1888418 - Allow to inline Math.min/max when the initial array is large

Status: RESOLVED FIXED

(Core :: JavaScript Engine: JIT, enhancement, P3)

Description

[André Bargull [:anba]]

CacheIR inlining for spread calls to Math.{min,max} is guarded by JIT_ARGS_LENGTH_MAX, but the actual compiled code works for any array length. We should investigate removing this restriction during CacheIR inlining, because the compiled code doesn't need that restriction.

Test case:

function f(...xss) {
  var N = 1_000_000;
  var r = 0;
  var t = performance.now();
  for (var i = 0; i < N; ++i) {
    var xs = xss[(i > (N / 2))|0];
    r += Math.max(...xs);
  }
  console.log(performance.now() - t, r);
}

// Fast when the initial array is small enough.
Function(`return ${f}`)()(
  Array(10).fill(0),
  Array(1000).fill(0),
);

// Slow when the initial array is too large.
Function(`return ${f}`)()(
  Array(1000).fill(0),
  Array(10).fill(0),
);

Comment 1

[Iain Ireland [:iain]]

Attachment: Bug 1888418: Allow spread call natives to be inlined with more than JIT_ARGS_LENGTH_MAX arguments r=anba

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/ee015f2a0371
https://hg.mozilla.org/integration/autoland/rev/9633b8a44119
Allow spread call natives to be inlined with more than JIT_ARGS_LENGTH_MAX arguments r=anba

Comment 3

[amarc]

https://hg.mozilla.org/mozilla-central/rev/9633b8a44119