float16-as-float32-specialization-for-math-f16round.js

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function float32(i) {

  // Unbox to Int32.

  i = i|0;

  // Float32 addition.

  let x = Math.fround(i + 0.1);

  // Float32 square root.

  let y = Math.fround(Math.sqrt(x));

  // Return as Float16.

  return Math.f16round(y);

function float64(i) {

  // Unbox to Int32.

  i = i|0;

  // Float32 addition.

  let x = Math.fround(i + 0.1);

  // Float64 square root.

  let y = Math.sqrt(x);

  // Return as Float16.

  return Math.f16round(y);

function toBaseline(f) {

  let source = f.toString();

  assertEq(source.at(-1), "}");

  // Add with-statement to disable Ion compilation.

  source = source.slice(0, -1) + "; with ({}); }";

  return Function(`return ${source};`)();

// Different results are expected for these inputs:

//

// Input    Float64-SQRT  Float32-SQRT

// -----------------------------------

// 1527     39.09375      39.0625

// 16464    128.375       128.25

// 18581    136.375       136.25

// 20826    144.375       144.25

// 23199    152.375       152.25

// 25700    160.375       160.25

// 28329    168.375       168.25

// 31086    176.375       176.25

//

// Limit execution to 1550 to avoid spending too much time on this single test.

//

// 1550 iterations should still be enough to allow tiering up to Ion, at least

// under eager compilation settings.

const LIMIT = 1550;

let float32_baseline = toBaseline(float32);

let float64_baseline = toBaseline(float64);

let n = 0;

for (let i = 0; i < LIMIT; ++i) {

  let x = float32(i);

  assertEq(x, float32_baseline(i));

  let y = float64(i);

  assertEq(y, float64_baseline(i));

  if (x !== y) {

    n++;

assertEq(n, 1);