diff options
Diffstat (limited to 'libquadmath/math/cacoshq.c')
| -rw-r--r-- | libquadmath/math/cacoshq.c | 61 |
1 files changed, 28 insertions, 33 deletions
diff --git a/libquadmath/math/cacoshq.c b/libquadmath/math/cacoshq.c index a7025dc917d..2b170880edc 100644 --- a/libquadmath/math/cacoshq.c +++ b/libquadmath/math/cacoshq.c @@ -1,5 +1,5 @@ -/* Return arc hyperbole cosine for __float128 value. - Copyright (C) 1997, 1998, 2006 Free Software Foundation, Inc. +/* Return arc hyperbolic cosine for a complex type. + Copyright (C) 1997-2018 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997. @@ -14,13 +14,11 @@ Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public - License along with the GNU C Library; if not, write to the Free - Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA - 02111-1307 USA. */ + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ #include "quadmath-imp.h" - __complex128 cacoshq (__complex128 x) { @@ -38,57 +36,54 @@ cacoshq (__complex128 x) __imag__ res = nanq (""); else __imag__ res = copysignq ((rcls == QUADFP_INFINITE - ? (__real__ x < 0.0 - ? M_PIq - M_PI_4q : M_PI_4q) - : M_PI_2q), __imag__ x); + ? (__real__ x < 0 + ? M_PIq - M_PI_4q + : M_PI_4q) + : M_PI_2q), __imag__ x); } else if (rcls == QUADFP_INFINITE) { __real__ res = HUGE_VALQ; if (icls >= QUADFP_ZERO) - __imag__ res = copysignq (signbitq (__real__ x) ? M_PIq : 0.0, - __imag__ x); + __imag__ res = copysignq (signbitq (__real__ x) + ? M_PIq : 0, __imag__ x); else __imag__ res = nanq (""); } else { __real__ res = nanq (""); - __imag__ res = nanq (""); + if (rcls == QUADFP_ZERO) + __imag__ res = M_PI_2q; + else + __imag__ res = nanq (""); } } else if (rcls == QUADFP_ZERO && icls == QUADFP_ZERO) { - __real__ res = 0.0; + __real__ res = 0; __imag__ res = copysignq (M_PI_2q, __imag__ x); } - /* The factor 16 is just a guess. */ - else if (16.0Q * fabsq (__imag__ x) < fabsq (__real__ x)) - { - /* Kahan's formula which avoid cancellation through subtraction in - some cases. */ - res = 2.0Q * clogq (csqrtq ((x + 1.0Q) / 2.0Q) - + csqrtq ((x - 1.0Q) / 2.0Q)); - if (signbitq (__real__ res)) - __real__ res = 0.0Q; - } else { __complex128 y; - __real__ y = (__real__ x - __imag__ x) * (__real__ x + __imag__ x) - 1.0; - __imag__ y = 2.0 * __real__ x * __imag__ x; - - y = csqrtq (y); + __real__ y = -__imag__ x; + __imag__ y = __real__ x; - if (signbitq (x)) - y = -y; + y = __quadmath_kernel_casinhq (y, 1); - __real__ y += __real__ x; - __imag__ y += __imag__ x; - - res = clogq (y); + if (signbitq (__imag__ x)) + { + __real__ res = __real__ y; + __imag__ res = -__imag__ y; + } + else + { + __real__ res = -__real__ y; + __imag__ res = __imag__ y; + } } return res; |