don't pack arrays passed to system tasks

- avoid packing memories used with read mem tasks
- fix detection of $readmem[hb] in logic conversion

src/Convert/Logic.hs

@@ -206,7 +206,7 @@ traverseStmtM (Timing timing stmt) =
     return $ Timing timing stmt
 traverseStmtM (Subroutine (Ident f) args) = do
     case args of
-        Args [_, Ident x, _] [] ->
+        Args (_ : Ident x : _) [] ->
             if f == "$readmemh" || f == "$readmemb"
                 then collectLHSM $ LHSIdent x
                 else return ()

src/Convert/UnpackedArray.hs

@@ -94,6 +94,8 @@ traverseStmtM =
     traverseStmtArgsM
 
 traverseStmtArgsM :: Stmt -> ST Stmt
+traverseStmtArgsM stmt @ (Subroutine (Ident ('$' : _)) _) =
+    return stmt
 traverseStmtArgsM stmt @ (Subroutine _ (Args args [])) =
     mapM_ flatUsageM args >> return stmt
 traverseStmtArgsM stmt = return stmt

test/core/tf_unpacked_input.mem

@@ -0,0 +1 @@
+ff aa bb cc

test/core/tf_unpacked_input.sv

@@ -20,4 +20,7 @@ module top;
         #1 arr2[2] = 9; dump(arr2);
         #1 arr2[3] = 7; dump(arr2);
     end
+    byte arr3 [4];
+    wire [31:0] arr3_flat = {arr3[0], arr3[1], arr3[2], arr3[3]};
+    initial $readmemh("tf_unpacked_input.mem", arr3);
 endmodule

test/core/tf_unpacked_input.v

@@ -19,4 +19,7 @@ module top;
         #1 arr2[2] = 9; dump(arr2);
         #1 arr2[3] = 7; dump(arr2);
     end
+    reg [7:0] arr3 [0:3];
+    wire [31:0] arr3_flat = {arr3[0], arr3[1], arr3[2], arr3[3]};
+    initial $readmemh("tf_unpacked_input.mem", arr3);
 endmodule