[ruby-cvs:78347] 6f27fa4f7d (master): prefer class_serial over m_tbl

卜部昌平	2019-11-27 14:42:30 +0900 (Wed, 27 Nov 2019)

  New Revision: 6f27fa4f7d

  https://github.com/ruby/ruby/commit/6f27fa4f7d

  Log:
    prefer class_serial over m_tbl
    
    Decades ago, among all the data that a class has, its method
    table was no doubt the most frequently accessed data.  Previous
    data structures were based on that assumption.
    
    Today that is no longer true.  The most frequently accessed field
    moved to class_serial.  That field is not always as wide as VALUE
    but if it is, let us swap m_tbl and class_serial.
    
    Calculating -------------------------------------
                                   ours       trunk
    Optcarrot Lan_Master.nes     47.363      46.630 fps
    
    Comparison:
                 Optcarrot Lan_Master.nes
                        ours:        47.4 fps
                       trunk:        46.6 fps - 1.02x  slower

  Modified files:
    gc.c
    internal.h