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			484 lines
		
	
	
		
			8.9 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			484 lines
		
	
	
		
			8.9 KiB
		
	
	
	
		
			C
		
	
	
	
| /* FPU-related code for systems with GNU libc.
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|    Copyright (C) 2005-2016 Free Software Foundation, Inc.
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|    Contributed by Francois-Xavier Coudert <coudert@clipper.ens.fr>
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| 
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| This file is part of the GNU Fortran runtime library (libgfortran).
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| 
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| Libgfortran is free software; you can redistribute it and/or
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| modify it under the terms of the GNU General Public
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| License as published by the Free Software Foundation; either
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| version 3 of the License, or (at your option) any later version.
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| 
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| Libgfortran 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
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| GNU General Public License for more details.
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| 
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| Under Section 7 of GPL version 3, you are granted additional
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| permissions described in the GCC Runtime Library Exception, version
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| 3.1, as published by the Free Software Foundation.
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| 
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| You should have received a copy of the GNU General Public License and
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| a copy of the GCC Runtime Library Exception along with this program;
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| see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
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| <http://www.gnu.org/licenses/>.  */
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| 
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| /* FPU-related code for systems with the GNU libc, providing the
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|    feenableexcept function in fenv.h to set individual exceptions
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|    (there's nothing to do that in C99).  */
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| 
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| #ifdef HAVE_FENV_H
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| #include <fenv.h>
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| #endif
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| 
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| 
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| /* Check we can actually store the FPU state in the allocated size.  */
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| _Static_assert (sizeof(fenv_t) <= (size_t) GFC_FPE_STATE_BUFFER_SIZE,
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| 		"GFC_FPE_STATE_BUFFER_SIZE is too small");
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| 
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| 
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| void set_fpu_trap_exceptions (int trap, int notrap)
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| {
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| #ifdef FE_INVALID
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|   if (trap & GFC_FPE_INVALID)
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|     feenableexcept (FE_INVALID);
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|   if (notrap & GFC_FPE_INVALID)
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|     fedisableexcept (FE_INVALID);
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| #endif
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| 
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| /* Some glibc targets (like alpha) have FE_DENORMAL, but not many.  */
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| #ifdef FE_DENORMAL
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|   if (trap & GFC_FPE_DENORMAL)
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|     feenableexcept (FE_DENORMAL);
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|   if (notrap & GFC_FPE_DENORMAL)
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|     fedisableexcept (FE_DENORMAL);
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| #endif
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| 
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| #ifdef FE_DIVBYZERO
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|   if (trap & GFC_FPE_ZERO)
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|     feenableexcept (FE_DIVBYZERO);
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|   if (notrap & GFC_FPE_ZERO)
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|     fedisableexcept (FE_DIVBYZERO);
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| #endif
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| 
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| #ifdef FE_OVERFLOW
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|   if (trap & GFC_FPE_OVERFLOW)
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|     feenableexcept (FE_OVERFLOW);
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|   if (notrap & GFC_FPE_OVERFLOW)
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|     fedisableexcept (FE_OVERFLOW);
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| #endif
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| 
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| #ifdef FE_UNDERFLOW
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|   if (trap & GFC_FPE_UNDERFLOW)
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|     feenableexcept (FE_UNDERFLOW);
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|   if (notrap & GFC_FPE_UNDERFLOW)
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|     fedisableexcept (FE_UNDERFLOW);
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| #endif
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| 
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| #ifdef FE_INEXACT
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|   if (trap & GFC_FPE_INEXACT)
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|     feenableexcept (FE_INEXACT);
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|   if (notrap & GFC_FPE_INEXACT)
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|     fedisableexcept (FE_INEXACT);
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| #endif
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| }
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| 
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| 
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| int
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| get_fpu_trap_exceptions (void)
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| {
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|   int exceptions = fegetexcept ();
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|   int res = 0;
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| 
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| #ifdef FE_INVALID
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|   if (exceptions & FE_INVALID) res |= GFC_FPE_INVALID;
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| #endif
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| 
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| #ifdef FE_DENORMAL
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|   if (exceptions & FE_DENORMAL) res |= GFC_FPE_DENORMAL;
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| #endif
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| 
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| #ifdef FE_DIVBYZERO
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|   if (exceptions & FE_DIVBYZERO) res |= GFC_FPE_ZERO;
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| #endif
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| 
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| #ifdef FE_OVERFLOW
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|   if (exceptions & FE_OVERFLOW) res |= GFC_FPE_OVERFLOW;
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| #endif
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| 
