Remove null check from Ion post barrier

RESOLVED FIXED in Firefox 55

Status

()

Core
JavaScript Engine: JIT
RESOLVED FIXED
a year ago
a year ago

People

(Reporter: jandem, Assigned: jandem)

Tracking

unspecified
mozilla55
Points:
---

Firefox Tracking Flags

(firefox55 fixed)

Details

Attachments

(1 attachment)

(Assignee)

Description

a year ago
Created attachment 8843977 [details] [diff] [review]
Patch

We need the null check if the value's type is MIRType::ObjectOrNull, but we don't need it in the more common MIRType::Object case.
Attachment #8843977 - Flags: review?(jcoppeard)
Comment on attachment 8843977 [details] [diff] [review]
Patch

Review of attachment 8843977 [details] [diff] [review]:
-----------------------------------------------------------------

Nice.
Attachment #8843977 - Flags: review?(jcoppeard) → review+

Comment 2

a year ago
Pushed by jandemooij@gmail.com:
https://hg.mozilla.org/integration/mozilla-inbound/rev/9c62ab1bfb8a
Eliminate unnecessary null check from Ion post barriers when we know the object is non-null. r=jonco

Comment 3

a year ago
This patch regressed Octane Deltablue and Richards on AWFY (but only on the Mac 64-bit machine)
(Assignee)

Comment 4

a year ago
(In reply to Guilherme Lima from comment #3)
> This patch regressed Octane Deltablue and Richards on AWFY (but only on the
> Mac 64-bit machine)

Yeah it's mysterious. The patch just eliminates a test+jump instruction so it must be some kind of caching or alignment issue.

Comment 5

a year ago
bugherder
https://hg.mozilla.org/mozilla-central/rev/9c62ab1bfb8a
Status: ASSIGNED → RESOLVED
Last Resolved: a year ago
status-firefox55: --- → fixed
Resolution: --- → FIXED
Target Milestone: --- → mozilla55
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