9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "gc/shared/barrierSetAssembler.hpp"
26 #include "memory/universe.hpp"
27 #include "utilities/globalDefinitions.hpp"
28
29 bool BarrierSetAssembler::needs_explicit_null_check(intptr_t offset) {
30 // Exception handler checks the nmethod's implicit null checks table
31 // only when this method returns false.
32 #ifdef _LP64
33 if (UseCompressedOops && Universe::narrow_oop_base() != NULL) {
34 assert (Universe::heap() != NULL, "java heap should be initialized");
35 // The first page after heap_base is unmapped and
36 // the 'offset' is equal to [heap_base + offset] for
37 // narrow oop implicit null checks.
38 uintptr_t base = (uintptr_t)Universe::narrow_oop_base();
39 if ((uintptr_t)offset >= base) {
40 // Normalize offset for the next check.
41 offset = (intptr_t)(pointer_delta((void*)offset, (void*)base, 1));
42 }
43 }
44 #endif
45 return offset < 0 || os::vm_page_size() <= offset;
46 }
|
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "gc/shared/barrierSetAssembler.hpp"
26 #include "memory/universe.hpp"
27 #include "utilities/globalDefinitions.hpp"
28
29 bool BarrierSetAssembler::needs_explicit_null_check(intptr_t offset) const {
30 // Exception handler checks the nmethod's implicit null checks table
31 // only when this method returns false.
32 #ifdef _LP64
33 if (UseCompressedOops && Universe::narrow_oop_base() != NULL) {
34 assert (Universe::heap() != NULL, "java heap should be initialized");
35 // The first page after heap_base is unmapped and
36 // the 'offset' is equal to [heap_base + offset] for
37 // narrow oop implicit null checks.
38 uintptr_t base = (uintptr_t)Universe::narrow_oop_base();
39 if ((uintptr_t)offset >= base) {
40 // Normalize offset for the next check.
41 offset = (intptr_t)(pointer_delta((void*)offset, (void*)base, 1));
42 }
43 }
44 #endif
45 return offset < 0 || os::vm_page_size() <= offset;
46 }
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