src/java.base/share/classes/java/lang/invoke/InvokerBytecodeGenerator.java

rev 49071 : 8198888: Reduce string allocation churn in InvokerBytecodeGenerator
Reviewed-by: psandoz, plevart

*** 91,100 ****
--- 91,104 ----
  
      /** ASM bytecode generation. */
      private ClassWriter cw;
      private MethodVisitor mv;
  
+     /** Single element internal class name lookup cache. */
+     private Class<?> lastClass;
+     private String lastInternalName;
+ 
      private static final MemberName.Factory MEMBERNAME_FACTORY = MemberName.getFactory();
      private static final Class<?> HOST_CLASS = LambdaForm.class;
  
      /** Main constructor; other constructors delegate to this one. */
      private InvokerBytecodeGenerator(LambdaForm lambdaForm, int localsMapSize,
*** 600,616 ****
              throw new InternalError("unknown return type: " + type);
          }
          mv.visitInsn(opcode);
      }
  
!     private static String getInternalName(Class<?> c) {
          if (c == Object.class)             return OBJ;
          else if (c == Object[].class)      return OBJARY;
          else if (c == Class.class)         return CLS;
          else if (c == MethodHandle.class)  return MH;
          assert(VerifyAccess.isTypeVisible(c, Object.class)) : c.getName();
!         return c.getName().replace('.', '/');
      }
  
      private static MemberName resolveFrom(String name, MethodType type, Class<?> holder) {
          MemberName member = new MemberName(holder, name, type, REF_invokeStatic);
          MemberName resolvedMember = MemberName.getFactory().resolveOrNull(REF_invokeStatic, member, holder);
--- 604,625 ----
              throw new InternalError("unknown return type: " + type);
          }
          mv.visitInsn(opcode);
      }
  
!     private String getInternalName(Class<?> c) {
          if (c == Object.class)             return OBJ;
          else if (c == Object[].class)      return OBJARY;
          else if (c == Class.class)         return CLS;
          else if (c == MethodHandle.class)  return MH;
          assert(VerifyAccess.isTypeVisible(c, Object.class)) : c.getName();
! 
!         if (c == lastClass) {
!             return lastInternalName;
!         }
!         lastClass = c;
!         return lastInternalName = c.getName().replace('.', '/');
      }
  
      private static MemberName resolveFrom(String name, MethodType type, Class<?> holder) {
          MemberName member = new MemberName(holder, name, type, REF_invokeStatic);
          MemberName resolvedMember = MemberName.getFactory().resolveOrNull(REF_invokeStatic, member, holder);