From eb104a727e5f029be319cfc180f2c7ac5ecfbcb2 Mon Sep 17 00:00:00 2001
From: Ethan Sifferman <ethan@sifferman.dev>
Date: Fri, 28 Jul 2023 22:22:15 -0700
Subject: [PATCH 1/4] initial commit

---
 Documentation/developer/guide/vvp/vvp.rst | 6 +++---
 tgt-vvp/vvp_scope.c                       | 8 ++++++--
 vvp/parse.y                               | 9 +++++++++
 3 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/Documentation/developer/guide/vvp/vvp.rst b/Documentation/developer/guide/vvp/vvp.rst
index 59439cc82..00b166023 100644
--- a/Documentation/developer/guide/vvp/vvp.rst
+++ b/Documentation/developer/guide/vvp/vvp.rst
@@ -765,13 +765,13 @@ The .ufunc statements define a call to a user defined function.
 ::
 
 	<label> .ufunc/real <flabel>, <wid>,
-            <isymbols> ( <psymbols> ) <ssymbol>;
+            [<isymbols> ( <psymbols> )] <ssymbol>;
 
 	<label> .ufunc/vec4 <flabel>, <wid>,
-            <isymbols> ( <psymbols> ) <ssymbol>;
+            [<isymbols> ( <psymbols> )] <ssymbol>;
 
 	<label> .ufunc/e <flabel>, <wid>, <trigger>,
-            <isymbols> ( <psymbols> ) <ssymbol>;
+            [<isymbols> ( <psymbols> )] <ssymbol>;
 
 The first variant is used for functions that only need to be called
 when one of their inputs changes value. The second variant is used
diff --git a/tgt-vvp/vvp_scope.c b/tgt-vvp/vvp_scope.c
index e8e4e4ec5..4fcd1084c 100644
--- a/tgt-vvp/vvp_scope.c
+++ b/tgt-vvp/vvp_scope.c
@@ -2077,11 +2077,14 @@ static void draw_lpm_ufunc(ivl_lpm_t net)
             fprintf(vvp_out, "L_%p%s .ufunc%s TD_%s, %u", net, dly, type_string,
                     vvp_mangle_id(ivl_scope_name(def)),
                     ivl_lpm_width(net));
+	fprintf(vvp_out, ", ");
 
 	/* Print all the net signals that connect to the input of the
 	   function. */
       for (idx = 0 ;  idx < ninp ;  idx += 1) {
-	    fprintf(vvp_out, ", %s", input_strings[idx]);
+		fprintf(vvp_out, "%s", input_strings[idx]);
+		if (idx != ninp-1)
+			fprintf(vvp_out, ", ");
       }
       free(input_strings);
 
@@ -2101,7 +2104,8 @@ static void draw_lpm_ufunc(ivl_lpm_t net)
 	    fprintf(vvp_out, "v%p_0", psig);
       }
 
-      fprintf(vvp_out, ")");
+	if (ninp > 0)
+		fprintf(vvp_out, ")");
 #if 0
 	/* Now print the reference to the signal from which the
 	   result is collected. */
diff --git a/vvp/parse.y b/vvp/parse.y
index 1224fa21a..15e056530 100644
--- a/vvp/parse.y
+++ b/vvp/parse.y
@@ -261,12 +261,21 @@ statement
   | T_LABEL K_UFUNC_REAL T_SYMBOL ',' T_NUMBER ',' symbols '(' symbols ')' T_SYMBOL ';'
       { compile_ufunc_real($1, $3, $5, $7.cnt, $7.vect, $9.cnt, $9.vect, $11, 0); }
 
+  | T_LABEL K_UFUNC_REAL T_SYMBOL ',' T_NUMBER ',' T_SYMBOL ';'
+      { compile_ufunc_real($1, $3, $5, 0, 0, 0, 0, $7, 0); }
+
   | T_LABEL K_UFUNC_VEC4 T_SYMBOL ',' T_NUMBER ',' symbols '(' symbols ')' T_SYMBOL ';'
       { compile_ufunc_vec4($1, $3, $5, $7.cnt, $7.vect, $9.cnt, $9.vect, $11, 0); }
 
+  | T_LABEL K_UFUNC_VEC4 T_SYMBOL ',' T_NUMBER ',' T_SYMBOL ';'
+      { compile_ufunc_vec4($1, $3, $5, 0, 0, 0, 0, $7, 0); }
+
   | T_LABEL K_UFUNC_E T_SYMBOL ',' T_NUMBER ',' T_SYMBOL ',' symbols '(' symbols ')' T_SYMBOL ';'
       { compile_ufunc_vec4($1, $3, $5, $9.cnt, $9.vect, $11.cnt, $11.vect, $13, $7); }
 
