/* $OpenBSD: ieee.h,v 1.4 2010/01/23 19:11:21 miod 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 | |

*/ | |

/* | |

* ieee.h defines the machine-dependent layout of the machine's IEEE | |

* floating point. It does *not* define (yet?) any of the rounding | |

* mode bits, exceptions, and so forth. | |

*/ | |

/* | |

* 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_FRACHBITS 20 | |

#define DBL_FRACLBITS 32 | |

#define DBL_FRACBITS 52 | |

#define EXT_EXPBITS 15 | |

#define EXT_FRACHBITS 16 | |

#define EXT_FRACHMBITS 32 | |

#define EXT_FRACLMBITS 32 | |

#define EXT_FRACLBITS 32 | |

#define EXT_FRACBITS 112 | |

#define EXT_IMPLICIT_NBIT | |

#define EXT_TO_ARRAY32(p, a) do { \ | |

(a)[0] = (uint32_t)(p)->ext_fracl; \ | |

(a)[1] = (uint32_t)(p)->ext_fraclm; \ | |

(a)[2] = (uint32_t)(p)->ext_frachm; \ | |

(a)[3] = (uint32_t)(p)->ext_frach; \ | |

} while(0) | |

struct ieee_single { | |

#ifdef __MIPSEB__ | |

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 { | |

#ifdef __MIPSEB__ | |

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 | |

}; | |

struct ieee_ext { | |

#ifdef __MIPSEB__ | |

u_int ext_sign:1; | |

u_int ext_exp:15; | |

u_int ext_frach:16; | |

u_int ext_frachm; | |

u_int ext_fraclm; | |

u_int ext_fracl; | |

#else | |

u_int ext_fracl; | |

u_int ext_fraclm; | |

u_int ext_frachm; | |

u_int ext_frach:16; | |

u_int ext_exp:15; | |

u_int ext_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 | |

#define EXT_EXP_INFNAN 32767 | |

#if 0 | |

#define SNG_QUIETNAN (1 << 22) | |

#define DBL_QUIETNAN (1 << 19) | |

#define EXT_QUIETNAN (1 << 15) | |

#endif | |

/* | |

* Exponent biases. | |

*/ | |

#define SNG_EXP_BIAS 127 | |

#define DBL_EXP_BIAS 1023 | |

#define EXT_EXP_BIAS 16383 |