84d9c625bf
- Fix for possible unset uid/gid in toproto
- Fix for default mtree style
- Update libelf
- Importing libexecinfo
- Resynchronize GCC, mpc, gmp, mpfr
- build.sh: Replace params with show-params.
This has been done as the make target has been renamed in the same
way, while a new target named params has been added. This new
target generates a file containing all the parameters, instead of
printing it on the console.
- Update test48 with new etc/services (Fix by Ben Gras <ben@minix3.org)
get getservbyport() out of the inner loop
Change-Id: Ie6ad5226fa2621ff9f0dee8782ea48f9443d2091
86 lines
2.3 KiB
C
86 lines
2.3 KiB
C
/* @(#)s_scalbn.c 5.1 93/09/24 */
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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 <sys/cdefs.h>
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#if defined(LIBM_SCCS) && !defined(lint)
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__RCSID("$NetBSD: s_scalbn.c,v 1.18 2013/05/20 19:40:09 joerg Exp $");
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#endif
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/*
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* scalbn (double x, int n)
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* scalbn(x,n) returns x* 2**n computed by exponent
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* manipulation rather than by actually performing an
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* exponentiation or a multiplication.
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*/
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#include "namespace.h"
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#include "math.h"
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#include "math_private.h"
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#ifndef _LP64
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__strong_alias(_scalbn, _scalbln)
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#endif
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#ifndef __HAVE_LONG_DOUBLE
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__strong_alias(_scalbnl, _scalbn)
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__strong_alias(_scalblnl, _scalbln)
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__weak_alias(scalbnl, _scalbnl)
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__weak_alias(scalblnl, _scalblnl)
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#endif
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#ifdef __weak_alias
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__weak_alias(scalbn, _scalbn)
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__weak_alias(scalbln, _scalbln)
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__weak_alias(ldexp, _scalbn)
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#endif
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static const double
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two54 = 0x1.0p54, /* 0x43500000, 0x00000000 */
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twom54 = 0x1.0p-54, /* 0x3C900000, 0x00000000 */
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huge = 1.0e+300,
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tiny = 1.0e-300;
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#ifdef _LP64
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double
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scalbn(double x, int n)
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{
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return scalbln(x, n);
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}
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#endif
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double
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scalbln(double x, long n)
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{
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int32_t k,hx,lx;
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EXTRACT_WORDS(hx,lx,x);
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k = ((uint32_t)hx&0x7ff00000)>>20; /* extract exponent */
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if (k==0) { /* 0 or subnormal x */
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if ((lx|(hx&0x7fffffff))==0) return x; /* +-0 */
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x *= two54;
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GET_HIGH_WORD(hx,x);
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k = (((uint32_t)hx&0x7ff00000)>>20) - 54;
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if (n< -50000) return tiny*x; /*underflow*/
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}
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if (k==0x7ff) return x+x; /* NaN or Inf */
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k = k+n;
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if (k > 0x7fe) return huge*copysign(huge,x); /* overflow */
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if (k > 0) /* normal result */
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{SET_HIGH_WORD(x,(hx&0x800fffff)|(k<<20)); return x;}
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if (k <= -54) {
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if (n > 50000) /* in case integer overflow in n+k */
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return huge*copysign(huge,x); /*overflow*/
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else return tiny*copysign(tiny,x); /*underflow*/
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}
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k += 54; /* subnormal result */
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SET_HIGH_WORD(x,(hx&0x800fffff)|(k<<20));
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return x*twom54;
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}
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