6420645: Create a vm that uses compressed oops for up to 32gb heapsizes

Summary: Compressed oops in instances, arrays, and headers. Code contributors are coleenp, phh, never, swamyv
Reviewed-by: jmasa, kamg, acorn, tbell, kvn, rasbold

3 files changed, 75 insertions, 27 deletions

diff --git a/src/share/vm/prims/jni.cpp b/src/share/vm/prims/jni.cpp
index 6f31afc98..91fb8cb3c 100644
--- a/src/share/vm/prims/jni.cpp
+++ b/src/share/vm/prims/jni.cpp
@@ -135,7 +135,10 @@ intptr_t jfieldIDWorkaround::encode_klass_hash(klassOop k, intptr_t offset) {
   if (offset <= small_offset_mask) {
     klassOop field_klass = k;
     klassOop super_klass = Klass::cast(field_klass)->super();
-    while (instanceKlass::cast(super_klass)->contains_field_offset(offset)) {
+    // With compressed oops the most super class with nonstatic fields would
+    // be the owner of fields embedded in the header.
+    while (instanceKlass::cast(super_klass)->has_nonstatic_fields() &&
+           instanceKlass::cast(super_klass)->contains_field_offset(offset)) {
       field_klass = super_klass;   // super contains the field also
       super_klass = Klass::cast(field_klass)->super();
     }
diff --git a/src/share/vm/prims/jvmtiTagMap.cpp b/src/share/vm/prims/jvmtiTagMap.cpp
index 23e46ede8..30d9fee46 100644
--- a/src/share/vm/prims/jvmtiTagMap.cpp
+++ b/src/share/vm/prims/jvmtiTagMap.cpp
@@ -2662,6 +2662,7 @@ class SimpleRootsClosure : public OopClosure {
     _continue = CallbackInvoker::report_simple_root(kind, o);
 
   }
+  virtual void do_oop(narrowOop* obj_p) { ShouldNotReachHere(); }
 };
 
 // A supporting closure used to process JNI locals
@@ -2704,6 +2705,7 @@ class JNILocalRootsClosure : public OopClosure {
     // invoke the callback
     _continue = CallbackInvoker::report_jni_local_root(_thread_tag, _tid, _depth, _method, o);
   }
+  virtual void do_oop(narrowOop* obj_p) { ShouldNotReachHere(); }
 };
 
 
@@ -2878,9 +2880,11 @@ inline bool VM_HeapWalkOperation::iterate_over_type_array(oop o) {
 }
 
 // verify that a static oop field is in range
-static inline bool verify_static_oop(instanceKlass* ik, oop* obj_p) {
-  oop* start = ik->start_of_static_fields();
-  oop* end = start + ik->static_oop_field_size();
+static inline bool verify_static_oop(instanceKlass* ik,
+                                     klassOop k, int offset) {
+  address obj_p = (address)k + offset;
+  address start = (address)ik->start_of_static_fields();
+  address end = start + (ik->static_oop_field_size() * heapOopSize);
   assert(end >= start, "sanity check");
 
   if (obj_p >= start && obj_p < end) {
@@ -2981,10 +2985,8 @@ inline bool VM_HeapWalkOperation::iterate_over_class(klassOop k) {
       ClassFieldDescriptor* field = field_map->field_at(i);
       char type = field->field_type();
       if (!is_primitive_field_type(type)) {
-        address addr = (address)k + field->field_offset();
-        oop* f = (oop*)addr;
-        assert(verify_static_oop(ik, f), "sanity check");
-        oop fld_o = *f;
+        oop fld_o = k->obj_field(field->field_offset());
+        assert(verify_static_oop(ik, k, field->field_offset()), "sanity check");
         if (fld_o != NULL) {
           int slot = field->field_index();
           if (!CallbackInvoker::report_static_field_reference(mirror, fld_o, slot)) {
@@ -3026,9 +3028,7 @@ inline bool VM_HeapWalkOperation::iterate_over_object(oop o) {
     ClassFieldDescriptor* field = field_map->field_at(i);
     char type = field->field_type();
     if (!is_primitive_field_type(type)) {
-      address addr = (address)o + field->field_offset();
-      oop* f = (oop*)addr;
-      oop fld_o = *f;
+      oop fld_o = o->obj_field(field->field_offset());
       if (fld_o != NULL) {
         // reflection code may have a reference to a klassOop.
         // - see sun.reflect.UnsafeStaticFieldAccessorImpl and sun.misc.Unsafe
diff --git a/src/share/vm/prims/unsafe.cpp b/src/share/vm/prims/unsafe.cpp
index adea25098..899a99296 100644
--- a/src/share/vm/prims/unsafe.cpp
+++ b/src/share/vm/prims/unsafe.cpp
@@ -100,7 +100,7 @@ inline void* index_oop_from_field_offset_long(oop p, jlong field_offset) {
     assert(byte_offset >= 0 && byte_offset <= (jlong)MAX_OBJECT_SIZE, "sane offset");
     if (byte_offset == (jint)byte_offset) {
       void* ptr_plus_disp = (address)p + byte_offset;
-      assert((void*)p->obj_field_addr((jint)byte_offset) == ptr_plus_disp,
+      assert((void*)p->obj_field_addr<oop>((jint)byte_offset) == ptr_plus_disp,
              "raw [ptr+disp] must be consistent with oop::field_base");
     }
   }
@@ -146,13 +146,36 @@ jint Unsafe_invocation_key_to_method_slot(jint key) {
   *(volatile type_name*)index_oop_from_field_offset_long(p, offset) = x; \
   OrderAccess::fence();
 
