Typed array iteration

JavaScript performance comparison

Revision 23 of this test case created

Info

Array iteration

Preparation code

<canvas width="512" height="512" id="canvas" style="border: 1px dashed black;">
</canvas>
<script>
  var classic = new Array(1048576);
  var context = document.getElementById("canvas").getContext("2d");
  var imageData = context.getImageData(0, 0, 512, 512);
  var canvas = imageData.data;
  if (typeof Uint8Array !== 'undefined') {
    var typed8 = new Uint8Array(1048576);
    var typed32 = new Uint32Array(1048576);
  }

  for (var i = 0; i < 1048576; ++i) {
    var number = ~~ (Math.random() * 254)
    classic[i] = number;
    canvas[i] = number;
    if (typeof Uint8Array !== 'undefined') {
      typed8[i] = number;
      typed32[i] = number;
    }
  }

  context.putImageData(imageData, 0, 0);

  function test_classic() {
    for (var ii = 0; ii < 1048576; ++ii) {
      classic[ii] += 1;
    }
  }

  function test_canvas() {
    for (var ii = 0; ii < 1048576; ++ii) {
      canvas[ii] += 1;
    }
  }

  function test_typed8() {
    if (typeof Uint8Array === 'undefined') {
      throw "Error";
    }

    for (var ii = 0; ii < 1048576; ++ii) {
      typed8[ii] += 1;
    }
  }

  function test_typed32() {
    if (typeof Uint8Array === 'undefined') {
      throw "Error";
    }

    for (var ii = 0; ii < 1048576; ++ii) {
      typed32[ii] += 1;
    }
  }
</script>

Preparation code output

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Testing in unknown unknown
Test Ops/sec
Classic
test_classic();
pending…
Canvas
test_canvas();
pending…
Typed 8
test_typed8();
pending…
Typed 32
test_typed32();
pending…

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