2 * Copyright (c) 2004-2005 David Schultz <das@FreeBSD.ORG>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * $FreeBSD: src/lib/msun/i387/fenv.c,v 1.3 2007/01/05 07:15:26 das Exp $
29 #include <sys/cdefs.h>
30 #include <sys/types.h>
32 #include <machine/npx.h>
36 const fenv_t __fe_dfl_env
= {
46 { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
47 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff }
50 enum __sse_support __has_sse
=
57 #define getfl(x) __asm __volatile("pushfl\n\tpopl %0" : "=mr" (*(x)))
58 #define setfl(x) __asm __volatile("pushl %0\n\tpopfl" : : "g" (x))
59 #define cpuid_dx(x) __asm __volatile("pushl %%ebx\n\tmovl $1, %%eax\n\t" \
60 "cpuid\n\tpopl %%ebx" \
61 : "=d" (*(x)) : : "eax", "ecx")
64 * Test for SSE support on this processor. We need to do this because
65 * we need to use ldmxcsr/stmxcsr to get correct results if any part
66 * of the program was compiled to use SSE floating-point, but we can't
67 * use SSE on older processors.
77 nflag
= flag
^ 0x200000;
81 /* Not a 486, so CPUID should work. */
82 cpuid_dx(&dx_features
);
83 if (dx_features
& 0x2000000) {
84 __has_sse
= __SSE_YES
;
93 fesetexceptflag(const fexcept_t
*flagp
, int excepts
)
99 env
.__status
&= ~excepts
;
100 env
.__status
|= *flagp
& excepts
;
106 mxcsr
|= *flagp
& excepts
;
114 feraiseexcept(int excepts
)
116 fexcept_t ex
= excepts
;
118 fesetexceptflag(&ex
, excepts
);
124 fegetenv(fenv_t
*envp
)
130 * fnstenv masks all exceptions, so we need to restore
131 * the old control word to avoid this side effect.
133 __fldcw(envp
->__control
);
136 __set_mxcsr(*envp
, mxcsr
);
142 feholdexcept(fenv_t
*envp
)
150 __set_mxcsr(*envp
, mxcsr
);
151 mxcsr
&= ~FE_ALL_EXCEPT
;
152 mxcsr
|= FE_ALL_EXCEPT
<< _SSE_EMASK_SHIFT
;
159 feupdateenv(const fenv_t
*envp
)
170 feraiseexcept((mxcsr
| status
) & FE_ALL_EXCEPT
);
175 __feenableexcept(int mask
)
177 int mxcsr
, control
, omask
;
179 mask
&= FE_ALL_EXCEPT
;
185 omask
= (control
| mxcsr
>> _SSE_EMASK_SHIFT
) & FE_ALL_EXCEPT
;
189 mxcsr
&= ~(mask
<< _SSE_EMASK_SHIFT
);
196 __fedisableexcept(int mask
)
198 int mxcsr
, control
, omask
;
200 mask
&= FE_ALL_EXCEPT
;
206 omask
= (control
| mxcsr
>> _SSE_EMASK_SHIFT
) & FE_ALL_EXCEPT
;
210 mxcsr
|= mask
<< _SSE_EMASK_SHIFT
;
216 __weak_reference(__feenableexcept
, feenableexcept
);
217 __weak_reference(__fedisableexcept
, fedisableexcept
);