diff options
Diffstat (limited to 'src/VBox/Runtime/common/math/x86/fenv-x86.c')
| -rw-r--r-- | src/VBox/Runtime/common/math/x86/fenv-x86.c | 218 |
1 files changed, 218 insertions, 0 deletions
diff --git a/src/VBox/Runtime/common/math/x86/fenv-x86.c b/src/VBox/Runtime/common/math/x86/fenv-x86.c new file mode 100644 index 00000000..c48ae291 --- /dev/null +++ b/src/VBox/Runtime/common/math/x86/fenv-x86.c @@ -0,0 +1,218 @@ +/*- + * 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/i387/fenv.c,v 1.2 2005/03/17 22:21:46 das Exp $ + */ + +/*#include "namespace.h" +#include <sys/cdefs.h> +#include <sys/types.h> +#include <machine/npx.h> +#include "fenv.h"*/ +#include <iprt/types.h> +#include <iprt/nocrt/fenv.h> + +#if 0 +const fenv_t __fe_dfl_env = { + __INITIAL_NPXCW__, + 0x0000, + 0x0000, + 0x1f80, + 0xffffffff, + { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff } +}; +#endif + +enum __sse_support __has_sse = +#ifdef __SSE__ + __SSE_YES; +#else + __SSE_UNK; +#endif + +#define getfl(x) __asm __volatile("pushfl\n\tpopl %0" : "=mr" (*(x))) +#define setfl(x) __asm __volatile("pushl %0\n\tpopfl" : : "g" (x)) +#define cpuid_dx(x) __asm __volatile("pushl %%ebx\n\tmovl $1, %%eax\n\t" \ + "cpuid\n\tpopl %%ebx" \ + : "=d" (*(x)) : : "eax", "ecx") + +/* + * Test for SSE support on this processor. We need to do this because + * we need to use ldmxcsr/stmxcsr to get correct results if any part + * of the program was compiled to use SSE floating-point, but we can't + * use SSE on older processors. + */ +int +__test_sse(void) +{ + int flag, nflag; + int dx_features; + + /* Am I a 486? */ + getfl(&flag); + nflag = flag ^ 0x200000; + setfl(nflag); + getfl(&nflag); + if (flag != nflag) { + /* Not a 486, so CPUID should work. */ + cpuid_dx(&dx_features); + if (dx_features & 0x2000000) { + __has_sse = __SSE_YES; + return (1); + } + } + __has_sse = __SSE_NO; + return (0); +} + +#if 0 /* later */ +int +_STD(fesetexceptflag)(const fexcept_t *flagp, int excepts) +{ + fenv_t env; + int mxcsr; + + __fnstenv(&env); + env.__status &= ~excepts; + env.__status |= *flagp & excepts; + __fldenv(env); + + if (__HAS_SSE()) { + __stmxcsr(&mxcsr); + mxcsr &= ~excepts; + mxcsr |= *flagp & excepts; + __ldmxcsr(mxcsr); + } + + return (0); +} + +int +_STD(feraiseexcept)(int excepts) +{ + fexcept_t ex = excepts; + + fesetexceptflag(&ex, excepts); + __fwait(); + return (0); +} + +int +_STD(fegetenv)(fenv_t *envp) +{ + int control, mxcsr; + + /* + * fnstenv masks all exceptions, so we need to save and + * restore the control word to avoid this side effect. + */ + __fnstcw(&control); + __fnstenv(envp); + if (__HAS_SSE()) { + __stmxcsr(&mxcsr); + __set_mxcsr(*envp, mxcsr); + } + __fldcw(control); + return (0); +} + +int +_STD(feholdexcept)(fenv_t *envp) +{ + int mxcsr; + + __fnstenv(envp); + __fnclex(); + if (__HAS_SSE()) { + __stmxcsr(&mxcsr); + __set_mxcsr(*envp, mxcsr); + mxcsr &= ~FE_ALL_EXCEPT; + mxcsr |= FE_ALL_EXCEPT << _SSE_EMASK_SHIFT; + __ldmxcsr(mxcsr); + } + return (0); +} + +int +_STD(feupdateenv)(const fenv_t *envp) +{ + int mxcsr, status; + + __fnstsw(&status); + if (__HAS_SSE()) + __stmxcsr(&mxcsr); + else + mxcsr = 0; + fesetenv(envp); + feraiseexcept((mxcsr | status) & FE_ALL_EXCEPT); + return (0); +} + +int +__feenableexcept(int mask) +{ + int mxcsr, control, omask; + + mask &= FE_ALL_EXCEPT; + __fnstcw(&control); + if (__HAS_SSE()) + __stmxcsr(&mxcsr); + else + mxcsr = 0; + omask = (control | mxcsr >> _SSE_EMASK_SHIFT) & FE_ALL_EXCEPT; + control &= ~mask; + __fldcw(control); + if (__HAS_SSE()) { + mxcsr &= ~(mask << _SSE_EMASK_SHIFT); + __ldmxcsr(mxcsr); + } + return (~omask); +} + +int +__fedisableexcept(int mask) +{ + int mxcsr, control, omask; + + mask &= FE_ALL_EXCEPT; + __fnstcw(&control); + if (__HAS_SSE()) + __stmxcsr(&mxcsr); + else + mxcsr = 0; + omask = (control | mxcsr >> _SSE_EMASK_SHIFT) & FE_ALL_EXCEPT; + control |= mask; + __fldcw(control); + if (__HAS_SSE()) { + mxcsr |= mask << _SSE_EMASK_SHIFT; + __ldmxcsr(mxcsr); + } + return (~omask); +} + +__weak_reference(__feenableexcept, feenableexcept); +__weak_reference(__fedisableexcept, fedisableexcept); +#endif /* later */ |