RFR (S) 8150669: C1 intrinsic for Class.isPrimitive

[Vladimir Ivanov]

>   http://cr.openjdk.java.net/~shade/8150669/webrev.02/

Overall, looks good.

+      ciType* t = c->value()->as_instance()->java_mirror_type();

as_instance() is redundant: InstanceConstant::value() already produces 
ciInstance:

class InstanceConstant: public InstanceType {
   ciInstance* value() const                      { return _value; }


+      set_constant(t->is_klass() ? 0 : 1);

I'd prefer to see ciType::is_primitive_type() instead which is more 
readable.

class ciType : public ciMetadata {
...
   // Returns true if this is not a klass or array (i.e., not a 
reference type).
   bool is_primitive_type() const            { return basic_type() != 
T_OBJECT && basic_type() != T_ARRAY; }


I have a general question: why did you decide to intrinsify the method 
into a native call? Class::is_primitive looks pretty trivial to 
translate it right into machine code:
   bool java_lang_Class::is_primitive(oop java_class) {
     bool is_primitive = (java_class->metadata_field(_klass_offset) == 
NULL);
...
     return is_primitive;
   }

Best regards,
Vladimir Ivanov