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	This is a preparatory patch to enable building a _Float128
variant to ease reuse when building a _Float128 variant to
alias this long double only symbol.
Notably, stubs are added where missing to the native _Float128
sysdep dir to prevent building these newly templated variants
created inside the build directories.
Also noteworthy are the changes around LIBM_SVID_COMPAT.  These
changes are not intuitive.  The templated version is only
enabled when !LIBM_SVID_COMPAT, and the compat version is
predicated entirely on LIBM_SVID_COMPAT.  Thus, exactly one is
stubbed out entirely when building.  The nldbl scalb compat
files are updated to account for this.
Likewise, fixup the reuse of m68k's e_scalb{f,l}.c to include
it's override of e_scalb.c.  Otherwise, the search path finds
the templated copy in the build directory.  This could be
futher simplified by providing an overridden template, but I
lack the hardware to verify.
		
	
		
			
				
	
	
		
			84 lines
		
	
	
		
			2.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			84 lines
		
	
	
		
			2.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/* Copyright (C) 2011-2020 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@gmail.com>, 2011.
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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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   <https://www.gnu.org/licenses/>.  */
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#include <errno.h>
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#include <math.h>
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#include <math_private.h>
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#include <math-svid-compat.h>
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#if LIBM_SVID_COMPAT
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static double
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__attribute__ ((noinline))
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sysv_scalb (double x, double fn)
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{
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  double z = __ieee754_scalb (x, fn);
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  if (__glibc_unlikely (isinf (z)))
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    {
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      if (isfinite (x))
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	return __kernel_standard (x, fn, 32); /* scalb overflow */
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      else
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	__set_errno (ERANGE);
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    }
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  else if (__builtin_expect (z == 0.0, 0) && z != x)
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    return __kernel_standard (x, fn, 33); /* scalb underflow */
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  return z;
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}
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/* Wrapper scalb */
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double
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__scalb (double x, double fn)
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{
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  if (__glibc_unlikely (_LIB_VERSION == _SVID_))
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    return sysv_scalb (x, fn);
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  else
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    {
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      double z = __ieee754_scalb (x, fn);
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      if (__glibc_unlikely (!isfinite (z) || z == 0.0))
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	{
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	  if (isnan (z))
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	    {
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	      if (!isnan (x) && !isnan (fn))
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		__set_errno (EDOM);
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	    }
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	  else if (isinf (z))
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	    {
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	      if (!isinf (x) && !isinf (fn))
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		__set_errno (ERANGE);
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	    }
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	  else
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	    {
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	      /* z == 0.  */
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	      if (x != 0.0 && !isinf (fn))
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		__set_errno (ERANGE);
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	    }
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	}
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      return z;
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    }
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}
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weak_alias (__scalb, scalb)
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# ifdef NO_LONG_DOUBLE
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strong_alias (__scalb, __scalbl)
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weak_alias (__scalb, scalbl)
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# endif
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#endif
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