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01dbacd22a
According to C99/C11 Annex G, cacos applied to a value with real part +Inf and finite imaginary part should produce a result with real part +0. glibc wrongly produces a result with real part -0 in FE_DOWNWARD mode. This patch fixes this by checking for zero results in the relevant case of non-finite arguments (where there should never be a result with -0 real part), and converts the tests of cacos to ALL_RM_TEST. Tested x86_64 and x86 and ulps updated accordingly. [BZ #16928] * math/s_cacos.c (__cacos): Ensure zero real part of result from non-finite arguments is +0. * math/s_cacosf.c (__cacosf): Likewise. * math/s_cacosl.c (__cacosl): Likewise. * math/libm-test.inc (cacos_test): Use ALL_RM_TEST. * sysdeps/i386/fpu/libm-test-ulps: Update. * sysdeps/x86_64/fpu/libm-test-ulps: Likewise.
59 lines
1.7 KiB
C
59 lines
1.7 KiB
C
/* Return cosine of complex double value.
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Copyright (C) 1997-2014 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#include <complex.h>
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#include <math.h>
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__complex__ double
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__cacos (__complex__ double x)
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{
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__complex__ double y;
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__complex__ double res;
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int rcls = fpclassify (__real__ x);
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int icls = fpclassify (__imag__ x);
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if (rcls <= FP_INFINITE || icls <= FP_INFINITE
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|| (rcls == FP_ZERO && icls == FP_ZERO))
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{
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y = __casin (x);
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__real__ res = (double) M_PI_2 - __real__ y;
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if (__real__ res == 0.0)
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__real__ res = 0.0;
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__imag__ res = -__imag__ y;
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}
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else
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{
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__real__ y = -__imag__ x;
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__imag__ y = __real__ x;
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y = __kernel_casinh (y, 1);
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__real__ res = __imag__ y;
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__imag__ res = __real__ y;
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}
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return res;
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}
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weak_alias (__cacos, cacos)
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#ifdef NO_LONG_DOUBLE
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strong_alias (__cacos, __cacosl)
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weak_alias (__cacos, cacosl)
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#endif
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