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- /* Copyright (C) 1997-2019 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
- <http://www.gnu.org/licenses/>. */
- #ifndef _FENV_H
- # error "Never use <bits/fenv.h> directly; include <fenv.h> instead."
- #endif
- /* Define bits representing the exception. We use the bit positions
- of the appropriate bits in the FPU control word. */
- enum
- {
- FE_INVALID =
- #define FE_INVALID 0x01
- FE_INVALID,
- __FE_DENORM = 0x02,
- FE_DIVBYZERO =
- #define FE_DIVBYZERO 0x04
- FE_DIVBYZERO,
- FE_OVERFLOW =
- #define FE_OVERFLOW 0x08
- FE_OVERFLOW,
- FE_UNDERFLOW =
- #define FE_UNDERFLOW 0x10
- FE_UNDERFLOW,
- FE_INEXACT =
- #define FE_INEXACT 0x20
- FE_INEXACT
- };
- #define FE_ALL_EXCEPT \
- (FE_INEXACT | FE_DIVBYZERO | FE_UNDERFLOW | FE_OVERFLOW | FE_INVALID)
- /* The ix87 FPU supports all of the four defined rounding modes. We
- use again the bit positions in the FPU control word as the values
- for the appropriate macros. */
- enum
- {
- FE_TONEAREST =
- #define FE_TONEAREST 0
- FE_TONEAREST,
- FE_DOWNWARD =
- #define FE_DOWNWARD 0x400
- FE_DOWNWARD,
- FE_UPWARD =
- #define FE_UPWARD 0x800
- FE_UPWARD,
- FE_TOWARDZERO =
- #define FE_TOWARDZERO 0xc00
- FE_TOWARDZERO
- };
- /* Type representing exception flags. */
- typedef unsigned short int fexcept_t;
- /* Type representing floating-point environment. This structure
- corresponds to the layout of the block written by the `fstenv'
- instruction and has additional fields for the contents of the MXCSR
- register as written by the `stmxcsr' instruction. */
- typedef struct
- {
- unsigned short int __control_word;
- unsigned short int __glibc_reserved1;
- unsigned short int __status_word;
- unsigned short int __glibc_reserved2;
- unsigned short int __tags;
- unsigned short int __glibc_reserved3;
- unsigned int __eip;
- unsigned short int __cs_selector;
- unsigned int __opcode:11;
- unsigned int __glibc_reserved4:5;
- unsigned int __data_offset;
- unsigned short int __data_selector;
- unsigned short int __glibc_reserved5;
- #ifdef __x86_64__
- unsigned int __mxcsr;
- #endif
- }
- fenv_t;
- /* If the default argument is used we use this value. */
- #define FE_DFL_ENV ((const fenv_t *) -1)
- #ifdef __USE_GNU
- /* Floating-point environment where none of the exception is masked. */
- # define FE_NOMASK_ENV ((const fenv_t *) -2)
- #endif
- #if __GLIBC_USE (IEC_60559_BFP_EXT)
- /* Type representing floating-point control modes. */
- typedef struct
- {
- unsigned short int __control_word;
- unsigned short int __glibc_reserved;
- unsigned int __mxcsr;
- }
- femode_t;
- /* Default floating-point control modes. */
- # define FE_DFL_MODE ((const femode_t *) -1L)
- #endif
- #ifdef __USE_EXTERN_INLINES
- __BEGIN_DECLS
- /* Optimized versions. */
- #ifndef _LIBC
- extern int __REDIRECT_NTH (__feraiseexcept_renamed, (int), feraiseexcept);
- #endif
- __extern_always_inline void
- __NTH (__feraiseexcept_invalid_divbyzero (int __excepts))
- {
- if ((FE_INVALID & __excepts) != 0)
- {
- /* One example of an invalid operation is 0.0 / 0.0. */
- float __f = 0.0;
- # ifdef __SSE_MATH__
- __asm__ __volatile__ ("divss %0, %0 " : : "x" (__f));
- # else
- __asm__ __volatile__ ("fdiv %%st, %%st(0); fwait"
- : "=t" (__f) : "0" (__f));
- # endif
- (void) &__f;
- }
- if ((FE_DIVBYZERO & __excepts) != 0)
- {
- float __f = 1.0;
- float __g = 0.0;
- # ifdef __SSE_MATH__
- __asm__ __volatile__ ("divss %1, %0" : : "x" (__f), "x" (__g));
- # else
- __asm__ __volatile__ ("fdivp %%st, %%st(1); fwait"
- : "=t" (__f) : "0" (__f), "u" (__g) : "st(1)");
- # endif
- (void) &__f;
- }
- }
- __extern_inline int
- __NTH (feraiseexcept (int __excepts))
- {
- if (__builtin_constant_p (__excepts)
- && (__excepts & ~(FE_INVALID | FE_DIVBYZERO)) == 0)
- {
- __feraiseexcept_invalid_divbyzero (__excepts);
- return 0;
- }
- return __feraiseexcept_renamed (__excepts);
- }
- __END_DECLS
- #endif
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