--- /dev/null
+/* $NetBSD: fenv.h,v 1.2 2017/01/14 12:00:13 martin Exp $ */
+
+/*-
+ * 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.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef _SYS_FENV_H_
+#define _SYS_FENV_H_
+
+#include <stdint.h>
+
+#ifdef __arch64__
+typedef uint64_t fenv_t;
+typedef uint64_t fexcept_t;
+#else
+typedef uint32_t fenv_t;
+typedef uint32_t fexcept_t;
+#endif
+
+/*
+ * Exception flags
+ *
+ * Symbols are defined in such a way, to correspond to the accrued
+ * exception bits (aexc) fields of FSR.
+ */
+#define FE_INEXACT 0x00000020 /* 0000100000 */
+#define FE_DIVBYZERO 0x00000040 /* 0001000000 */
+#define FE_UNDERFLOW 0x00000080 /* 0010000000 */
+#define FE_OVERFLOW 0x00000100 /* 0100000000 */
+#define FE_INVALID 0x00000200 /* 1000000000 */
+
+#define FE_ALL_EXCEPT (FE_DIVBYZERO | FE_INEXACT | \
+ FE_INVALID | FE_OVERFLOW | FE_UNDERFLOW)
+
+/*
+ * Rounding modes
+ *
+ * We can't just use the hardware bit values here, because that would
+ * make FE_UPWARD and FE_DOWNWARD negative, which is not allowed.
+ */
+#define FE_TONEAREST 0 /* round to nearest representable number */
+#define FE_TOWARDZERO 1 /* round to zero (truncate) */
+#define FE_UPWARD 2 /* round toward positive infinity */
+#define FE_DOWNWARD 3 /* round toward negative infinity */
+#define _ROUND_MASK (FE_TONEAREST | FE_DOWNWARD | \
+ FE_UPWARD | FE_TOWARDZERO)
+#define _ROUND_SHIFT 30
+
+
+
+/* Default floating-point environment */
+extern const fenv_t *_fe_dfl_env;
+#define FE_DFL_ENV _fe_dfl_env
+
+/* We need to be able to map status flag positions to mask flag positions */
+#define _FPUSW_SHIFT 18
+#define _ENABLE_MASK (FE_ALL_EXCEPT << _FPUSW_SHIFT)
+
+
+
+#endif /* !_SYS_FENV_H_ */
--- /dev/null
+/* $NetBSD: fenv.c,v 1.2 2017/03/22 23:11:09 chs Exp $ */
+
+/*-
+ * 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
+ */
+#include <sys/cdefs.h>
+__RCSID("$NetBSD: fenv.c,v 1.2 2017/03/22 23:11:09 chs Exp $");
+
+
+
+#include <assert.h>
+#include <fenv.h>
+
+#define _DIAGASSERT(x) assert(x)
+
+#ifdef __weak_alias
+__weak_alias(feclearexcept,_feclearexcept)
+__weak_alias(fedisableexcept,_fedisableexcept)
+__weak_alias(feenableexcept,_feenableexcept)
+__weak_alias(fegetenv,_fegetenv)
+__weak_alias(fegetexcept,_fegetexcept)
+__weak_alias(fegetexceptflag,_fegetexceptflag)
+__weak_alias(fegetround,_fegetround)
+__weak_alias(feholdexcept,_feholdexcept)
+__weak_alias(feraiseexcept,_feraiseexcept)
+__weak_alias(fesetenv,_fesetenv)
+__weak_alias(fesetexceptflag,_fesetexceptflag)
+__weak_alias(fesetround,_fesetround)
+__weak_alias(fetestexcept,_fetestexcept)
+__weak_alias(feupdateenv,_feupdateenv)
+#endif
+
+/* Load floating-point state register (32bits) */
+#define __ldfsr(__r) __asm__ __volatile__ \
+ ("ld %0, %%fsr" : : "m" (__r))
+
+/* Save floating-point state register (32bits) */
+#define __stfsr(__r) __asm__ __volatile__ \
+ ("st %%fsr, %0" : "=m" (*(__r)))
+
+/*
+ * The feclearexcept() function clears the supported floating-point exceptions
+ * represented by `excepts'.
