diff options
Diffstat (limited to 'lib/libm')
-rw-r--r-- | lib/libm/arch/alpha/fenv.c | 362 |
1 files changed, 362 insertions, 0 deletions
diff --git a/lib/libm/arch/alpha/fenv.c b/lib/libm/arch/alpha/fenv.c new file mode 100644 index 00000000000..f0db3a3dbee --- /dev/null +++ b/lib/libm/arch/alpha/fenv.c @@ -0,0 +1,362 @@ +/* $OpenBSD: fenv.c,v 1.1 2011/04/23 22:39:14 martynas Exp $ */ + +/* + * Copyright (c) 2011 Martynas Venckus <martynas@openbsd.org> + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +#include <sys/types.h> +#include <machine/sysarch.h> + +#include <fenv.h> + +/* + * The following constant represents the default floating-point environment + * (that is, the one installed at program startup) and has type pointer to + * const-qualified fenv_t. + * + * It can be used as an argument to the functions within the <fenv.h> header + * that manage the floating-point environment, namely fesetenv() and + * feupdateenv(). + */ +fenv_t __fe_dfl_env = { + 0, + 0, + FE_TONEAREST +}; + +/* + * The feclearexcept() function clears the supported floating-point exceptions + * represented by `excepts'. + */ +int +feclearexcept(int excepts) +{ + unsigned int fpsticky; + struct alpha_fp_except_args a; + + excepts &= FE_ALL_EXCEPT; + + /* Store the current floating-point sticky flags */ + fpsticky = sysarch(ALPHA_FPGETSTICKY, 0L); + + /* Clear the requested floating-point exceptions */ + fpsticky &= ~excepts; + + /* Load the floating-point sticky flags */ + a.mask = fpsticky; + sysarch(ALPHA_FPSETSTICKY, &a); + + 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) +{ + unsigned int fpsticky; + + excepts &= FE_ALL_EXCEPT; + + /* Store the current floating-point sticky flags */ + fpsticky = sysarch(ALPHA_FPGETSTICKY, 0L); + + /* Store the results in flagp */ + *flagp = fpsticky & excepts; + + return (0); +} + +/* + * The feraiseexcept() function raises the supported floating-point exceptions + * represented by the argument `excepts'. + */ +int +feraiseexcept(int excepts) +{ + excepts &= FE_ALL_EXCEPT; + + fesetexceptflag((fexcept_t *)&excepts, excepts); + + 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) +{ + unsigned int fpsticky; + struct alpha_fp_except_args a; + + excepts &= FE_ALL_EXCEPT; + + /* Store the current floating-point sticky flags */ + fpsticky = sysarch(ALPHA_FPGETSTICKY, 0L); + + /* Set the requested status flags */ + fpsticky &= ~excepts; + fpsticky |= *flagp & excepts; + + /* Load the floating-point sticky flags */ + a.mask = fpsticky; + sysarch(ALPHA_FPSETSTICKY, &a); + + 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) +{ + unsigned int fpsticky; + + excepts &= FE_ALL_EXCEPT; + + /* Store the current floating-point sticky flags */ + fpsticky = sysarch(ALPHA_FPGETSTICKY, 0L); + + return (fpsticky & excepts); +} + +/* + * The fegetround() function gets the current rounding direction. + */ +int +fegetround(void) +{ + unsigned long fpcr; + + /* Store the current floating-point control register */ + __asm__ __volatile__ ("trapb"); + __asm__ __volatile__ ("mf_fpcr %0" : "=f" (fpcr)); + __asm__ __volatile__ ("trapb"); + + return ((fpcr >> _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) +{ + unsigned long fpcr; + + /* Check whether requested rounding direction is supported */ + if (round & ~_ROUND_MASK) + return (-1); + + /* Store the current floating-point control register */ + __asm__ __volatile__ ("trapb"); + __asm__ __volatile__ ("mf_fpcr %0" : "=f" (fpcr)); + __asm__ __volatile__ ("trapb"); + + /* + * Set the rounding direction + */ + fpcr &= ~((unsigned long)_ROUND_MASK << _ROUND_SHIFT); + fpcr |= (unsigned long)round << _ROUND_SHIFT; + + /* Load the floating-point control register */ + __asm__ __volatile__ ("trapb"); + __asm__ __volatile__ ("mt_fpcr %0" : : "f" (fpcr)); + __asm__ __volatile__ ("trapb"); + + 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) +{ + unsigned long fpcr; + + /* Store the current floating-point sticky flags */ + envp->__excepts = sysarch(ALPHA_FPGETSTICKY, 0L); + + /* Store the current floating-point masks */ + envp->__mask = sysarch(ALPHA_FPGETMASK, 0L); + + /* Store the current floating-point control register */ + __asm__ __volatile__ ("trapb"); + __asm__ __volatile__ ("mf_fpcr %0" : "=f" (fpcr)); + __asm__ __volatile__ ("trapb"); + envp->__round = (fpcr >> _ROUND_SHIFT) & _ROUND_MASK; + + 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) +{ + struct alpha_fp_except_args a; + + /* Store the current floating-point environment */ + fegetenv(envp); + + /* Clear exception flags */ + a.mask = envp->__excepts; + a.mask &= ~FE_ALL_EXCEPT; + sysarch(ALPHA_FPSETSTICKY, &a); + + /* Mask all exceptions */ + a.mask = envp->__excepts; + a.mask &= ~FE_ALL_EXCEPT; + sysarch(ALPHA_FPSETMASK, &a); + + 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) +{ + unsigned long fpcr; + struct alpha_fp_except_args a; + + /* Load the floating-point sticky flags */ + a.mask = envp->__excepts & FE_ALL_EXCEPT; + sysarch(ALPHA_FPSETSTICKY, &a); + + /* Load the floating-point masks */ + a.mask = envp->__mask & FE_ALL_EXCEPT; + sysarch(ALPHA_FPSETMASK, &a); + + /* Store the current floating-point control register */ + __asm__ __volatile__ ("trapb"); + __asm__ __volatile__ ("mf_fpcr %0" : "=f" (fpcr)); + __asm__ __volatile__ ("trapb"); + + fpcr &= ~((unsigned long)_ROUND_MASK << _ROUND_SHIFT); + fpcr |= ((unsigned long)envp->__round & _ROUND_MASK) << _ROUND_SHIFT; + + /* Load the floating-point control register */ + __asm__ __volatile__ ("trapb"); + __asm__ __volatile__ ("mt_fpcr %0" : : "f" (fpcr)); + __asm__ __volatile__ ("trapb"); + + 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) +{ + unsigned int fpsticky; + + /* Store the current floating-point sticky flags */ + fpsticky = sysarch(ALPHA_FPGETSTICKY, 0L); + + /* Install new floating-point environment */ + fesetenv(envp); + + /* Raise any previously accumulated exceptions */ + feraiseexcept(fpsticky); + + return (0); +} + +/* + * The following functions are extentions to the standard + */ +int +feenableexcept(int mask) +{ + unsigned int fpmask, omask; + struct alpha_fp_except_args a; + + mask &= FE_ALL_EXCEPT; + + /* Store the current floating-point masks */ + fpmask = sysarch(ALPHA_FPGETMASK, 0L); + + omask = fpmask & FE_ALL_EXCEPT; + fpmask |= mask; + + /* Load the floating-point masks */ + a.mask = fpmask; + sysarch(ALPHA_FPSETMASK, &a); + + return (omask); + +} + +int +fedisableexcept(int mask) +{ + unsigned int fpmask, omask; + struct alpha_fp_except_args a; + + mask &= FE_ALL_EXCEPT; + + /* Store the current floating-point masks */ + fpmask = sysarch(ALPHA_FPGETMASK, 0L); + + omask = fpmask & FE_ALL_EXCEPT; + fpmask &= ~mask; + + /* Load the floating-point masks */ + a.mask = fpmask; + sysarch(ALPHA_FPSETMASK, &a); + + return (omask); +} + +int +fegetexcept(void) +{ + unsigned int fpmask; + + /* Store the current floating-point masks */ + fpmask = sysarch(ALPHA_FPGETMASK, 0L); + + return (fpmask & FE_ALL_EXCEPT); +} |