1eba086706
PR libquadmath/65757 * quadmath-imp.h (math_opt_barrier, math_force_eval, math_narrow_eval, math_check_force_underflow, math_check_force_underflow_nonneg): Define. * math/ceilq.c: Backport changes from upstream glibc between 2012-11-01 and 2017-07-13. * math/remquoq.c: Likewise. * math/expq.c: Likewise. * math/llroundq.c: Likewise. * math/logq.c: Likewise. * math/atanq.c: Likewise. * math/nearbyintq.c: Likewise. * math/scalblnq.c: Likewise. * math/finiteq.c: Likewise. * math/atanhq.c: Likewise. * math/expm1q.c: Likewise. * math/sinhq.c: Likewise. * math/log10q.c: Likewise. * math/rintq.c: Likewise. * math/roundq.c: Likewise. * math/fmaq.c: Likewise. * math/erfq.c: Likewise. * math/log2q.c: Likewise. * math/lroundq.c: Likewise. * math/j1q.c: Likewise. * math/scalbnq.c: Likewise. * math/truncq.c: Likewise. * math/frexpq.c: Likewise. * math/sincosq.c: Likewise. * math/tanhq.c: Likewise. * math/asinq.c: Likewise. * math/coshq.c: Likewise. * math/j0q.c: Likewise. * math/asinhq.c: Likewise. * math/floorq.c: Likewise. * math/sinq_kernel.c: Likewise. * math/powq.c: Likewise. * math/hypotq.c: Likewise. * math/sincos_table.c: Likewise. * math/rem_pio2q.c: Likewise. * math/nextafterq.c: Likewise. * math/log1pq.c: Likewise. * math/sincosq_kernel.c: Likewise. * math/tanq.c: Likewise. * math/acosq.c: Likewise. * math/lrintq.c: Likewise. * math/llrintq.c: Likewise. From-SVN: r250343
98 lines
2.7 KiB
C
98 lines
2.7 KiB
C
/* s_tanhl.c -- __float128 version of s_tanh.c.
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* Conversion to __float128 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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/* Changes for 128-bit __float128 contributed by
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Stephen L. Moshier <moshier@na-net.ornl.gov> */
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/* tanhl(x)
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* Return the Hyperbolic Tangent of x
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*
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* Method :
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* x -x
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* e - e
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* 0. tanhl(x) is defined to be -----------
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* x -x
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* e + e
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* 1. reduce x to non-negative by tanhl(-x) = -tanhl(x).
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* 2. 0 <= x <= 2**-57 : tanhl(x) := x*(one+x)
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* -t
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* 2**-57 < x <= 1 : tanhl(x) := -----; t = expm1l(-2x)
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* t + 2
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* 2
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* 1 <= x <= 40.0 : tanhl(x) := 1- ----- ; t=expm1l(2x)
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* t + 2
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* 40.0 < x <= INF : tanhl(x) := 1.
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*
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* Special cases:
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* tanhl(NaN) is NaN;
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* only tanhl(0)=0 is exact for finite argument.
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*/
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#include "quadmath-imp.h"
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static const __float128 one = 1.0Q, two = 2.0Q, tiny = 1.0e-4900Q;
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__float128
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tanhq (__float128 x)
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{
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__float128 t, z;
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uint32_t jx, ix;
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ieee854_float128 u;
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/* Words of |x|. */
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u.value = x;
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jx = u.words32.w0;
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ix = jx & 0x7fffffff;
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/* x is INF or NaN */
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if (ix >= 0x7fff0000)
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{
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/* for NaN it's not important which branch: tanhl(NaN) = NaN */
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if (jx & 0x80000000)
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return one / x - one; /* tanhl(-inf)= -1; */
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else
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return one / x + one; /* tanhl(+inf)=+1 */
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}
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/* |x| < 40 */
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if (ix < 0x40044000)
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{
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if (u.value == 0)
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return x; /* x == +- 0 */
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if (ix < 0x3fc60000) /* |x| < 2^-57 */
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{
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math_check_force_underflow (x);
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return x * (one + tiny); /* tanh(small) = small */
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}
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u.words32.w0 = ix; /* Absolute value of x. */
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if (ix >= 0x3fff0000)
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{ /* |x| >= 1 */
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t = expm1q (two * u.value);
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z = one - two / (t + two);
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}
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else
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{
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t = expm1q (-two * u.value);
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z = -t / (t + two);
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}
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/* |x| > 40, return +-1 */
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}
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else
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{
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z = one - tiny; /* raised inexact flag */
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}
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return (jx & 0x80000000) ? -z : z;
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}
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