873155 - Remove StackFrame argument duplication

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Jan de Mooij [:jandem]]

Attachment: Patch

When there are more actuals than formals, formals are duplicated on the stack so that JM could access them at a fixed offset. Now that JM is gone, we can remove this.

Patch also gets rid of the OVERFLOW_ARGS and UNDERFLOW_ARGS StackFrame flags.

Comment 1

[Jan de Mooij [:jandem]]

Attachment: Patch

Update a comment.

Comment 2

[Luke Wagner [:luke]]

Comment on attachment 750562 [details] [diff] [review]
Patch

Review of attachment 750562 [details] [diff] [review]:
-----------------------------------------------------------------

Ahh, much nicer.

::: js/src/vm/ArgumentsObject.cpp
@@ +31,5 @@
>      JS_ASSERT_IF(frame.isStackFrame(), !frame.asStackFrame()->runningInIon());
>  
> +    JS_ASSERT(frame.numActualArgs() <= totalArgs);
> +    JS_ASSERT(frame.numFormalArgs() <= totalArgs);
> +    JS_ASSERT(Max(frame.numActualArgs(), frame.numFormalArgs()) == totalArgs);

Seems like the third assert subsumes the first two and they could be removed.

Comment 3

[Jan de Mooij [:jandem]]

Pushed with nit addressed:

https://hg.mozilla.org/integration/mozilla-inbound/rev/b52106ac0817

Comment 4

[Ryan VanderMeulen [:RyanVM]]

Backed out for jit-test bustage at Jan's request.
https://hg.mozilla.org/integration/mozilla-inbound/rev/0e3678635f5b

Comment 5

[Jan de Mooij [:jandem]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/10106fdd2873

(Try: https://tbpl.mozilla.org/?tree=Try&rev=4bab52e636eb)

Comment 6

[Phil Ringnalda (:philor)]

https://hg.mozilla.org/mozilla-central/rev/10106fdd2873