floats.hpp

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/* Copyright 1994 - 1996, LongView Technologies L.L.C. $Revision: 1.9 $ */
/* Copyright (c) 2006, Sun Microsystems, Inc.
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// Floats describes the floating point operations of the interpreter
// and implements stub routines used to execute this operations.
// Note: The Floats stub routines are *inside* the interpreter code.

class Floats: AllStatic {
 public:
  enum Some_constants {
    magic                       = 0xbadbabe0,   // indicates floats in the frame if stored in temp1
    max_number_of_functions     = 256,
  };

  // Function codes for float operations.
  // Note: When changing these codes, make sure that the bytecode compiler
  //       is updated as well! (use delta +GenerateSmalltalk to generate
  //       an updated file-in file for Smalltalk).
  enum Function {
    // nullary functions
    zero,                       // float(i) := 0.0
    one,                        // float(i) := 1.0

    // unary functions
    abs,                        // float(i) := |float(i)|
    negated,                    // float(i) := -float(i)
    squared,                    // float(i) := float(i) * float(i)
    sqrt,                       // float(i) := sqrt(float(i))
    sin,                        // float(i) := sin(float(i))
    cos,                        // float(i) := cos(float(i))
    tan,                        // float(i) := tan(float(i))
    exp,                        // float(i) := exp(float(i))
    ln,                         // float(i) := ln(float(i))

    // binary functions
    add,                        // float(i) := float(i) + float(i + 1)
    subtract,                   // float(i) := float(i) - float(i + 1)
    multiply,                   // float(i) := float(i) * float(i + 1)
    divide,                     // float(i) := float(i) / float(i + 1)
    modulo,                     // float(i) := float(i) \ float(i + 1)

    // unary functions to oop
    is_zero,                    // tos := float(i) =  0.0
    is_not_zero,                // tos := float(i) ~= 1.0
    oopify,                     // tos := oop(float(i))
    
    // binary functions to oop
    is_equal,                   // tos := float(i) =  float(i + 1)
    is_not_equal,               // tos := float(i) ~= float(i + 1)
    is_less,                    // tos := float(i) <  float(i + 1)
    is_less_equal,              // tos := float(i) <= float(i + 1)
    is_greater,                 // tos := float(i) >  float(i + 1)
    is_greater_equal,           // tos := float(i) >= float(i + 1)

    number_of_functions,

    // debugging & other purposes only (not actually generated in the bytecodes)
    undefined,                  // error handling
    floatify                    // used only to find selectors (MethodIterator)
  };

 private:
  private:
  static bool  _is_initialized; // true if Floats has been initialized
  static char* _function_names[];

  static void  generate_tst(MacroAssembler* masm, Assembler::Condition cc);
  static void  generate_cmp(MacroAssembler* masm, Assembler::Condition cc);
  static void  generate(MacroAssembler* masm, Function f);

 public:
  // Dispatch (interpreter)
  // Note: _function_table is bigger than number_of_functions to catch illegal (byte) indices
  static char* _function_table[max_number_of_functions];

  // Debugging/Printing
  static char* function_name_for(Function f);

  // Tells if there is a selector for the float operation
  static bool  has_selector_for(Function f);

  // Returns the selector for the float operation; NULL is there is no selector
  static symbolOop selector_for(Function f);

  static oop magic_value() { return smiOop(magic); }

  // Initialization/debugging
  static bool  is_initialized() { return _is_initialized; }
  static void  init(MacroAssembler* masm);
  static void  print();
};

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