Mercurial > jdk8-mips64-public > hotspot / file diff

     1.1 --- a/src/share/vm/asm/assembler.hpp	Tue Mar 03 18:25:57 2009 -0800
     1.2 +++ b/src/share/vm/asm/assembler.hpp	Wed Mar 04 09:58:39 2009 -0800
     1.3 @@ -140,6 +140,28 @@
     1.4    }
     1.5  };
     1.6  
     1.7 +// A union type for code which has to assemble both constant and
     1.8 +// non-constant operands, when the distinction cannot be made
     1.9 +// statically.
    1.10 +class RegisterConstant VALUE_OBJ_CLASS_SPEC {
    1.11 + private:
    1.12 +  Register _r;
    1.13 +  intptr_t _c;
    1.14 +
    1.15 + public:
    1.16 +  RegisterConstant(): _r(noreg), _c(0) {}
    1.17 +  RegisterConstant(Register r): _r(r), _c(0) {}
    1.18 +  RegisterConstant(intptr_t c): _r(noreg), _c(c) {}
    1.19 +
    1.20 +  Register as_register() const { assert(is_register(),""); return _r; }
    1.21 +  intptr_t as_constant() const { assert(is_constant(),""); return _c; }
    1.22 +
    1.23 +  Register register_or_noreg() const { return _r; }
    1.24 +  intptr_t constant_or_zero() const  { return _c; }
    1.25 +
    1.26 +  bool is_register() const { return _r != noreg; }
    1.27 +  bool is_constant() const { return _r == noreg; }
    1.28 +};
    1.29  
    1.30  // The Abstract Assembler: Pure assembler doing NO optimizations on the
    1.31  // instruction level; i.e., what you write is what you get.
    1.32 @@ -280,6 +302,26 @@
    1.33    inline address address_constant(Label& L);
    1.34    inline address address_table_constant(GrowableArray<Label*> label);
    1.35  
    1.36 +  // Bootstrapping aid to cope with delayed determination of constants.
    1.37 +  // Returns a static address which will eventually contain the constant.
    1.38 +  // The value zero (NULL) stands instead of a constant which is still uncomputed.
    1.39 +  // Thus, the eventual value of the constant must not be zero.
    1.40 +  // This is fine, since this is designed for embedding object field
    1.41 +  // offsets in code which must be generated before the object class is loaded.
    1.42 +  // Field offsets are never zero, since an object's header (mark word)
    1.43 +  // is located at offset zero.
    1.44 +  RegisterConstant delayed_value(int(*value_fn)(), Register tmp, int offset = 0) {
    1.45 +    return delayed_value(delayed_value_addr(value_fn), tmp, offset);
    1.46 +  }
    1.47 +  RegisterConstant delayed_value(address(*value_fn)(), Register tmp, int offset = 0) {
    1.48 +    return delayed_value(delayed_value_addr(value_fn), tmp, offset);
    1.49 +  }
    1.50 +  virtual RegisterConstant delayed_value(intptr_t* delayed_value_addr, Register tmp, int offset) = 0;
    1.51 +  // Last overloading is platform-dependent; look in assembler_<arch>.cpp.
    1.52 +  static intptr_t* delayed_value_addr(int(*constant_fn)());
    1.53 +  static intptr_t* delayed_value_addr(address(*constant_fn)());
    1.54 +  static void update_delayed_values();
    1.55 +
    1.56    // Bang stack to trigger StackOverflowError at a safe location
    1.57    // implementation delegates to machine-specific bang_stack_with_offset
    1.58    void generate_stack_overflow_check( int frame_size_in_bytes );