------------------------------------------------------------------------------ | |

-- -- | |

-- GNAT COMPILER COMPONENTS -- | |

-- -- | |

-- S Y S T E M . P O W T E N _ T A B L E -- | |

-- -- | |

-- S p e c -- | |

-- -- | |

-- Copyright (C) 1992-1999 Free Software Foundation, Inc. -- | |

-- -- | |

-- GNAT is free software; you can redistribute it and/or modify it under -- | |

-- terms of the GNU General Public License as published by the Free Soft- -- | |

-- ware Foundation; either version 2, or (at your option) any later ver- -- | |

-- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- | |

-- OUT 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 distributed with GNAT; see file COPYING. If not, write -- | |

-- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, -- | |

-- MA 02111-1307, USA. -- | |

-- -- | |

-- As a special exception, if other files instantiate generics from this -- | |

-- unit, or you link this unit with other files to produce an executable, -- | |

-- this unit does not by itself cause the resulting executable to be -- | |

-- covered by the GNU General Public License. This exception does not -- | |

-- however invalidate any other reasons why the executable file might be -- | |

-- covered by the GNU Public License. -- | |

-- -- | |

-- GNAT was originally developed by the GNAT team at New York University. -- | |

-- Extensive contributions were provided by Ada Core Technologies Inc. -- | |

-- -- | |

------------------------------------------------------------------------------ | |

-- This package provides a powers of ten table used for real conversions | |

package System.Powten_Table is | |

pragma Pure (Powten_Table); | |

Maxpow : constant := 22; | |

-- The number of entries in this table is chosen to include powers of ten | |

-- that are exactly representable with long_long_float. Assuming that on | |

-- all targets we have 53 bits of mantissa for the type, the upper bound is | |

-- given by 53/(log 5). If the scaling factor for a string is greater than | |

-- Maxpow, it can be obtained by several multiplications, which is less | |

-- efficient than with a bigger table, but avoids anomalies at end points. | |

Powten : constant array (0 .. Maxpow) of Long_Long_Float := | |

(00 => 1.0E+00, | |

01 => 1.0E+01, | |

02 => 1.0E+02, | |

03 => 1.0E+03, | |

04 => 1.0E+04, | |

05 => 1.0E+05, | |

06 => 1.0E+06, | |

07 => 1.0E+07, | |

08 => 1.0E+08, | |

09 => 1.0E+09, | |

10 => 1.0E+10, | |

11 => 1.0E+11, | |

12 => 1.0E+12, | |

13 => 1.0E+13, | |

14 => 1.0E+14, | |

15 => 1.0E+15, | |

16 => 1.0E+16, | |

17 => 1.0E+17, | |

18 => 1.0E+18, | |

19 => 1.0E+19, | |

20 => 1.0E+20, | |

21 => 1.0E+21, | |

22 => 1.0E+22); | |

end System.Powten_Table; |