984000 - Expose default use count thresholds to the shell

Status: RESOLVED WORKSFORME

(Core :: JavaScript Engine: JIT, defect)

Description

[Jan de Mooij [:jandem]]

Kannan posted this in bug 960523:

(In reply to Kannan Vijayan [:djvj] from comment #14)
> Reading this test case, it occurs to me that it might be useful to expose
> JitOptions such as the useCount thresholds for various optimization tiers to
> the shell for use in cases like this, so we don't have to build them into
> the loop constants into these tests with no explanation...
> 
> Not sure if that's relevant for this patch, though...  could you make a bug
> for that and CC me?  It would be a good quick pick up bug or a mentor bug
> for a new contributor.

I don't think we want to expose the current use counts as a shell function/constant, because it means tests will run differently based on the shell flags. It would be nice if loops ran the same number of iterations etc with/without --ion-eager et al.

As a start though we could expose the default Baseline and Ion thresholds, independent of the current shell flags.

Also, Ion uses a slightly higher threshold for (nested) loops, so we'll probably want to expose that value instead.

Comment 1

[Jan de Mooij [:jandem]]

(In the TM days we had something like this: a HOTLOOP constant that was 8 or so.)

Comment 2

[Nicolas B. Pierron [:nbp]]

The thresholds are now mutable using some shell testing function which are exposing all JitOptions as mutable.
So I guess this bug had been fixed.