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| #ifdef FE_UNDERFLOW
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|   if (exceptions & FE_UNDERFLOW) res |= GFC_FPE_UNDERFLOW;
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| #endif
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| 
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| #ifdef FE_INEXACT
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|   if (exceptions & FE_INEXACT) res |= GFC_FPE_INEXACT;
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| #endif
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| 
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|   return res;
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| }
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| 
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| 
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| int
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| support_fpu_trap (int flag)
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| {
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|   return support_fpu_flag (flag);
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| }
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| 
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| 
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| void set_fpu (void)
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| {
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| #ifndef FE_INVALID
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|   if (options.fpe & GFC_FPE_INVALID)
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|     estr_write ("Fortran runtime warning: IEEE 'invalid operation' "
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| 	        "exception not supported.\n");
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| #endif
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| 
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| #ifndef FE_DENORMAL
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|   if (options.fpe & GFC_FPE_DENORMAL)
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|     estr_write ("Fortran runtime warning: Floating point 'denormal operand' "
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| 	        "exception not supported.\n");
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| #endif
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| 
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| #ifndef FE_DIVBYZERO
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|   if (options.fpe & GFC_FPE_ZERO)
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|     estr_write ("Fortran runtime warning: IEEE 'division by zero' "
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| 	        "exception not supported.\n");
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| #endif
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| 
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| #ifndef FE_OVERFLOW
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|   if (options.fpe & GFC_FPE_OVERFLOW)
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|     estr_write ("Fortran runtime warning: IEEE 'overflow' "
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| 	        "exception not supported.\n");
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| #endif
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| 
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| #ifndef FE_UNDERFLOW
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|   if (options.fpe & GFC_FPE_UNDERFLOW)
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|     estr_write ("Fortran runtime warning: IEEE 'underflow' "
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| 	        "exception not supported.\n");
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| #endif
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| 
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| #ifndef FE_INEXACT
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|   if (options.fpe & GFC_FPE_INEXACT)
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|     estr_write ("Fortran runtime warning: IEEE 'inexact' "
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| 	        "exception not supported.\n");
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| #endif
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| 
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|   set_fpu_trap_exceptions (options.fpe, 0);
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| }
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| 
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| 
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| int
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| get_fpu_except_flags (void)
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| {
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|   int result, set_excepts;
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| 
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|   result = 0;
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|   set_excepts = fetestexcept (FE_ALL_EXCEPT);
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| 
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| #ifdef FE_INVALID
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|   if (set_excepts & FE_INVALID)
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|     result |= GFC_FPE_INVALID;
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| #endif
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| 
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| #ifdef FE_DIVBYZERO
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|   if (set_excepts & FE_DIVBYZERO)
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|     result |= GFC_FPE_ZERO;
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| #endif
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| 
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| #ifdef FE_OVERFLOW
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|   if (set_excepts & FE_OVERFLOW)
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|     result |= GFC_FPE_OVERFLOW;
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| #endif
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| 
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| #ifdef FE_UNDERFLOW
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|   if (set_excepts & FE_UNDERFLOW)
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|     result |= GFC_FPE_UNDERFLOW;
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| #endif
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| 
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| #ifdef FE_DENORMAL
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|   if (set_excepts & FE_DENORMAL)
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|     result |= GFC_FPE_DENORMAL;
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| #endif
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| 
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| #ifdef FE_INEXACT
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|   if (set_excepts & FE_INEXACT)
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|     result |= GFC_FPE_INEXACT;
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| #endif
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| 
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|   return result;
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| }
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| 
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| 
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| void
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| set_fpu_except_flags (int set, int clear)
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| {
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|   int exc_set = 0, exc_clr = 0;
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| 
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| #ifdef FE_INVALID
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|   if (set & GFC_FPE_INVALID)
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|     exc_set |= FE_INVALID;
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|   else if (clear & GFC_FPE_INVALID)
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|     exc_clr |= FE_INVALID;
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| #endif
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| 
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| #ifdef FE_DIVBYZERO
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|   if (set & GFC_FPE_ZERO)
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|     exc_set |= FE_DIVBYZERO;
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|   else if (clear & GFC_FPE_ZERO)
