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-- PSL - HDL interface.
-- Copyright (C) 2002-2016 Tristan Gingold
--
-- GHDL is free software; you can redistribute it and/or modify it under
-- the terms of the GNU General Public License as published by the Free
-- Software Foundation; either version 2, or (at your option) any later
-- version.
--
-- GHDL is distributed in the hope that it will be useful, but WITHOUT 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
-- along with GHDL; see the file COPYING. If not, write to the Free
-- Software Foundation, 59 Temple Place - Suite 330, Boston, MA
-- 02111-1307, USA.
with Tables;
package body PSL.Hash is
type Index_Type is new Natural;
No_Index : constant Index_Type := 0;
type Cell_Record is record
Res : Node;
Next : Index_Type;
end record;
Hash_Size : constant Index_Type := 127;
package Cells is new Tables
(Table_Component_Type => Cell_Record,
Table_Index_Type => Index_Type,
Table_Low_Bound => 0,
Table_Initial => 256);
procedure Init is
begin
Cells.Set_Last (Hash_Size - 1);
for I in 0 .. Hash_Size - 1 loop
Cells.Table (I) := (Res => Null_Node, Next => No_Index);
end loop;
end Init;
function Get_PSL_Node (Hdl : Int32) return Node is
Idx : Index_Type := Index_Type (Hdl mod Int32 (Hash_Size));
N_Idx : Index_Type;
Res : Node;
begin
-- In the primary table.
Res := Cells.Table (Idx).Res;
if Res = Null_Node then
Res := Create_Node (N_HDL_Expr);
Set_HDL_Node (Res, Hdl);
Cells.Table (Idx).Res := Res;
return Res;
end if;
loop
if Get_HDL_Node (Res) = Hdl then
return Res;
end if;
-- Look in collisions chain
N_Idx := Cells.Table (Idx).Next;
exit when N_Idx = No_Index;
Idx := N_Idx;
Res := Cells.Table (Idx).Res;
end loop;
Res := Create_Node (N_HDL_Expr);
Set_HDL_Node (Res, Hdl);
Cells.Append ((Res => Res, Next => No_Index));
Cells.Table (Idx).Next := Cells.Last;
return Res;
end Get_PSL_Node;
end PSL.Hash;
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