OpenWebPerf

Pushing Open Web performance by documenting platform performance bottlenecks.

Goals

• Document performance bottlenecks within the lower platform levels (like JIT, layout engine, CSS parsing, etc)
• Raise the issues to the platform team and track progress
• Build a reference of do's and dont's

Test Cases

3D Matrix Transforms

Rotate 200 surfaces using CSS3 transforms with a 3d-matrix, using gl-matrix and typed arrays.

Related bugs:

• 998995: Consider using an auto array in CSSParserImpl::ParseFunction

Direct String Concatenation

Profiles:

• Firefox Nightly, 34.0a1 (2014-08-19)

Remarks:

• Layout team offered to look into jitting the element.style.transform = '3dmatrix(… assignment and comparing to adding a new API (like element.mozSetTransform(Float32Array)

For-Loop Concatenation

Profiles:

• Firefox Nightly, 34.0a1 (2014-08-19)

Remarks

• The layout team remarked that the loop will not be jitted as the length is too short
• The values are normalized to optimize for 0, which the CSS parser already does internally

Less precision & Direct