2 * SPDX-License-Identifier: BSD-4-Clause
4 * Copyright (c) 2003 Peter Wemm.
5 * Copyright (c) 1990 Andrew Moore, Talke Studio
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
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12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
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16 * 3. All advertising materials mentioning features or use of this software
17 * must display the following acknowledgement:
18 * This product includes software developed by the University of
19 * California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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36 * from: @(#) ieeefp.h 1.0 (Berkeley) 9/23/93
40 #ifndef _MACHINE_IEEEFP_H_
41 #define _MACHINE_IEEEFP_H_
44 * Deprecated historical FPU control interface
46 * IEEE floating point type, constant and function definitions.
47 * XXX: FP*FLD and FP*OFF are undocumented pollution.
51 #error this file needs sys/cdefs.h as a prerequisite
58 FP_RN=0, /* round to nearest */
59 FP_RM, /* round down towards minus infinity */
60 FP_RP, /* round up towards plus infinity */
65 * Precision (i.e., rounding precision) modes.
68 FP_PS=0, /* 24 bit (single-precision) */
69 FP_PRS, /* reserved */
70 FP_PD, /* 53 bit (double-precision) */
71 FP_PE /* 64 bit (extended-precision) */
74 #define fp_except_t int
77 * Exception bit masks.
79 #define FP_X_INV 0x01 /* invalid operation */
80 #define FP_X_DNML 0x02 /* denormal */
81 #define FP_X_DZ 0x04 /* zero divide */
82 #define FP_X_OFL 0x08 /* overflow */
83 #define FP_X_UFL 0x10 /* underflow */
84 #define FP_X_IMP 0x20 /* (im)precision */
85 #define FP_X_STK 0x40 /* stack fault */
88 * FPU control word bit-field masks.
90 #define FP_MSKS_FLD 0x3f /* exception masks field */
91 #define FP_PRC_FLD 0x300 /* precision control field */
92 #define FP_RND_FLD 0xc00 /* rounding control field */
95 * FPU status word bit-field masks.
97 #define FP_STKY_FLD 0x3f /* sticky flags field */
100 * FPU control word bit-field offsets (shift counts).
102 #define FP_MSKS_OFF 0 /* exception masks offset */
103 #define FP_PRC_OFF 8 /* precision control offset */
104 #define FP_RND_OFF 10 /* rounding control offset */
107 * FPU status word bit-field offsets (shift counts).
109 #define FP_STKY_OFF 0 /* sticky flags offset */
111 #ifdef __GNUCLIKE_ASM
113 #define __fldcw(addr) __asm __volatile("fldcw %0" : : "m" (*(addr)))
114 #define __fldenv(addr) __asm __volatile("fldenv %0" : : "m" (*(addr)))
115 #define __fnclex() __asm __volatile("fnclex")
116 #define __fnstcw(addr) __asm __volatile("fnstcw %0" : "=m" (*(addr)))
117 #define __fnstenv(addr) __asm __volatile("fnstenv %0" : "=m" (*(addr)))
118 #define __fnstsw(addr) __asm __volatile("fnstsw %0" : "=m" (*(addr)))
121 * Load the control word. Be careful not to trap if there is a currently
122 * unmasked exception (ones that will become freshly unmasked are not a
123 * problem). This case must be handled by a save/restore of the
124 * environment or even of the full x87 state. Accessing the environment
125 * is very inefficient, so only do it when necessary.
128 __fnldcw(unsigned short _cw, unsigned short _newcw)
136 if ((_cw & FP_MSKS_FLD) != FP_MSKS_FLD) {
138 if (((_sw & ~_cw) & FP_STKY_FLD) != 0) {
148 static __inline fp_rnd_t
154 return ((fp_rnd_t)((_cw & FP_RND_FLD) >> FP_RND_OFF));
157 static __inline fp_rnd_t
158 fpsetround(fp_rnd_t _m)
161 unsigned short _cw, _newcw;
164 _p = (fp_rnd_t)((_cw & FP_RND_FLD) >> FP_RND_OFF);
165 _newcw = _cw & ~FP_RND_FLD;
166 _newcw |= (_m << FP_RND_OFF) & FP_RND_FLD;
167 __fnldcw(_cw, _newcw);
171 static __inline fp_prec_t
177 return ((fp_prec_t)((_cw & FP_PRC_FLD) >> FP_PRC_OFF));
180 static __inline fp_prec_t
181 fpsetprec(fp_prec_t _m)
184 unsigned short _cw, _newcw;
187 _p = (fp_prec_t)((_cw & FP_PRC_FLD) >> FP_PRC_OFF);
188 _newcw = _cw & ~FP_PRC_FLD;
189 _newcw |= (_m << FP_PRC_OFF) & FP_PRC_FLD;
190 __fnldcw(_cw, _newcw);
195 * Get or set the exception mask.
196 * Note that the x87 mask bits are inverted by the API -- a mask bit of 1
197 * means disable for x87 and SSE, but for fp*mask() it means enable.
200 static __inline fp_except_t
206 return ((~_cw & FP_MSKS_FLD) >> FP_MSKS_OFF);
209 static __inline fp_except_t
210 fpsetmask(fp_except_t _m)
213 unsigned short _cw, _newcw;
216 _p = (~_cw & FP_MSKS_FLD) >> FP_MSKS_OFF;
217 _newcw = _cw & ~FP_MSKS_FLD;
218 _newcw |= (~_m << FP_MSKS_OFF) & FP_MSKS_FLD;
219 __fnldcw(_cw, _newcw);
223 static __inline fp_except_t
230 _ex = (_sw & FP_STKY_FLD) >> FP_STKY_OFF;
231 return ((fp_except_t)_ex);
234 static __inline fp_except_t
235 fpresetsticky(fp_except_t _m)
244 _m &= FP_STKY_FLD >> FP_STKY_OFF;
246 if ((_p & ~_m) == _p)
248 if ((_p & ~_m) == 0) {
258 #endif /* __GNUCLIKE_ASM */
260 #endif /* !_MACHINE_IEEEFP_H_ */