SIMD

We cover Single Instruction, Multiple Data (SIMD) in more detail in the Async & Performance title of this series, but it bears a brief mention here, as it’s one of the next likely features to land in a future JS.

The SIMD API exposes various low-level (CPU) instructions that can operate on more than a single number value at a time. For example, you’ll be able to specify two vectors of 4 or 8 numbers each, and multiply the respective elements all at once (data parallelism!).

Consider:

  1. var v1 = SIMD.float32x4( 3.14159, 21.0, 32.3, 55.55 );
  2. var v2 = SIMD.float32x4( 2.1, 3.2, 4.3, 5.4 );
  4. SIMD.float32x4.mul( v1, v2 );
  5. // [ 6.597339, 67.2, 138.89, 299.97 ]

SIMD will include several other operations besides mul(..) (multiplication), such as sub(), div(), abs(), neg(), sqrt(), and many more.

Parallel math operations are critical for the next generations of high performance JS applications.