Annotation of sys/arch/hppa64/include/ieee.h, Revision 1.1
1.1 ! nbrk 1: /* $OpenBSD: ieee.h,v 1.1 2005/04/01 10:40:48 mickey 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:
! 43: /*
! 44: * ieee.h defines the machine-dependent layout of the machine's IEEE
! 45: * floating point. It does *not* define (yet?) any of the rounding
! 46: * mode bits, exceptions, and so forth.
! 47: */
! 48:
! 49: /*
! 50: * Define the number of bits in each fraction and exponent.
! 51: *
! 52: * k k+1
! 53: * Note that 1.0 x 2 == 0.1 x 2 and that denorms are represented
! 54: *
! 55: * (-exp_bias+1)
! 56: * as fractions that look like 0.fffff x 2 . This means that
! 57: *
! 58: * -126
! 59: * the number 0.10000 x 2 , for instance, is the same as the normalized
! 60: *
! 61: * -127 -128
! 62: * float 1.0 x 2 . Thus, to represent 2 , we need one leading zero
! 63: *
! 64: * -129
! 65: * in the fraction; to represent 2 , we need two, and so on. This
! 66: *
! 67: * (-exp_bias-fracbits+1)
! 68: * implies that the smallest denormalized number is 2
! 69: *
! 70: * for whichever format we are talking about: for single precision, for
! 71: *
! 72: * -126 -149
! 73: * instance, we get .00000000000000000000001 x 2 , or 1.0 x 2 , and
! 74: *
! 75: * -149 == -127 - 23 + 1.
! 76: */
! 77: #define SNG_EXPBITS 8
! 78: #define SNG_FRACBITS 23
! 79:
! 80: #define DBL_EXPBITS 11
! 81: #define DBL_FRACBITS 52
! 82:
! 83: #ifdef notyet
! 84: #define E80_EXPBITS 15
! 85: #define E80_FRACBITS 64
! 86: #endif
! 87:
! 88: #define EXT_EXPBITS 15
! 89: #define EXT_FRACBITS 112
! 90:
! 91: struct ieee_single {
! 92: u_int sng_sign:1;
! 93: u_int sng_exp:8;
! 94: u_int sng_frac:23;
! 95: };
! 96:
! 97: struct ieee_double {
! 98: u_int dbl_sign:1;
! 99: u_int dbl_exp:11;
! 100: u_int dbl_frach:20;
! 101: u_int dbl_fracl;
! 102: };
! 103:
! 104: struct ieee_ext {
! 105: u_int ext_sign:1;
! 106: u_int ext_exp:15;
! 107: u_int ext_frach:16;
! 108: u_int ext_frachm;
! 109: u_int ext_fraclm;
! 110: u_int ext_fracl;
! 111: };
! 112:
! 113: /*
! 114: * Floats whose exponent is in [1..INFNAN) (of whatever type) are
! 115: * `normal'. Floats whose exponent is INFNAN are either Inf or NaN.
! 116: * Floats whose exponent is zero are either zero (iff all fraction
! 117: * bits are zero) or subnormal values.
! 118: *
! 119: * A NaN is a `signalling NaN' if its QUIETNAN bit is clear in its
! 120: * high fraction; if the bit is set, it is a `quiet NaN'.
! 121: */
! 122: #define SNG_EXP_INFNAN 255
! 123: #define DBL_EXP_INFNAN 2047
! 124: #define EXT_EXP_INFNAN 32767
! 125:
! 126: #if 0
! 127: #define SNG_QUIETNAN (1 << 22)
! 128: #define DBL_QUIETNAN (1 << 19)
! 129: #define EXT_QUIETNAN (1 << 15)
! 130: #endif
! 131:
! 132: /*
! 133: * Exponent biases.
! 134: */
! 135: #define SNG_EXP_BIAS 127
! 136: #define DBL_EXP_BIAS 1023
! 137: #define EXT_EXP_BIAS 16383
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