1 | /* Conversion routines from GCC internal float representation to MPFR. |
---|---|

2 | Copyright (C) 2010-2017 Free Software Foundation, Inc. |

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 "tree.h" |

24 | #include "realmpfr.h" |

25 | #include "stor-layout.h" |

26 | |

27 | /* Convert from REAL_VALUE_TYPE to MPFR. The caller is responsible |

28 | for initializing and clearing the MPFR parameter. */ |

29 | |

30 | void |

31 | mpfr_from_real (mpfr_ptr m, const REAL_VALUE_TYPE *r, mp_rnd_t rndmode) |

32 | { |

33 | /* We use a string as an intermediate type. */ |

34 | char buf[128]; |

35 | int ret; |

36 | |

37 | /* Take care of Infinity and NaN. */ |

38 | if (r->cl == rvc_inf) |

39 | { |

40 | mpfr_set_inf (m, r->sign == 1 ? -1 : 1); |

41 | return; |

42 | } |

43 | |

44 | if (r->cl == rvc_nan) |

45 | { |

46 | mpfr_set_nan (m); |

47 | return; |

48 | } |

49 | |

50 | real_to_hexadecimal (buf, r, sizeof (buf), 0, 1); |

51 | /* mpfr_set_str() parses hexadecimal floats from strings in the same |

52 | format that GCC will output them. Nothing extra is needed. */ |

53 | ret = mpfr_set_str (m, buf, 16, rndmode); |

54 | gcc_assert (ret == 0); |

55 | } |

56 | |

57 | /* Convert from MPFR to REAL_VALUE_TYPE, for a given format FORMAT and |

58 | rounding mode RNDMODE. FORMAT is only relevant if M is a NaN. */ |

59 | |

60 | void |

61 | real_from_mpfr (REAL_VALUE_TYPE *r, mpfr_srcptr m, const real_format *format, |

62 | mp_rnd_t rndmode) |

63 | { |

64 | /* We use a string as an intermediate type. */ |

65 | char buf[128], *rstr; |

66 | mp_exp_t exp; |

67 | |

68 | /* Take care of Infinity and NaN. */ |

69 | if (mpfr_inf_p (m)) |

70 | { |

71 | real_inf (r); |

72 | if (mpfr_sgn (m) < 0) |

73 | *r = real_value_negate (r); |

74 | return; |

75 | } |

76 | |

77 | if (mpfr_nan_p (m)) |

78 | { |

79 | real_nan (r, "", 1, format); |

80 | return; |

81 | } |

82 | |

83 | rstr = mpfr_get_str (NULL, &exp, 16, 0, m, rndmode); |

84 | |

85 | /* The additional 12 chars add space for the sprintf below. This |

86 | leaves 6 digits for the exponent which is supposedly enough. */ |

87 | gcc_assert (rstr != NULL && strlen (rstr) < sizeof (buf) - 12); |

88 | |

89 | /* REAL_VALUE_ATOF expects the exponent for mantissa * 2**exp, |

90 | mpfr_get_str returns the exponent for mantissa * 16**exp, adjust |

91 | for that. */ |

92 | exp *= 4; |

93 | |

94 | if (rstr[0] == '-') |

95 | sprintf (buf, "-0x.%sp%d", &rstr[ 1], (int) exp); |

96 | else |

97 | sprintf (buf, "0x.%sp%d", rstr, ( int) exp); |

98 | |

99 | mpfr_free_str (rstr); |

100 | |

101 | real_from_string (r, buf); |

102 | } |

103 | |

104 | /* Convert from MPFR to REAL_VALUE_TYPE, for a given type TYPE and rounding |

105 | mode RNDMODE. TYPE is only relevant if M is a NaN. */ |

106 | |

107 | void |

108 | real_from_mpfr (REAL_VALUE_TYPE *r, mpfr_srcptr m, tree type, mp_rnd_t rndmode) |

109 | { |

110 | real_from_mpfr (r, m, type ? REAL_MODE_FORMAT (TYPE_MODE (type)) : NULL, |

111 | rndmode); |

112 | } |

113 | |

114 |