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Diffstat (limited to 'gcc/ada/s-veboop.adb')
-rw-r--r-- | gcc/ada/s-veboop.adb | 121 |
1 files changed, 121 insertions, 0 deletions
diff --git a/gcc/ada/s-veboop.adb b/gcc/ada/s-veboop.adb new file mode 100644 index 00000000000..ddbb376a89a --- /dev/null +++ b/gcc/ada/s-veboop.adb @@ -0,0 +1,121 @@ +------------------------------------------------------------------------------ +-- -- +-- GNU ADA RUNTIME LIBRARY (GNARL) COMPONENTS -- +-- -- +-- S Y S T E M . V E C T O R S . B O O L E A N _ O P E R A T I O N S -- +-- -- +-- B o d y -- +-- -- +-- Copyright (C) 2002 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. -- +-- -- +------------------------------------------------------------------------------ + +package body System.Vectors.Boolean_Operations is + + type Boolean_Array is array (Integer range <>) of Boolean; + pragma Assert (Boolean_Array'Component_Size = 8); + -- Unfortunately Boolean_Array'Component_Size is not a compile-time-known + -- value, so assume it is 8 in order to be able to determine True_Val at + -- compile time. + + -- NOTE: The boolean literals must be qualified here to avoid visibility + -- anomalies when this package is compiled through Rtsfind, in a context + -- that includes a user-defined type derived from boolean. + + True_Val : constant Vector := Standard.True'Enum_Rep + + Standard.True'Enum_Rep * 2**8 + + Standard.True'Enum_Rep * 2**(8 * 2) + + Standard.True'Enum_Rep * 2**(8 * 3) + + Standard.True'Enum_Rep * 2**(8 * 4) + + Standard.True'Enum_Rep * 2**(8 * 5) + + Standard.True'Enum_Rep * 2**(8 * 6) + + Standard.True'Enum_Rep * 2**(8 * 7); + -- This constant represents the bits to be flipped to perform a logical + -- "not" on a vector of booleans, independent of the actual + -- representation of True. + + -- The representations of (False, True) are assumed to be zero/one and + -- the maximum number of unpacked booleans per Vector is assumed to be 8. + + pragma Assert (Standard.False'Enum_Rep = 0); + pragma Assert (Standard.True'Enum_Rep = 1); + pragma Assert (Vector'Size / Storage_Unit <= 8); + + -- The reason we need to do these gymnastics is that no call to + -- Unchecked_Conversion can be made at the library level since this + -- unit is pure. Also a conversion from the array type to the Vector type + -- inside the body of "not" is inefficient because of alignment issues. + + ----------- + -- "not" -- + ----------- + + function "not" (Item : Vectors.Vector) return Vectors.Vector is + begin + return Item xor True_Val; + end "not"; + + ---------- + -- Nand -- + ---------- + + function Nand (Left, Right : Boolean) return Boolean is + begin + return not (Left and Right); + end Nand; + + function Nand (Left, Right : Vectors.Vector) return Vectors.Vector is + begin + return not (Left and Right); + end Nand; + + --------- + -- Nor -- + --------- + + function Nor (Left, Right : Boolean) return Boolean is + begin + return not (Left or Right); + end Nor; + + function Nor (Left, Right : Vectors.Vector) return Vectors.Vector is + begin + return not (Left or Right); + end Nor; + + ---------- + -- Nxor -- + ---------- + + function Nxor (Left, Right : Boolean) return Boolean is + begin + return not (Left xor Right); + end Nxor; + + function Nxor (Left, Right : Vectors.Vector) return Vectors.Vector is + begin + return not (Left xor Right); + end Nxor; + +end System.Vectors.Boolean_Operations; |