Tario's Project: agosto 2012

Fastruby is a gem which allows to execute ruby code much faster than normal, currently in a state of transition between a spike and a usable gem, it is released when possible with incremental improvements.

In previous post I promised to Improve speed of dynamic call lookups, this is because the speed optimization used to depend heavly on the possibility of inlining and therefore on the type information found at build-time. When no type information for method call receivers can be obtained at build-time, the method call is encoded as dynamic, and the method used to resolve dynamic calls so far was not optimal leading to results significantly worst than MRI 1.9

For example, the next code run faster because of the type information provided by lvar_type directive

view plain print ?

class Y
def bar(x)
i = 1000000
lvar_type(i,Fixnum)
ret = 0
while i > 0
ret = x.foo(i,i)
i = i - 1
end
return ret
end
end

class Y
  def bar(x)
    i = 1000000
    lvar_type(i,Fixnum)
   
    ret = 0
    while i > 0
      ret = x.foo(i,i)
      i = i - 1
    end
    return ret
  end
end

Else, removing lvar_type:

view plain print ?

class Y
def bar(x)
i = 1000000
#removed lvar_type
ret = 0
while i > 0
ret = x.foo(i,i)
i = i - 1
end
return ret
end
end

class Y
  def bar(x)
    i = 1000000
    #removed lvar_type
   
    ret = 0
    while i > 0
      ret = x.foo(i,i)
      i = i - 1
    end
    return ret
  end
end

Will result on this (for version without lvar_type):

Before (v0.0.21 and prior)