From 9d2dd782c07575be22d942bcdfc4fefd128289e3 Mon Sep 17 00:00:00 2001
From: Stephen Williams <steve@icarus.com>
Date: Fri, 15 Jun 2007 16:59:24 -0700
Subject: [PATCH] Get offsets right for non-zero and reversed part selects.

Signed-off-by: Stephen Williams <steve@icarus.com>
---
 elab_expr.cc | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/elab_expr.cc b/elab_expr.cc
index 3e730dfec..14a789e87 100644
--- a/elab_expr.cc
+++ b/elab_expr.cc
@@ -1264,8 +1264,14 @@ NetExpr* PEIdent::elaborate_expr_net_idx_up_(Design*des, NetScope*scope,
 	    return ss;
       }
 
-      if (long offset = net->lsi())
-	    base = make_add_expr(base, 0-offset);
+      if (net->msi() > net->lsi()) {
+	    if (long offset = net->lsi())
+		  base = make_add_expr(base, 0-offset);
+      } else {
+	    long vwid = net->lsi() - net->msi() + 1;
+	    long offset = net->msi();
+	    base = make_sub_expr(vwid-offset-wid, base);
+      }
 
       NetESelect*ss = new NetESelect(net, base, wid);
       ss->set_line(*this);