737df6e617
2012-10-31 Tobias Burnus <burnus@net-b.de>
Joseph Myers <joseph@codesourcery.com>
David S. Miller <davem@davemloft.net>
Ulrich Drepper <drepper@redhat.com>
Marek Polacek <polacek@redhat.com>:
Petr Baudis <pasky@suse.cz>
* math/complex.c (csqrtq): NaN and INF fixes.
* math/sqrtq.c (sqrt): NaN, INF and < 0 fixes.
* math/expm1q.c (expm1q): Changes from GLIBC. Use expq for
large parameters. Fix errno for boundary conditions.
* math/finiteq.c (finiteq): Add comment.
* math/fmaq.c (fmaq): Changes from GLIBC. Fix missing underflows
and bad results for some subnormal results. Fix sign of inexact
zero return. Fix sign of exact zero return.
Ensure additions are not scheduled after fetestexcept.
* math/jnq.c (jnq): Changes from GLIBC. Set up errno properly
for ynq. Fix jnq precision.
* math/nearbyintq.c (nearbyintq): Changes from GLIBC. Do not
manipulate bits before adding and subtracting TWO112[sx].
* math/rintq.c (rintq): Ditto.
* math/scalbnq.c (scalbnq): Changes from GLIBC. Fix integer
overflow.
Co-Authored-By: David S. Miller <davem@davemloft.net>
Co-Authored-By: Joseph Myers <joseph@codesourcery.com>
Co-Authored-By: Ulrich Drepper <drepper@redhat.com>
From-SVN: r193037
59 lines
1.9 KiB
C
59 lines
1.9 KiB
C
/* s_scalbnl.c -- long double version of s_scalbn.c.
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* Conversion to IEEE quad long double by Jakub Jelinek, jj@ultra.linux.cz.
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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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/*
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* scalbnq (__float128 x, int n)
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* scalbnq(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 "quadmath-imp.h"
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static const __float128
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two114 = 2.0769187434139310514121985316880384E+34Q, /* 0x4071000000000000, 0 */
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twom114 = 4.8148248609680896326399448564623183E-35Q, /* 0x3F8D000000000000, 0 */
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huge = 1.0E+4900Q,
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tiny = 1.0E-4900Q;
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__float128
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scalbnq (__float128 x, int n)
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{
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int64_t k,hx,lx;
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GET_FLT128_WORDS64(hx,lx,x);
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k = (hx>>48)&0x7fff; /* extract exponent */
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if (k==0) { /* 0 or subnormal x */
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if ((lx|(hx&0x7fffffffffffffffULL))==0) return x; /* +-0 */
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x *= two114;
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GET_FLT128_MSW64(hx,x);
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k = ((hx>>48)&0x7fff) - 114;
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}
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if (k==0x7fff) return x+x; /* NaN or Inf */
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if (n< -50000) return tiny*copysignq(tiny,x); /*underflow*/
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if (n> 50000 || k+n > 0x7ffe)
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return huge*copysignq(huge,x); /* overflow */
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/* Now k and n are bounded we know that k = k+n does not
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overflow. */
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k = k+n;
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if (k > 0) /* normal result */
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{SET_FLT128_MSW64(x,(hx&0x8000ffffffffffffULL)|(k<<48)); return x;}
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if (k <= -114)
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return tiny*copysignq(tiny,x); /*underflow*/
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k += 114; /* subnormal result */
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SET_FLT128_MSW64(x,(hx&0x8000ffffffffffffULL)|(k<<48));
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return x*twom114;
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}
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