/* Copyright (C) 1997-2021 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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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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/*
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* ISO C99 7.6: Floating-point environment <fenv.h>
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*/
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#ifndef _FENV_H
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#define _FENV_H 1
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#define __GLIBC_INTERNAL_STARTING_HEADER_IMPLEMENTATION
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#include <bits/libc-header-start.h>
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/* Get the architecture dependend definitions. The following definitions
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are expected to be done:
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fenv_t type for object representing an entire floating-point
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environment
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FE_DFL_ENV macro of type pointer to fenv_t to be used as the argument
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to functions taking an argument of type fenv_t; in this
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case the default environment will be used
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fexcept_t type for object representing the floating-point exception
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flags including status associated with the flags
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femode_t type for object representing floating-point control modes
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FE_DFL_MODE macro of type pointer to const femode_t to be used as the
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argument to fesetmode; in this case the default control
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modes will be used
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The following macros are defined iff the implementation supports this
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kind of exception.
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FE_INEXACT inexact result
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FE_DIVBYZERO division by zero
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FE_UNDERFLOW result not representable due to underflow
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FE_OVERFLOW result not representable due to overflow
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FE_INVALID invalid operation
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FE_ALL_EXCEPT bitwise OR of all supported exceptions
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The next macros are defined iff the appropriate rounding mode is
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supported by the implementation.
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FE_TONEAREST round to nearest
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FE_UPWARD round toward +Inf
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FE_DOWNWARD round toward -Inf
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FE_TOWARDZERO round toward 0
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*/
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#include <bits/fenv.h>
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__BEGIN_DECLS
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/* Floating-point exception handling. */
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/* Clear the supported exceptions represented by EXCEPTS. */
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extern int feclearexcept (int __excepts) __THROW;
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/* Store implementation-defined representation of the exception flags
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indicated by EXCEPTS in the object pointed to by FLAGP. */
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extern int fegetexceptflag (fexcept_t *__flagp, int __excepts) __THROW;
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/* Raise the supported exceptions represented by EXCEPTS. */
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extern int feraiseexcept (int __excepts) __THROW;
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#if __GLIBC_USE (IEC_60559_BFP_EXT_C2X)
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/* Set the supported exception flags represented by EXCEPTS, without
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causing enabled traps to be taken. */
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extern int fesetexcept (int __excepts) __THROW;
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#endif
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/* Set complete status for exceptions indicated by EXCEPTS according to
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the representation in the object pointed to by FLAGP. */
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extern int fesetexceptflag (const fexcept_t *__flagp, int __excepts) __THROW;
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/* Determine which of subset of the exceptions specified by EXCEPTS are
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currently set. */
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extern int fetestexcept (int __excepts) __THROW;
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#if __GLIBC_USE (IEC_60559_BFP_EXT_C2X)
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/* Determine which of subset of the exceptions specified by EXCEPTS
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are set in *FLAGP. */
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extern int fetestexceptflag (const fexcept_t *__flagp, int __excepts) __THROW;
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#endif
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/* Rounding control. */
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/* Get current rounding direction. */
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extern int fegetround (void) __THROW __attribute_pure__;
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/* Establish the rounding direction represented by ROUND. */
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extern int fesetround (int __rounding_direction) __THROW;
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/* Floating-point environment. */
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/* Store the current floating-point environment in the object pointed
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to by ENVP. */
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extern int fegetenv (fenv_t *__envp) __THROW;
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/* Save the current environment in the object pointed to by ENVP, clear
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exception flags and install a non-stop mode (if available) for all
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exceptions. */
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extern int feholdexcept (fenv_t *__envp) __THROW;
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/* Establish the floating-point environment represented by the object
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pointed to by ENVP. */
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extern int fesetenv (const fenv_t *__envp) __THROW;
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/* Save current exceptions in temporary storage, install environment
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represented by object pointed to by ENVP and raise exceptions
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according to saved exceptions. */
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extern int feupdateenv (const fenv_t *__envp) __THROW;
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/* Control modes. */
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#if __GLIBC_USE (IEC_60559_BFP_EXT_C2X)
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/* Store the current floating-point control modes in the object
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pointed to by MODEP. */
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extern int fegetmode (femode_t *__modep) __THROW;
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/* Establish the floating-point control modes represented by the
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object pointed to by MODEP. */
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extern int fesetmode (const femode_t *__modep) __THROW;
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#endif
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/* NaN support. */
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#if (__GLIBC_USE (IEC_60559_BFP_EXT_C2X) \
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&& defined FE_INVALID \
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&& defined __SUPPORT_SNAN__)
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# define FE_SNANS_ALWAYS_SIGNAL 1
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#endif
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#ifdef __USE_GNU
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/* Enable individual exceptions. Will not enable more exceptions than
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EXCEPTS specifies. Returns the previous enabled exceptions if all
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exceptions are successfully set, otherwise returns -1. */
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extern int feenableexcept (int __excepts) __THROW;
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/* Disable individual exceptions. Will not disable more exceptions than
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EXCEPTS specifies. Returns the previous enabled exceptions if all
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exceptions are successfully disabled, otherwise returns -1. */
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extern int fedisableexcept (int __excepts) __THROW;
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/* Return enabled exceptions. */
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extern int fegetexcept (void) __THROW;
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#endif
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__END_DECLS
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#endif /* fenv.h */
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