+// Macros for oops that check UseCompressedOops
+
+#define GET_OOP_FIELD(obj, offset, v) \
+  oop p = JNIHandles::resolve(obj);   \
+  oop v;                              \
+  if (UseCompressedOops) {            \
+    narrowOop n = *(narrowOop*)index_oop_from_field_offset_long(p, offset); \
+    v = oopDesc::decode_heap_oop(n);                                \
+  } else {                            \
+    v = *(oop*)index_oop_from_field_offset_long(p, offset);                 \
+  }
+
+#define GET_OOP_FIELD_VOLATILE(obj, offset, v) \
+  oop p = JNIHandles::resolve(obj);   \
+  volatile oop v;                     \
+  if (UseCompressedOops) {            \
+    volatile narrowOop n = *(volatile narrowOop*)index_oop_from_field_offset_long(p, offset); \
+    v = oopDesc::decode_heap_oop(n);                               \
+  } else {                            \
+    v = *(volatile oop*)index_oop_from_field_offset_long(p, offset);       \
+  }
+
+
 // Get/SetObject must be special-cased, since it works with handles.
 
 // The xxx140 variants for backward compatibility do not allow a full-width offset.
 UNSAFE_ENTRY(jobject, Unsafe_GetObject140(JNIEnv *env, jobject unsafe, jobject obj, jint offset))
   UnsafeWrapper("Unsafe_GetObject");
   if (obj == NULL)  THROW_0(vmSymbols::java_lang_NullPointerException());
-  GET_FIELD(obj, offset, oop, v);
+  GET_OOP_FIELD(obj, offset, v)
   return JNIHandles::make_local(env, v);
 UNSAFE_END
 
@@ -162,11 +185,21 @@ UNSAFE_ENTRY(void, Unsafe_SetObject140(JNIEnv *env, jobject unsafe, jobject obj,
   oop x = JNIHandles::resolve(x_h);
   //SET_FIELD(obj, offset, oop, x);
   oop p = JNIHandles::resolve(obj);
-  if (x != NULL) {
-    // If there is a heap base pointer, we are obliged to emit a store barrier.
-    oop_store((oop*)index_oop_from_field_offset_long(p, offset), x);
+  if (UseCompressedOops) {
+    if (x != NULL) {
+      // If there is a heap base pointer, we are obliged to emit a store barrier.
+      oop_store((narrowOop*)index_oop_from_field_offset_long(p, offset), x);
+    } else {
+      narrowOop n = oopDesc::encode_heap_oop_not_null(x);
+      *(narrowOop*)index_oop_from_field_offset_long(p, offset) = n;
+    }
   } else {
-    *(oop*)index_oop_from_field_offset_long(p, offset) = x;
+    if (x != NULL) {
+      // If there is a heap base pointer, we are obliged to emit a store barrier.
+      oop_store((oop*)index_oop_from_field_offset_long(p, offset), x);
+    } else {
+      *(oop*)index_oop_from_field_offset_long(p, offset) = x;
+    }
   }
 UNSAFE_END
 
