diff options
Diffstat (limited to 'libm/amd64/fenv.c')
| -rw-r--r-- | libm/amd64/fenv.c | 148 |
1 files changed, 148 insertions, 0 deletions
diff --git a/libm/amd64/fenv.c b/libm/amd64/fenv.c new file mode 100644 index 0000000..2b43678 --- /dev/null +++ b/libm/amd64/fenv.c @@ -0,0 +1,148 @@ +/*- + * 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: src/lib/msun/amd64/fenv.c,v 1.3 2005/03/16 19:03:45 das Exp $ + */ + +#include <sys/cdefs.h> +#include <sys/types.h> +#include <machine/fpu.h> +#include <fenv.h> + +const fenv_t __fe_dfl_env = { + { 0xffff0000 | __INITIAL_FPUCW__, + 0xffff0000, + 0xffffffff, + { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff } + }, + __INITIAL_MXCSR__ +}; + +int +fesetexceptflag(const fexcept_t *flagp, int excepts) +{ + fenv_t env; + + __fnstenv(&env.__x87); + env.__x87.__status &= ~excepts; + env.__x87.__status |= *flagp & excepts; + __fldenv(env.__x87); + + __stmxcsr(&env.__mxcsr); + env.__mxcsr &= ~excepts; + env.__mxcsr |= *flagp & excepts; + __ldmxcsr(env.__mxcsr); + + return (0); +} + +int +feraiseexcept(int excepts) +{ + fexcept_t ex = excepts; + + fesetexceptflag(&ex, excepts); + __fwait(); + return (0); +} + +int +fegetenv(fenv_t *envp) +{ + int control; + + /* + * fnstenv masks all exceptions, so we need to save and + * restore the control word to avoid this side effect. + */ + __fnstcw(&control); + __fnstenv(&envp->__x87); + __stmxcsr(&envp->__mxcsr); + __fldcw(control); + return (0); +} + +int +feholdexcept(fenv_t *envp) +{ + int mxcsr; + + __stmxcsr(&mxcsr); + __fnstenv(&envp->__x87); + __fnclex(); + envp->__mxcsr = mxcsr; + mxcsr &= ~FE_ALL_EXCEPT; + mxcsr |= FE_ALL_EXCEPT << _SSE_EMASK_SHIFT; + __ldmxcsr(mxcsr); + return (0); +} + +int +feupdateenv(const fenv_t *envp) +{ + int mxcsr, status; + + __fnstsw(&status); + __stmxcsr(&mxcsr); + fesetenv(envp); + feraiseexcept((mxcsr | status) & FE_ALL_EXCEPT); + return (0); +} + +int +__feenableexcept(int mask) +{ + int mxcsr, control, omask; + + mask &= FE_ALL_EXCEPT; + __fnstcw(&control); + __stmxcsr(&mxcsr); + omask = (control | mxcsr >> _SSE_EMASK_SHIFT) & FE_ALL_EXCEPT; + control &= ~mask; + __fldcw(control); + mxcsr &= ~(mask << _SSE_EMASK_SHIFT); + __ldmxcsr(mxcsr); + return (~omask); +} + +int +__fedisableexcept(int mask) +{ + int mxcsr, control, omask; + + mask &= FE_ALL_EXCEPT; + __fnstcw(&control); + __stmxcsr(&mxcsr); + omask = (control | mxcsr >> _SSE_EMASK_SHIFT) & FE_ALL_EXCEPT; + control |= mask; + __fldcw(control); + mxcsr |= mask << _SSE_EMASK_SHIFT; + __ldmxcsr(mxcsr); + return (~omask); +} + +__weak_reference(__feenableexcept, feenableexcept); +__weak_reference(__fedisableexcept, fedisableexcept); |