Update most of libquadmath/math/ from glibc, automate update (PR libquadmath/68686).

[thirdparty/gcc.git] / libquadmath / math / catanhq.c

diff --git a/libquadmath/math/catanhq.c b/libquadmath/math/catanhq.c
index 6a86e2d0202d3c4073d78d722a00e173a1e66b7a..adc0a9dddec1dc053bf96cc88a9c713eabb18f67 100644 (file)
--- a/libquadmath/math/catanhq.c
+++ b/libquadmath/math/catanhq.c
@@ -1,5 +1,5 @@
-/* Return arc hyperbole tangent for __float128 value.
-   Copyright (C) 1997, 1998 Free Software Foundation, Inc.
+/* Return arc hyperbolic tangent for a complex float 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
 catanhq (__complex128 x)
 {
@@ -28,16 +26,16 @@ catanhq (__complex128 x)
   int rcls = fpclassifyq (__real__ x);
   int icls = fpclassifyq (__imag__ x);
 
-  if (rcls <= QUADFP_INFINITE || icls <= QUADFP_INFINITE)
+  if (__glibc_unlikely (rcls <= QUADFP_INFINITE || icls <= QUADFP_INFINITE))
     {
       if (icls == QUADFP_INFINITE)
        {
-         __real__ res = copysignq (0.0, __real__ x);
+         __real__ res = copysignq (0, __real__ x);
          __imag__ res = copysignq (M_PI_2q, __imag__ x);
        }
       else if (rcls == QUADFP_INFINITE || rcls == QUADFP_ZERO)
        {
-         __real__ res = copysignq (0.0, __real__ x);
+         __real__ res = copysignq (0, __real__ x);
          if (icls >= QUADFP_ZERO)
            __imag__ res = copysignq (M_PI_2q, __imag__ x);
          else
@@ -49,27 +47,83 @@ catanhq (__complex128 x)
          __imag__ res = nanq ("");
        }
     }
-  else if (rcls == QUADFP_ZERO && icls == QUADFP_ZERO)
+  else if (__glibc_unlikely (rcls == QUADFP_ZERO && icls == QUADFP_ZERO))
     {
       res = x;
     }
   else
     {
-      __float128 i2, num, den;
+      if (fabsq (__real__ x) >= 16 / FLT128_EPSILON
+         || fabsq (__imag__ x) >= 16 / FLT128_EPSILON)
+       {
+         __imag__ res = copysignq (M_PI_2q, __imag__ x);
+         if (fabsq (__imag__ x) <= 1)
+           __real__ res = 1 / __real__ x;
+         else if (fabsq (__real__ x) <= 1)
+           __real__ res = __real__ x / __imag__ x / __imag__ x;
+         else
+           {
+             __float128 h = hypotq (__real__ x / 2, __imag__ x / 2);
+             __real__ res = __real__ x / h / h / 4;
+           }
+       }
+      else
+       {
+         if (fabsq (__real__ x) == 1
+             && fabsq (__imag__ x) < FLT128_EPSILON * FLT128_EPSILON)
+           __real__ res = (copysignq (0.5Q, __real__ x)
+                           * ((__float128) M_LN2q
+                              - logq (fabsq (__imag__ x))));
+         else
+           {
+             __float128 i2 = 0;
+             if (fabsq (__imag__ x) >= FLT128_EPSILON * FLT128_EPSILON)
+               i2 = __imag__ x * __imag__ x;
+
+             __float128 num = 1 + __real__ x;
+             num = i2 + num * num;
 
-      i2 = __imag__ x * __imag__ x;
+             __float128 den = 1 - __real__ x;
+             den = i2 + den * den;
 
-      num = 1.0 + __real__ x;
-      num = i2 + num * num;
+             __float128 f = num / den;
+             if (f < 0.5Q)
+               __real__ res = 0.25Q * logq (f);
+             else
+               {
+                 num = 4 * __real__ x;
+                 __real__ res = 0.25Q * log1pq (num / den);
+               }
+           }
 
-      den = 1.0 - __real__ x;
-      den = i2 + den * den;
+         __float128 absx, absy, den;
 
-      __real__ res = 0.25 * (logq (num) - logq (den));
+         absx = fabsq (__real__ x);
+         absy = fabsq (__imag__ x);
+         if (absx < absy)
+           {
+             __float128 t = absx;
+             absx = absy;
+             absy = t;
+           }
 
-      den = 1 - __real__ x * __real__ x - i2;
+         if (absy < FLT128_EPSILON / 2)
+           {
+             den = (1 - absx) * (1 + absx);
+             if (den == 0)
+               den = 0;
+           }
+         else if (absx >= 1)
+           den = (1 - absx) * (1 + absx) - absy * absy;
+         else if (absx >= 0.75Q || absy >= 0.5Q)
+           den = -__quadmath_x2y2m1q (absx, absy);
+         else
+           den = (1 - absx) * (1 + absx) - absy * absy;
+
+         __imag__ res = 0.5Q * atan2q (2 * __imag__ x, den);
+       }
 
-      __imag__ res = 0.5 * atan2q (2.0 * __imag__ x, den);
+      math_check_force_underflow_complex (res);
     }
 
   return res;