From: "Kroeger, Simon (ext)" <simon.kroeger.ext@...>
Date: 2006-07-21T21:32:08+09:00
Subject: Re: One-Click Installer: MinGW? or VC2005?

 

> From: stu [mailto:yakumo9275@gmail.com] 
> Sent: Friday, July 21, 2006 1:40 PM
> 
> > VC has still a much better optimizer then gcc, if you use 
> it with care
> > about 10% faster, which today where CPU's are not getting faster as
> > fast is still important.
> 
> 10% is a LOT! I'd like to see these numbers that proove 10%.
> I'd be sure there is a difference but 10% is ridiculous.

I know this does not say much, but without fiddling with optimizer
flags I got the following numbers (again, for a *very* small set
of tests - does someone suggested a performance-test-suit?)

-------------------------------------------------------------------
D:\simon\ruby-snapshot>ruby-vc6\ruby.exe -v sudoku-solver.rb
ruby 1.8.5 (2006-07-20) [i386-mswin32]
time elapsed: 26.969 sec.
...

D:\simon\ruby-snapshot>ruby-vc2005\ruby.exe -v sudoku-solver.rb
ruby 1.8.5 (2006-07-20) [i386-mswin32_80]
time elapsed: 19.766 sec.
...

D:\simon\ruby-snapshot>ruby-mingw\ruby.exe -v sudoku-solver.rb
ruby 1.8.5 (2006-07-20) [i386-mingw32]
time elapsed: 19.812 sec.
...
-------------------------------------------------------------------

I don't dare to say anything about vc2005 and gcc 3.4.5 (which 
was used in the mingw build) but obviously we would benefit from
loosing the old vc6.

cheers

Simon

The test code was striped from ruby-talk: (shall I try anything else?)
-------------------------------------------------------------------
$count = 0

def valid?(state, x, y)
  # check in col and row
  0.upto(8) do |i|
    return false if i != y and state[x][i] == state[x][y]
    return false if i != x and state[i][y] == state[x][y]
  end

  # check in box
  x_from = (x / 3) * 3
  y_from = (y / 3) * 3
  x_from.upto(x_from + 2) do |xx|
    y_from.upto(y_from + 2) do |yy|
      return false if (xx != x or yy != y) and state[xx][yy] ==
state[x][y]
    end
  end

  true
end



def next_state(state, x, y)
  $count = $count + 1
  y = 0 and x = x + 1 if y == 9
  return true if x == 9

  unless state[x][y].zero?
    return false unless valid?(state, x, y)
    return next_state(state, x, y + 1)
  else
    1.upto(9) do |i|  
    state[x][y] = i
      return true if valid?(state, x, y) and next_state(state, x, y + 1)
    end
  end
  
  state[x][y] = 0
  false
end


## MAIN ##

start =
[
  [ 0, 0, 0, 4, 0, 5, 0, 0, 1 ],
  [ 0, 7, 0, 0, 0, 0, 0, 3, 0 ],
  [ 0, 0, 4, 0, 0, 0, 9, 0, 0 ],
  [ 0, 0, 3, 5, 0, 4, 1, 0, 0 ],
  [ 0, 0, 7, 0, 0, 0, 4, 0, 0 ],
  [ 0, 0, 8, 9, 0, 1, 0, 0, 0 ],
  [ 0, 0, 9, 0, 0, 0, 6, 0, 0 ],
  [ 0, 8, 0, 0, 0, 0, 0, 2, 0 ],
  [ 4, 0, 0, 2, 0, 0, 0, 0, 0 ]
]

start_time = Time.new

if next_state(start, 0, 0)
  puts "time elapsed: #{Time.new - start_time} sec."
  puts "count: #{$count}"
  start.each do |val|
    puts val.join(" ")
  end
else
  puts "Not solveable!"
end
-------------------------------------------------------------------