diff options
Diffstat (limited to 'src/synth/synth-environment.adb')
| -rw-r--r-- | src/synth/synth-environment.adb | 120 |
1 files changed, 95 insertions, 25 deletions
diff --git a/src/synth/synth-environment.adb b/src/synth/synth-environment.adb index cf5384eb3..ff295dba9 100644 --- a/src/synth/synth-environment.adb +++ b/src/synth/synth-environment.adb @@ -156,6 +156,11 @@ package body Synth.Environment is return Assign_Table.Table (Asgn).Val.Asgns; end Get_Assign_Partial; + function Get_Assign_Partial (Asgn : Seq_Assign) return Seq_Assign_Value is + begin + return Assign_Table.Table (Asgn).Val; + end Get_Assign_Partial; + function New_Partial_Assign (Val : Net; Offset : Uns32) return Partial_Assign is begin @@ -198,8 +203,9 @@ package body Synth.Environment is Nbr => 0)); end Push_Phi; + -- Concatenate when possible partial assignments of HEAD. procedure Merge_Partial_Assignments - (Ctxt : Context_Acc; Head : Partial_Assign) + (Ctxt : Context_Acc; Head : Seq_Assign_Value) is use Netlists.Concats; First : Partial_Assign; @@ -209,7 +215,11 @@ package body Synth.Environment is Next_Off : Uns32; Next_Val : Net; begin - First := Head; + if Head.Is_Static then + return; + end if; + + First := Head.Asgns; loop exit when First = No_Partial_Assign; @@ -1310,26 +1320,81 @@ package body Synth.Environment is end Merge_Assigns; -- Force the value of a Seq_Assign to be a net if needed, return it. - function Get_Assign_Partial_Force (Asgn : Seq_Assign) return Partial_Assign + function Get_Assign_Value_Force (Val : Seq_Assign_Value) + return Partial_Assign is - Asgn_Rec : Seq_Assign_Record renames Assign_Table.Table (Asgn); N : Net; - Res : Partial_Assign; begin - if Asgn_Rec.Val.Is_Static then - N := Synth.Context.Get_Memtyp_Net (Asgn_Rec.Val.Val); - Res := New_Partial_Assign (N, 0); - if False then - -- Overwrite ? - Asgn_Rec.Val := (Is_Static => False, - Asgns => Res); - end if; + if Val.Is_Static then + N := Synth.Context.Get_Memtyp_Net (Val.Val); + return New_Partial_Assign (N, 0); else - Res := Asgn_Rec.Val.Asgns; + return Val.Asgns; end if; - return Res; + end Get_Assign_Value_Force; + + -- Force the value of a Seq_Assign to be a net if needed, return it. + function Get_Assign_Partial_Force (Asgn : Seq_Assign) + return Partial_Assign is + begin + return Get_Assign_Value_Force (Get_Assign_Partial (Asgn)); end Get_Assign_Partial_Force; + function Merge_Static_Assigns (Wid : Wire_Id; Tv, Fv : Seq_Assign_Value) + return Boolean + is + Prev : Memtyp; + begin + -- First case: both TV and FV are static. + if Tv.Is_Static and then Fv.Is_Static then + if Is_Equal (Tv.Val, Fv.Val) then + Phi_Assign_Static (Wid, Tv.Val); + return True; + else + return False; + end if; + end if; + + -- If either TV or FV are not static, they cannot be merged. + if not Tv.Is_Static and then Tv.Asgns /= No_Partial_Assign + then + return False; + end if; + if not Fv.Is_Static and then Fv.Asgns /= No_Partial_Assign + then + return False; + end if; + + -- Get the previous value. + declare + Wire_Rec : Wire_Id_Record renames Wire_Id_Table.Table (Wid); + pragma Assert (Wire_Rec.Kind /= Wire_None); + First_Seq : Seq_Assign; + begin + -- Latest seq assign + First_Seq := Wire_Rec.Cur_Assign; + + -- If no seq assign, fails. + if First_Seq = No_Seq_Assign then + return False; + end if; + + if not Get_Assign_Is_Static (First_Seq) then + return False; + end if; + Prev := Get_Assign_Static_Val (First_Seq); + end; + + if Tv.Is_Static then + pragma Assert (Fv = No_Seq_Assign_Value); + return Is_Equal (Tv.Val, Prev); + else + pragma Assert (Fv.Is_Static); + pragma Assert (Tv = No_Seq_Assign_Value); + return Is_Equal (Fv.Val, Prev); + end if; + end Merge_Static_Assigns; + -- Add muxes for two lists T and F of assignments. procedure Merge_Phis (Ctxt : Builders.Context_Acc; Sel : Net; @@ -1339,7 +1404,7 @@ package body Synth.Environment is T_Asgns : Seq_Assign; F_Asgns : Seq_Assign; W : Wire_Id; - Tp, Fp : Partial_Assign; + Tv, Fv : Seq_Assign_Value; begin T_Asgns := Sort_Phi (T); F_Asgns := Sort_Phi (F); @@ -1352,8 +1417,8 @@ package body Synth.Environment is then -- Has an assignment only for the false branch. W := Get_Wire_Id (F_Asgns); - Fp := Get_Assign_Partial_Force (F_Asgns); - Tp := No_Partial_Assign; + Fv := Get_Assign_Partial (F_Asgns); + Tv := No_Seq_Assign_Value; F_Asgns := Get_Assign_Chain (F_Asgns); elsif F_Asgns = No_Seq_Assign or else (T_Asgns /= No_Seq_Assign @@ -1361,23 +1426,28 @@ package body Synth.Environment is then -- Has an assignment only for the true branch. W := Get_Wire_Id (T_Asgns); - Fp := No_Partial_Assign; - Tp := Get_Assign_Partial_Force (T_Asgns); + Fv := No_Seq_Assign_Value; + Tv := Get_Assign_Partial (T_Asgns); T_Asgns := Get_Assign_Chain (T_Asgns); else -- Has assignments for both the true and the false branch. pragma Assert (Get_Wire_Id (F_Asgns) = Get_Wire_Id (T_Asgns)); W := Get_Wire_Id (F_Asgns); - Fp := Get_Assign_Partial_Force (F_Asgns); - Tp := Get_Assign_Partial_Force (T_Asgns); + Fv := Get_Assign_Partial (F_Asgns); + Tv := Get_Assign_Partial (T_Asgns); T_Asgns := Get_Assign_Chain (T_Asgns); F_Asgns := Get_Assign_Chain (F_Asgns); end if; -- Merge partial assigns as much as possible. This reduce -- propagation of splits. - Merge_Partial_Assignments (Ctxt, Fp); - Merge_Partial_Assignments (Ctxt, Tp); - Merge_Assigns (Ctxt, W, Sel, Fp, Tp, Stmt); + Merge_Partial_Assignments (Ctxt, Fv); + Merge_Partial_Assignments (Ctxt, Tv); + if not Merge_Static_Assigns (W, Tv, Fv) then + Merge_Assigns (Ctxt, W, Sel, + Get_Assign_Value_Force (Fv), + Get_Assign_Value_Force (Tv), + Stmt); + end if; end loop; end Merge_Phis; |