1737561 - Use loadArgumentFixedSlot to load fixed arguments

Status: RESOLVED FIXED

(Core :: JavaScript Engine: JIT, task)

Description

[André Bargull [:anba]]

Two issues:

• tryAttachObjectIsPrototypeOf() and tryAttachObjectToString() are using loadArgumentDynamicSlot() instead of loadArgumentFixedSlot() to load the this value.
• loadStandardCallArgument() should be replaced with loadArgumentFixedSlot(), so it's easier to experiment inlining natives through Function.prototype.call. (*)

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(*) Background info: I've investigated bug 1131996, which is now easy to fix because the arguments analysis is gone - I can upload the patch if there's interest for it, but when I then checked the actual web impact, I've seen that supporting scalar replacement for the pattern [].slice.call(arguments) is more useful. But to support that pattern, we first need to be able to inline natives through Function.prototype.call.

Comment 1

[André Bargull [:anba]]

Attachment: Bug 1737561 - Part 1: Use loadArgumentFixedSlot() to load the this-value for Object.prototype.{isPrototypeOf,toString}. r=jandem!

Using loadArgumentDynamicSlot() doesn't help to share the IC code for multiple callers,
because we only attach the IC code when the arguments count is fixed.

Comment 2

[André Bargull [:anba]]

Attachment: Bug 1737561 - Part 2: Use loadArgumentFixedSlot() instead of loadStandardCallArgument() for Math.hypot. r=jandem!

Depends on D129383

Comment 3

[André Bargull [:anba]]

Attachment: Bug 1737561 - Part 3: Use loadArgumentFixedSlot() instead of loadStandardCallArgument() for Math.{min,max}. r=jandem!

And then remove loadStandardCallArgument() because it's no longer used.

Depends on D129384

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/9146c852fd52
Part 1: Use loadArgumentFixedSlot() to load the this-value for Object.prototype.{isPrototypeOf,toString}. r=jandem
https://hg.mozilla.org/integration/autoland/rev/a71d43be04c6
Part 2: Use loadArgumentFixedSlot() instead of loadStandardCallArgument() for Math.hypot. r=jandem
https://hg.mozilla.org/integration/autoland/rev/1b8c01e8d2a3
Part 3: Use loadArgumentFixedSlot() instead of loadStandardCallArgument() for Math.{min,max}. r=jandem

Comment 5

[Iain Ireland [:iain]]

(For what it's worth, if the fix is easy, my vote is for landing the patch for bug 1131996. I'm sure there's still code out there using that pattern.)

Comment 6

[Natalia Csoregi [:nataliaCs]]

https://hg.mozilla.org/mozilla-central/rev/9146c852fd52
https://hg.mozilla.org/mozilla-central/rev/a71d43be04c6
https://hg.mozilla.org/mozilla-central/rev/1b8c01e8d2a3