js-matrix-transpose-benchmark

Attempt to benchmark moving elements around within matrices by benchmarking matrix transpose in JS using 3 different implementations:

• Using regular 2D JS array of arrays.

• Using a 1D TypedArray buffer, manually mapping 2D indexing into 1D.

• Using WASM heap memory via emscripten, manually mapping 2D indexing into 1D.

Here are some representative result in milliseconds (takes a couple of minutes to run on my desktop because of test setup/teardown overhead):

{ JSMatrix: 1307, BufMatrix: 235, WasmMatrix: 284 }
{ JSMatrix: 1280, BufMatrix: 276, WasmMatrix: 303 }
{ JSMatrix: 1341, BufMatrix: 263, WasmMatrix: 287 }

Surprisingly, the TypedArray implementation does better than the WASM implementation; speculate on JIT optimizations??

[Code based on nodejs 14.x, probably uses many of the newer JS language features.]