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	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.
		
			
				
	
	
		
			57 lines
		
	
	
		
			1.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			57 lines
		
	
	
		
			1.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* Return cosine of complex float 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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| 
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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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| 
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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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| 
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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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| 
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| #include <complex.h>
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| #include <math.h>
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| 
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| __complex__ float
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| __cacosf (__complex__ float x)
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| {
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|   __complex__ float y;
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|   __complex__ float res;
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|   int rcls = fpclassify (__real__ x);
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|   int icls = fpclassify (__imag__ x);
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| 
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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 = __casinf (x);
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| 
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|       __real__ res = (float) M_PI_2 - __real__ y;
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|       if (__real__ res == 0.0f)
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| 	__real__ res = 0.0f;
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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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| 
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|       y = __kernel_casinhf (y, 1);
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| 
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|       __real__ res = __imag__ y;
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|       __imag__ res = __real__ y;
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|     }
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| 
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|   return res;
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| }
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| #ifndef __cacosf
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| weak_alias (__cacosf, cacosf)
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| #endif
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