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142 lines
3.9 KiB
C
142 lines
3.9 KiB
C
/* Copyright (C) 1997-2012 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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<http://www.gnu.org/licenses/>. */
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#ifndef _FENV_H
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# error "Never use <bits/fenv.h> directly; include <fenv.h> instead."
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#endif
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/* Define bits representing the exception. We use the bit positions
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of the appropriate bits in the FPU control word. */
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enum
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{
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FE_INVALID = 0x01,
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#define FE_INVALID FE_INVALID
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__FE_DENORM = 0x02,
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FE_DIVBYZERO = 0x04,
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#define FE_DIVBYZERO FE_DIVBYZERO
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FE_OVERFLOW = 0x08,
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#define FE_OVERFLOW FE_OVERFLOW
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FE_UNDERFLOW = 0x10,
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#define FE_UNDERFLOW FE_UNDERFLOW
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FE_INEXACT = 0x20
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#define FE_INEXACT FE_INEXACT
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};
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#define FE_ALL_EXCEPT \
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(FE_INEXACT | FE_DIVBYZERO | FE_UNDERFLOW | FE_OVERFLOW | FE_INVALID)
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/* The ix87 FPU supports all of the four defined rounding modes. We
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use again the bit positions in the FPU control word as the values
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for the appropriate macros. */
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enum
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{
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FE_TONEAREST = 0,
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#define FE_TONEAREST FE_TONEAREST
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FE_DOWNWARD = 0x400,
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#define FE_DOWNWARD FE_DOWNWARD
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FE_UPWARD = 0x800,
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#define FE_UPWARD FE_UPWARD
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FE_TOWARDZERO = 0xc00
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#define FE_TOWARDZERO FE_TOWARDZERO
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};
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/* Type representing exception flags. */
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typedef unsigned short int fexcept_t;
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/* Type representing floating-point environment. This structure
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corresponds to the layout of the block written by the `fstenv'
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instruction and has additional fields for the contents of the MXCSR
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register as written by the `stmxcsr' instruction. */
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typedef struct
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{
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unsigned short int __control_word;
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unsigned short int __unused1;
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unsigned short int __status_word;
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unsigned short int __unused2;
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unsigned short int __tags;
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unsigned short int __unused3;
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unsigned int __eip;
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unsigned short int __cs_selector;
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unsigned int __opcode:11;
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unsigned int __unused4:5;
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unsigned int __data_offset;
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unsigned short int __data_selector;
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unsigned short int __unused5;
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#ifdef __x86_64__
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unsigned int __mxcsr;
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#endif
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}
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fenv_t;
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/* If the default argument is used we use this value. */
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#define FE_DFL_ENV ((const fenv_t *) -1)
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#ifdef __USE_GNU
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/* Floating-point environment where none of the exception is masked. */
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# define FE_NOMASK_ENV ((const fenv_t *) -2)
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#endif
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#ifdef __USE_EXTERN_INLINES
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__BEGIN_DECLS
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/* Optimized versions. */
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extern int __REDIRECT_NTH (__feraiseexcept_renamed, (int), feraiseexcept);
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__extern_inline int
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__NTH (feraiseexcept (int __excepts))
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{
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if (__builtin_constant_p (__excepts)
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&& (__excepts & ~(FE_INVALID | FE_DIVBYZERO)) == 0)
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{
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if ((FE_INVALID & __excepts) != 0)
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{
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/* One example of a invalid operation is 0.0 / 0.0. */
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float __f = 0.0;
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# ifdef __SSE_MATH__
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__asm__ __volatile__ ("divss %0, %0 " : : "x" (__f));
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# else
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__asm__ __volatile__ ("fdiv %%st, %%st(0); fwait"
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: "=t" (__f) : "0" (__f));
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# endif
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(void) &__f;
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}
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if ((FE_DIVBYZERO & __excepts) != 0)
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{
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float __f = 1.0;
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float __g = 0.0;
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# ifdef __SSE_MATH__
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__asm__ __volatile__ ("divss %1, %0" : : "x" (__f), "x" (__g));
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# else
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__asm__ __volatile__ ("fdivp %%st, %%st(1); fwait"
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: "=t" (__f) : "0" (__f), "u" (__g) : "st(1)");
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# endif
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(void) &__f;
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}
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return 0;
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}
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return __feraiseexcept_renamed (__excepts);
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}
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__END_DECLS
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#endif
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