Ruby » Ruby master

Improve Time#<=> performance

• time.c (wcmp): use internal cmp() function for comparing internal Fixnum value
  in Time objects. On 64-bit machine, Time object might have Fixnum object
  internally by default and cmp() can compare the Fixnum objects directly.

  Time#<=> will be faster around 60% on 64-bit machine.

• time.c (cmp): add optimized path for comparing internal Bignum value by using
  rb_big_cmp() API. On 32-bit machine, Time object might have Bignum object
  internally by default.

  Time#<=> will be faster around 50% on 32-bit machine.

  [ruby-dev:50034] [Bug #13354] [Fix GH-1546]

Before¶

         user     system      total        real

Fixnum 1.410000 0.000000 1.410000 ( 1.407848)
Bignum 1.550000 0.000000 1.550000 ( 1.549145)

After¶

         user     system      total        real

Fixnum 0.880000 0.000000 0.880000 ( 0.886662)
Bignum 1.050000 0.000000 1.050000 ( 1.047994)

Test code¶

require 'benchmark'

Benchmark.bmbm do |x|

x.report "Fixnum" do
t1 = Time.now
t2 = Time.now
10000000.times do
t1 <=> t2
end
end

x.report "Bignum" do
t1 = Time.at(2 ** 64)
t2 = Time.at(2 ** 64 + 1)
10000000.times do
t1 <=> t2
end
end

end

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@58828 b2dd03c8-39d4-4d8f-98ff-823fe69b080e