/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2004-2005 David Schultz <das@FreeBSD.ORG>
 * All rights reserved.
 *
 * 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.
 */

#ifndef	_FENV_H_
#define	_FENV_H_

#include <sys/cdefs.h>
#include <sys/_types.h>

#ifndef	__fenv_static
#define	__fenv_static	static
#endif

typedef	__uint32_t	fenv_t;
typedef	__uint32_t	femode_t;
typedef	__uint32_t	fexcept_t;

/* Exception flags */
#define	FE_INVALID	0x0001
#define	FE_DIVBYZERO	0x0002
#define	FE_OVERFLOW	0x0004
#define	FE_UNDERFLOW	0x0008
#define	FE_INEXACT	0x0010
#ifdef __ARM_PCS_VFP
#define	FE_DENORMAL	0x0080
#define	FE_ALL_EXCEPT	(FE_DIVBYZERO | FE_INEXACT | \
			 FE_INVALID | FE_OVERFLOW | FE_UNDERFLOW | FE_DENORMAL)
#else
#define	FE_ALL_EXCEPT	(FE_DIVBYZERO | FE_INEXACT | \
			 FE_INVALID | FE_OVERFLOW | FE_UNDERFLOW)
#endif

/* Rounding modes */
#define	VFP_FE_TONEAREST	0x00000000
#define	VFP_FE_UPWARD		0x00400000
#define	VFP_FE_DOWNWARD		0x00800000
#define	VFP_FE_TOWARDZERO	0x00c00000

#ifdef __ARM_PCS_VFP
#define	FE_TONEAREST	VFP_FE_TONEAREST
#define	FE_UPWARD	VFP_FE_UPWARD
#define	FE_DOWNWARD	VFP_FE_DOWNWARD
#define	FE_TOWARDZERO	VFP_FE_TOWARDZERO
#else
#define	FE_TONEAREST	0x0000
#define	FE_TOWARDZERO	0x0001
#define	FE_UPWARD	0x0002
#define	FE_DOWNWARD	0x0003
#endif
#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)

/* Default floating-point control modes */
extern const femode_t	__fe_dfl_mode;
#define	FE_DFL_MODE	(&__fe_dfl_mode)

/* We need to be able to map status flag positions to mask flag positions */
#ifndef __ARM_PCS_VFP
#define	_FPUSW_SHIFT	16
#define	_ENABLE_MASK	(FE_ALL_EXCEPT << _FPUSW_SHIFT)
#endif

#ifndef __ARM_PCS_VFP

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 fegetmode(femode_t *__modep);
int fesetmode(const femode_t *__modep);
int fegetenv(fenv_t *__envp);
int feholdexcept(fenv_t *__envp);
int fesetenv(const fenv_t *__envp);
int feupdateenv(const fenv_t *__envp);
#if __BSD_VISIBLE
int feenableexcept(int __mask);
int fedisableexcept(int __mask);
int fegetexcept(void);
#endif

#else	/* __ARM_PCS_VFP */

#define	vmrs_fpscr(__r)	__asm __volatile("vmrs %0, fpscr" : "=&r"(__r))
#define	vmsr_fpscr(__r)	__asm __volatile("vmsr fpscr, %0" : : "r"(__r))

#define _FPU_MASK_SHIFT	8

int feclearexcept(int);
int fegetexceptflag(fexcept_t *, int);
int fesetexceptflag(const fexcept_t *, int);
int feraiseexcept(int);
int fetestexcept(int);
int fegetround(void);
int fesetround(int);
int fegetmode(femode_t *);
int fesetmode(const femode_t *);
int fegetenv(fenv_t *);
int feholdexcept(fenv_t *);
int fesetenv(const fenv_t *);
int feupdateenv(const fenv_t *);
int fegetexcept(void);
#if __BSD_VISIBLE
int feenableexcept(int);
int fedisableexcept(int);
int fegetexcept(void);
#endif

/*
 * C permits a standard library function to also be exposed as a function-like
 * macro (C23 7.1.4), and msun uses that here to inline the fast path.  C++
 * forbids it: <cfenv> imports these names into namespace std (using
 * ::feclearexcept; etc.), so std::feclearexcept() and friends must denote the
 * actual functions.  Expose the inlining macros to C only; C++ uses the real
 * extern functions (defined in the matching lib/msun/<arch>/fenv.c).
 */
#ifndef __cplusplus
#define	feclearexcept(a)	__feclearexcept_int(a)
#define	fegetexceptflag(e, a)	__fegetexceptflag_int(e, a)
#define	fesetexceptflag(e, a)	__fesetexceptflag_int(e, a)
#define	feraiseexcept(a)	__feraiseexcept_int(a)
#define	fetestexcept(a)		__fetestexcept_int(a)
#define	fegetround()		__fegetround_int()
#define	fesetround(a)		__fesetround_int(a)
#define	fegetmode(m)		__fegetmode_int(m)
#define	fesetmode(m)		__fesetmode_int(m)
#define	fegetenv(e)		__fegetenv_int(e)
#define	feholdexcept(e)		__feholdexcept_int(e)
#define	fesetenv(e)		__fesetenv_int(e)
#define	feupdateenv(e)		__feupdateenv_int(e)
#if __BSD_VISIBLE
#define	feenableexcept(a)	__feenableexcept_int(a)
#define	fedisableexcept(a)	__fedisableexcept_int(a)
#define	fegetexcept()		__fegetexcept_int()
#endif
#endif /* !__cplusplus */

