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Diffstat (limited to 'lib/libm/arch/m88k/fenv.c')
-rw-r--r-- | lib/libm/arch/m88k/fenv.c | 358 |
1 files changed, 358 insertions, 0 deletions
diff --git a/lib/libm/arch/m88k/fenv.c b/lib/libm/arch/m88k/fenv.c new file mode 100644 index 00000000000..c0a34508188 --- /dev/null +++ b/lib/libm/arch/m88k/fenv.c @@ -0,0 +1,358 @@ +/* $OpenBSD: fenv.c,v 1.1 2011/04/28 17:34:23 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/cdefs.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 = { + 0x00000000, /* Control register */ + 0x00000000 /* Status register */ +}; + +/* + * The feclearexcept() function clears the supported floating-point exceptions + * represented by `excepts'. + */ +int +feclearexcept(int excepts) +{ + unsigned int fpsr; + + excepts &= FE_ALL_EXCEPT; + + /* Store the current floating-point status register */ + __asm__ __volatile__ ("fldcr %0, fcr62" : "=r" (fpsr)); + + /* Clear the requested floating-point exceptions */ + fpsr &= ~excepts; + + /* Load the floating-point status register */ + __asm__ __volatile__ ("fstcr %0, fcr62" : : "r" (fpsr)); + + 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 fpsr; + + excepts &= FE_ALL_EXCEPT; + + /* Store the current floating-point status register */ + __asm__ __volatile__ ("fldcr %0, fcr62" : "=r" (fpsr)); + + /* Store the results in flagp */ + *flagp = fpsr & excepts; + + return (0); +} + +/* + * The feraiseexcept() function raises the supported floating-point exceptions + * represented by the argument `excepts'. + */ +int +feraiseexcept(int excepts) +{ + volatile double d; + + 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 (excepts & FE_INVALID) { + d = 0.0; + d = 0.0 / d; + } + if (excepts & FE_DIVBYZERO) { + d = 0.0; + d = 1.0 / d; + } + if (excepts & FE_OVERFLOW) { + d = 0x1.ffp1023; + d *= 2.0; + } + if (excepts & FE_UNDERFLOW) { + d = 0x1p-1022; + d /= 0x1p1023; + } + if (excepts & FE_INEXACT) { + d = 0x1p-1022; + d += 1.0; + } + __asm__ __volatile__ ("fnop"); + + 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 fpsr; + + excepts &= FE_ALL_EXCEPT; + + /* Store the current floating-point status register */ + __asm__ __volatile__ ("fldcr %0, fcr62" : "=r" (fpsr)); + + /* Set the requested status flags */ + fpsr &= ~excepts; + fpsr |= *flagp & excepts; + + /* Load the floating-point status register */ + __asm__ __volatile__ ("fstcr %0, fcr62" : : "r" (fpsr)); + + 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 fpsr; + + excepts &= FE_ALL_EXCEPT; + + /* Store the current floating-point status register */ + __asm__ __volatile__ ("fldcr %0, fcr62" : "=r" (fpsr)); + + return (fpsr & excepts); +} + +/* + * The fegetround() function gets the current rounding direction. + */ +int +fegetround(void) +{ + unsigned int fpcr; + + /* Store the current floating-point control register */ + __asm__ __volatile__ ("fldcr %0, fcr63" : "=r" (fpcr)); + + return (fpcr & _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 int fpcr; + + /* Check whether requested rounding direction is supported */ + if (round & ~_ROUND_MASK) + return (-1); + + /* Store the current floating-point control register */ + __asm__ __volatile__ ("fldcr %0, fcr63" : "=r" (fpcr)); + + /* Set the rounding direction */ + fpcr &= ~_ROUND_MASK; + fpcr |= round; + + /* Load the floating-point control register */ + __asm__ __volatile__ ("fstcr %0, fcr63" : : "r" (fpcr)); + + 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) +{ + /* Store the current floating-point control and status registers */ + __asm__ __volatile__ ("fldcr %0, fcr63" : "=r" (envp->__control)); + __asm__ __volatile__ ("fldcr %0, fcr62" : "=r" (envp->__status)); + + 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) +{ + unsigned int fpsr, fpcr; + + /* Store the current floating-point control and status registers */ + __asm__ __volatile__ ("fldcr %0, fcr63" : "=r" (envp->__control)); + __asm__ __volatile__ ("fldcr %0, fcr62" : "=r" (envp->__status)); + + /* Clear exception flags in FPSR */ + fpsr = envp->__status; + fpsr &= ~FE_ALL_EXCEPT; + __asm__ __volatile__ ("fstcr %0, fcr62" : : "r" (fpsr)); + + /* Mask all exceptions */ + fpcr = envp->__control; + fpcr &= ~FE_ALL_EXCEPT; + __asm__ __volatile__ ("fstcr %0, fcr63" : : "r" (fpcr)); + + 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) +{ + fenv_t fenv; + + /* Store the current floating-point control and status registers */ + __asm__ __volatile__ ("fldcr %0, fcr63" : "=r" (fenv.__control)); + __asm__ __volatile__ ("fldcr %0, fcr62" : "=r" (fenv.__status)); + + /* Set the requested control flags */ + fenv.__control &= ~(FE_ALL_EXCEPT | _ROUND_MASK); + fenv.__control |= envp->__control & (FE_ALL_EXCEPT | _ROUND_MASK); + + /* Set the requested status flags */ + fenv.__status &= ~FE_ALL_EXCEPT; + fenv.__status |= envp->__status & FE_ALL_EXCEPT; + + /* Load the floating-point control and status registers */ + __asm__ __volatile__ ("fstcr %0, fcr63" : : "r" (fenv.__control)); + __asm__ __volatile__ ("fstcr %0, fcr62" : : "r" (fenv.__status)); + + 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 fpsr; + + /* Store the current floating-point status register */ + __asm__ __volatile__ ("fldcr %0, fcr62" : "=r" (fpsr)); + + /* Install new floating-point environment */ + fesetenv(envp); + + /* Raise any previously accumulated exceptions */ + feraiseexcept(fpsr); + + return (0); +} + +/* + * The following functions are extentions to the standard + */ +int +feenableexcept(int mask) +{ + unsigned int fpcr, omask; + + mask &= FE_ALL_EXCEPT; + + /* Store the current floating-point control register */ + __asm__ __volatile__ ("fldcr %0, fcr63" : "=r" (fpcr)); + + omask = fpcr & FE_ALL_EXCEPT; + fpcr |= mask; + + /* Load the floating-point control register */ + __asm__ __volatile__ ("fstcr %0, fcr63" : : "r" (fpcr)); + + return (omask); + +} + +int +fedisableexcept(int mask) +{ + unsigned int fpcr, omask; + + mask &= FE_ALL_EXCEPT; + + /* Store the current floating-point control register */ + __asm__ __volatile__ ("fldcr %0, fcr63" : "=r" (fpcr)); + + omask = fpcr & FE_ALL_EXCEPT; + fpcr &= ~mask; + + /* Load the floating-point control register */ + __asm__ __volatile__ ("fstcr %0, fcr63" : : "r" (fpcr)); + + return (omask); +} + +int +fegetexcept(void) +{ + unsigned int fpcr; + + /* Store the current floating-point control register */ + __asm__ __volatile__ ("fldcr %0, fcr63" : "=r" (fpcr)); + + return (fpcr & FE_ALL_EXCEPT); +} |