| /* $OpenBSD: ieee.h,v 1.1 2004/02/01 05:09:49 drahn Exp $ */ |
| /* $NetBSD: ieee.h,v 1.2 2001/02/21 17:43:50 bjh21 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. 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, Berkeley and its contributors. |
| * 4. 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. |
| */ |
| |
| /* |
| * 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. |
| */ |
| |
| /* |
| * The ARM has two sets of FP data formats. The FPA supports 32-bit, 64-bit |
| * and 96-bit IEEE formats, with the words in big-endian order. VFP supports |
| * 32-bin and 64-bit IEEE formats with the words in the CPU's native byte |
| * order. |
| * |
| * The FPA also has two packed decimal formats, but we ignore them here. |
| */ |
| |
| #define SNG_EXPBITS 8 |
| #define SNG_FRACBITS 23 |
| |
| #define DBL_EXPBITS 11 |
| #define DBL_FRACBITS 52 |
| |
| #ifndef __VFP_FP__ |
| #define E80_EXPBITS 15 |
| #define E80_FRACBITS 64 |
| |
| #define EXT_EXPBITS 15 |
| #define EXT_FRACBITS 112 |
| #endif |
| |
| struct ieee_single { |
| u_int sng_frac:23; |
| u_int sng_exponent:8; |
| u_int sng_sign:1; |
| }; |
| |
| #ifdef __VFP_FP__ |
| struct ieee_double { |
| #ifdef __ARMEB__ |
| u_int dbl_sign:1; |
| u_int dbl_exp:11; |
| u_int dbl_frach:20; |
| u_int dbl_fracl; |
| #else /* !__ARMEB__ */ |
| u_int dbl_fracl; |
| u_int dbl_frach:20; |
| u_int dbl_exp:11; |
| u_int dbl_sign:1; |
| #endif /* !__ARMEB__ */ |
| }; |
| #else /* !__VFP_FP__ */ |
| struct ieee_double { |
| u_int dbl_frach:20; |
| u_int dbl_exp:11; |
| u_int dbl_sign:1; |
| u_int dbl_fracl; |
| }; |
| |
| union ieee_double_u { |
| double dblu_d; |
| struct ieee_double dblu_dbl; |
| }; |
| |
| |
| struct ieee_e80 { |
| u_int e80_exp:15; |
| u_int e80_zero:16; |
| u_int e80_sign:1; |
| u_int e80_frach:31; |
| u_int e80_j:1; |
| u_int e80_fracl; |
| }; |
| |
| struct ieee_ext { |
| u_int ext_frach:16; |
| u_int ext_exp:15; |
| u_int ext_sign:1; |
| u_int ext_frachm; |
| u_int ext_fraclm; |
| u_int ext_fracl; |
| }; |
| #endif /* !__VFP_FP__ */ |
| |
| /* |
| * 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 |
| #ifndef __VFP_FP__ |
| #define E80_EXP_INFNAN 32767 |
| #define EXT_EXP_INFNAN 32767 |
| #endif /* !__VFP_FP__ */ |
| |
| #if 0 |
| #define SNG_QUIETNAN (1 << 22) |
| #define DBL_QUIETNAN (1 << 19) |
| #ifndef __VFP_FP__ |
| #define E80_QUIETNAN (1 << 15) |
| #define EXT_QUIETNAN (1 << 15) |
| #endif /* !__VFP_FP__ */ |
| #endif |
| |
| /* |
| * Exponent biases. |
| */ |
| #define SNG_EXP_BIAS 127 |
| #define DBL_EXP_BIAS 1023 |
| #ifndef __VFP_FP__ |
| #define E80_EXP_BIAS 16383 |
| #define EXT_EXP_BIAS 16383 |
| #endif /* !__VFP_FP__ */ |