__fenv_static inline int
__feclearexcept_int(int __excepts)
{
	fexcept_t __fpsr;

	vmrs_fpscr(__fpsr);
	__fpsr &= ~__excepts;
	vmsr_fpscr(__fpsr);
	return (0);
}

__fenv_static inline int
__fegetexceptflag_int(fexcept_t *__flagp, int __excepts)
{
	fexcept_t __fpsr;

	vmrs_fpscr(__fpsr);
	*__flagp = __fpsr & __excepts;
	return (0);
}

__fenv_static inline int
__fesetexceptflag_int(const fexcept_t *__flagp, int __excepts)
{
	fexcept_t __fpsr;

	vmrs_fpscr(__fpsr);
	__fpsr &= ~__excepts;
	__fpsr |= *__flagp & __excepts;
	vmsr_fpscr(__fpsr);
	return (0);
}

__fenv_static inline int
__feraiseexcept_int(int __excepts)
{
	fexcept_t __ex = __excepts;

	fesetexceptflag(&__ex, __excepts);	/* XXX */
	return (0);
}

__fenv_static inline int
__fetestexcept_int(int __excepts)
{
	fexcept_t __fpsr;

	vmrs_fpscr(__fpsr);
	return (__fpsr & __excepts);
}

__fenv_static inline int
__fegetround_int(void)
{
	fenv_t __fpsr;

	vmrs_fpscr(__fpsr);
	return (__fpsr & _ROUND_MASK);
}

__fenv_static inline int
__fesetround_int(int __round)
{
	fenv_t __fpsr;

	vmrs_fpscr(__fpsr);
	__fpsr &= ~(_ROUND_MASK);
	__fpsr |= __round;
	vmsr_fpscr(__fpsr);
	return (0);
}

__fenv_static inline int
__fegetmode_int(femode_t *__modep)
{
	fenv_t __fpsr;

	vmrs_fpscr(__fpsr);
	*__modep = __fpsr & ~FE_ALL_EXCEPT;
	return (0);
}

__fenv_static inline int
__fesetmode_int(const femode_t *__modep)
{
	fenv_t __fpsr;

	vmrs_fpscr(__fpsr);
	__fpsr &= FE_ALL_EXCEPT;
	__fpsr |= *__modep & ~FE_ALL_EXCEPT;
	vmsr_fpscr(__fpsr);
	return (0);
}

__fenv_static inline int
__fegetenv_int(fenv_t *__envp)
{

	vmrs_fpscr(*__envp);
	return (0);
}

__fenv_static inline int
__feholdexcept_int(fenv_t *__envp)
{
	fenv_t __env;

	vmrs_fpscr(__env);
	*__envp = __env;
	__env &= ~(FE_ALL_EXCEPT);
	vmsr_fpscr(__env);
	return (0);
}

__fenv_static inline int
__fesetenv_int(const fenv_t *__envp)
{

	vmsr_fpscr(*__envp);
	return (0);
}

__fenv_static inline int
__feupdateenv_int(const fenv_t *__envp)
{
	fexcept_t __fpsr;

	vmrs_fpscr(__fpsr);
	vmsr_fpscr(*__envp);
	feraiseexcept(__fpsr & FE_ALL_EXCEPT);
	return (0);
}

#if __BSD_VISIBLE

/* We currently provide no external definitions of the functions below. */

__fenv_static inline int
__feenableexcept_int(int __mask)
{
	fenv_t __old_fpsr, __new_fpsr;

	vmrs_fpscr(__old_fpsr);
	__new_fpsr = __old_fpsr |
	    ((__mask & FE_ALL_EXCEPT) << _FPU_MASK_SHIFT);
	vmsr_fpscr(__new_fpsr);
	return ((__old_fpsr >> _FPU_MASK_SHIFT) & FE_ALL_EXCEPT);
}

__fenv_static inline int
__fedisableexcept_int(int __mask)
{
	fenv_t __old_fpsr, __new_fpsr;

	vmrs_fpscr(__old_fpsr);
	__new_fpsr = __old_fpsr &
	    ~((__mask & FE_ALL_EXCEPT) << _FPU_MASK_SHIFT);
	vmsr_fpscr(__new_fpsr);
	return ((__old_fpsr >> _FPU_MASK_SHIFT) & FE_ALL_EXCEPT);
}

__fenv_static inline int
__fegetexcept_int(void)
{
	fenv_t __fpsr;

	vmrs_fpscr(__fpsr);
	return (__fpsr & FE_ALL_EXCEPT);
}

#endif /* __BSD_VISIBLE */

#endif	/* __ARM_PCS_VFP */

__END_DECLS

#endif	/* !_FENV_H_ */