RFR(XXS): 8231025: Incorrect method tag offset for big endian platform

[Markus Gronlund]

Greetings,

Can I please have a review for the following changeset, description in bug.

Bug: https://bugs.openjdk.java.net/browse/JDK-8231025

Change set:
diff -r caa25ab47aca src/hotspot/share/jfr/support/jfrTraceIdExtension.hpp
--- a/src/hotspot/share/jfr/support/jfrTraceIdExtension.hpp Sat Sep 14 14:40:09 2019 +0200
+++ b/src/hotspot/share/jfr/support/jfrTraceIdExtension.hpp Sat Sep 14 17:52:10 2019 +0200
@@ -26,6 +26,7 @@
 #define SHARE_JFR_SUPPORT_JFRTRACEIDEXTENSION_HPP

 #include "jfr/recorder/checkpoint/types/traceid/jfrTraceId.hpp"
+#include "utilities/macros.hpp"

 #define DEFINE_TRACE_ID_FIELD mutable traceid _trace_id

@@ -59,10 +60,19 @@
   }

   jbyte* flags_addr() const {
+#ifdef VM_LITTLE_ENDIAN
     return (jbyte*)&_flags;
+#else
+ return ((jbyte*)&_flags) + 1;
+#endif
   }
+
   jbyte* meta_addr() const {
- return ((jbyte*)&_flags) + 1;
+#ifdef VM_LITTLE_ENDIAN
+ return (jbyte*)(&_flags) + 1;
+#else
+ return (jbyte*)&_flags;
+#endif
   }
 };

Thank you
Markus