1752099 - Improve JIT CPU testing flags a bit after bug 1732362

Status: RESOLVED FIXED

(Core :: JavaScript Engine: JIT, task, P3)

Description

[Jan de Mooij [:jandem]]

After the changes in bug 1732362 we can improve and simplify this a bit.

Comment 1

[Jan de Mooij [:jandem]]

Attachment: Bug 1752099 part 1 - Remove lazy CPU flags computation on x86/x64. r?lth!

We always compute these on start-up so we can change some checks to asserts.

Comment 2

[Jan de Mooij [:jandem]]

Attachment: Bug 1752099 part 2 - Always parse ARM HwCap strings in InitARMFlags. r?lth!

We can now handle command line flags before initializing the engine, so use this
for the --arm-hwcap flag. Then store this string for InitARMFlags to use.

Depends on D137023

Comment 3

[Jan de Mooij [:jandem]]

Attachment: Bug 1752099 part 3 - Inline ComputeJitSupportFlags into its now sole caller. r?lth!

Depends on D137024

Comment 4

[Jan de Mooij [:jandem]]

Attachment: Bug 1752099 part 4 - Initialize x86/x64 testing flags before CPU flags are computed. r?lth!

Depends on D137025

Comment 5

[Jan de Mooij [:jandem]]

Attachment: Bug 1752099 part 5 - Move executable memory initialization into InitializeJit. r?lth!

This makes it a bit easier to reason about the ordering of these.

Depends on D137026

Comment 6

[Jan de Mooij [:jandem]]

Attachment: Bug 1752099 part 6 - Move ARM64 setup into InitializeJit. r?lth!

Also remove some WASI code that we no longer need because the callers have
HasJitBackend checks.

Depends on D137027

Comment 7

[Jan de Mooij [:jandem]]

Attachment: Bug 1752099 part 7 - Disable the JIT backend on platforms without floating-point support. r?lth!

This removes JitOptions.supportsFloatingPoint and instead uses the new
JitOptions.disableJitBackend flag.

The JS and Wasm compilers already checked the supportsFloatingPoint flag, only
the regular expression JIT might be affected.

The goal is to have a single runtime switch to enable/disable the JIT backend.

Depends on D137028

Comment 8

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/2b64bd930401
part 1 - Remove lazy CPU flags computation on x86/x64. r=lth
https://hg.mozilla.org/integration/autoland/rev/04d591b0098f
part 2 - Always parse ARM HwCap strings in InitARMFlags. r=lth
https://hg.mozilla.org/integration/autoland/rev/3ee867ff9af9
part 3 - Inline ComputeJitSupportFlags into its now sole caller. r=lth
https://hg.mozilla.org/integration/autoland/rev/ee91717522d8
part 4 - Initialize x86/x64 testing flags before CPU flags are computed. r=lth
https://hg.mozilla.org/integration/autoland/rev/92c4becbc088
part 5 - Move executable memory initialization into InitializeJit. r=lth
https://hg.mozilla.org/integration/autoland/rev/32b8805332fc
part 6 - Move ARM64 setup into InitializeJit. r=lth
https://hg.mozilla.org/integration/autoland/rev/97cfa0fc475c
part 7 - Disable the JIT backend on platforms without floating-point support. r=lth

Comment 9

[Iulian Moraru]

https://hg.mozilla.org/mozilla-central/rev/2b64bd930401
https://hg.mozilla.org/mozilla-central/rev/04d591b0098f
https://hg.mozilla.org/mozilla-central/rev/3ee867ff9af9
https://hg.mozilla.org/mozilla-central/rev/ee91717522d8
https://hg.mozilla.org/mozilla-central/rev/92c4becbc088
https://hg.mozilla.org/mozilla-central/rev/32b8805332fc
https://hg.mozilla.org/mozilla-central/rev/97cfa0fc475c