Negative-zero makes me sad. :'-(
Created attachment 24242 [details] The patch No performance change
Comment on attachment 24242 [details] The patch r=me, but you need to add a test (or change existing test results to match this).
Created attachment 24245 [details] The patch too
Comment on attachment 24245 [details] The patch too r=me
http://trac.webkit.org/changeset/37453