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-rw-r--r--src/synth/netlists-inference.adb224
1 files changed, 153 insertions, 71 deletions
diff --git a/src/synth/netlists-inference.adb b/src/synth/netlists-inference.adb
index 8786d42eb..44a419eff 100644
--- a/src/synth/netlists-inference.adb
+++ b/src/synth/netlists-inference.adb
@@ -318,6 +318,156 @@ package body Netlists.Inference is
and then Get_Input_Net (Inst, 0) = Prev_Val;
end Is_Prev_FF_Value;
+ function Infere_FF_Else (Ctxt : Context_Acc;
+ Prev_Val : Net;
+ Off : Uns32;
+ Last_Mux : Instance;
+ Clk : Net;
+ Clk_Enable : Net;
+ Stmt : Synth.Source.Syn_Src) return Net;
+
+ procedure Infere_FF_Mux (Ctxt : Context_Acc;
+ Prev_Val : Net;
+ Off : Uns32;
+ Last_Mux : Instance;
+ Stmt : Synth.Source.Syn_Src;
+ Els : out Net;
+ Data : out Net)
+ is
+ Mux_Loc : constant Location_Type := Get_Location (Last_Mux);
+ Sel : constant Input := Get_Mux2_Sel (Last_Mux);
+ I0 : constant Input := Get_Mux2_I0 (Last_Mux);
+ I1 : constant Input := Get_Mux2_I1 (Last_Mux);
+ Els_Inst : Instance;
+ Els_Clk : Net;
+ Els_En : Net;
+ begin
+ -- There must be no 'else' part for clock expression.
+ Els := Get_Driver (I0);
+ if Is_Prev_FF_Value (Els, Prev_Val, Off) then
+ -- The loop.
+ Els := No_Net;
+ else
+ Els_Inst := Get_Net_Parent (Els);
+ if Get_Id (Els_Inst) = Id_Mux2 then
+ Extract_Clock (Ctxt, Get_Driver (Get_Mux2_Sel (Els_Inst)),
+ Els_Clk, Els_En);
+ else
+ Els_Clk := No_Net;
+ end if;
+ if Els_Clk = No_Net then
+ Error_Msg_Synth
+ (Mux_Loc, "clocked logic requires clocked logic on else part");
+ Els := No_Net;
+ else
+ Els := Infere_FF_Else (Ctxt, Prev_Val, Off, Els_Inst,
+ Els_Clk, Els_En, Stmt);
+ end if;
+ end if;
+
+ Disconnect (Sel);
+ -- Don't try to free driver of I0 as this is Prev_Val or a selection
+ -- of it.
+ Disconnect (I0);
+ Data := Get_Driver (I1);
+ -- Don't try to free driver of I1 as it is reconnected.
+ Disconnect (I1);
+ end Infere_FF_Mux;
+
+ function Infere_FF_Create (Ctxt : Context_Acc;
+ Rst : Net;
+ Rst_Val : Net;
+ Init : Net;
+ Clk : Net;
+ Data : Net;
+ Els : Net;
+ Loc : Location_Type) return Net
+ is
+ Res : Net;
+ begin
+ if Rst = No_Net then
+ pragma Assert (Rst_Val = No_Net);
+ if Els = No_Net then
+ if Init /= No_Net then
+ Res := Build_Idff (Ctxt, Clk, D => Data, Init => Init);
+ else
+ Res := Build_Dff (Ctxt, Clk, D => Data);
+ end if;
+ else
+ if Init /= No_Net then
+ Res := Build_Midff (Ctxt, Clk, D => Data,
+ Els => Els, Init => Init);
+ else
+ Res := Build_Mdff (Ctxt, Clk, D => Data, Els => Els);
+ end if;
+ end if;
+ else
+ if Els /= No_Net then
+ Error_Msg_Synth
+ (Loc, "synchronous code does not expect else part");
+ end if;
+
+ if Init /= No_Net then
+ Res := Build_Iadff (Ctxt, Clk, D => Data,
+ Rst => Rst, Rst_Val => Rst_Val,
+ Init => Init);
+ else
+ Res := Build_Adff (Ctxt, Clk, D => Data,
+ Rst => Rst, Rst_Val => Rst_Val);
+ end if;
+ end if;
+
+ Set_Location (Res, Loc);
+
+ return Res;
+ end Infere_FF_Create;
+
+ function Infere_FF_Else (Ctxt : Context_Acc;
+ Prev_Val : Net;
+ Off : Uns32;
+ Last_Mux : Instance;
+ Clk : Net;
+ Clk_Enable : Net;
+ Stmt : Synth.Source.Syn_Src) return Net
+ is
+ Mux_Loc : constant Location_Type := Get_Location (Last_Mux);
+ Data : Net;
+ Res : Net;
+ Els : Net;
+ begin
+ -- Create and return the DFF.
