Run results for: 32bit copyWithin: is it fast?

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/93.0.4577.63 Safari/537.36

Browser: Chrome 93

Operating system: Windows

Device Platform: Desktop

Date tested: 2 years ago

Test name	Executions per second
Uint32 copyWithin	3037017.0 Ops/sec
Int32 Iteration	4.4 Ops/sec
Uint32 copy within	3827.9 Ops/sec

Script Preparation code:

// starting with a plain array buffer, what is fastest?
var buffer = new ArrayBuffer(1024 * 1024);
var originalIntView = new Uint32Array(buffer);
for (var i = 0; i < originalIntView.length; i++) {
  originalIntView[i] = Math.round(Math.random() * 256);
}

Tests:

Uint32 copyWithin
originalIntView.copyWithin(0, 512*1024, 1024*1024)
Int32 Iteration
for (var i = 0; i < 1024 * 512; i++) { originalIntView[i] = originalIntView[i + 1024 * 512]; }
Uint32 copy within
var int32View = new Uint32Array(originalIntView.buffer, originalIntView.byteOffset, originalIntView.byteLength / 4); for (var i = 0; i < 1024 * 512 / 4; i++) { int32View[i] = int32View[i + 1024 * 512 / 4]; }

Run results for: 32bit copyWithin: is it fast?

Is copyWithin fast?

Uint32 copyWithin

Int32 Iteration

Uint32 copy within