# HG changeset patch
# User johnc
# Date 1241586935 25200
# Node ID a2957df801a1a718da7726c759367ab0efc6fc26
# Parent  20c6f43950b5c19cf0a9a56ad60967cd43ae5ea5
6833576: G1: assert illegal index, growableArray.hpp:186
Summary: The code that calculates the heap region index for an object address incorrectly used signed arithmetic.
Reviewed-by: jcoomes, ysr

diff -r 20c6f43950b5 -r a2957df801a1 src/share/vm/gc_implementation/g1/g1CollectedHeap.inline.hpp
--- a/src/share/vm/gc_implementation/g1/g1CollectedHeap.inline.hpp	Thu Apr 30 15:07:53 2009 -0700
+++ b/src/share/vm/gc_implementation/g1/g1CollectedHeap.inline.hpp	Tue May 05 22:15:35 2009 -0700
@@ -37,8 +37,9 @@
 inline HeapRegion*
 G1CollectedHeap::heap_region_containing_raw(const void* addr) const {
   assert(_g1_reserved.contains(addr), "invariant");
-  size_t index = ((intptr_t) addr - (intptr_t) _g1_reserved.start())
-                                              >> HeapRegion::LogOfHRGrainBytes;
+  size_t index = pointer_delta(addr, _g1_reserved.start(), 1)
+                                        >> HeapRegion::LogOfHRGrainBytes;
+
   HeapRegion* res = _hrs->at(index);
   assert(res == _hrs->addr_to_region(addr), "sanity");
   return res;