8265711: C1: Intrinsify Class.getModifier method

Reviewed-by: thartmann, kvn

src/hotspot/share/c1/c1_Canonicalizer.cpp

@@ -546,6 +546,22 @@ void Canonicalizer::do_Intrinsic      (Intrinsic*       x) {
     }
     break;
   }
+  case vmIntrinsics::_getModifiers: {
+    assert(x->number_of_arguments() == 1, "wrong type");
+
+    // Optimize for Foo.class.getModifier()
+    InstanceConstant* c = x->argument_at(0)->type()->as_InstanceConstant();
+    if (c != NULL && !c->value()->is_null_object()) {
+      ciType* t = c->value()->java_mirror_type();
+      if (t->is_klass()) {
+        set_constant(t->as_klass()->modifier_flags());
+      } else {
+        assert(t->is_primitive_type(), "should be a primitive type");
+        set_constant(JVM_ACC_ABSTRACT | JVM_ACC_FINAL | JVM_ACC_PUBLIC);
+      }
+    }
+    break;
+  }
   default:
     break;
   }

src/hotspot/share/c1/c1_Compiler.cpp

@@ -150,6 +150,7 @@ bool Compiler::is_intrinsic_supported(const methodHandle& method) {
   case vmIntrinsics::_getClass:
   case vmIntrinsics::_isInstance:
   case vmIntrinsics::_isPrimitive:
+  case vmIntrinsics::_getModifiers:
   case vmIntrinsics::_currentThread:
   case vmIntrinsics::_dabs:
   case vmIntrinsics::_dsqrt:

src/hotspot/share/c1/c1_LIRGenerator.cpp

@@ -1306,6 +1306,34 @@ void LIRGenerator::do_isPrimitive(Intrinsic* x) {
   __ cmove(lir_cond_notEqual, LIR_OprFact::intConst(0), LIR_OprFact::intConst(1), result, T_BOOLEAN);
 }
 
+// Example: Foo.class.getModifiers()
+void LIRGenerator::do_getModifiers(Intrinsic* x) {
+  assert(x->number_of_arguments() == 1, "wrong type");
+
+  LIRItem receiver(x->argument_at(0), this);
+  receiver.load_item();
+  LIR_Opr result = rlock_result(x);
+
+  CodeEmitInfo* info = NULL;
+  if (x->needs_null_check()) {
+    info = state_for(x);
+  }
+
+  LabelObj* L_not_prim = new LabelObj();
+  LabelObj* L_done = new LabelObj();
+
+  LIR_Opr klass = new_register(T_METADATA);
+  // Checking if it's a java mirror of primitive type
+  __ move(new LIR_Address(receiver.result(), java_lang_Class::klass_offset(), T_ADDRESS), klass, info);
+  __ cmp(lir_cond_notEqual, klass, LIR_OprFact::metadataConst(0));
+  __ branch(lir_cond_notEqual, L_not_prim->label());
+  __ move(LIR_OprFact::intConst(JVM_ACC_ABSTRACT | JVM_ACC_FINAL | JVM_ACC_PUBLIC), result);
+  __ branch(lir_cond_always, L_done->label());
+
+  __ branch_destination(L_not_prim->label());
+  __ move(new LIR_Address(klass, in_bytes(Klass::modifier_flags_offset()), T_INT), result);
+  __ branch_destination(L_done->label());
+}
 
 // Example: Thread.currentThread()
 void LIRGenerator::do_currentThread(Intrinsic* x) {
@@ -3125,6 +3153,7 @@ void LIRGenerator::do_Intrinsic(Intrinsic* x) {
   case vmIntrinsics::_Object_init:    do_RegisterFinalizer(x); break;
   case vmIntrinsics::_isInstance:     do_isInstance(x);    break;
   case vmIntrinsics::_isPrimitive:    do_isPrimitive(x);   break;
+  case vmIntrinsics::_getModifiers:   do_getModifiers(x);  break;
   case vmIntrinsics::_getClass:       do_getClass(x);      break;
   case vmIntrinsics::_currentThread:  do_currentThread(x); break;
   case vmIntrinsics::_getObjectSize:  do_getObjectSize(x); break;

src/hotspot/share/c1/c1_LIRGenerator.hpp

@@ -251,6 +251,7 @@ class LIRGenerator: public InstructionVisitor, public BlockClosure {
   void do_RegisterFinalizer(Intrinsic* x);
   void do_isInstance(Intrinsic* x);
   void do_isPrimitive(Intrinsic* x);
+  void do_getModifiers(Intrinsic* x);
   void do_getClass(Intrinsic* x);
   void do_currentThread(Intrinsic* x);
   void do_getObjectSize(Intrinsic* x);

