openlibm_fenv_riscv.h

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/*-
 * Copyright (c) 2004-2005 David Schultz <das@FreeBSD.ORG>
 * Copyright (c) 2015-2016 Ruslan Bukin <br@bsdpad.com>
 * All rights reserved.
 *
 * Portions of this software were developed by SRI International and the
 * University of Cambridge Computer Laboratory under DARPA/AFRL contract
 * FA8750-10-C-0237 ("CTSRD"), as part of the DARPA CRASH research programme.
 *
 * Portions of this software were developed by the University of Cambridge
 * Computer Laboratory as part of the CTSRD Project, with support from the
 * UK Higher Education Innovation Fund (HEIF).
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * $FreeBSD: head/lib/msun/riscv/fenv.h 332792 2018-04-19 20:36:15Z brooks $
 */
 
#ifndef _FENV_H_
#define _FENV_H_
 
#include <stdint.h>
#include "../inc/cdefs-compat.h"
 
#ifndef __fenv_static
#define __fenv_static   static
#endif
 
typedef __uint64_t  fenv_t;
typedef __uint64_t  fexcept_t;
 
/* Exception flags */
#define FE_INVALID  0x0010
#define FE_DIVBYZERO    0x0008
#define FE_OVERFLOW 0x0004
#define FE_UNDERFLOW    0x0002
#define FE_INEXACT  0x0001
#define FE_ALL_EXCEPT   (FE_DIVBYZERO | FE_INEXACT | \
             FE_INVALID | FE_OVERFLOW | FE_UNDERFLOW)
 
/*
 * RISC-V Rounding modes
 */
#define _ROUND_SHIFT    5
#define FE_TONEAREST    (0x00 << _ROUND_SHIFT)
#define FE_TOWARDZERO   (0x01 << _ROUND_SHIFT)
#define FE_DOWNWARD (0x02 << _ROUND_SHIFT)
#define FE_UPWARD   (0x03 << _ROUND_SHIFT)
#define _ROUND_MASK (FE_TONEAREST | FE_DOWNWARD | \
             FE_UPWARD | FE_TOWARDZERO)
 
__BEGIN_DECLS
 
/* Default floating-point environment */
extern const fenv_t __fe_dfl_env;
#define FE_DFL_ENV  (&__fe_dfl_env)
 
#if !defined(__riscv_float_abi_soft) && !defined(__riscv_float_abi_double)
#if defined(__riscv_float_abi_single)
#error single precision floating point ABI not supported
#else
#error compiler did not set soft/hard float macros
#endif
#endif
 
#ifndef __riscv_float_abi_soft
#define __rfs(__fcsr)   __asm __volatile("csrr %0, fcsr" : "=r" (__fcsr))
#define __wfs(__fcsr)   __asm __volatile("csrw fcsr, %0" :: "r" (__fcsr))
#endif
 
#ifdef __riscv_float_abi_soft
int feclearexcept(int __excepts);
int fegetexceptflag(fexcept_t *__flagp, int __excepts);
int fesetexceptflag(const fexcept_t *__flagp, int __excepts);
int feraiseexcept(int __excepts);
int fetestexcept(int __excepts);
int fegetround(void);
int fesetround(int __round);
int fegetenv(fenv_t *__envp);
int feholdexcept(fenv_t *__envp);
int fesetenv(const fenv_t *__envp);
int feupdateenv(const fenv_t *__envp);
#else
__fenv_static inline int
feclearexcept(int __excepts)
{
 
    __asm __volatile("csrc fflags, %0" :: "r"(__excepts));
 
    return (0);
}
 
__fenv_static inline int
fegetexceptflag(fexcept_t *__flagp, int __excepts)
{
    fexcept_t __fcsr;
 
    __rfs(__fcsr);
    *__flagp = __fcsr & __excepts;
 
    return (0);
}
 
__fenv_static inline int
fesetexceptflag(const fexcept_t *__flagp, int __excepts)
{
    fexcept_t __fcsr;
 
    __fcsr = *__flagp;
    __asm __volatile("csrc fflags, %0" :: "r"(__excepts));
    __asm __volatile("csrs fflags, %0" :: "r"(__fcsr & __excepts));
 
    return (0);
}
 
__fenv_static inline int
feraiseexcept(int __excepts)
{
 
    __asm __volatile("csrs fflags, %0" :: "r"(__excepts));
 
    return (0);
}
 
__fenv_static inline int
fetestexcept(int __excepts)
{
    fexcept_t __fcsr;
 
    __rfs(__fcsr);
 
    return (__fcsr & __excepts);
}
 
__fenv_static inline int
fegetround(void)
{
    fexcept_t __fcsr;
 
    __rfs(__fcsr);
 
    return (__fcsr & _ROUND_MASK);
}
 
__fenv_static inline int
fesetround(int __round)
{
    fexcept_t __fcsr;
 
    if (__round & ~_ROUND_MASK)
        return (-1);
 
    __rfs(__fcsr);
    __fcsr &= ~_ROUND_MASK;
    __fcsr |= __round;
    __wfs(__fcsr);
 
    return (0);
}
 
__fenv_static inline int
fegetenv(fenv_t *__envp)
{
 
    __rfs(*__envp);
 
    return (0);
}
 
__fenv_static inline int
feholdexcept(fenv_t *__envp)
{
 
    /* No exception traps. */
 
    return (-1);
}
 
__fenv_static inline int
fesetenv(const fenv_t *__envp)
{
 
    __wfs(*__envp);
 
    return (0);
}
 
__fenv_static inline int
feupdateenv(const fenv_t *__envp)
{
    fexcept_t __fcsr;
 
    __rfs(__fcsr);
    __wfs(*__envp);
    feraiseexcept(__fcsr & FE_ALL_EXCEPT);
 
    return (0);
}
#endif /* !__riscv_float_abi_soft */
 
#if __BSD_VISIBLE
 
/* We currently provide no external definitions of the functions below. */
 
#ifdef __riscv_float_abi_soft
int feenableexcept(int __mask);
int fedisableexcept(int __mask);
int fegetexcept(void);
#else
static inline int
feenableexcept(int __mask)
{
 
    /* No exception traps. */
 
    return (-1);
}
 
static inline int
fedisableexcept(int __mask)
{
 
    /* No exception traps. */
 
    return (0);
}
 
static inline int
fegetexcept(void)
{
 
    /* No exception traps. */
 
    return (0);
}
#endif /* !__riscv_float_abi_soft */
 
#endif /* __BSD_VISIBLE */
 
__END_DECLS
 
#endif  /* !_FENV_H_ */