diff --git a/src/hotspot/share/jvmci/jvmciCodeInstaller.cpp b/src/hotspot/share/jvmci/jvmciCodeInstaller.cpp
index 6bca2aa644e..dc3eecd5791 100644
--- a/src/hotspot/share/jvmci/jvmciCodeInstaller.cpp
+++ b/src/hotspot/share/jvmci/jvmciCodeInstaller.cpp
@@ -343,6 +343,7 @@ narrowKlass CodeInstaller::record_narrow_metadata_reference(CodeSection* section
int index = _oop_recorder->find_index(klass);
section->relocate(dest, metadata_Relocation::spec(index));
JVMCI_event_3("narrowKlass[%d of %d] = %s", index, _oop_recorder->metadata_count(), klass->name()->as_C_string());
+ guarantee(CompressedKlassPointers::is_encodable(klass), "klass cannot be compressed: %s", klass->external_name());
return CompressedKlassPointers::encode(klass);
}
#endif
diff --git a/src/jdk.internal.vm.ci/share/classes/jdk/vm/ci/hotspot/DirectHotSpotObjectConstantImpl.java b/src/jdk.internal.vm.ci/share/classes/jdk/vm/ci/hotspot/DirectHotSpotObjectConstantImpl.java
index cc553a39f89..8385aaa6560 100644
--- a/src/jdk.internal.vm.ci/share/classes/jdk/vm/ci/hotspot/DirectHotSpotObjectConstantImpl.java
+++ b/src/jdk.internal.vm.ci/share/classes/jdk/vm/ci/hotspot/DirectHotSpotObjectConstantImpl.java
@@ -51,13 +51,17 @@ final class DirectHotSpotObjectConstantImpl extends HotSpotObjectConstantImpl {
@Override
public JavaConstant compress() {
- assert !compressed;
+ if (compressed) {
+ throw new IllegalArgumentException("already compressed: " + this);
+ }
return new DirectHotSpotObjectConstantImpl(object, true);
}
@Override
public JavaConstant uncompress() {
- assert compressed;
+ if (!compressed) {
+ throw new IllegalArgumentException("not compressed: " + this);
+ }
return new DirectHotSpotObjectConstantImpl(object, false);
}
diff --git a/src/jdk.internal.vm.ci/share/classes/jdk/vm/ci/hotspot/HotSpotCompressedNullConstant.java b/src/jdk.internal.vm.ci/share/classes/jdk/vm/ci/hotspot/HotSpotCompressedNullConstant.java
index 7c6d94bba99..0becdf29976 100644
--- a/src/jdk.internal.vm.ci/share/classes/jdk/vm/ci/hotspot/HotSpotCompressedNullConstant.java
+++ b/src/jdk.internal.vm.ci/share/classes/jdk/vm/ci/hotspot/HotSpotCompressedNullConstant.java
@@ -51,9 +51,14 @@ public final class HotSpotCompressedNullConstant implements JavaConstant, HotSpo
return true;
}
+ @Override
+ public boolean isCompressible() {
+ return false;
+ }
+
@Override
public Constant compress() {
- throw new IllegalArgumentException();
+ throw new IllegalArgumentException("not compressible");
}
@Override
diff --git a/src/jdk.internal.vm.ci/share/classes/jdk/vm/ci/hotspot/HotSpotConstant.java b/src/jdk.internal.vm.ci/share/classes/jdk/vm/ci/hotspot/HotSpotConstant.java
index ee4cb7bb397..e0ae6b4c881 100644
--- a/src/jdk.internal.vm.ci/share/classes/jdk/vm/ci/hotspot/HotSpotConstant.java
+++ b/src/jdk.internal.vm.ci/share/classes/jdk/vm/ci/hotspot/HotSpotConstant.java
@@ -25,13 +25,34 @@ package jdk.vm.ci.hotspot;
import jdk.vm.ci.meta.Constant;
/**
- * Marker interface for hotspot specific constants.
+ * A value in a space managed by Hotspot (e.g. heap or metaspace).
+ * Some of these values can be referenced with a compressed pointer
+ * instead of a full word-sized pointer.
*/
public interface HotSpotConstant extends Constant {
+ /**
+ * Determines if this constant is compressed.
+ */
boolean isCompressed();
+ /**
+ * Determines if this constant is compressible.
+ */
+ boolean isCompressible();
+
+ /**
+ * Gets a compressed version of this uncompressed constant.
+ *
+ * @throws IllegalArgumentException if this constant is not compressible
+ */
Constant compress();
+ /**
+ * Gets an uncompressed version of this compressed constant.
