Function dcopy

Performs the operation $$y \leftarrow x$$ — double-double (Dekker) f64 emulation of scopy, since WGSL has no native f64 type.

import { init, cleanup } from "wgblas";
import { dcopy } from "wgblas/dcopy";

const device = await init();

const n = 5;
const x = new Float64Array([1, 2, 3, 4, 5]);
const y = new Float64Array([10, 20, 30, 40, 50]);

console.log("x before:", x);
console.log("y before:", y);
const { y: resultY } = await dcopy(device, n, x, 1, y, 1);
console.log("y after: ", resultY);
if (typeof process !== "undefined") cleanup();
Copy

Browser (standalone HTML):

<!doctype html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <title>dcopy — wgblas browser example</title>
    <script src="https://unpkg.com/wgblas/dist/wgblas.browser.js"></script>
  </head>
  <body>
    <pre id="out">Running…</pre>
    <script>
      const { init, dcopy, cleanup } = window.wgblas;

      (async () => {
        const device = await init();

        const n = 5;
        const x = new Float64Array([1, 2, 3, 4, 5]);
        const y = new Float64Array([10, 20, 30, 40, 50]);

        const xBefore = Array.from(x).map(v => v.toFixed(4)).join(", ");
        const yBefore = Array.from(y).map(v => v.toFixed(4)).join(", ");

        const { y: resultY } = await dcopy(device, n, x, 1, y, 1);

        document.getElementById("out").textContent =
          "x before: " + xBefore +
          "\ny before: " + yBefore +
          "\ny after:  " + Array.from(resultY).map(v => v.toFixed(4)).join(", ");

        cleanup();
      })();
    </script>
  </body>
</html>
Copy

Performs the operation $$y \leftarrow x$$ — GPU-resident overload; see the Float64Array overload above for the routine itself.

import { init, cleanup } from "wgblas";
import { dcopy } from "wgblas/dcopy";
import { dscal } from "wgblas/dscal";
import { GpuVector } from "wgblas/classes/GpuVector";

const device = await init();

const n = 5;
const scale = 2.0;
const x = new Float64Array([1, 2, 3, 4, 5]);
const y = new Float64Array(n);

const xGpu = GpuVector.from(x);
const yGpu = GpuVector.from(y);

console.log("x:      ", x);

// copy x into y, then scale y — all on GPU with single readback
await dcopy(device, n, xGpu, 1, yGpu, 1);
await dscal(device, n, scale, yGpu, 1);

const result = await yGpu.read();
console.log("result: ", result);

xGpu.destroy();
yGpu.destroy();

if (typeof process !== "undefined") cleanup();
Copy