------------------------------------------------------------------------------ -- -- -- GNAT RUN-TIME COMPONENTS -- -- -- -- S Y S T E M . F L O A T _ C O N T R O L -- -- -- -- S p e c -- -- -- -- Copyright (C) 2000-2011, AdaCore -- -- -- -- 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 3, 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. -- -- -- -- As a special exception under Section 7 of GPL version 3, you are granted -- -- additional permissions described in the GCC Runtime Library Exception, -- -- version 3.1, as published by the Free Software Foundation. -- -- -- -- You should have received a copy of the GNU General Public License and -- -- a copy of the GCC Runtime Library Exception along with this program; -- -- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see -- -- . -- -- -- -- GNAT was originally developed by the GNAT team at New York University. -- -- Extensive contributions were provided by Ada Core Technologies Inc. -- -- -- ------------------------------------------------------------------------------ -- Control functions for floating-point unit package System.Float_Control is pragma Pure; -- This is not fully correct, but this unit is with-ed by pure units -- (eg s-imgrea). procedure Reset; pragma Inline (Reset); -- Reset the floating-point processor to the default state needed to get -- correct Ada semantics for the target. Some third party tools change -- the settings for the floating-point processor. Reset can be called -- to reset the floating-point processor into the mode required by GNAT -- for correct operation. Use this call after a call to foreign code if -- you suspect incorrect floating-point operation after the call. -- -- For example under Windows NT some system DLL calls change the default -- FPU arithmetic to 64 bit precision mode. However, since in Ada 95 it -- is required to provide full access to the floating-point types of the -- architecture, GNAT requires full 80-bit precision mode, and Reset makes -- sure this mode is established. -- -- Similarly on the PPC processor, it is important that overflow and -- underflow exceptions be disabled. -- -- The call to Reset simply has no effect if the target environment -- does not give rise to such concerns. end System.Float_Control;