src/hotspot/cpu/x86/x86.ad

*** 2724,10 ***
--- 2724,43 ---
        __ jccb(Assembler::equal, L);
        // Die if stack mismatch
        __ int3();
        __ bind(L);
      }
+     if (tf()->returns_inline_type_as_fields() && !_method->is_method_handle_intrinsic()) {
+       // The last return value is not set by the callee but used to pass IsInit information to compiled code.
+       // Search for the corresponding projection, get the register and emit code that initialized it.
+       uint con = (tf()->range_cc()->cnt() - 1);
+       for (DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++) {
+         ProjNode* proj = fast_out(i)->as_Proj();
+         if (proj->_con == con) {
+           // Set IsInit if rax is non-null (a non-null value is returned buffered or scalarized)
+           OptoReg::Name optoReg = ra_->get_reg_first(proj);
+           VMReg reg = OptoReg::as_VMReg(optoReg, ra_->_framesize, OptoReg::reg2stack(ra_->_matcher._new_SP));
+           Register toReg = reg->is_reg() ? reg->as_Register() : rscratch1;
+           __ testq(rax, rax);
+           __ setb(Assembler::notZero, toReg);
+           __ movzbl(toReg, toReg);
+           if (reg->is_stack()) {
+             int st_off = reg->reg2stack() * VMRegImpl::stack_slot_size;
+             __ movq(Address(rsp, st_off), toReg);
+           }
+           break;
+         }
+       }
+       if (return_value_is_used()) {
+         // An inline type is returned as fields in multiple registers.
+         // Rax either contains an oop if the inline type is buffered or a pointer
+         // to the corresponding InlineKlass with the lowest bit set to 1. Zero rax
+         // if the lowest bit is set to allow C2 to use the oop after null checking.
+         // rax &= (rax & 1) - 1
+         __ movptr(rscratch1, rax);
+         __ andptr(rscratch1, 0x1);
+         __ subptr(rscratch1, 0x1);
+         __ andptr(rax, rscratch1);
+       }
+     }
    %}
  
  %}
  
  // Operands for bound floating pointer register arguments