Mercurial > octave
view liboctave/system/cmach-info.c @ 25054:6652d3823428 stable
maint: Update copyright dates in all source files.
author | John W. Eaton <jwe@octave.org> |
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date | Fri, 30 Mar 2018 09:19:05 -0400 |
parents | 194eb4bd202b |
children | 00f796120a6d |
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/* Copyright (C) 1996-2018 John W. Eaton This file is part of Octave. Octave is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. Octave is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with Octave; see the file COPYING. If not, see <https://www.gnu.org/licenses/>. */ #if defined (HAVE_CONFIG_H) # include "config.h" #endif #include <stdint.h> #include "cmach-info.h" #include "f77-fcn.h" extern double F77_FUNC (d1mach, D1MACH) (const F77_INT*); typedef union { double d; int32_t i[2]; } equiv; typedef struct { int fp_fmt; equiv fp_par[4]; } float_params; #define INIT_FLT_PAR(fp, fmt, sm1, sm2, lrg1, lrg2, rt1, rt2, dv1, dv2) \ do \ { \ fp.fp_fmt = (fmt); \ fp.fp_par[0].i[0] = (sm1); fp.fp_par[0].i[1] = (sm2); \ fp.fp_par[1].i[0] = (lrg1); fp.fp_par[1].i[1] = (lrg2); \ fp.fp_par[2].i[0] = (rt1); fp.fp_par[2].i[1] = (rt2); \ fp.fp_par[3].i[0] = (dv1); fp.fp_par[3].i[1] = (dv2); \ } \ while (0) static int equiv_compare (const equiv *std, const equiv *v, int len) { int i; for (i = 0; i < len; i++) if (v[i].i[0] != std[i].i[0] || v[i].i[1] != std[i].i[1]) return 0; return 1; } // Return 0 if the floating point format is unknown, 1 if it is IEEE // little endian, or 2 if it is IEEE big endian. // // If the return values change, you must also change the values of the // float format enum in mach-info.h and the correspondence between the // integer and enum values in octave::mach_info::get_float_format. int octave_get_float_format (void) { int retval = 0; float_params fp[3]; INIT_FLT_PAR (fp[0], 1, 0, 1048576, -1, 2146435071, 0, 1017118720, 0, 1018167296); INIT_FLT_PAR (fp[1], 2, 1048576, 0, 2146435071, -1, 1017118720, 0, 1018167296, 0); INIT_FLT_PAR (fp[2], 0, 0, 0, 0, 0, 0, 0, 0, 0); equiv mach_fp_par[4]; F77_INT opt; opt = 1; mach_fp_par[0].d = F77_FUNC (d1mach, D1MACH) (&opt); opt = 2; mach_fp_par[1].d = F77_FUNC (d1mach, D1MACH) (&opt); opt = 3; mach_fp_par[2].d = F77_FUNC (d1mach, D1MACH) (&opt); opt = 4; mach_fp_par[3].d = F77_FUNC (d1mach, D1MACH) (&opt); int i = 0; do { if (equiv_compare (fp[i].fp_par, mach_fp_par, 4)) { retval = fp[i].fp_fmt; break; } } while (fp[++i].fp_fmt != 0); return retval; } int octave_is_big_endian (void) { // Are we little or big endian? From Harbison & Steele. union { long l; char c[sizeof (long)]; } u; u.l = 1; return (u.c[sizeof (long) - 1] == 1); }