agent/src/share/classes/sun/jvm/hotspot/runtime/VM.java

rev 3688 : 7054512: Compress class pointers after perm gen removal
Summary: support of compress class pointers in the compilers.
Reviewed-by:

@@ -101,10 +101,11 @@
   private int          objectAlignmentInBytes;
   private int          minObjAlignmentInBytes;
   private int          logMinObjAlignmentInBytes;
   private int          heapWordSize;
   private int          heapOopSize;
+  private int          klassPtrSize;
   private int          oopSize;
   /** This is only present in a non-core build */
   private CodeCache    codeCache;
   /** This is only present in a C1 build */
   private Runtime1     runtime1;

@@ -127,11 +128,11 @@
   private static Type intxType;
   private static Type uintxType;
   private static CIntegerType boolType;
   private Boolean sharingEnabled;
   private Boolean compressedOopsEnabled;
-  private Boolean compressedHeadersEnabled;
+  private Boolean compressedKlassPointersEnabled;
 
   // command line flags supplied to VM - see struct Flag in globals.hpp
   public static final class Flag {
      private String type;
      private String name;

@@ -348,10 +349,16 @@
       // Size info for oops within java objects is fixed
       heapOopSize = (int)getIntSize();
     } else {
       heapOopSize = (int)getOopSize();
     }
+
+    if (isCompressedKlassPointersEnabled()) {
+      klassPtrSize = (int)getIntSize();
+    } else {
+      klassPtrSize = (int)getOopSize(); // same as an oop
+    }
   }
 
   /** This could be used by a reflective runtime system */
   public static void initialize(TypeDataBase db, boolean isBigEndian) {
     if (soleInstance != null) {

@@ -372,12 +379,13 @@
 
     for (Iterator iter = vmInitializedObservers.iterator(); iter.hasNext(); ) {
       ((Observer) iter.next()).update(null, null);
     }
 
-    debugger.putHeapConst(soleInstance.getHeapOopSize(), Universe.getNarrowOopBase(),
-                          Universe.getNarrowOopShift());
+    debugger.putHeapConst(soleInstance.getHeapOopSize(), soleInstance.getKlassPtrSize(), 
+                          Universe.getNarrowOopBase(), Universe.getNarrowOopShift(),
+                          Universe.getNarrowKlassBase(), Universe.getNarrowKlassShift());
   }
 
   /** This is used by the debugging system */
   public static void shutdown() {
     soleInstance = null;

@@ -534,10 +542,14 @@
   }
 
   public int getHeapOopSize() {
     return heapOopSize;
   }
+
+  public int getKlassPtrSize() {
+    return klassPtrSize;
+  }
   /** Utility routine for getting data structure alignment correct */
   public long alignUp(long size, long alignment) {
     return (size + alignment - 1) & ~(alignment - 1);
   }
 

@@ -782,17 +794,17 @@
              (flag.getBool()? Boolean.TRUE: Boolean.FALSE);
     }
     return compressedOopsEnabled.booleanValue();
   }
 
-  public boolean isCompressedHeadersEnabled() {
-    if (compressedHeadersEnabled == null) {
-        Flag flag = getCommandLineFlag("UseCompressedHeaders");
-        compressedHeadersEnabled = (flag == null) ? Boolean.FALSE:
+  public boolean isCompressedKlassPointersEnabled() {
+    if (compressedKlassPointersEnabled == null) {
+        Flag flag = getCommandLineFlag("UseCompressedKlassPointers");
+        compressedKlassPointersEnabled = (flag == null) ? Boolean.FALSE:
              (flag.getBool()? Boolean.TRUE: Boolean.FALSE);
     }
-    return compressedHeadersEnabled.booleanValue();
+    return compressedKlassPointersEnabled.booleanValue();
   }
 
   public int getObjectAlignmentInBytes() {
     if (objectAlignmentInBytes == 0) {
         Flag flag = getCommandLineFlag("ObjectAlignmentInBytes");