test/hotspot/jtreg/compiler/c1/CanonicalizeGetModifiers.java

@@ -0,0 +1,127 @@
+/*
+ * Copyright (c) 2021, Alibaba Group Holding Limited. All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+/*
+ * @test
+ * @author Yi Yang
+ * @summary Canonicalizes Foo.class.getModifiers() with interpreter mode
+ * @library /test/lib
+ * @run main/othervm -Xint
+ *                   -XX:CompileCommand=compileonly,*CanonicalizeGetModifiers.test
+ *                   compiler.c1.CanonicalizeGetModifiers
+ */
+
+/*
+ * @test
+ * @author Yi Yang
+ * @summary Canonicalizes Foo.class.getModifiers() with C1 mode
+ * @requires vm.compiler1.enabled
+ * @library /test/lib
+ * @run main/othervm -XX:TieredStopAtLevel=1 -XX:+TieredCompilation
+ *                   -XX:CompileCommand=compileonly,*CanonicalizeGetModifiers.test
+ *                   compiler.c1.CanonicalizeGetModifiers
+ */
+
+/*
+ * @test
+ * @author Yi Yang
+ * @summary Canonicalizes Foo.class.getModifiers() with C2 mode
+ * @requires vm.compiler2.enabled
+ * @library /test/lib
+ * @run main/othervm -XX:-TieredCompilation
+ *                   -XX:CompileCommand=compileonly,*CanonicalizeGetModifiers.test
+ *                   compiler.c1.CanonicalizeGetModifiers
+ */
+
+package compiler.c1;
+
+import java.lang.reflect.Modifier;
+
+import jdk.test.lib.Asserts;
+
+public class CanonicalizeGetModifiers {
+    public static class T1 {
+    }
+
+    public static final class T2 {
+    }
+
+    private static class T3 {
+    }
+
+    protected static class T4 {
+    }
+
+    class T5 {
+    }
+
+    interface T6 {
+    }
+
+    static void test(Class poison) {
+        Asserts.assertEQ(CanonicalizeGetModifiers.class.getModifiers(), Modifier.PUBLIC);
+        Asserts.assertEQ(T1.class.getModifiers(), Modifier.PUBLIC | Modifier.STATIC);
+        Asserts.assertEQ(T2.class.getModifiers(), Modifier.PUBLIC | Modifier.FINAL | Modifier.STATIC);
+        Asserts.assertEQ(T3.class.getModifiers(), Modifier.PRIVATE | Modifier.STATIC);
+        Asserts.assertEQ(T4.class.getModifiers(), Modifier.PROTECTED | Modifier.STATIC);
+        Asserts.assertEQ(new CanonicalizeGetModifiers().new T5().getClass().getModifiers(), 0/* NONE */);
+        Asserts.assertEQ(T6.class.getModifiers(), Modifier.ABSTRACT | Modifier.STATIC | Modifier.INTERFACE);
+
+        Asserts.assertEQ(int.class.getModifiers(), Modifier.PUBLIC | Modifier.ABSTRACT | Modifier.FINAL);
+        Asserts.assertEQ(long.class.getModifiers(), Modifier.PUBLIC | Modifier.ABSTRACT | Modifier.FINAL);
+        Asserts.assertEQ(double.class.getModifiers(), Modifier.PUBLIC | Modifier.ABSTRACT | Modifier.FINAL);
+        Asserts.assertEQ(float.class.getModifiers(), Modifier.PUBLIC | Modifier.ABSTRACT | Modifier.FINAL);
+        Asserts.assertEQ(char.class.getModifiers(), Modifier.PUBLIC | Modifier.ABSTRACT | Modifier.FINAL);
+        Asserts.assertEQ(byte.class.getModifiers(), Modifier.PUBLIC | Modifier.ABSTRACT | Modifier.FINAL);
+        Asserts.assertEQ(short.class.getModifiers(), Modifier.PUBLIC | Modifier.ABSTRACT | Modifier.FINAL);
+        Asserts.assertEQ(void.class.getModifiers(), Modifier.PUBLIC | Modifier.ABSTRACT | Modifier.FINAL);
+        Asserts.assertEQ(int[].class.getModifiers(), Modifier.PUBLIC | Modifier.ABSTRACT | Modifier.FINAL);
+        Asserts.assertEQ(long[].class.getModifiers(), Modifier.PUBLIC | Modifier.ABSTRACT | Modifier.FINAL);
+        Asserts.assertEQ(double[].class.getModifiers(), Modifier.PUBLIC | Modifier.ABSTRACT | Modifier.FINAL);
+        Asserts.assertEQ(float[].class.getModifiers(), Modifier.PUBLIC | Modifier.ABSTRACT | Modifier.FINAL);
+        Asserts.assertEQ(char[].class.getModifiers(), Modifier.PUBLIC | Modifier.ABSTRACT | Modifier.FINAL);
+        Asserts.assertEQ(byte[].class.getModifiers(), Modifier.PUBLIC | Modifier.ABSTRACT | Modifier.FINAL);
+        Asserts.assertEQ(short[].class.getModifiers(), Modifier.PUBLIC | Modifier.ABSTRACT | Modifier.FINAL);
+        Asserts.assertEQ(Object[].class.getModifiers(), Modifier.PUBLIC | Modifier.ABSTRACT | Modifier.FINAL);
+        Asserts.assertEQ(CanonicalizeGetModifiers[].class.getModifiers(), Modifier.PUBLIC | Modifier.ABSTRACT | Modifier.FINAL);
+
+        Asserts.assertEQ(new CanonicalizeGetModifiers().getClass().getModifiers(), Modifier.PUBLIC);
+        Asserts.assertEQ(new T1().getClass().getModifiers(), Modifier.PUBLIC | Modifier.STATIC);
+        Asserts.assertEQ(new T2().getClass().getModifiers(), Modifier.PUBLIC | Modifier.FINAL | Modifier.STATIC);
+        Asserts.assertEQ(new T3().getClass().getModifiers(), Modifier.PRIVATE | Modifier.STATIC);
+        Asserts.assertEQ(new T4().getClass().getModifiers(), Modifier.PROTECTED | Modifier.STATIC);
+        try {
+            // null_check
+            poison.getModifiers();
+        } catch(NullPointerException npe) {
+            // got it!
+        }
+    }
+
+    public static void main(String... args) {
+        for (int i = 0; i < 10_000; i++) {
+            test(i == 9999 ? null : CanonicalizeGetModifiers.class);
+        }
+    }
+}