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
39 typedef __uint16_t fexcept_t;
42 #define FE_INVALID 0x01
43 #define FE_DENORMAL 0x02
44 #define FE_DIVBYZERO 0x04
45 #define FE_OVERFLOW 0x08
46 #define FE_UNDERFLOW 0x10
47 #define FE_INEXACT 0x20
48 #define FE_ALL_EXCEPT (FE_DIVBYZERO | FE_DENORMAL | FE_INEXACT | \
49 FE_INVALID | FE_OVERFLOW | FE_UNDERFLOW)
52 #define FE_TONEAREST 0x0000
53 #define FE_DOWNWARD 0x0400
54 #define FE_UPWARD 0x0800
55 #define FE_TOWARDZERO 0x0c00
56 #define _ROUND_MASK (FE_TONEAREST | FE_DOWNWARD | \
57 FE_UPWARD | FE_TOWARDZERO)
60 * As compared to the x87 control word, the SSE unit's control word
61 * has the rounding control bits offset by 3 and the exception mask
64 #define _SSE_ROUND_SHIFT 3
65 #define _SSE_EMASK_SHIFT 7
69 * To preserve binary compatibility with FreeBSD 5.3, we pack the
70 * mxcsr into some reserved fields, rather than changing sizeof(fenv_t).
74 __uint16_t __mxcsr_hi;
76 __uint16_t __mxcsr_lo;
94 /* Default floating-point environment */
95 extern const fenv_t __fe_dfl_env;
96 #define FE_DFL_ENV (&__fe_dfl_env)
98 #define __fldcw(__cw) __asm __volatile("fldcw %0" : : "m" (__cw))
99 #define __fldenv(__env) __asm __volatile("fldenv %0" : : "m" (__env))
100 #define __fldenvx(__env) __asm __volatile("fldenv %0" : : "m" (__env) \
101 : "st", "st(1)", "st(2)", "st(3)", "st(4)", \
102 "st(5)", "st(6)", "st(7)")
103 #define __fnclex() __asm __volatile("fnclex")
104 #define __fnstenv(__env) __asm __volatile("fnstenv %0" : "=m" (*(__env)))
105 #define __fnstcw(__cw) __asm __volatile("fnstcw %0" : "=m" (*(__cw)))
106 #define __fnstsw(__sw) __asm __volatile("fnstsw %0" : "=am" (*(__sw)))
107 #define __fwait() __asm __volatile("fwait")
108 #define __ldmxcsr(__csr) __asm __volatile("ldmxcsr %0" : : "m" (__csr))
109 #define __stmxcsr(__csr) __asm __volatile("stmxcsr %0" : "=m" (*(__csr)))
111 int fegetenv(fenv_t *__envp);
112 int feholdexcept(fenv_t *__envp);
113 int fesetexceptflag(const fexcept_t *__flagp, int __excepts);
114 int feraiseexcept(int __excepts);
115 int feupdateenv(const fenv_t *__envp);
117 __fenv_static inline int
120 __uint16_t __control;
123 * We assume that the x87 and the SSE unit agree on the
124 * rounding mode. Reading the control word on the x87 turns
125 * out to be about 5 times faster than reading it on the SSE
126 * unit on an Opteron 244.
