gen/fhdl/instance: First cleanup pass.

litex/gen/fhdl/instance.py

@@ -4,52 +4,69 @@
 # This file is Copyright (c) 2013-2014 Sebastien Bourdeauducq <sb@m-labs.hk>
 # SPDX-License-Identifier: BSD-2-Clause
 
-from migen.fhdl.structure    import *
-from migen.fhdl.verilog      import _printexpr as verilog_printexpr
-from migen.fhdl.specials     import *
+from migen.fhdl.structure import *
+from migen.fhdl.verilog   import _printexpr as verilog_printexpr
+from migen.fhdl.specials  import *
 
 # LiteX Instance Verilog Generation ----------------------------------------------------------------
 
 def _instance_generate_verilog(instance, ns, add_data_file):
     r = instance.of + " "
+
+    # Instance Parameters.
+    # --------------------
     parameters = list(filter(lambda i: isinstance(i, Instance.Parameter), instance.items))
     if parameters:
         r += "#(\n"
-        firstp = True
+        first = True
         for p in parameters:
-            if not firstp:
+            if not first:
                 r += ",\n"
-            firstp = False
+            first = False
             r += "\t." + p.name + "("
+            # Constant.
             if isinstance(p.value, Constant):
                 r += verilog_printexpr(ns, p.value)[0]
+            # Float.
             elif isinstance(p.value, float):
                 r += str(p.value)
+            # Preformatted.
             elif isinstance(p.value, Instance.PreformattedParam):
                 r += p.value
+            # String.
             elif isinstance(p.value, str):
                 r += "\"" + p.value + "\""
             else:
                 raise TypeError
             r += ")"
         r += "\n) "
+
+    # Instance IOs.
+    # -------------
     r += ns.get_name(instance)
-    if parameters: r += " "
+    if parameters:
+        r += " "
     r += "(\n"
-    firstp = True
-    for p in instance.items:
-        if isinstance(p, Instance._IO):
-            name_inst = p.name
-            name_design = verilog_printexpr(ns, p.expr)[0]
-            if not firstp:
+    first = True
+    for io in instance.items:
+        if isinstance(io, Instance._IO):
+            name_inst   = io.name
+            name_design = verilog_printexpr(ns, io.expr)[0]
+            if not first:
                 r += ",\n"
-            firstp = False
+            first = False
             r += "\t." + name_inst + "(" + name_design + ")"
-    if not firstp:
+    if not first:
         r += "\n"
+
+    # Instance Synthesis Directive.
+    # -----------------------------
     if instance.synthesis_directive is not None:
-        synthesis_directive = "/* synthesis {} */".format(instance.synthesis_directive)
-        r += ")" + synthesis_directive + ";\n\n"
+        synthesis_directive = f"/* synthesis {instance.synthesis_directive} */"
+        r += ")" + synthesis_directive + ";\n"
     else:
-        r += ");\n\n"
+        r += ");\n"
+
+    r += "\n"
+
     return r