1665927 - Enable PackingStrategy::LowBitTagIsError also for non-pointer types

Status: RESOLVED FIXED

(Core :: MFBT, task)

Description

[Simon Giesecke [:sg] [he/him]]

In particular, enable it for empty types.

Also, the size of Result can be smaller than a pointer if both the value and error type are smaller (e.g. both empty).

Comment 1

[Simon Giesecke [:sg] [he/him]]

Attachment: Bug 1665927 - Use free LSB optimization for empty types with mozilla::Result. r=emilio

Depends on D90676

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/1467e76399e8
Use free LSB optimization for empty types with mozilla::Result. r=emilio

Comment 3

[Atila Butkovits]

Backed out for causing bustage on Result.h.

Backout link: https://hg.mozilla.org/integration/autoland/rev/32d03662a363850006f648c22e825b3e886b29bc

Push with failures: https://treeherder.mozilla.org/#/jobs?repo=autoland&resultStatus=testfailed%2Cbusted%2Cexception&revision=1467e76399e88bfdb0d78770366613d782d1477a&selectedTaskRun=dmKuZ8QhRQKi315Rnt1eHw.0

Failure log : https://treeherder.mozilla.org/logviewer.html#/jobs?job_id=316240410&repo=autoland&lineNumber=79127

Comment 4

[Simon Giesecke [:sg] [he/him]]

Reproduced and fixed the build bustage with gcc.

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/353266aee10d
Use free LSB optimization for empty types with mozilla::Result. r=emilio

Comment 6

[Dorel Luca [:dluca]]

https://hg.mozilla.org/mozilla-central/rev/353266aee10d