From f34a3020a6952f4e0066f5abf177100b5620a7eb Mon Sep 17 00:00:00 2001
From: Martin Whitaker <icarus@martin-whitaker.me.uk>
Date: Mon, 11 Apr 2011 22:20:52 +0100
Subject: [PATCH] Fix for lossless width estimation in shift operations.

If the right hand operand of a shift is a signed vector value, it
is coerced to an unsigned value. This needs to be allowed for when
estimating the width expansion caused by a shift in a lossless
expression.
---
 elab_expr.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/elab_expr.cc b/elab_expr.cc
index 7194909a6..3a5ee321a 100644
--- a/elab_expr.cc
+++ b/elab_expr.cc
@@ -625,7 +625,7 @@ unsigned PEBLeftWidth::test_width(Design*des, NetScope*scope, width_mode_t&mode)
             long r_val = LONG_MAX;
             if (r_width < sizeof(long)*8) {
                   r_val = (1L << r_width) - 1L;
-                  if (right_->has_sign())
+                  if ((op_ == 'p') && right_->has_sign())
                         r_val >>= 1;
             }