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Diffstat (limited to 'src/synth/netlists-butils.ads')
-rw-r--r-- | src/synth/netlists-butils.ads | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/src/synth/netlists-butils.ads b/src/synth/netlists-butils.ads new file mode 100644 index 000000000..c0d79734a --- /dev/null +++ b/src/synth/netlists-butils.ads @@ -0,0 +1,55 @@ +-- Build utilities +-- Copyright (C) 2019 Tristan Gingold +-- +-- This file is part of GHDL. +-- +-- This program 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 of the License, or +-- (at your option) any later version. +-- +-- This program 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 this program; if not, write to the Free Software +-- Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, +-- MA 02110-1301, USA. + +with Ada.Unchecked_Deallocation; + +with Netlists.Builders; use Netlists.Builders; + +with Synth.Source; use Synth.Source; + +package Netlists.Butils is + type Case_Element is record + Sel : Uns64; + Val : Net; + end record; + + type Case_Element_Array is array (Natural range <>) of Case_Element; + type Case_Element_Array_Acc is access Case_Element_Array; + procedure Free_Case_Element_Array is new Ada.Unchecked_Deallocation + (Case_Element_Array, Case_Element_Array_Acc); + + -- Generate a netlist for a 'big' mux selected by SEL. The inputs are + -- described by ELS: E.Val must be selected when SEL = E.Sel; if there + -- is no E in Els for a value, DEFAULT is selected. + -- The result of the netlist is stored in RES. + -- + -- A tree of MUX4 is built. + -- + -- ELS must be sorted by SEL values. + -- ELS is overwritten/modified so after the call it contains garbage. The + -- reason is that ELS might be large, so temporary arrays are not allocated + -- on the stack, and ELS is expected to be built only for this subprogram. + procedure Synth_Case (Ctxt : Context_Acc; + Sel : Net; + Els : in out Case_Element_Array; + Default : Net; + Res : out Net; + Sel_Loc : Syn_Src); +end Netlists.Butils; |