src/hotspot/share/opto/mulnode.cpp

@@ -195,10 +195,22 @@
      const Type *zero = add_id();        // The multiplicative zero
      if( t1->higher_equal( zero ) ) return zero;
      if( t2->higher_equal( zero ) ) return zero;
    }
  
+   // Code pattern on return from a call that returns an __Value.  Can
+   // be optimized away if the return value turns out to be an oop.
+   if (op == Op_AndX &&
+       in(1) != nullptr &&
+       in(1)->Opcode() == Op_CastP2X &&
+       in(1)->in(1) != nullptr &&
+       phase->type(in(1)->in(1))->isa_oopptr() &&
+       t2->isa_intptr_t()->_lo >= 0 &&
+       t2->isa_intptr_t()->_hi <= MinObjAlignmentInBytesMask) {
+     return add_id();
+   }
+ 
    // Either input is BOTTOM ==> the result is the local BOTTOM
    if( t1 == Type::BOTTOM || t2 == Type::BOTTOM )
      return bottom_type();
  
  #if defined(IA32)

@@ -868,10 +880,51 @@
          return new AndLNode(zshift, in(2));
        }
      }
    }
  
+   // Search for GraphKit::mark_word_test patterns and fold the test if the result is statically known
+   Node* load1 = in(1);
+   Node* load2 = nullptr;
+   if (load1->is_Phi() && phase->type(load1)->isa_long()) {
+     load1 = in(1)->in(1);
+     load2 = in(1)->in(2);
+   }
+   if (load1 != nullptr && load1->is_Load() && phase->type(load1)->isa_long() &&
+       (load2 == nullptr || (load2->is_Load() && phase->type(load2)->isa_long()))) {
+     const TypePtr* adr_t1 = phase->type(load1->in(MemNode::Address))->isa_ptr();
+     const TypePtr* adr_t2 = (load2 != nullptr) ? phase->type(load2->in(MemNode::Address))->isa_ptr() : nullptr;
+     if (adr_t1 != nullptr && adr_t1->offset() == oopDesc::mark_offset_in_bytes() &&
+         (load2 == nullptr || (adr_t2 != nullptr && adr_t2->offset() == in_bytes(Klass::prototype_header_offset())))) {
+       if (mask == markWord::inline_type_pattern) {
+         if (adr_t1->is_inlinetypeptr()) {
+           set_req_X(1, in(2), phase);
+           return this;
+         } else if (!adr_t1->can_be_inline_type()) {
+           set_req_X(1, phase->longcon(0), phase);
+           return this;
+         }
+       } else if (mask == markWord::null_free_array_bit_in_place) {
+         if (adr_t1->is_null_free()) {
+           set_req_X(1, in(2), phase);
+           return this;
+         } else if (adr_t1->is_not_null_free()) {
+           set_req_X(1, phase->longcon(0), phase);
+           return this;
+         }
+       } else if (mask == markWord::flat_array_bit_in_place) {
+         if (adr_t1->is_flat()) {
+           set_req_X(1, in(2), phase);
+           return this;
+         } else if (adr_t1->is_not_flat()) {
+           set_req_X(1, phase->longcon(0), phase);
+           return this;
+         }
+       }
+     }
+   }
+ 
    return MulNode::Ideal(phase, can_reshape);
  }
  
  LShiftNode* LShiftNode::make(Node* in1, Node* in2, BasicType bt) {
    switch (bt) {