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|     exc_clr |= FE_DIVBYZERO;
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| #endif
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| 
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| #ifdef FE_OVERFLOW
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|   if (set & GFC_FPE_OVERFLOW)
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|     exc_set |= FE_OVERFLOW;
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|   else if (clear & GFC_FPE_OVERFLOW)
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|     exc_clr |= FE_OVERFLOW;
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| #endif
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| 
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| #ifdef FE_UNDERFLOW
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|   if (set & GFC_FPE_UNDERFLOW)
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|     exc_set |= FE_UNDERFLOW;
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|   else if (clear & GFC_FPE_UNDERFLOW)
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|     exc_clr |= FE_UNDERFLOW;
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| #endif
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| 
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| #ifdef FE_DENORMAL
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|   if (set & GFC_FPE_DENORMAL)
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|     exc_set |= FE_DENORMAL;
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|   else if (clear & GFC_FPE_DENORMAL)
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|     exc_clr |= FE_DENORMAL;
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| #endif
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| 
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| #ifdef FE_INEXACT
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|   if (set & GFC_FPE_INEXACT)
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|     exc_set |= FE_INEXACT;
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|   else if (clear & GFC_FPE_INEXACT)
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|     exc_clr |= FE_INEXACT;
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| #endif
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| 
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|   feclearexcept (exc_clr);
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|   feraiseexcept (exc_set);
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| }
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| 
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| 
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| int
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| support_fpu_flag (int flag)
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| {
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|   if (flag & GFC_FPE_INVALID)
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|   {
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| #ifndef FE_INVALID
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|     return 0;
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| #endif
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|   }
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|   else if (flag & GFC_FPE_ZERO)
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|   {
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| #ifndef FE_DIVBYZERO
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|     return 0;
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| #endif
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|   }
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|   else if (flag & GFC_FPE_OVERFLOW)
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|   {
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| #ifndef FE_OVERFLOW
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|     return 0;
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| #endif
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|   }
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|   else if (flag & GFC_FPE_UNDERFLOW)
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|   {
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| #ifndef FE_UNDERFLOW
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|     return 0;
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| #endif
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|   }
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|   else if (flag & GFC_FPE_DENORMAL)
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|   {
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| #ifndef FE_DENORMAL
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|     return 0;
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| #endif
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|   }
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|   else if (flag & GFC_FPE_INEXACT)
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|   {
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| #ifndef FE_INEXACT
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|     return 0;
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| #endif
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|   }
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| 
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|   return 1;
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| }
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| 
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| 
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| int
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| get_fpu_rounding_mode (void)
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| {
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|   int rnd_mode;
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| 
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|   rnd_mode = fegetround ();
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| 
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|   switch (rnd_mode)
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|     {
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| #ifdef FE_TONEAREST
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|       case FE_TONEAREST:
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| 	return GFC_FPE_TONEAREST;
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| #endif
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| 
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| #ifdef FE_UPWARD
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|       case FE_UPWARD:
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| 	return GFC_FPE_UPWARD;
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| #endif
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| 
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| #ifdef FE_DOWNWARD
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|       case FE_DOWNWARD:
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| 	return GFC_FPE_DOWNWARD;
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| #endif
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| 
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| #ifdef FE_TOWARDZERO
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|       case FE_TOWARDZERO:
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| 	return GFC_FPE_TOWARDZERO;
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| #endif
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| 
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|       default:
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| 	return 0; /* Should be unreachable.  */
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|     }
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| }
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| 
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| 
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| void
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| set_fpu_rounding_mode (int mode)
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| {
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|   int rnd_mode;
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| 
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|   switch (mode)
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|     {
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| #ifdef FE_TONEAREST
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|       case GFC_FPE_TONEAREST:
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| 	rnd_mode = FE_TONEAREST;
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| 	break;
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| #endif
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| 
