From: Andreas Hansson <andreas.hansson@arm.com>
Date: Tue, 26 May 2015 07:21:40 +0000 (-0400)
Subject: base: Allow multiple interleaved ranges
X-Git-Tag: stable_2015_09_03~22
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=53a360985b5d298e03ed0102d750b2c362ec1d90;p=gem5.git

base: Allow multiple interleaved ranges

This patch changes how the address range calculates intersection such
that a system can have a number of non-overlapping interleaved ranges
without complaining. Without this patch we end up with a panic.
---

diff --git a/src/base/addr_range.hh b/src/base/addr_range.hh
index 2a20863b4..ed0259ff7 100644
--- a/src/base/addr_range.hh
+++ b/src/base/addr_range.hh
@@ -282,26 +282,26 @@ class AddrRange
      */
     bool intersects(const AddrRange& r) const
     {
-        if (!interleaved()) {
-            return _start <= r._end && _end >= r._start;
-        }
-
-        // the current range is interleaved, split the check up in
-        // three cases
+        if (_start > r._end || _end < r._start)
+            // start with the simple case of no overlap at all,
+            // applicable even if we have interleaved ranges
+            return false;
+        else if (!interleaved() && !r.interleaved())
+            // if neither range is interleaved, we are done
+            return true;
+
+        // now it gets complicated, focus on the cases we care about
         if (r.size() == 1)
             // keep it simple and check if the address is within
             // this range
             return contains(r.start());
-        else if (!r.interleaved())
-            // be conservative and ignore the interleaving
-            return _start <= r._end && _end >= r._start;
         else if (mergesWith(r))
             // restrict the check to ranges that belong to the
             // same chunk
             return intlvMatch == r.intlvMatch;
         else
-            panic("Cannot test intersection of interleaved range %s\n",
-                  to_string());
+            panic("Cannot test intersection of %s and %s\n",
+                  to_string(), r.to_string());
     }
 
     /**