1448039 - Use ICState consistently for all ICs

Status: RESOLVED FIXED

(Core :: JavaScript Engine: JIT, enhancement, P2)

Description

[Matthew Gaudet (he/him) [:mgaudet]]

While exploring something else, it became clear that the InstanceOf IC attempts to attach regardless of how many failures it has seen. 

The test case here: 

```
function bar() { this.y = 10; }
bar.__proto__ = {}
k = new bar();

for (var i =0; i < 100; i++) {
    assertEq(k instanceof bar, true);
}
```

The IC will fail to attach; yet, if run with either CACHEIR_LOGS=1 or IONFLAGS=bl-ic-fb it's clear that we attempt to attach the stub nearly 100 times.

Comment 1

[Matthew Gaudet (he/him) [:mgaudet]]

I'm seeing a similar problem on Google Docs (Bug 1488435). I have a CacheIR log that has thousands of IC attachment failures for a particular pc that look like this: 

    Type	InstanceOf 	
    Mode	Specialized
    Location	https://docs.google.com/static/document/client/js/1419346799-kix_main_i18n_kix_core.js:1183
    Column	1018
    PC	12862ded0
    LHS	Object 1267ab7e0 (shape: 0)
    RHS	Function 125ba9780 (shape: 126472d30)

It seems for a particular PC, we ought not try to attach an IC 3063 times... seems wasteful.

Comment 2

[Matthew Gaudet (he/him) [:mgaudet]]

This is not just for InstanceOf; I have similar issues that show up for BinaryArith

Comment 3

[Ashley Hauck [:khyperia]]

Leaving a note for myself: I'm in this area due to weird interactions with https://bugzilla.mozilla.org/show_bug.cgi?id=1487022 , and I think I figured out the issue. Once I'm done with that bug, I'll look at this one.

mgaudet, do you mind if I steal the assignment?

Comment 4

[Matthew Gaudet (he/him) [:mgaudet]]

Not at all. I have done it for you :)

Comment 5

[Ted Campbell [:tcampbell]]

I think :khyperia has a stack of patches here to cover (roughly):
- Converting the stub->noteUnoptimized* to use ICState failed-to-attach counts
- Template out the boring baseline fallback functions since they are almost identical.

The result should end up fixing the Comment 0 issue.

Comment 6

[Ashley Hauck [:khyperia]]

Attachment: Bug 1448039 - Remove UNOPTIMIZEABLE bits from baseline IC fallback stubs.

Comment 7

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/57de113fc712
Remove UNOPTIMIZEABLE bits from baseline IC fallback stubs. r=tcampbell

Comment 8

[Arthur Iakab [arthur_iakab]]

https://hg.mozilla.org/mozilla-central/rev/57de113fc712