From ba06a7c392b9c49df0288de3531288424ae1dd1e Mon Sep 17 00:00:00 2001 From: Mike Frysinger Date: Wed, 18 Jan 2006 23:40:51 +0000 Subject: sync fenv.h with glibc --- libc/sysdeps/linux/alpha/bits/fenv.h | 123 +++++++++++++++++++++++++++++++++++ 1 file changed, 123 insertions(+) create mode 100644 libc/sysdeps/linux/alpha/bits/fenv.h (limited to 'libc/sysdeps/linux/alpha/bits') diff --git a/libc/sysdeps/linux/alpha/bits/fenv.h b/libc/sysdeps/linux/alpha/bits/fenv.h new file mode 100644 index 000000000..a9e89b498 --- /dev/null +++ b/libc/sysdeps/linux/alpha/bits/fenv.h @@ -0,0 +1,123 @@ +/* Copyright (C) 1997, 1998, 1999, 2000 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, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#ifndef _FENV_H +# error "Never use directly; include instead." +#endif + + +/* Define the bits representing the exception. + + Note that these are the bit positions as defined by the OSF/1 + ieee_{get,set}_control_word interface and not by the hardware fpcr. + + See the Alpha Architecture Handbook section 4.7.7.3 for details, + but in summary, trap shadows mean the hardware register can acquire + extra exception bits so for proper IEEE support the tracking has to + be done in software -- in this case with kernel support. + + As to why the system call interface isn't in the same format as + the hardware register, only those crazy folks at DEC can tell you. */ + +enum + { +#ifdef __USE_GNU + FE_DENORMAL = 1UL << 22, +#define FE_DENORMAL FE_DENORMAL +#endif + + FE_INEXACT = 1UL << 21, +#define FE_INEXACT FE_INEXACT + + FE_UNDERFLOW = 1UL << 20, +#define FE_UNDERFLOW FE_UNDERFLOW + + FE_OVERFLOW = 1UL << 19, +#define FE_OVERFLOW FE_OVERFLOW + + FE_DIVBYZERO = 1UL << 18, +#define FE_DIVBYZERO FE_DIVBYZERO + + FE_INVALID = 1UL << 17, +#define FE_INVALID FE_INVALID + + FE_ALL_EXCEPT = 0x3f << 17 +#define FE_ALL_EXCEPT FE_ALL_EXCEPT + }; + +/* Alpha chips support all four defined rouding modes. + + Note that code must be compiled to use dynamic rounding (/d) instructions + to see these changes. For gcc this is -mfp-rounding-mode=d; for DEC cc + this is -fprm d. The default for both is static rounding to nearest. + + These are shifted down 58 bits from the hardware fpcr because the + functions are declared to take integers. */ + +enum + { + FE_TOWARDZERO = 0, +#define FE_TOWARDZERO FE_TOWARDZERO + + FE_DOWNWARD = 1, +#define FE_DOWNWARD FE_DOWNWARD + + FE_TONEAREST = 2, +#define FE_TONEAREST FE_TONEAREST + + FE_UPWARD = 3, +#define FE_UPWARD FE_UPWARD + }; + +#ifdef __USE_GNU +/* On later hardware, and later kernels for earlier hardware, we can forcibly + underflow denormal inputs and outputs. This can speed up certain programs + significantly, usually without affecting accuracy. */ +enum + { + FE_MAP_DMZ = 1UL << 12, /* Map denorm inputs to zero */ +#define FE_MAP_DMZ FE_MAP_DMZ + + FE_MAP_UMZ = 1UL << 13, /* Map underflowed outputs to zero */ +#define FE_MAP_UMZ FE_MAP_UMZ + }; +#endif + +/* Type representing exception flags. */ +typedef unsigned long int fexcept_t; + +/* Type representing floating-point environment. */ +typedef unsigned long int fenv_t; + +/* If the default argument is used we use this value. Note that due to + architecture-specified page mappings, no user-space pointer will ever + have its two high bits set. Co-opt one. */ +#define FE_DFL_ENV ((__const fenv_t *) 0x8800000000000000UL) + +#ifdef __USE_GNU +/* Floating-point environment where none of the exceptions are masked. */ +# define FE_NOMASK_ENV ((__const fenv_t *) 0x880000000000003eUL) + +/* Floating-point environment with (processor-dependent) non-IEEE floating + point. In this case, mapping denormals to zero. */ +# define FE_NONIEEE_ENV ((__const fenv_t *) 0x8800000000003000UL) +#endif + +/* The system calls to talk to the kernel's FP code. */ +extern unsigned long int __ieee_get_fp_control (void) __THROW; +extern void __ieee_set_fp_control (unsigned long int __value) __THROW; -- cgit v1.2.3