+  | T_LABEL K_UFUNC_E T_SYMBOL ',' T_NUMBER ',' T_SYMBOL ',' T_SYMBOL ';'
+      { compile_ufunc_vec4($1, $3, $5, 0, 0, 0, 0, $7, 0); }
+
   /* Resolver statements are very much like functors. They are
      compiled to functors of a different mode. */
 

From 44badf50de6e76253c2575581fb0daff0416f032 Mon Sep 17 00:00:00 2001
From: Ethan Sifferman <ethan@sifferman.dev>
Date: Fri, 28 Jul 2023 23:51:02 -0700
Subject: [PATCH 2/4] added test

---
 ivtest/ivltests/sv_argumentless_func.v     | 29 ++++++++++++++++++++++
 ivtest/regress-vvp.list                    |  1 +
 ivtest/vvp_tests/sv_argumentless_func.json |  5 ++++
 3 files changed, 35 insertions(+)
 create mode 100644 ivtest/ivltests/sv_argumentless_func.v
 create mode 100644 ivtest/vvp_tests/sv_argumentless_func.json

diff --git a/ivtest/ivltests/sv_argumentless_func.v b/ivtest/ivltests/sv_argumentless_func.v
new file mode 100644
index 000000000..858da97f0
--- /dev/null
+++ b/ivtest/ivltests/sv_argumentless_func.v
@@ -0,0 +1,29 @@
+
+module test;
+
+function automatic [7:0] test_func;
+    input _unused;
+    test_func = _unused;
+endfunction
+
+logic [7:0] test_assign;
+assign test_assign = test_func(0);
+
+wire [7:0] test_wire = test_func(0);
+
+initial begin
+    if (test_assign !== test_func(0)) begin
+        $display("FAILED -- test_assign=%h, expect %h", test_assign, test_func(0));
+        $finish;
+    end
+
+    if (test_wire !== test_func(0)) begin
+        $display("FAILED -- test_wire=%h, expect %h", test_wire, test_func(0));
+        $finish;
+    end
+
+    $display("PASSED");
+    $finish;
+end
+
+endmodule
diff --git a/ivtest/regress-vvp.list b/ivtest/regress-vvp.list
index 11f9dc682..a3a38b0ed 100644
--- a/ivtest/regress-vvp.list
+++ b/ivtest/regress-vvp.list
@@ -56,6 +56,7 @@ sv_ap_uarray5			vvp_tests/sv_ap_uarray5.json
 sv_ap_uarray6			vvp_tests/sv_ap_uarray6.json
 sv_ap_uarray_fail1		vvp_tests/sv_ap_uarray_fail1.json
 sv_ap_uarray_fail2		vvp_tests/sv_ap_uarray_fail2.json
+sv_argumentless_func		vvp_tests/sv_argumentless_func.json
 sv_array_assign_fail1	vvp_tests/sv_array_assign_fail1.json
 sv_array_assign_fail2	vvp_tests/sv_array_assign_fail2.json
 sv_array_cassign6		vvp_tests/sv_array_cassign6.json
diff --git a/ivtest/vvp_tests/sv_argumentless_func.json b/ivtest/vvp_tests/sv_argumentless_func.json
new file mode 100644
index 000000000..6cf5de5aa
--- /dev/null
+++ b/ivtest/vvp_tests/sv_argumentless_func.json
@@ -0,0 +1,5 @@
+{
+    "type"          : "normal",
+    "source"        : "sv_argumentless_func.v",
+    "iverilog-args" : [ "-g2012" ]
+}

From de2f506644a8cdb339b95f14a272f96f862d37a6 Mon Sep 17 00:00:00 2001
From: Ethan Sifferman <ethan@sifferman.dev>
Date: Sat, 29 Jul 2023 00:21:31 -0700
Subject: [PATCH 3/4] improved test

---
 ivtest/ivltests/sv_argumentless_func.v | 45 ++++++++++++++++++++------
 1 file changed, 36 insertions(+), 9 deletions(-)

diff --git a/ivtest/ivltests/sv_argumentless_func.v b/ivtest/ivltests/sv_argumentless_func.v
index 858da97f0..6ca061900 100644
--- a/ivtest/ivltests/sv_argumentless_func.v
+++ b/ivtest/ivltests/sv_argumentless_func.v
@@ -2,23 +2,50 @@
 module test;
 
 function automatic [7:0] test_func;
-    input _unused;
-    test_func = _unused;
+    test_func = 8'h1;
 endfunction
 
