/* Copyright (C) 1997-2001,2004,2011,2012 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 . */ #ifndef _FENV_H # error "Never use directly; include instead." #endif #include /* Define bits representing the exception. We use the bit positions of the appropriate bits in the FPU control word. */ enum { FE_INVALID = 0x01, #define FE_INVALID FE_INVALID __FE_DENORM = 0x02, FE_DIVBYZERO = 0x04, #define FE_DIVBYZERO FE_DIVBYZERO FE_OVERFLOW = 0x08, #define FE_OVERFLOW FE_OVERFLOW FE_UNDERFLOW = 0x10, #define FE_UNDERFLOW FE_UNDERFLOW FE_INEXACT = 0x20 #define FE_INEXACT 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 = 0, #define FE_TONEAREST FE_TONEAREST FE_DOWNWARD = 0x400, #define FE_DOWNWARD FE_DOWNWARD FE_UPWARD = 0x800, #define FE_UPWARD FE_UPWARD FE_TOWARDZERO = 0xc00 #define FE_TOWARDZERO 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 __unused1; unsigned short int __status_word; unsigned short int __unused2; unsigned short int __tags; unsigned short int __unused3; unsigned int __eip; unsigned short int __cs_selector; unsigned int __opcode:11; unsigned int __unused4:5; unsigned int __data_offset; unsigned short int __data_selector; unsigned short int __unused5; #if __WORDSIZE == 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 #ifdef __USE_EXTERN_INLINES __BEGIN_DECLS /* Optimized versions. */ extern int __REDIRECT_NTH (__feraiseexcept_renamed, (int), feraiseexcept); __extern_inline int __NTH (feraiseexcept (int __excepts)) { if (__builtin_constant_p (__excepts) && (__excepts & ~(FE_INVALID | FE_DIVBYZERO)) == 0) { if ((FE_INVALID & __excepts) != 0) { /* One example of a invalid operation is 0.0 / 0.0. */ float __f = 0.0; __asm__ __volatile__ ("divss %0, %0 " : : "x" (__f)); (void) &__f; } if ((FE_DIVBYZERO & __excepts) != 0) { float __f = 1.0; float __g = 0.0; __asm__ __volatile__ ("divss %1, %0" : : "x" (__f), "x" (__g)); (void) &__f; } return 0; } return __feraiseexcept_renamed (__excepts); } __END_DECLS #endif