1 /* Conversion routines from GCC internal float representation to MPFR. 2 Copyright (C) 2010 3 4 This file is part of GCC. 5 6 GCC is free software; you can redistribute it and/or modify it under 7 the terms of the GNU General Public License as published by the Free 8 Software Foundation; either version 3, or (at your option) any later 9 version. 10 11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY 12 WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 for more details. 15 16 You should have received a copy of the GNU General Public License 17 along with GCC; see the file COPYING3. If not see 18 <http://www.gnu.org/licenses/>. */ 19 20 #include "config.h" 21 #include "system.h" 22 #include "coretypes.h" 23 #include "realmpfr.h" 24 #include "tree.h" /* For TYPE_MODE in real_from_mpfr. */ 25 26 /* Convert from REAL_VALUE_TYPE to MPFR. The caller is responsible 27 for initializing and clearing the MPFR parameter. */ 28 29 void 30 mpfr_from_real (mpfr_ptr m, const REAL_VALUE_TYPE *r, mp_rnd_t rndmode) 31 { 32 /* We use a string as an intermediate type. */ 33 char buf[128]; 34 int ret; 35 36 /* Take care of Infinity and NaN. */ 37 if (r->cl == rvc_inf) 38 { 39 mpfr_set_inf (m, r->sign == 1 ? -1 : 1); 40 return; 41 } 42 43 if (r->cl == rvc_nan) 44 { 45 mpfr_set_nan (m); 46 return; 47 } 48 49 real_to_hexadecimal (buf, r, sizeof (buf), 0, 1); 50 /* mpfr_set_str() parses hexadecimal floats from strings in the same 51 format that GCC will output them. Nothing extra is needed. */ 52 ret = mpfr_set_str (m, buf, 16, rndmode); 53 gcc_assert (ret == 0); 54 } 55 56 /* Convert from MPFR to REAL_VALUE_TYPE, for a given type TYPE and rounding 57 mode RNDMODE. TYPE is only relevant if M is a NaN. */ 58 59 void 60 real_from_mpfr (REAL_VALUE_TYPE *r, mpfr_srcptr m, tree type, mp_rnd_t rndmode) 61 { 62 /* We use a string as an intermediate type. */ 63 char buf[128], *rstr; 64 mp_exp_t exp; 65 66 /* Take care of Infinity and NaN. */ 67 if (mpfr_inf_p (m)) 68 { 69 real_inf (r); 70 if (mpfr_sgn (m) < 0) 71 *r = real_value_negate (r); 72 return; 73 } 74 75 if (mpfr_nan_p (m)) 76 { 77 real_nan (r, "", 1, TYPE_MODE (type)); 78 return; 79 } 80 81 rstr = mpfr_get_str (NULL, &exp, 16, 0, m, rndmode); 82 83 /* The additional 12 chars add space for the sprintf below. This 84 leaves 6 digits for the exponent which is supposedly enough. */ 85 gcc_assert (rstr != NULL && strlen (rstr) < sizeof (buf) - 12); 86 87 /* REAL_VALUE_ATOF expects the exponent for mantissa * 2**exp, 88 mpfr_get_str returns the exponent for mantissa * 16**exp, adjust 89 for that. */ 90 exp *= 4; 91 92 if (rstr[0] == '-') 93 sprintf (buf, "-0x.%sp%d", &rstr[1], (int) exp); 94 else 95 sprintf (buf, "0x.%sp%d", rstr, (int) exp); 96 97 mpfr_free_str (rstr); 98 99 real_from_string (r, buf); 100 } 101 102