netlists-folds: add Buil2_Imp

2 files changed, 24 insertions, 4 deletions

diff --git a/src/synth/netlists-folds.adb b/src/synth/netlists-folds.adb
index e591c35cf..a46aef583 100644
--- a/src/synth/netlists-folds.adb
+++ b/src/synth/netlists-folds.adb
@@ -270,4 +270,18 @@ package body Netlists.Folds is
          return Build_Extract (Ctxt, I, Off, W);
       end if;
    end Build2_Extract;
+
+   function Build2_Imp (Ctxt : Context_Acc;
+                        A, B : Net;
+                        Loc : Location_Type := No_Location)
+                       return Net
+   is
+      N : Net;
+   begin
+      N := Build_Monadic (Ctxt, Id_Not, A);
+      Set_Location (N, Loc);
+      N := Build_Dyadic (Ctxt, Id_Or, N, B);
+      Set_Location (N, Loc);
+      return N;
+   end Build2_Imp;
 end Netlists.Folds;
diff --git a/src/synth/netlists-folds.ads b/src/synth/netlists-folds.ads
index 68c6ba5a4..f00ded470 100644
--- a/src/synth/netlists-folds.ads
+++ b/src/synth/netlists-folds.ads
@@ -60,13 +60,19 @@ package Netlists.Folds is
 
    --  If IS_SIGNED is true, this is Build2_Sresize, otherwise Build2_Uresize.
    function Build2_Resize (Ctxt : Context_Acc;
-                            I : Net;
-                            W : Width;
-                            Is_Signed : Boolean;
-                            Loc : Location_Type := No_Location)
+                           I : Net;
+                           W : Width;
+                           Is_Signed : Boolean;
+                           Loc : Location_Type := No_Location)
                           return Net;
 
    --  Same as Build_Extract, but return I iff extract all the bits.
    function Build2_Extract
      (Ctxt : Context_Acc; I : Net; Off, W : Width) return Net;
+
+   --  Return A -> B  ==  !A || B
+   function Build2_Imp (Ctxt : Context_Acc;
+                        A, B : Net;
+                        Loc : Location_Type := No_Location)
+                       return Net;
 end Netlists.Folds;