aboutsummaryrefslogtreecommitdiff
path: root/math/s_clog_template.c
diff options
context:
space:
mode:
authorPaul E. Murphy <murphyp@linux.vnet.ibm.com>2016-07-01 11:03:51 -0500
committerPaul E. Murphy <murphyp@linux.vnet.ibm.com>2016-08-29 11:55:41 -0500
commit1dbc54f61e281d3f2c1712dadd12864c42f8a64a (patch)
tree039c7754e2f843648b93acddbb5c4e92f4a74b06 /math/s_clog_template.c
parentd47d27d6c08fa95c1ed49a8ce96cef2e37736b72 (diff)
downloadglibc-1dbc54f61e281d3f2c1712dadd12864c42f8a64a.tar
glibc-1dbc54f61e281d3f2c1712dadd12864c42f8a64a.tar.gz
glibc-1dbc54f61e281d3f2c1712dadd12864c42f8a64a.tar.bz2
glibc-1dbc54f61e281d3f2c1712dadd12864c42f8a64a.zip
Prepare to convert remaining _Complex functions
This patch has no function changes, except to ensure the git history correctly tracks the changes to convert the double version of these functions into a templated version.
Diffstat (limited to 'math/s_clog_template.c')
-rw-r--r--math/s_clog_template.c118
1 files changed, 118 insertions, 0 deletions
diff --git a/math/s_clog_template.c b/math/s_clog_template.c
new file mode 100644
index 0000000000..b546030313
--- /dev/null
+++ b/math/s_clog_template.c
@@ -0,0 +1,118 @@
+/* Compute complex natural logarithm.
+ Copyright (C) 1997-2016 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ 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, see
+ <http://www.gnu.org/licenses/>. */
+
+#include <complex.h>
+#include <math.h>
+#include <math_private.h>
+#include <float.h>
+
+__complex__ double
+__clog (__complex__ double x)
+{
+ __complex__ double result;
+ int rcls = fpclassify (__real__ x);
+ int icls = fpclassify (__imag__ x);
+
+ if (__glibc_unlikely (rcls == FP_ZERO && icls == FP_ZERO))
+ {
+ /* Real and imaginary part are 0.0. */
+ __imag__ result = signbit (__real__ x) ? M_PI : 0.0;
+ __imag__ result = __copysign (__imag__ result, __imag__ x);
+ /* Yes, the following line raises an exception. */
+ __real__ result = -1.0 / fabs (__real__ x);
+ }
+ else if (__glibc_likely (rcls != FP_NAN && icls != FP_NAN))
+ {
+ /* Neither real nor imaginary part is NaN. */
+ double absx = fabs (__real__ x), absy = fabs (__imag__ x);
+ int scale = 0;
+
+ if (absx < absy)
+ {
+ double t = absx;
+ absx = absy;
+ absy = t;
+ }
+
+ if (absx > DBL_MAX / 2.0)
+ {
+ scale = -1;
+ absx = __scalbn (absx, scale);
+ absy = (absy >= DBL_MIN * 2.0 ? __scalbn (absy, scale) : 0.0);
+ }
+ else if (absx < DBL_MIN && absy < DBL_MIN)
+ {
+ scale = DBL_MANT_DIG;
+ absx = __scalbn (absx, scale);
+ absy = __scalbn (absy, scale);
+ }
+
+ if (absx == 1.0 && scale == 0)
+ {
+ __real__ result = __log1p (absy * absy) / 2.0;
+ math_check_force_underflow_nonneg (__real__ result);
+ }
+ else if (absx > 1.0 && absx < 2.0 && absy < 1.0 && scale == 0)
+ {
+ double d2m1 = (absx - 1.0) * (absx + 1.0);
+ if (absy >= DBL_EPSILON)
+ d2m1 += absy * absy;
+ __real__ result = __log1p (d2m1) / 2.0;
+ }
+ else if (absx < 1.0
+ && absx >= 0.5
+ && absy < DBL_EPSILON / 2.0
+ && scale == 0)
+ {
+ double d2m1 = (absx - 1.0) * (absx + 1.0);
+ __real__ result = __log1p (d2m1) / 2.0;
+ }
+ else if (absx < 1.0
+ && absx >= 0.5
+ && scale == 0
+ && absx * absx + absy * absy >= 0.5)
+ {
+ double d2m1 = __x2y2m1 (absx, absy);
+ __real__ result = __log1p (d2m1) / 2.0;
+ }
+ else
+ {
+ double d = __ieee754_hypot (absx, absy);
+ __real__ result = __ieee754_log (d) - scale * M_LN2;
+ }
+
+ __imag__ result = __ieee754_atan2 (__imag__ x, __real__ x);
+ }
+ else
+ {
+ __imag__ result = __nan ("");
+ if (rcls == FP_INFINITE || icls == FP_INFINITE)
+ /* Real or imaginary part is infinite. */
+ __real__ result = HUGE_VAL;
+ else
+ __real__ result = __nan ("");
+ }
+
+ return result;
+}
+weak_alias (__clog, clog)
+#ifdef NO_LONG_DOUBLE
+strong_alias (__clog, __clogl)
+weak_alias (__clog, clogl)
+#endif