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| author | kenner <kenner@138bc75d-0d04-0410-961f-82ee72b054a4> | 2001-10-02 14:30:19 +0000 |
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| committer | kenner <kenner@138bc75d-0d04-0410-961f-82ee72b054a4> | 2001-10-02 14:30:19 +0000 |
| commit | c32d045231e086867f117700fbe01dbbbce3ea14 (patch) | |
| tree | 86d33ed164722c539e5c03eb27ae96b8b7667e75 /gcc/ada/s-powtab.ads | |
| parent | 49d882a7d8c985758c04737e801f6028d5b7240f (diff) | |
| download | gcc-c32d045231e086867f117700fbe01dbbbce3ea14.tar.gz | |
New Language: Ada
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@45957 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'gcc/ada/s-powtab.ads')
| -rw-r--r-- | gcc/ada/s-powtab.ads | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/gcc/ada/s-powtab.ads b/gcc/ada/s-powtab.ads new file mode 100644 index 00000000000..6cadc429609 --- /dev/null +++ b/gcc/ada/s-powtab.ads @@ -0,0 +1,74 @@ +------------------------------------------------------------------------------ +-- -- +-- GNAT COMPILER COMPONENTS -- +-- -- +-- S Y S T E M . P O W T E N _ T A B L E -- +-- -- +-- S p e c -- +-- -- +-- $Revision: 1.6 $ +-- -- +-- 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. -- +-- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). -- +-- -- +------------------------------------------------------------------------------ + +-- 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; |