1 /* $NetBSD: ieee.h,v 1.13 2024/01/02 19:28:25 christos Exp $ */ 2 3 /* 4 * Copyright (c) 1992, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This software was developed by the Computer Systems Engineering group 8 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and 9 * contributed to Berkeley. 10 * 11 * All advertising materials mentioning features or use of this software 12 * must display the following acknowledgement: 13 * This product includes software developed by the University of 14 * California, Lawrence Berkeley Laboratory. 15 * 16 * Redistribution and use in source and binary forms, with or without 17 * modification, are permitted provided that the following conditions 18 * are met: 19 * 1. Redistributions of source code must retain the above copyright 20 * notice, this list of conditions and the following disclaimer. 21 * 2. Redistributions in binary form must reproduce the above copyright 22 * notice, this list of conditions and the following disclaimer in the 23 * documentation and/or other materials provided with the distribution. 24 * 3. Neither the name of the University nor the names of its contributors 25 * may be used to endorse or promote products derived from this software 26 * without specific prior written permission. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 31 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 38 * SUCH DAMAGE. 39 * 40 * @(#)ieee.h 8.1 (Berkeley) 6/11/93 41 */ 42 #ifndef _X86_IEEE_H_ 43 #define _X86_IEEE_H_ 44 45 /* 46 * ieee.h defines the machine-dependent layout of the machine's IEEE 47 * floating point. It does *not* define (yet?) any of the rounding 48 * mode bits, exceptions, and so forth. 49 */ 50 51 #include <sys/ieee754.h> 52 53 #define EXT_EXPBITS 15 54 #define EXT_FRACHBITS 32 55 #define EXT_FRACLBITS 32 56 #define EXT_FRACBITS (EXT_FRACLBITS + EXT_FRACHBITS) 57 58 #define EXT_TO_ARRAY32(u, a) do { \ 59 (a)[0] = (uint32_t)(u).extu_ext.ext_fracl; \ 60 (a)[1] = (uint32_t)(u).extu_ext.ext_frach; \ 61 } while(/*CONSTCOND*/0) 62 63 /* 64 * struct ieee_ext is the raw storage layout of the 80-bit 65 * extended-precision type as implemented by the FPU. Per the 66 * respective ABI specifications, it is followed by a tail padding of 67 * 68 * amd64: 48 bits, 69 * i386: 16 bits. 70 */ 71 struct ieee_ext { 72 uint32_t ext_fracl:EXT_FRACLBITS; 73 uint32_t ext_frach:EXT_FRACHBITS; 74 #if 0 75 uint32_t ext_int:1; 76 #endif 77 uint32_t ext_exp:EXT_EXPBITS; 78 uint32_t ext_sign:1; 79 }; 80 81 /* 82 * Floats whose exponent is in [1..INFNAN) (of whatever type) are 83 * `normal'. Floats whose exponent is INFNAN are either Inf or NaN. 84 * Floats whose exponent is zero are either zero (iff all fraction 85 * bits are zero) or subnormal values. 86 * 87 * A NaN is a `signalling NaN' if its QUIETNAN bit is clear in its 88 * high fraction; if the bit is set, it is a `quiet NaN'. 89 */ 90 #define EXT_EXP_INFNAN 0x7fff 91 #define EXT_EXP_INF 0x7fff 92 #define EXT_EXP_NAN 0x7fff 93 94 #if 0 95 #define SNG_QUIETNAN (1 << 22) 96 #define DBL_QUIETNAN (1 << 19) 97 #define EXT_QUIETNAN (1 << 30) 98 #endif 99 100 /* 101 * Exponent biases. 102 */ 103 #define EXT_EXP_BIAS 16383 104 105 /* 106 * Convenience data structures. 107 */ 108 union ieee_ext_u { 109 long double extu_ld; 110 struct ieee_ext extu_ext; 111 }; 112 113 #define extu_exp extu_ext.ext_exp 114 #define extu_sign extu_ext.ext_sign 115 #define extu_fracl extu_ext.ext_fracl 116 #define extu_frach extu_ext.ext_frach 117 118 #define LDBL_NBIT 0x80000000 119 #define mask_nbit_l(u) ((u).extu_frach &= ~LDBL_NBIT) 120 121 #endif /* _X86_IEEE_H_ */ 122