Feature #2561: 1.8.7 Patch reduces time cost of Rational operations by 50%.

• Status: Closed
• Assignee: knu (Akinori MUSHA)
• Target version: -

[kstephens (Kurt Stephens)]

=begin
This changes adds a specialize Fixnum#gcd and a tuned rational.rb.
Reduced overall time on Rational operations by > 50%.

                                               user     system      total        real
 test_it                                  22.380000   2.140000  24.520000 ( 24.559388)
 test_it ks_rational                      17.870000   1.830000  19.700000 ( 19.687221)
 test_it ks_rational + Fixnum#gcd         10.660000   0.000000  10.660000 ( 10.665765)
 

The patch will perform better with Fixnum#gcd on numeric.c but still is faster with only the rational.rb changes.

I have a version for 1.8.6 if someone wants it.
=end

[naruse (Yui NARUSE)]

• Status changed from Open to Assigned
• Assignee set to knu (Akinori MUSHA)

=begin
Discuss in Ruby 1.8 first,
=end

[kstephens (Kurt Stephens)]

• File rational_performance.rb rational_performance.rb added
• File ruby-1.8.7-rational.patch ruby-1.8.7-rational.patch added

=begin
New version:

Avoid additional method calls to Float(), call #to_f directly. Avoid Rational() when its clear that denominator will never be 1.

=end

[kstephens (Kurt Stephens)]

• File ruby-1.8.7-rational.patch ruby-1.8.7-rational.patch added
• File gcd_test.rb gcd_test.rb added

=begin
Fixed Fixnum#gcd for FIXNUM_MIN.

Ref: http://github.com/kstephens/rubyenterpriseedition187/commit/877d5e4c7892248bb7486f24c076cb23d565a466

gcd_test.rb should pass on 32-bit builds.

=end

[kstephens (Kurt Stephens)]

• File gcd_test.rb gcd_test.rb added
• File ruby-1.8.7-fixnum_gcd.patch ruby-1.8.7-fixnum_gcd.patch added

=begin
Fixed Fixnum#gcd to FIXNUM_MIN on 64-bit longs.

Ref: http://github.com/kstephens/rubyenterpriseedition187-248/commit/4863695e774d427d95c0828f8d2d5a92a433a1c4

gcd_test.rb should pass on 64-bit builds.

=end

[knu (Akinori MUSHA)]

=begin
Patches look fine to me. I'll handle this as soon as I can take the time, hopefully within a couple weeks.

I think it's better to have the C part as extension rather than putting Fixnum#gcd solely in the core,
so I'll make some layout changes to bring this in in the best shape for future maintainability.

=end

[knu (Akinori MUSHA)]

• Status changed from Assigned to Closed
• % Done changed from 0 to 100

=begin
This issue was solved with changeset r26581.
Kurt , thank you for reporting this issue.
Your contribution to Ruby is greatly appreciated.
May Ruby be with you.

=end