From 5cfe47da2bc268fb74e7ccd2afd385d76ed58c7b Mon Sep 17 00:00:00 2001
From: Stephen Williams <steve@icarus.com>
Date: Sat, 4 Oct 2008 21:44:10 -0700
Subject: [PATCH] Don't try to shrink a valid r-vlaue width.

In assignments, the expression width may be defined by the width of
operands, and not that of the l-value. Choose whichever is creater and
set (or pad) the expression to that width.
---
 elaborate.cc | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/elaborate.cc b/elaborate.cc
index 9464b2dcd..59130d660 100644
--- a/elaborate.cc
+++ b/elaborate.cc
@@ -1954,9 +1954,11 @@ NetProc* PAssign::elaborate(Design*des, NetScope*scope) const
 
       } else {
 	    unsigned wid = count_lval_width(lv);
-	    rv->set_width(wid);
-	    rv = pad_to_width(rv, wid);
-	    assert(rv->expr_width() >= wid);
+	    if (wid > rv->expr_width()) {
+		  rv->set_width(wid);
+		  rv = pad_to_width(rv, wid);
+	    }
+	    ivl_assert(*this, rv->expr_width() >= wid);
       }
 
       NetAssign*cur = new NetAssign(lv, rv);