-- --
-- S p e c --
-- --
--- --
--- Copyright (C) 1992-2001 Free Software Foundation, Inc. --
+-- Copyright (C) 1992-2006 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- --
-- 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. --
+-- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, --
+-- Boston, MA 02110-1301, 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, --
type T is digits <>;
package System.Fat_Gen is
-pragma Pure (Fat_Gen);
+ pragma Pure;
subtype UI is Integer;
-- The runtime representation of universal integer for the purposes of
function Machine (X : T) return T;
+ function Machine_Rounding (X : T) return T;
+
function Model (X : T) return T;
function Pred (X : T) return T;
function Unbiased_Rounding (X : T) return T;
- function Valid (X : access T) return Boolean;
+ function Valid (X : not null access T) return Boolean;
-- This function checks if the object of type T referenced by X
-- is valid, and returns True/False accordingly. The parameter is
-- passed by reference (access) here, as the object of type T may
-- be an abnormal value that cannot be passed in a floating-point
-- register, and the whole point of 'Valid is to prevent exceptions.
+ -- Note that the object of type T must have the natural alignment
+ -- for type T. See Unaligned_Valid for further discussion.
+ --
+ -- Note: this routine does not work for Vax_Float ???
+
+ function Unaligned_Valid (A : System.Address) return Boolean;
+ -- This version of Valid is used if the floating-point value to
+ -- be checked is not known to be aligned (for example it appears
+ -- in a packed record). In this case, we cannot call Valid since
+ -- Valid assumes proper full alignment. Instead Unaligned_Valid
+ -- performs the same processing for a possibly unaligned float,
+ -- by first doing a copy and then calling Valid. One might think
+ -- that the front end could simply do a copy to an aligned temp,
+ -- but remember that we may have an abnormal value that cannot
+ -- be copied into a floating-point register, so things are a bit
+ -- trickier than one might expect.
+ --
+ -- Note: Unaligned_Valid is never called for a target which does
+ -- not require strict alignment (e.g. the ia32/x86), since on a
+ -- target not requiring strict alignment, it is fine to pass a
+ -- non-aligned value to the standard Valid routine.
+ --
+ -- Note: this routine does not work for Vax_Float ???
private
pragma Inline (Machine);
pragma Inline (Model);
- pragma Inline_Always (Valid);
+
+ -- Note: previously the validity checking subprograms (Unaligned_Valid and
+ -- Valid) were also inlined, but this was changed since there were some
+ -- problems with this inlining in optimized mode, and in any case it seems
+ -- better to avoid this inlining (space and robustness considerations).
end System.Fat_Gen;
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