fix sun.misc.Unsafe.getLongVolatile for static fields on 32-bit platforms

The existing code did not handle static field lookups for
synchronization on 32-bit systems, which is necessary because such
systems generally don't support atomic operations on 64-bit values.

src/classpath-openjdk.cpp

@@ -2292,11 +2292,28 @@ fieldForOffsetInClass(Thread* t, object c, unsigned offset)
 object
 fieldForOffset(Thread* t, object o, unsigned offset)
 {
-  object field = fieldForOffsetInClass(t, objectClass(t, o), offset);
+  object c = objectClass(t, o);
-  if (field) {
+  if (classVmFlags(t, c) & SingletonFlag) {
-    return field;
+    c = singletonObject(t, o, 0);
-  } else {
+    object table = classFieldTable(t, c);
+    if (table) {
+      for (unsigned i = 0; i < objectArrayLength(t, table); ++i) {
+        object field = objectArrayBody(t, table, i);
+        if ((fieldFlags(t, field) & ACC_STATIC)
+            and fieldOffset(t, field) == offset)
+        {
+          return field;
+        }
+      }
+    }
     abort(t);
+  } else {
+    object field = fieldForOffsetInClass(t, c, offset);
+    if (field) {
+      return field;
+    } else {
+      abort(t);
+    }
   }
 }
 

src/machine.cpp

@@ -1128,7 +1128,7 @@ parseFieldTable(Thread* t, Stream& s, object class_, object pool)
 
   unsigned count = s.read2();
   if (count) {
-    unsigned staticOffset = BytesPerWord * 2;
+    unsigned staticOffset = BytesPerWord * 3;
     unsigned staticCount = 0;
   
     object fieldTable = makeArray(t, count);
@@ -1242,7 +1242,10 @@ parseFieldTable(Thread* t, Stream& s, object class_, object pool)
       uint8_t* body = reinterpret_cast<uint8_t*>
         (&singletonBody(t, staticTable, 0));
 
-      for (unsigned i = 0, offset = 0; i < staticCount; ++i) {
+      memcpy(body, &class_, BytesPerWord);
+      singletonMarkObject(t, staticTable, 0);
+
+      for (unsigned i = 0, offset = BytesPerWord; i < staticCount; ++i) {
         unsigned size = fieldSize(t, RUNTIME_ARRAY_BODY(staticTypes)[i]);
         while (offset % size) {
           ++ offset;