src/hotspot/share/opto/mulnode.cpp

rev 52443 : 8213473: Prevent transformation of LoadB->AndI->CmpI pattern to facilitate testb instruction matching

*** 488,498 ****
        return new AndINode(ldus, phase->intcon(mask & 0xFFFF));
      }
  
      // Masking sign bits off of a Byte?  Do an unsigned byte load plus
      // an and.
!     if (lop == Op_LoadB && (mask & 0xFFFFFF00) == 0) {
        Node* ldub = load->as_Load()->convert_to_unsigned_load(*phase);
        ldub = phase->transform(ldub);
        return new AndINode(ldub, phase->intcon(mask));
      }
    }
--- 488,503 ----
        return new AndINode(ldus, phase->intcon(mask & 0xFFFF));
      }
  
      // Masking sign bits off of a Byte?  Do an unsigned byte load plus
      // an and.
!     // Prevent transform if it feeds to CmpI. We have special matcher
!     // for LoadB+AndI+CmpI that generates a single instruction.
!     bool feeds_to_cmpi_zero = outcnt() == 1 &&
!                               unique_out()->Opcode() == Op_CmpI &&
!                               phase->type(unique_out()->in(2))->is_zero_type();
!     if (lop == Op_LoadB && (mask & 0xFFFFFF00) == 0 && !feeds_to_cmpi_zero) {
        Node* ldub = load->as_Load()->convert_to_unsigned_load(*phase);
        ldub = phase->transform(ldub);
        return new AndINode(ldub, phase->intcon(mask));
      }
    }