128 __fnstcw(&__control);
129 return (__control & _ROUND_MASK);
134 int feenableexcept(int __mask);
135 int fedisableexcept(int __mask);
137 /* We currently provide no external definition of fegetexcept(). */
141 __uint16_t __control;
144 * We assume that the masks for the x87 and the SSE unit are
147 __fnstcw(&__control);
148 return (~__control & FE_ALL_EXCEPT);
151 #endif /* __BSD_VISIBLE */
155 /* After testing for SSE support once, we cache the result in __has_sse. */
156 enum __sse_support { __SSE_YES, __SSE_NO, __SSE_UNK };
157 extern enum __sse_support __has_sse;
158 int __test_sse(void);
160 #define __HAS_SSE() 1
162 #define __HAS_SSE() (__has_sse == __SSE_YES || \
163 (__has_sse == __SSE_UNK && __test_sse()))
166 #define __get_mxcsr(env) (((env).__mxcsr_hi << 16) | \
168 #define __set_mxcsr(env, x) do { \
169 (env).__mxcsr_hi = (__uint32_t)(x) >> 16; \
170 (env).__mxcsr_lo = (__uint16_t)(x); \
173 __fenv_static inline int
174 feclearexcept(int __excepts)
179 if (__excepts == FE_ALL_EXCEPT) {
183 __env.__status &= ~__excepts;
188 __mxcsr &= ~__excepts;
194 __fenv_static inline int
195 fegetexceptflag(fexcept_t *__flagp, int __excepts)
205 *__flagp = (__mxcsr | __status) & __excepts;
209 __fenv_static inline int
210 fetestexcept(int __excepts)
220 return ((__status | __mxcsr) & __excepts);
223 __fenv_static inline int
224 fesetround(int __round)
227 __uint16_t __control;
229 if (__round & ~_ROUND_MASK)
232 __fnstcw(&__control);
233 __control &= ~_ROUND_MASK;
234 __control |= __round;
239 __mxcsr &= ~(_ROUND_MASK << _SSE_ROUND_SHIFT);
240 __mxcsr |= __round << _SSE_ROUND_SHIFT;
247 __fenv_static inline int
248 fesetenv(const fenv_t *__envp)
250 fenv_t __env = *__envp;
253 __mxcsr = __get_mxcsr(__env);
254 __set_mxcsr(__env, 0xffffffff);
256 * XXX Using fldenvx() instead of fldenv() tells the compiler that this
257 * instruction clobbers the i387 register stack. This happens because
258 * we restore the tag word from the saved environment. Normally, this
259 * would happen anyway and we wouldn't care, because the ABI allows
260 * function calls to clobber the i387 regs. However, fesetenv() is
261 * inlined, so we need to be more careful.
269 #else /* __amd64__ */
271 __fenv_static inline int
272 feclearexcept(int __excepts)
276 if (__excepts == FE_ALL_EXCEPT) {
279 __fnstenv(&__env.__x87);
280 __env.__x87.__status &= ~__excepts;
281 __fldenv(__env.__x87);
283 __stmxcsr(&__env.__mxcsr);
284 __env.__mxcsr &= ~__excepts;
285 __ldmxcsr(__env.__mxcsr);
289 __fenv_static inline int
290 fegetexceptflag(fexcept_t *__flagp, int __excepts)
297 *__flagp = (__mxcsr | __status) & __excepts;
301 __fenv_static inline int
302 fetestexcept(int __excepts)
309 return ((__status | __mxcsr) & __excepts);
312 __fenv_static inline int
313 fesetround(int __round)
316 __uint16_t __control;
318 if (__round & ~_ROUND_MASK)
321 __fnstcw(&__control);
322 __control &= ~_ROUND_MASK;
323 __control |= __round;
327 __mxcsr &= ~(_ROUND_MASK << _SSE_ROUND_SHIFT);
328 __mxcsr |= __round << _SSE_ROUND_SHIFT;
334 __fenv_static inline int
335 fesetenv(const fenv_t *__envp)
339 * XXX Using fldenvx() instead of fldenv() tells the compiler that this
340 * instruction clobbers the i387 register stack. This happens because
341 * we restore the tag word from the saved environment. Normally, this
342 * would happen anyway and we wouldn't care, because the ABI allows
343 * function calls to clobber the i387 regs. However, fesetenv() is
344 * inlined, so we need to be more careful.
346 __fldenvx(__envp->__x87);
347 __ldmxcsr(__envp->__mxcsr);
351 #endif /* __i386__ */
355 #endif /* !_FENV_H_ */