <1.0
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* and the corresponding binary exponent "exp". That is
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* arg = x*2^exp.
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* If arg is inf, 0.0, or NaN, then frexpl(arg,&exp) returns arg
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* with *exp=0.
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*/
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#include <float.h>
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#include <math.h>
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#include <math_private.h>
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static const long double
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#if LDBL_MANT_DIG == 64
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two65 = 3.68934881474191032320e+19L; /* 0x4040, 0x80000000, 0x00000000 */
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#else
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# error "Cannot handle this MANT_DIG"
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#endif
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long double __frexpl(long double x, int *eptr)
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{
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u_int32_t se, hx, ix, lx;
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GET_LDOUBLE_WORDS(se,hx,lx,x);
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ix = 0x7fff&se;
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*eptr = 0;
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if(ix==0x7fff||((ix|hx|lx)==0)) return x; /* 0,inf,nan */
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if (ix==0x0000) { /* subnormal */
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x *= two65;
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GET_LDOUBLE_EXP(se,x);
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ix = se&0x7fff;
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*eptr = -65;
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}
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*eptr += ix-16382;
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se = (se & 0x8000) | 0x3ffe;
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SET_LDOUBLE_EXP(x,se);
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return x;
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}
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weak_alias (__frexpl, frexpl)
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