From 0e8d894a354652c6dd361f31818e8b9e625efc77 Mon Sep 17 00:00:00 2001
From: Sebastien Bourdeauducq <sebastien@milkymist.org>
Date: Mon, 5 Dec 2011 22:00:06 +0100
Subject: [PATCH] Variable conversion

---
 migen/fhdl/convtools.py | 15 +++++++++++++++
 migen/fhdl/verilog.py   | 21 ++++++++++++---------
 2 files changed, 27 insertions(+), 9 deletions(-)

diff --git a/migen/fhdl/convtools.py b/migen/fhdl/convtools.py
index bb71ed4fc..3dce8a889 100644
--- a/migen/fhdl/convtools.py
+++ b/migen/fhdl/convtools.py
@@ -73,6 +73,21 @@ def ListTargets(node):
 	else:
 		raise TypeError
 
+def IsVariable(node):
+	if isinstance(node, Signal):
+		return node.variable
+	elif isinstance(node, Slice):
+		return IsVariable(node.value)
+	elif isinstance(node, Cat):
+		arevars = list(map(IsVariable, node.l))
+		r = arevars[0]
+		for x in arevars:
+			if x != r:
+				raise TypeError
+		return r
+	else:
+		raise TypeError
+
 def InsertReset(rst, sl):
 	targets = ListTargets(sl)
 	resetcode = []
diff --git a/migen/fhdl/verilog.py b/migen/fhdl/verilog.py
index a79dfcc5b..6fac3f7f8 100644
--- a/migen/fhdl/verilog.py
+++ b/migen/fhdl/verilog.py
@@ -50,25 +50,28 @@ def Convert(f, outs=set(), ins=set(), name="top", clkname="sys_clk", rstname="sy
 		else:
 			raise TypeError
 	
-	def printnode(level, node):
+	def printnode(level, comb, node):
 		if isinstance(node, Assign):
-			# TODO: variables
-			return "\t"*level + printexpr(node.l) + " <= " + printexpr(node.r) + ";\n"
+			if comb or IsVariable(node.l):
+				assignment = " = "
+			else:
+				assignment = " <= "
+			return "\t"*level + printexpr(node.l) + assignment + printexpr(node.r) + ";\n"
 		elif isinstance(node, StatementList):
-			return "".join(list(map(partial(printnode, level), node.l)))
+			return "".join(list(map(partial(printnode, level, comb), node.l)))
 		elif isinstance(node, If):
 			r = "\t"*level + "if (" + printexpr(node.cond) + ") begin\n"
-			r += printnode(level + 1, node.t)
+			r += printnode(level + 1, comb, node.t)
 			if node.f.l:
 				r += "\t"*level + "end else begin\n"
-				r += printnode(level + 1, node.f)
+				r += printnode(level + 1, comb, node.f)
 			r += "\t"*level + "end\n"
 			return r
 		elif isinstance(node, Case):
 			r = "\t"*level + "case (" + printexpr(node.test) + ")\n"
 			for case in node.cases:
 				r += "\t"*(level + 1) + printexpr(case[0]) + ": begin\n"
-				r += printnode(level + 2, case[1])
+				r += printnode(level + 2, comb, case[1])
 				r += "\t"*(level + 1) + "end\n"
 			r += "\t"*level + "endcase\n"
 			return r
@@ -91,12 +94,12 @@ def Convert(f, outs=set(), ins=set(), name="top", clkname="sys_clk", rstname="sy
 	
 	if f.comb.l:
 		r += "always @(*) begin\n"
-		r += printnode(1, f.comb)
+		r += printnode(1, True, f.comb)
 		r += "end\n\n"
 	
 	if f.sync.l:
 		r += "always @(posedge " + clk + ") begin\n"
-		r += printnode(1, InsertReset(rsts, f.sync))
+		r += printnode(1, False, InsertReset(rsts, f.sync))
 		r += "end\n\n"
 	
 	r += "endmodule\n"