+ */
+int
+feclearexcept(int excepts)
+{
+ fexcept_t r;
+ int ex;
+
+ _DIAGASSERT((excepts & ~FE_ALL_EXCEPT) == 0);
+
+ ex = excepts & FE_ALL_EXCEPT;
+
+ __stfsr(&r);
+ r &= ~ex;
+ __ldfsr(r);
+
+ /* Success */
+ return 0;
+}
+
+/*
+ * The fegetexceptflag() function stores an implementation-defined
+ * representation of the states of the floating-point status flags indicated
+ * by the argument excepts in the object pointed to by the argument flagp.
+ */
+int
+fegetexceptflag(fexcept_t *flagp, int excepts)
+{
+ fexcept_t r;
+ int ex;
+
+ _DIAGASSERT(flagp != NULL);
+ _DIAGASSERT((excepts & ~FE_ALL_EXCEPT) == 0);
+
+ ex = excepts & FE_ALL_EXCEPT;
+
+ __stfsr(&r);
+ *flagp = r & ex;
+
+ /* Success */
+ return 0;
+}
+
+
+/*
+ * This function sets the floating-point status flags indicated by the argument
+ * `excepts' to the states stored in the object pointed to by `flagp'. It does
+ * NOT raise any floating-point exceptions, but only sets the state of the flags.
+ */
+int
+fesetexceptflag(const fexcept_t *flagp, int excepts)
+{
+ fexcept_t r;
+ int ex;
+
+ _DIAGASSERT(flagp != NULL);
+ _DIAGASSERT((excepts & ~FE_ALL_EXCEPT) == 0);
+
+ ex = excepts & FE_ALL_EXCEPT;
+
+ __stfsr(&r);
+ r &= ~ex;
+ r |= *flagp & ex;
+ __ldfsr(r);
+
+ /* Success */
+ return 0;
+}
+
+/*
+ * The feraiseexcept() function raises the supported floating-point exceptions
+ * represented by the argument `excepts'.
+ *
+ * The order in which these floating-point exceptions are raised is unspecified
+ * (by the standard).
+ */
+int
+feraiseexcept(int excepts)
+{
+ volatile double d;
+ int ex;
+
+ _DIAGASSERT((excepts & ~FE_ALL_EXCEPT) == 0);
+
+ ex = excepts & FE_ALL_EXCEPT;
+
+ /*
+ * With a compiler that supports the FENV_ACCESS pragma properly, simple
+ * expressions like '0.0 / 0.0' should be sufficient to generate traps.
+ * Unfortunately, we need to bring a volatile variable into the equation
+ * to prevent incorrect optimizations.
+ */
+ if (ex & FE_INVALID) {
+ d = 0.0;
+ d = 0.0 / d;
+ }
+ if (ex & FE_DIVBYZERO) {
+ d = 0.0;
+ d = 1.0 / d;
+ }
+ if (ex & FE_OVERFLOW) {
+ d = 0x1.ffp1023;
+ d *= 2.0;
+ }
+ if (ex & FE_UNDERFLOW) {
+ d = 0x1p-1022;
+ d /= 0x1p1023;
+ }
+ if (ex & FE_INEXACT) {
+ d = 0x1p-1022;
+ d += 1.0;
+ }
+
+ /* Success */
+ return 0;
+}
+
+/*
+ * The fetestexcept() function determines which of a specified subset of the
+ * floating-point exception flags are currently set. The `excepts' argument
+ * specifies the floating-point status flags to be queried.
+ */
+int
+fetestexcept(int excepts)
+{
+ fexcept_t r;
+
+ _DIAGASSERT((excepts & ~FE_ALL_EXCEPT) == 0);
+
+ __stfsr(&r);
+
+ return r & (excepts & FE_ALL_EXCEPT);
+}
+
+/*
+ * The fegetround() function gets the current rounding direction.
