837747 - BaselineCompiler: Add optimized stub for calls via JSOP_NEW

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Kannan Vijayan [:djvj]]

JSOP_NEW is not optimized, so we're entering the VM and re-entering baseline (or ion) for each of these.  Fix.

Comment 1

[Kannan Vijayan [:djvj]]

Attachment: Patch

Comment 2

[Kannan Vijayan [:djvj]]

Attachment: Patch 2.

New patch with fixes: previous one forgot to mark the Callee in the ICCall_NewScripted stub.

Comment 3

[Jan de Mooij [:jandem]]

Comment on attachment 710335 [details] [diff] [review]
Patch 2.

Review of attachment 710335 [details] [diff] [review]:
-----------------------------------------------------------------

::: js/src/ion/BaselineIC.cpp
@@ +3198,5 @@
> +typedef bool (*CreateThisFn)(JSContext *cx, HandleObject callee, MutableHandleValue rval);
> +static const VMFunction CreateThisInfo = FunctionInfo<CreateThisFn>(CreateThis);
> +
> +bool
> +ICCall_NewScripted::Compiler::generateStubCode(MacroAssembler &masm)

I think we can avoid a lot of code duplication if we use the Call_Scripted stub for JSOP_NEW as well (Ion's LCallGeneric also works with both constructing and non-constructing). We can make getKey encode the isConstructing bit, and wrap the CreateThis and check-return-type-is-primitive parts in an "if (isConstructing)" or something. Would you mind giving this a try? I think it would be really nice if we can make it work.

Comment 4

[Kannan Vijayan [:djvj]]

I thought about doing this, but the main issue I have with it is that register usage gets really tight on x86.

The combined version may have a couple of extra pushes or pops, but I suppose that's not too bad of a price to pay.  I'll look into it.

Comment 5

[Kannan Vijayan [:djvj]]

Attachment: Patch 3.

Fixed up to reuse code for ICCall_Scripted.

Comment 6

[Jan de Mooij [:jandem]]

Comment on attachment 710920 [details] [diff] [review]
Patch 3.

Review of attachment 710920 [details] [diff] [review]:
-----------------------------------------------------------------

Looks great.

Comment 7

[Kannan Vijayan [:djvj]]

https://hg.mozilla.org/projects/ionmonkey/rev/38ee7277e1e3