@@ -175,7 +208,7 @@ UNSAFE_END
 // That is, it should be in the range [0, MAX_OBJECT_SIZE].
 UNSAFE_ENTRY(jobject, Unsafe_GetObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset))
   UnsafeWrapper("Unsafe_GetObject");
-  GET_FIELD(obj, offset, oop, v);
+  GET_OOP_FIELD(obj, offset, v)
   return JNIHandles::make_local(env, v);
 UNSAFE_END
 
@@ -183,12 +216,16 @@ UNSAFE_ENTRY(void, Unsafe_SetObject(JNIEnv *env, jobject unsafe, jobject obj, jl
   UnsafeWrapper("Unsafe_SetObject");
   oop x = JNIHandles::resolve(x_h);
   oop p = JNIHandles::resolve(obj);
-  oop_store((oop*)index_oop_from_field_offset_long(p, offset), x);
+  if (UseCompressedOops) {
+    oop_store((narrowOop*)index_oop_from_field_offset_long(p, offset), x);
+  } else {
+    oop_store((oop*)index_oop_from_field_offset_long(p, offset), x);
+  }
 UNSAFE_END
 
 UNSAFE_ENTRY(jobject, Unsafe_GetObjectVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset))
   UnsafeWrapper("Unsafe_GetObjectVolatile");
-  GET_FIELD_VOLATILE(obj, offset, oop, v);
+  GET_OOP_FIELD_VOLATILE(obj, offset, v)
   return JNIHandles::make_local(env, v);
 UNSAFE_END
 
@@ -196,7 +233,11 @@ UNSAFE_ENTRY(void, Unsafe_SetObjectVolatile(JNIEnv *env, jobject unsafe, jobject
   UnsafeWrapper("Unsafe_SetObjectVolatile");
   oop x = JNIHandles::resolve(x_h);
   oop p = JNIHandles::resolve(obj);
-  oop_store((oop*)index_oop_from_field_offset_long(p, offset), x);
+  if (UseCompressedOops) {
+    oop_store((narrowOop*)index_oop_from_field_offset_long(p, offset), x);
+  } else {
+    oop_store((oop*)index_oop_from_field_offset_long(p, offset), x);
+  }
   OrderAccess::fence();
 UNSAFE_END
 
@@ -311,7 +352,11 @@ UNSAFE_ENTRY(void, Unsafe_SetOrderedObject(JNIEnv *env, jobject unsafe, jobject
   UnsafeWrapper("Unsafe_SetOrderedObject");
   oop x = JNIHandles::resolve(x_h);
   oop p = JNIHandles::resolve(obj);
-  oop_store((oop*)index_oop_from_field_offset_long(p, offset), x);
+  if (UseCompressedOops) {
+    oop_store((narrowOop*)index_oop_from_field_offset_long(p, offset), x);
+  } else {
+    oop_store((oop*)index_oop_from_field_offset_long(p, offset), x);
+  }
   OrderAccess::fence();
 UNSAFE_END
 
@@ -647,7 +692,7 @@ static void getBaseAndScale(int& base, int& scale, jclass acls, TRAPS) {
     THROW(vmSymbols::java_lang_InvalidClassException());
   } else if (k->klass_part()->oop_is_objArray()) {
     base  = arrayOopDesc::base_offset_in_bytes(T_OBJECT);
-    scale = oopSize;
+    scale = heapOopSize;
   } else if (k->klass_part()->oop_is_typeArray()) {
     typeArrayKlass* tak = typeArrayKlass::cast(k);
     base  = tak->array_header_in_bytes();
@@ -845,11 +890,11 @@ UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSwapObject(JNIEnv *env, jobject unsafe,
   oop x = JNIHandles::resolve(x_h);
   oop e = JNIHandles::resolve(e_h);
   oop p = JNIHandles::resolve(obj);
-  intptr_t* addr = (intptr_t *)index_oop_from_field_offset_long(p, offset);
-  intptr_t res = Atomic::cmpxchg_ptr((intptr_t)x, addr, (intptr_t)e);
-  jboolean success  = (res == (intptr_t)e);
+  HeapWord* addr = (HeapWord *)index_oop_from_field_offset_long(p, offset);
+  oop res = oopDesc::atomic_compare_exchange_oop(x, addr, e);
+  jboolean success  = (res == e);
   if (success)
-    update_barrier_set((oop*)addr, x);
+    update_barrier_set((void*)addr, x);
   return success;
 UNSAFE_END