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
32 #include <sys/cdefs.h>
33 #include <sys/_types.h>
36 #define __fenv_static static
49 typedef __uint16_t fexcept_t;
52 #define FE_INVALID 0x01
53 #define FE_DENORMAL 0x02
54 #define FE_DIVBYZERO 0x04
55 #define FE_OVERFLOW 0x08
56 #define FE_UNDERFLOW 0x10
57 #define FE_INEXACT 0x20
58 #define FE_ALL_EXCEPT (FE_DIVBYZERO | FE_DENORMAL | FE_INEXACT | \
59 FE_INVALID | FE_OVERFLOW | FE_UNDERFLOW)
62 #define FE_TONEAREST 0x0000
63 #define FE_DOWNWARD 0x0400
64 #define FE_UPWARD 0x0800
65 #define FE_TOWARDZERO 0x0c00
66 #define _ROUND_MASK (FE_TONEAREST | FE_DOWNWARD | \
67 FE_UPWARD | FE_TOWARDZERO)
70 * As compared to the x87 control word, the SSE unit's control word
71 * has the rounding control bits offset by 3 and the exception mask
74 #define _SSE_ROUND_SHIFT 3
75 #define _SSE_EMASK_SHIFT 7
79 /* Default floating-point environment */
80 extern const fenv_t __fe_dfl_env;
81 #define FE_DFL_ENV (&__fe_dfl_env)
83 #define __fldcw(__cw) __asm __volatile("fldcw %0" : : "m" (__cw))
84 #define __fldenv(__env) __asm __volatile("fldenv %0" : : "m" (__env))
85 #define __fldenvx(__env) __asm __volatile("fldenv %0" : : "m" (__env) \
86 : "st", "st(1)", "st(2)", "st(3)", "st(4)", \
87 "st(5)", "st(6)", "st(7)")
88 #define __fnclex() __asm __volatile("fnclex")
89 #define __fnstenv(__env) __asm __volatile("fnstenv %0" : "=m" (*(__env)))
90 #define __fnstcw(__cw) __asm __volatile("fnstcw %0" : "=m" (*(__cw)))
91 #define __fnstsw(__sw) __asm __volatile("fnstsw %0" : "=am" (*(__sw)))
92 #define __fwait() __asm __volatile("fwait")
93 #define __ldmxcsr(__csr) __asm __volatile("ldmxcsr %0" : : "m" (__csr))
94 #define __stmxcsr(__csr) __asm __volatile("stmxcsr %0" : "=m" (*(__csr)))
96 __fenv_static inline int
97 feclearexcept(int __excepts)
101 if (__excepts == FE_ALL_EXCEPT) {
104 __fnstenv(&__env.__x87);
105 __env.__x87.__status &= ~__excepts;
106 __fldenv(__env.__x87);
108 __stmxcsr(&__env.__mxcsr);
109 __env.__mxcsr &= ~__excepts;
110 __ldmxcsr(__env.__mxcsr);
114 __fenv_static inline int
115 fegetexceptflag(fexcept_t *__flagp, int __excepts)
122 *__flagp = (__mxcsr | __status) & __excepts;
126 int fesetexceptflag(const fexcept_t *__flagp, int __excepts);
127 int feraiseexcept(int __excepts);
129 __fenv_static inline int
130 fetestexcept(int __excepts)
137 return ((__status | __mxcsr) & __excepts);
140 __fenv_static inline int
143 __uint16_t __control;
146 * We assume that the x87 and the SSE unit agree on the
147 * rounding mode. Reading the control word on the x87 turns
148 * out to be about 5 times faster than reading it on the SSE
149 * unit on an Opteron 244.
151 __fnstcw(&__control);
152 return (__control & _ROUND_MASK);
155 __fenv_static inline int
156 fesetround(int __round)
159 __uint16_t __control;
161 if (__round & ~_ROUND_MASK)
164 __fnstcw(&__control);
165 __control &= ~_ROUND_MASK;
166 __control |= __round;
170 __mxcsr &= ~(_ROUND_MASK << _SSE_ROUND_SHIFT);
171 __mxcsr |= __round << _SSE_ROUND_SHIFT;
177 int fegetenv(fenv_t *__envp);
178 int feholdexcept(fenv_t *__envp);
180 __fenv_static inline int
181 fesetenv(const fenv_t *__envp)
185 * XXX Using fldenvx() instead of fldenv() tells the compiler that this
186 * instruction clobbers the i387 register stack. This happens because
187 * we restore the tag word from the saved environment. Normally, this
188 * would happen anyway and we wouldn't care, because the ABI allows
189 * function calls to clobber the i387 regs. However, fesetenv() is
190 * inlined, so we need to be more careful.
192 __fldenvx(__envp->__x87);
193 __ldmxcsr(__envp->__mxcsr);
197 int feupdateenv(const fenv_t *__envp);
201 int feenableexcept(int __mask);
202 int fedisableexcept(int __mask);
204 /* We currently provide no external definition of fegetexcept(). */
208 __uint16_t __control;
211 * We assume that the masks for the x87 and the SSE unit are
214 __fnstcw(&__control);
215 return (~__control & FE_ALL_EXCEPT);
218 #endif /* __BSD_VISIBLE */
222 #endif /* !_FENV_H_ */