+
+ -- 1. Remove the mux that creates the loop (will be replaced by the
+ -- dff).
+ Infere_FF_Mux (Ctxt, Prev_Val, Off, Last_Mux, Stmt, Els, Data);
+
+ Free_Instance (Last_Mux);
+
+ if Off = 0
+ and then Can_Infere_RAM (Data, Prev_Val)
+ then
+ -- Maybe it is a RAM.
+ Data := Infere_RAM (Ctxt, Data, Clk_Enable);
+ elsif Clk_Enable /= No_Net then
+ -- If there is a condition with the clock, that's an enable which
+ -- keep the previous value if the condition is false. Add the mux
+ -- for it.
+ declare
+ Prev : Net;
+ begin
+ Prev := Build2_Extract (Ctxt, Prev_Val, Off, Get_Width (Data));
+
+ Data := Build_Mux2 (Ctxt, Clk_Enable, Prev, Data);
+ Copy_Location (Data, Clk_Enable);
+ end;
+ end if;
+
+ -- Create the FF.
+ Res := Infere_FF_Create (Ctxt, No_Net, No_Net, No_Net, Clk, Data,
+ Els, Mux_Loc);
+ return Res;
+ end Infere_FF_Else;
+
-- LAST_MUX is the mux whose input 0 is the loop and clock for selector.
function Infere_FF (Ctxt : Context_Acc;
Prev_Val : Net;
@@ -342,45 +492,7 @@ package body Netlists.Inference is
-- 1. Remove the mux that creates the loop (will be replaced by the
-- dff).
- declare
- Sel : constant Input := Get_Mux2_Sel (Last_Mux);
- I0 : constant Input := Get_Mux2_I0 (Last_Mux);
- I1 : constant Input := Get_Mux2_I1 (Last_Mux);
- Els_Inst : Instance;
- Els_Clk : Net;
- Els_En : Net;
- begin
- -- There must be no 'else' part for clock expression.
- Els := Get_Driver (I0);
- if Is_Prev_FF_Value (Els, Prev_Val, Off) then
- -- The loop.
- Els := No_Net;
- else
- Els_Inst := Get_Net_Parent (Els);
- if Get_Id (Els_Inst) = Id_Mux2 then
- Extract_Clock (Ctxt, Get_Driver (Get_Mux2_Sel (Els_Inst)),
- Els_Clk, Els_En);
- else
- Els_Clk := No_Net;
- end if;
- if Els_Clk = No_Net then
- Error_Msg_Synth
- (+Stmt, "clocked logic requires clocked logic on else part");
- Els := No_Net;
- else
- Els := Infere_FF (Ctxt, Prev_Val, Off, Els_Inst,
- Els_Clk, Els_En, Stmt);
- end if;
- end if;
-
- Disconnect (Sel);
- -- Don't try to free driver of I0 as this is Prev_Val or a selection
- -- of it.
- Disconnect (I0);
- Data := Get_Driver (I1);
- -- Don't try to free driver of I1 as it is reconnected.
- Disconnect (I1);
- end;
+ Infere_FF_Mux (Ctxt, Prev_Val, Off, Last_Mux, Stmt, Els, Data);
-- If the signal declaration has an initial value, get it.
Sig := Get_Net_Parent (Prev_Val);
@@ -514,38 +626,8 @@ package body Netlists.Inference is
end if;
-- Create the FF.
- if Rst = No_Net then
- pragma Assert (Rst_Val = No_Net);
- if Els = No_Net then
- if Init /= No_Net then
- Res := Build_Idff (Ctxt, Clk, D => Data, Init => Init);
- else
- Res := Build_Dff (Ctxt, Clk, D => Data);
- end if;
- else
- if Init /= No_Net then
- raise Internal_Error;
- else
- Res := Build_Mdff (Ctxt, Clk, D => Data, Els => Els);
- end if;
- end if;
- else
- if Els /= No_Net then
- Error_Msg_Synth
- (+Stmt, "synchronous code does not expect else part");
- end if;
-
- if Init /= No_Net then
- Res := Build_Iadff (Ctxt, Clk, D => Data,
- Rst => Rst, Rst_Val => Rst_Val,
- Init => Init);
- else
- Res := Build_Adff (Ctxt, Clk, D => Data,
- Rst => Rst, Rst_Val => Rst_Val);
- end if;
- end if;
- Set_Location (Res, Mux_Loc);
-
+ Res := Infere_FF_Create (Ctxt, Rst, Rst_Val, Init, Clk, Data,
+ Els, Mux_Loc);
return Res;
end Infere_FF;