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Diffstat (limited to 'sys/mips/include/ieee.h')
| -rw-r--r-- | sys/mips/include/ieee.h | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/sys/mips/include/ieee.h b/sys/mips/include/ieee.h new file mode 100644 index 0000000..a7411dd --- /dev/null +++ b/sys/mips/include/ieee.h @@ -0,0 +1,154 @@ +/* $NetBSD: ieee754.h,v 1.4 2003/10/27 02:30:26 simonb Exp $ */ + +/*- + * Copyright (c) 1992, 1993 + * The Regents of the University of California. All rights reserved. + * + * This software was developed by the Computer Systems Engineering group + * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and + * contributed to Berkeley. + * + * All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by the University of + * California, Lawrence Berkeley Laboratory. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * @(#)ieee.h 8.1 (Berkeley) 6/11/93 + * + * $FreeBSD$ + * + */ + +/* + * NOTICE: This is not a standalone file. To use it, #include it in + * your port's ieee.h header. + */ + +#include <machine/endian.h> + +/* + * <sys/ieee754.h> defines the layout of IEEE 754 floating point types. + * Only single-precision and double-precision types are defined here; + * extended types, if available, are defined in the machine-dependent + * header. + */ + +/* + * Define the number of bits in each fraction and exponent. + * + * k k+1 + * Note that 1.0 x 2 == 0.1 x 2 and that denorms are represented + * + * (-exp_bias+1) + * as fractions that look like 0.fffff x 2 . This means that + * + * -126 + * the number 0.10000 x 2 , for instance, is the same as the normalized + * + * -127 -128 + * float 1.0 x 2 . Thus, to represent 2 , we need one leading zero + * + * -129 + * in the fraction; to represent 2 , we need two, and so on. This + * + * (-exp_bias-fracbits+1) + * implies that the smallest denormalized number is 2 + * + * for whichever format we are talking about: for single precision, for + * + * -126 -149 + * instance, we get .00000000000000000000001 x 2 , or 1.0 x 2 , and + * + * -149 == -127 - 23 + 1. + */ +#define SNG_EXPBITS 8 +#define SNG_FRACBITS 23 + +#define DBL_EXPBITS 11 +#define DBL_FRACBITS 52 + +struct ieee_single { +#if _BYTE_ORDER == _BIG_ENDIAN + u_int sng_sign:1; + u_int sng_exp:8; + u_int sng_frac:23; +#else + u_int sng_frac:23; + u_int sng_exp:8; + u_int sng_sign:1; +#endif +}; + +struct ieee_double { +#if _BYTE_ORDER == _BIG_ENDIAN + u_int dbl_sign:1; + u_int dbl_exp:11; + u_int dbl_frach:20; + u_int dbl_fracl; +#else + u_int dbl_fracl; + u_int dbl_frach:20; + u_int dbl_exp:11; + u_int dbl_sign:1; +#endif +}; + +/* + * Floats whose exponent is in [1..INFNAN) (of whatever type) are + * `normal'. Floats whose exponent is INFNAN are either Inf or NaN. + * Floats whose exponent is zero are either zero (iff all fraction + * bits are zero) or subnormal values. + * + * A NaN is a `signalling NaN' if its QUIETNAN bit is clear in its + * high fraction; if the bit is set, it is a `quiet NaN'. + */ +#define SNG_EXP_INFNAN 255 +#define DBL_EXP_INFNAN 2047 + +#if 0 +#define SNG_QUIETNAN (1 << 22) +#define DBL_QUIETNAN (1 << 19) +#endif + +/* + * Exponent biases. + */ +#define SNG_EXP_BIAS 127 +#define DBL_EXP_BIAS 1023 + +/* + * Convenience data structures. + */ +union ieee_single_u { + float sngu_f; + struct ieee_single sngu_sng; +}; + +union ieee_double_u { + double dblu_d; + struct ieee_double dblu_dbl; +}; |
