diff options
Diffstat (limited to 'src/synth/netlists-memories.adb')
| -rw-r--r-- | src/synth/netlists-memories.adb | 157 |
1 files changed, 154 insertions, 3 deletions
diff --git a/src/synth/netlists-memories.adb b/src/synth/netlists-memories.adb index 62025eb61..0d8ca9e1c 100644 --- a/src/synth/netlists-memories.adb +++ b/src/synth/netlists-memories.adb @@ -525,7 +525,7 @@ package body Netlists.Memories is -- swap the dff and the concat. This will allow to merge the dff during -- the build of mem_rd_sync. -- This creates new gates (the dff is replicated) that will be removed. - procedure Maybe_Swap_Concat_Dff (Ctxt : Context_Acc; Extract : Instance) + procedure Maybe_Swap_Concat_Mux_Dff (Ctxt : Context_Acc; Extract : Instance) is Extr_Out : constant Net := Get_Output (Extract, 0); Concat : Instance; @@ -603,7 +603,155 @@ package body Netlists.Memories is -- Reconnect the concat. Redirect_Inputs (Get_Output (Dff, 0), Concat_Out); Remove_Instance (Dff); - end Maybe_Swap_Concat_Dff; + end Maybe_Swap_Concat_Mux_Dff; + + procedure Maybe_Swap_Mux_Concat_Dff (Ctxt : Context_Acc; Extract : Instance) + is + Concat : Instance; + Concat_Out : Net; + Dff : Instance; + Dff_Inp : Input; + Dff_Out : Net; + Dff_Off : Uns32; + Clk, En : Net; + Loc : Location_Type; + begin + declare + Extr_Out : constant Net := Get_Output (Extract, 0); + Mux_Inp : Input; + Mux : Instance; + Mux_Out : Net; + Concat_Inp : Input; + begin + if not Has_One_Connection (Extr_Out) then + -- The dyn_extract is connected to more than one gate. + return; + end if; + + -- The output is connected to a Mux2. + Mux_Inp := Get_First_Sink (Extr_Out); + Mux := Get_Input_Parent (Mux_Inp); + if Get_Id (Mux) /= Id_Mux2 then + -- Not a mux2. + return; + end if; + Mux_Out := Get_Output (Mux, 0); + + if not Has_One_Connection (Mux_Out) then + return; + end if; + + -- The Mux2 output is connected to a concat. + Concat_Inp := Get_First_Sink (Mux_Out); + Concat := Get_Input_Parent (Concat_Inp); + case Get_Id (Concat) is + when Concat_Module_Id + | Id_Concatn => + null; + when others => + -- Not a concat. + return; + end case; + + -- The concat is connected to a dff. + Concat_Out := Get_Output (Concat, 0); + if not Has_One_Connection (Concat_Out) then + -- The concat is connected to more than one gate. + return; + end if; + Dff_Inp := Get_First_Sink (Concat_Out); + Dff := Get_Input_Parent (Dff_Inp); + if Get_Id (Dff) /= Id_Dff then + return; + end if; + end; + + -- Check all concat inputs are connected to a mux2, which is + -- connected to a dyn_extract. + Dff_Out := Get_Output (Dff, 0); + Dff_Off := 0; + for I in reverse 1 .. Get_Nbr_Inputs (Concat) loop + declare + Mux_Net : constant Net := Get_Input_Net (Concat, I - 1); + Mux_Inst : constant Instance := Get_Net_Parent (Mux_Net); + Extr_Net : Net; + Extr_Inst : Instance; + begin + if Get_Id (Mux_Inst) /= Id_Mux2 then + return; + end if; + if not Has_One_Connection (Mux_Net) then + -- A source of concat drives something else! + return; + end if; + + Extr_Net := Get_Input_Net (Mux_Inst, 2); + if Get_Id (Get_Net_Parent (Extr_Net)) /= Id_Dyn_Extract then + -- A source of concat is not a dyn_extract. + return; + end if; + if not Has_One_Connection (Extr_Net) then + -- A source of concat drives something else! + return; + end if; + + -- Check the Mux2 is a enable for the dff. + Extr_Net := Get_Input_Net (Mux_Inst, 1); + Extr_Inst := Get_Net_Parent (Extr_Net); + if Get_Id (Extr_Inst) /= Id_Extract then + return; + end if; + if Get_Param_Uns32 (Extr_Inst, 0) /= Dff_Off then + return; + end if; + if Get_Input_Net (Extr_Inst, 0) /= Dff_Out then + return; + end if; + Dff_Off := Dff_Off + Get_Width (Mux_Net); + end; + end loop; + + Extract_Extract_Dff (Ctxt, Concat, Dff, Clk, En); + if Clk = No_Net then + return; + end if; + -- There is no additional enabler for the dff. + pragma Assert (En = No_Net); + + -- Replicate the dff. + Loc := Get_Location (Dff); + for I in 1 .. Get_Nbr_Inputs (Concat) loop + declare + Inp : constant Input := Get_Input (Concat, I - 1); + Dff2 : Net; + Mux_Inst2 : Instance; + Mux_Inp2 : Input; + Src : Net; + Extr_Out2 : Net; + Extr_Inst2 : Instance; + begin + -- Disconnect the mux2. + Src := Disconnect_And_Get (Inp); + + Dff2 := Build_Dff (Ctxt, Clk, Src); + Set_Location (Dff2, Loc); + Connect (Inp, Dff2); + + Mux_Inst2 := Get_Net_Parent (Src); + Mux_Inp2 := Get_Input (Mux_Inst2, 1); + Extr_Out2 := Disconnect_And_Get (Mux_Inp2); + Connect (Mux_Inp2, Dff2); + + Extr_Inst2 := Get_Net_Parent (Extr_Out2); + Disconnect (Get_Input (Extr_Inst2, 0)); + Remove_Instance (Extr_Inst2); + end; + end loop; + + -- Reconnect the concat. + Redirect_Inputs (Get_Output (Dff, 0), Concat_Out); + Remove_Instance (Dff); + end Maybe_Swap_Mux_Concat_Dff; -- Create a mem_rd/mem_rd_sync from a dyn_extract gate. -- LAST is the last memory port on the chain. @@ -1561,7 +1709,10 @@ package body Netlists.Memories is Addr := Get_Driver (Inp2); Disconnect (Inp2); Convert_Memidx (Ctxt, Mem_Sz, Addr, Mem_W); - Maybe_Swap_Concat_Dff (Ctxt, In_Inst); + + Maybe_Swap_Concat_Mux_Dff (Ctxt, In_Inst); + Maybe_Swap_Mux_Concat_Dff (Ctxt, In_Inst); + Extract_Extract_Dff (Ctxt, In_Inst, Last_Inst, Clk, En); if Clk /= No_Net and then En = No_Net then En := Build_Const_UB32 (Ctxt, 1, 1); |