-logic [7:0] test_assign;
-assign test_assign = test_func(0);
+logic [7:0] test_alwayscomb;
+always_comb test_alwayscomb = test_func();
 
-wire [7:0] test_wire = test_func(0);
+logic [7:0] test_alwaysff;
+logic clk;
+always_ff @(posedge clk) test_alwaysff <= test_func();
+
+logic [7:0] test_assign;
+assign test_assign = test_func();
+
+wire [7:0] test_wire = test_func();
 
 initial begin
-    if (test_assign !== test_func(0)) begin
-        $display("FAILED -- test_assign=%h, expect %h", test_assign, test_func(0));
+    #1;
+
+    if (test_func() !== 8'h1) begin
+        $display("FAILED -- test_func()=%h, expect %h", test_func(), 8'h1);
         $finish;
     end
 
-    if (test_wire !== test_func(0)) begin
-        $display("FAILED -- test_wire=%h, expect %h", test_wire, test_func(0));
+    if (test_alwayscomb !== test_func()) begin
+        $display("FAILED -- test_alwayscomb=%h, expect %h", test_alwayscomb, test_func());
+        $finish;
+    end
+
+    if (test_assign !== test_func()) begin
+        $display("FAILED -- test_assign=%h, expect %h", test_assign, test_func());
+        $finish;
+    end
+
+    if (test_wire !== test_func()) begin
+        $display("FAILED -- test_wire=%h, expect %h", test_wire, test_func());
+        $finish;
+    end
+
+    clk = 0;
+    #1;
+    clk = 1;
+    #1;
+    if (test_alwaysff !== test_func()) begin
+        $display("FAILED -- test_alwaysff=%h, expect %h", test_alwaysff, test_func());
         $finish;
     end
 

From 470a3da703d0b481207bec29fb930cf4875db3f7 Mon Sep 17 00:00:00 2001
From: Ethan Sifferman <ethan@sifferman.dev>
Date: Sun, 30 Jul 2023 22:44:19 -0700
Subject: [PATCH 4/4] removed wire and assign from test

---
 ivtest/ivltests/sv_argumentless_func.v | 37 +++++++++++++++-----------
 1 file changed, 22 insertions(+), 15 deletions(-)

diff --git a/ivtest/ivltests/sv_argumentless_func.v b/ivtest/ivltests/sv_argumentless_func.v
index 6ca061900..cd32b3299 100644
--- a/ivtest/ivltests/sv_argumentless_func.v
+++ b/ivtest/ivltests/sv_argumentless_func.v
@@ -5,40 +5,47 @@ function automatic [7:0] test_func;
     test_func = 8'h1;
 endfunction
 
+parameter test_parameter = test_func();
+
 logic [7:0] test_alwayscomb;
 always_comb test_alwayscomb = test_func();
 
+// logic [7:0] test_assign;
+// assign test_assign = test_func();
+
+// wire [7:0] test_wire = test_func();
+
 logic [7:0] test_alwaysff;
 logic clk;
 always_ff @(posedge clk) test_alwaysff <= test_func();
 
-logic [7:0] test_assign;
-assign test_assign = test_func();
-
-wire [7:0] test_wire = test_func();
-
 initial begin
-    #1;
-
     if (test_func() !== 8'h1) begin
         $display("FAILED -- test_func()=%h, expect %h", test_func(), 8'h1);
         $finish;
     end
 
+    if (test_parameter !== test_func()) begin
+        $display("FAILED -- test_parameter=%h, expect %h", test_parameter, test_func());
+        $finish;
+    end
+
+    #1;
+
     if (test_alwayscomb !== test_func()) begin
         $display("FAILED -- test_alwayscomb=%h, expect %h", test_alwayscomb, test_func());
         $finish;
     end
 
-    if (test_assign !== test_func()) begin
-        $display("FAILED -- test_assign=%h, expect %h", test_assign, test_func());
-        $finish;
-    end
+    // if (test_assign !== test_func()) begin
+    //     $display("FAILED -- test_assign=%h, expect %h", test_assign, test_func());
+    //     $finish;
+    // end
 
-    if (test_wire !== test_func()) begin
-        $display("FAILED -- test_wire=%h, expect %h", test_wire, test_func());
-        $finish;
-    end
+    // if (test_wire !== test_func()) begin
+    //     $display("FAILED -- test_wire=%h, expect %h", test_wire, test_func());
+    //     $finish;
+    // end
 
     clk = 0;
     #1;