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Editing: fenv.h
/* Copyright (C) 1997-2018 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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