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| #ifdef FE_UPWARD
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|       case GFC_FPE_UPWARD:
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| 	rnd_mode = FE_UPWARD;
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| 	break;
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| #endif
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| 
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| #ifdef FE_DOWNWARD
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|       case GFC_FPE_DOWNWARD:
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| 	rnd_mode = FE_DOWNWARD;
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| 	break;
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| #endif
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| 
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| #ifdef FE_TOWARDZERO
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|       case GFC_FPE_TOWARDZERO:
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| 	rnd_mode = FE_TOWARDZERO;
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| 	break;
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| #endif
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| 
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|       default:
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| 	return; /* Should be unreachable.  */
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|     }
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| 
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|   fesetround (rnd_mode);
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| }
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| 
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| 
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| int
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| support_fpu_rounding_mode (int mode)
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| {
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|   switch (mode)
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|     {
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|       case GFC_FPE_TONEAREST:
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| #ifdef FE_TONEAREST
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| 	return 1;
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| #else
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| 	return 0;
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| #endif
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| 
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|       case GFC_FPE_UPWARD:
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| #ifdef FE_UPWARD
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| 	return 1;
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| #else
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| 	return 0;
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| #endif
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| 
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|       case GFC_FPE_DOWNWARD:
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| #ifdef FE_DOWNWARD
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| 	return 1;
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| #else
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| 	return 0;
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| #endif
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| 
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|       case GFC_FPE_TOWARDZERO:
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| #ifdef FE_TOWARDZERO
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| 	return 1;
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| #else
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| 	return 0;
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| #endif
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| 
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|       default:
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| 	return 0; /* Should be unreachable.  */
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|     }
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| }
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| 
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| 
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| void
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| get_fpu_state (void *state)
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| {
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|   fegetenv (state);
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| }
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| 
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| 
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| void
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| set_fpu_state (void *state)
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| {
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|   fesetenv (state);
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| }
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| 
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| 
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| /* Underflow in glibc is currently only supported on alpha, through
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|    the FE_MAP_UMZ macro and __ieee_set_fp_control() function call.  */
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| 
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| int
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| support_fpu_underflow_control (int kind __attribute__((unused)))
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| {
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| #if defined(__alpha__) && defined(FE_MAP_UMZ)
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|   return (kind == 4 || kind == 8) ? 1 : 0;
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| #else
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|   return 0;
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| #endif
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| }
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| 
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| 
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| int
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| get_fpu_underflow_mode (void)
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| {
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| #if defined(__alpha__) && defined(FE_MAP_UMZ)
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| 
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|   fenv_t state = __ieee_get_fp_control ();
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| 
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|   /* Return 0 for abrupt underflow (flush to zero), 1 for gradual underflow.  */
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|   return (state & FE_MAP_UMZ) ? 0 : 1;
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| 
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| #else
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| 
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|   return 0;
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| 
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| #endif
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| }
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| 
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| 
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| void
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| set_fpu_underflow_mode (int gradual __attribute__((unused)))
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| {
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| #if defined(__alpha__) && defined(FE_MAP_UMZ)
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| 
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|   fenv_t state = __ieee_get_fp_control ();
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| 
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|   if (gradual)
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|     state &= ~FE_MAP_UMZ;
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|   else
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|     state |= FE_MAP_UMZ;
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| 
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|   __ieee_set_fp_control (state);
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| 
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| #endif
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| }
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| 
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