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Edit File: fenv.h
/* Copyright (C) 1997-2021 Free Software Foundation, Inc. This file is part of the GNU C Library. The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. The GNU C Library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with the GNU C Library; if not, see <https://www.gnu.org/licenses/>. */ /* * ISO C99 7.6: Floating-point environment <fenv.h> */ #ifndef _FENV_H #define _FENV_H 1 #define __GLIBC_INTERNAL_STARTING_HEADER_IMPLEMENTATION #include <bits/libc-header-start.h> /* Get the architecture dependend definitions. The following definitions are expected to be done: fenv_t type for object representing an entire floating-point environment FE_DFL_ENV macro of type pointer to fenv_t to be used as the argument to functions taking an argument of type fenv_t; in this case the default environment will be used fexcept_t type for object representing the floating-point exception flags including status associated with the flags femode_t type for object representing floating-point control modes FE_DFL_MODE macro of type pointer to const femode_t to be used as the argument to fesetmode; in this case the default control modes will be used The following macros are defined iff the implementation supports this kind of exception. FE_INEXACT inexact result FE_DIVBYZERO division by zero FE_UNDERFLOW result not representable due to underflow FE_OVERFLOW result not representable due to overflow FE_INVALID invalid operation FE_ALL_EXCEPT bitwise OR of all supported exceptions The next macros are defined iff the appropriate rounding mode is supported by the implementation. FE_TONEAREST round to nearest FE_UPWARD round toward +Inf FE_DOWNWARD round toward -Inf FE_TOWARDZERO round toward 0 */ #include <bits/fenv.h> __BEGIN_DECLS /* Floating-point exception handling. */ /* Clear the supported exceptions represented by EXCEPTS. */ extern int feclearexcept (int __excepts) __THROW; /* Store implementation-defined representation of the exception flags indicated by EXCEPTS in the object pointed to by FLAGP. */ extern int fegetexceptflag (fexcept_t *__flagp, int __excepts) __THROW; /* Raise the supported exceptions represented by EXCEPTS. */ extern int feraiseexcept (int __excepts) __THROW; #if __GLIBC_USE (IEC_60559_BFP_EXT_C2X) /* Set the supported exception flags represented by EXCEPTS, without causing enabled traps to be taken. */ extern int fesetexcept (int __excepts) __THROW; #endif /* Set complete status for exceptions indicated by EXCEPTS according to the representation in the object pointed to by FLAGP. */ extern int fesetexceptflag (const fexcept_t *__flagp, int __excepts) __THROW; /* Determine which of subset of the exceptions specified by EXCEPTS are currently set. */ extern int fetestexcept (int __excepts) __THROW; #if __GLIBC_USE (IEC_60559_BFP_EXT_C2X) /* Determine which of subset of the exceptions specified by EXCEPTS are set in *FLAGP. */ extern int fetestexceptflag (const fexcept_t *__flagp, int __excepts) __THROW; #endif /* Rounding control. */ /* Get current rounding direction. */ extern int fegetround (void) __THROW __attribute_pure__; /* Establish the rounding direction represented by ROUND. */ extern int fesetround (int __rounding_direction) __THROW; /* Floating-point environment. */ /* Store the current floating-point environment in the object pointed to by ENVP. */ extern int fegetenv (fenv_t *__envp) __THROW; /* Save the current environment in the object pointed to by ENVP, clear exception flags and install a non-stop mode (if available) for all exceptions. */ extern int feholdexcept (fenv_t *__envp) __THROW; /* Establish the floating-point environment represented by the object pointed to by ENVP. */ extern int fesetenv (const fenv_t *__envp) __THROW; /* Save current exceptions in temporary storage, install environment represented by object pointed to by ENVP and raise exceptions according to saved exceptions. */ extern int feupdateenv (const fenv_t *__envp) __THROW; /* Control modes. */ #if __GLIBC_USE (IEC_60559_BFP_EXT_C2X) /* Store the current floating-point control modes in the object pointed to by MODEP. */ extern int fegetmode (femode_t *__modep) __THROW; /* Establish the floating-point control modes represented by the object pointed to by MODEP. */ extern int fesetmode (const femode_t *__modep) __THROW; #endif /* NaN support. */ #if (__GLIBC_USE (IEC_60559_BFP_EXT_C2X) \ && defined FE_INVALID \ && defined __SUPPORT_SNAN__) # define FE_SNANS_ALWAYS_SIGNAL 1 #endif #ifdef __USE_GNU /* Enable individual exceptions. Will not enable more exceptions than EXCEPTS specifies. Returns the previous enabled exceptions if all exceptions are successfully set, otherwise returns -1. */ extern int feenableexcept (int __excepts) __THROW; /* Disable individual exceptions. Will not disable more exceptions than EXCEPTS specifies. Returns the previous enabled exceptions if all exceptions are successfully disabled, otherwise returns -1. */ extern int fedisableexcept (int __excepts) __THROW; /* Return enabled exceptions. */ extern int fegetexcept (void) __THROW; #endif __END_DECLS #endif /* fenv.h */