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>
31 #include <machine/npx.h>
34 const fenv_t __fe_dfl_env = {
39 { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
40 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff }
43 enum __sse_support __has_sse =
50 #define getfl(x) __asm __volatile("pushfl\n\tpopl %0" : "=mr" (*(x)))
51 #define setfl(x) __asm __volatile("pushl %0\n\tpopfl" : : "g" (x))
52 #define cpuid_dx(x) __asm __volatile("pushl %%ebx\n\tmovl $1, %%eax\n\t" \
53 "cpuid\n\tpopl %%ebx" \
54 : "=d" (*(x)) : : "eax", "ecx")
57 * Test for SSE support on this processor. We need to do this because
58 * we need to use ldmxcsr/stmxcsr to get correct results if any part
59 * of the program was compiled to use SSE floating-point, but we can't
60 * use SSE on older processors.
70 nflag = flag ^ 0x200000;
74 /* Not a 486, so CPUID should work. */
75 cpuid_dx(&dx_features);
76 if (dx_features & 0x2000000) {
77 __has_sse = __SSE_YES;
86 fesetexceptflag(const fexcept_t *flagp, int excepts)
92 env.__status &= ~excepts;
93 env.__status |= *flagp & excepts;
99 mxcsr |= *flagp & excepts;
107 feraiseexcept(int excepts)
109 fexcept_t ex = excepts;
111 fesetexceptflag(&ex, excepts);
117 fegetenv(fenv_t *envp)
123 * fnstenv masks all exceptions, so we need to restore
124 * the old control word to avoid this side effect.
126 __fldcw(envp->__control);
129 envp->__mxcsr = mxcsr;
135 feholdexcept(fenv_t *envp)
143 envp->__mxcsr = mxcsr;
144 mxcsr &= ~FE_ALL_EXCEPT;
145 mxcsr |= FE_ALL_EXCEPT << _SSE_EMASK_SHIFT;
152 feupdateenv(const fenv_t *envp)
163 feraiseexcept((mxcsr | status) & FE_ALL_EXCEPT);
168 __feenableexcept(int mask)
170 int mxcsr, control, omask;
172 mask &= FE_ALL_EXCEPT;
178 omask = (control | mxcsr >> _SSE_EMASK_SHIFT) & FE_ALL_EXCEPT;
182 mxcsr &= ~(mask << _SSE_EMASK_SHIFT);
189 __fedisableexcept(int mask)
191 __uint32_t mxcsr, omask;
194 mask &= FE_ALL_EXCEPT;
200 omask = (control | mxcsr >> _SSE_EMASK_SHIFT) & FE_ALL_EXCEPT;
204 mxcsr |= mask << _SSE_EMASK_SHIFT;
210 __weak_reference(__feenableexcept, feenableexcept);
211 __weak_reference(__fedisableexcept, fedisableexcept);