+ *
+ * @throws IllegalArgumentException if this is an uncompressed constant
+ * or this constant is not compressible
+ */
Constant uncompress();
}
diff --git a/src/jdk.internal.vm.ci/share/classes/jdk/vm/ci/hotspot/HotSpotMetaspaceConstantImpl.java b/src/jdk.internal.vm.ci/share/classes/jdk/vm/ci/hotspot/HotSpotMetaspaceConstantImpl.java
index b819eaf7484..358441d0b22 100644
--- a/src/jdk.internal.vm.ci/share/classes/jdk/vm/ci/hotspot/HotSpotMetaspaceConstantImpl.java
+++ b/src/jdk.internal.vm.ci/share/classes/jdk/vm/ci/hotspot/HotSpotMetaspaceConstantImpl.java
@@ -43,6 +43,9 @@ final class HotSpotMetaspaceConstantImpl implements HotSpotMetaspaceConstant, VM
private HotSpotMetaspaceConstantImpl(MetaspaceObject metaspaceObject, boolean compressed) {
this.metaspaceObject = metaspaceObject;
this.compressed = compressed;
+ if (compressed && !canBeStoredInCompressibleMetaSpace()) {
+ throw new IllegalArgumentException("constant cannot be compressed: " + metaspaceObject);
+ }
}
@Override
@@ -83,9 +86,28 @@ final class HotSpotMetaspaceConstantImpl implements HotSpotMetaspaceConstant, VM
return compressed;
}
+ @Override
+ public boolean isCompressible() {
+ if (compressed) {
+ return false;
+ }
+ return canBeStoredInCompressibleMetaSpace();
+ }
+
+ private boolean canBeStoredInCompressibleMetaSpace() {
+ if (metaspaceObject instanceof HotSpotResolvedJavaType t && !t.isArray()) {
+ // As of JDK-8338526, interface and abstract types are not stored
+ // in compressible metaspace.
+ return !t.isInterface() && !t.isAbstract();
+ }
+ return true;
+ }
+
@Override
public Constant compress() {
- assert !isCompressed();
+ if (compressed) {
+ throw new IllegalArgumentException("already compressed: " + this);
+ }
HotSpotMetaspaceConstantImpl res = HotSpotMetaspaceConstantImpl.forMetaspaceObject(metaspaceObject, true);
assert res.isCompressed();
return res;
@@ -93,7 +115,9 @@ final class HotSpotMetaspaceConstantImpl implements HotSpotMetaspaceConstant, VM
@Override
public Constant uncompress() {
- assert isCompressed();
+ if (!compressed) {
+ throw new IllegalArgumentException("not compressed: " + this);
+ }
HotSpotMetaspaceConstantImpl res = HotSpotMetaspaceConstantImpl.forMetaspaceObject(metaspaceObject, false);
assert !res.isCompressed();
return res;
diff --git a/src/jdk.internal.vm.ci/share/classes/jdk/vm/ci/hotspot/HotSpotObjectConstantImpl.java b/src/jdk.internal.vm.ci/share/classes/jdk/vm/ci/hotspot/HotSpotObjectConstantImpl.java
index 443673a8783..e4a77daf0d4 100644
--- a/src/jdk.internal.vm.ci/share/classes/jdk/vm/ci/hotspot/HotSpotObjectConstantImpl.java
+++ b/src/jdk.internal.vm.ci/share/classes/jdk/vm/ci/hotspot/HotSpotObjectConstantImpl.java
@@ -52,6 +52,11 @@ abstract class HotSpotObjectConstantImpl implements HotSpotObjectConstant {
return compressed;
}
+ @Override
+ public boolean isCompressible() {
+ return !compressed;
+ }
+
@Override
public abstract JavaConstant compress();
diff --git a/src/jdk.internal.vm.ci/share/classes/jdk/vm/ci/hotspot/IndirectHotSpotObjectConstantImpl.java b/src/jdk.internal.vm.ci/share/classes/jdk/vm/ci/hotspot/IndirectHotSpotObjectConstantImpl.java
index 33c6fde3b18..fe268e90476 100644
--- a/src/jdk.internal.vm.ci/share/classes/jdk/vm/ci/hotspot/IndirectHotSpotObjectConstantImpl.java
+++ b/src/jdk.internal.vm.ci/share/classes/jdk/vm/ci/hotspot/IndirectHotSpotObjectConstantImpl.java
@@ -164,13 +164,17 @@ final class IndirectHotSpotObjectConstantImpl extends HotSpotObjectConstantImpl
@Override
public JavaConstant compress() {
- assert !compressed;
+ if (compressed) {
+ throw new IllegalArgumentException("already compressed: " + this);
+ }
return new IndirectHotSpotObjectConstantImpl(this, true);
}
@Override
public JavaConstant uncompress() {
- assert compressed;
+ if (!compressed) {
+ throw new IllegalArgumentException("not compressed: " + this);
+ }
return new IndirectHotSpotObjectConstantImpl(this, false);
}