+ */
+int
+fegetround(void)
+{
+ fenv_t r;
+
+ __stfsr(&r);
+
+ return (r >> _ROUND_SHIFT) & _ROUND_MASK;
+}
+
+/*
+ * The fesetround() function establishes the rounding direction represented by
+ * its argument `round'. If the argument is not equal to the value of a rounding
+ * direction macro, the rounding direction is not changed.
+ */
+int
+fesetround(int round)
+{
+ fenv_t r;
+
+ _DIAGASSERT((round & ~_ROUND_MASK) == 0);
+ if (round & ~_ROUND_MASK)
+ return -1;
+
+ __stfsr(&r);
+ r &= ~(_ROUND_MASK << _ROUND_SHIFT);
+ r |= round << _ROUND_SHIFT;
+ __ldfsr(r);
+
+ /* Success */
+ return 0;
+}
+
+/*
+ * The fegetenv() function attempts to store the current floating-point
+ * environment in the object pointed to by envp.
+ */
+int
+fegetenv(fenv_t *envp)
+{
+ _DIAGASSERT(envp != NULL);
+
+ __stfsr(envp);
+
+ /* Success */
+ return 0;
+}
+
+
+/*
+ * The feholdexcept() function saves the current floating-point environment
+ * in the object pointed to by envp, clears the floating-point status flags, and
+ * then installs a non-stop (continue on floating-point exceptions) mode, if
+ * available, for all floating-point exceptions.
+ */
+int
+feholdexcept(fenv_t *envp)
+{
+ fenv_t r;
+
+ _DIAGASSERT(envp != NULL);
+
+ __stfsr(&r);
+ *envp = r;
+ r &= ~(FE_ALL_EXCEPT | _ENABLE_MASK);
+ __ldfsr(r);
+
+ /* Success */
+ return 0;
+}
+
+/*
+ * The fesetenv() function attempts to establish the floating-point environment
+ * represented by the object pointed to by envp. The argument `envp' points
+ * to an object set by a call to fegetenv() or feholdexcept(), or equal a
+ * floating-point environment macro. The fesetenv() function does not raise
+ * floating-point exceptions, but only installs the state of the floating-point
+ * status flags represented through its argument.
+ */
+int
+fesetenv(const fenv_t *envp)
+{
+ _DIAGASSERT(envp != NULL);
+
+ __ldfsr(*envp);
+
+ /* Success */
+ return 0;
+}
+
+
+/*
+ * The feupdateenv() function saves the currently raised floating-point
+ * exceptions in its automatic storage, installs the floating-point environment
+ * represented by the object pointed to by `envp', and then raises the saved
+ * floating-point exceptions. The argument `envp' shall point to an object set
+ * by a call to feholdexcept() or fegetenv(), or equal a floating-point
+ * environment macro.
+ */
+int
+feupdateenv(const fenv_t *envp)
+{
+ fexcept_t r;
+
+ _DIAGASSERT(envp != NULL);
+
+ __stfsr(&r);
+ __ldfsr(*envp);
+
+ _DIAGASSERT((r & ~FE_ALL_EXCEPT) == 0);
+ feraiseexcept(r & FE_ALL_EXCEPT);
+
+ /* Success */
+ return 0;
+}
+
+/*
+ * The following functions are extentions to the standard
+ */
+int
+feenableexcept(int mask)
+{
+ fenv_t old_r, new_r;
+
+ __stfsr(&old_r);
+ new_r = old_r | ((mask & FE_ALL_EXCEPT) << _FPUSW_SHIFT);
+ __ldfsr(new_r);
+
+ return (old_r >> _FPUSW_SHIFT) & FE_ALL_EXCEPT;
+}
+
+int
+fedisableexcept(int mask)
+{
+ fenv_t old_r, new_r;
+
+ __stfsr(&old_r);
+ new_r = old_r & ~((mask & FE_ALL_EXCEPT) << _FPUSW_SHIFT);
+ __ldfsr(new_r);
+
+ return (old_r >> _FPUSW_SHIFT) & FE_ALL_EXCEPT;
+}
+
+int
+fegetexcept(void)
+{
+ fenv_t r;
+
+ __stfsr(&r);
+ return (r & _ENABLE_MASK) >> _FPUSW_SHIFT;
+}