1727084 - Wasm64: Implement basic functionality

Status: RESOLVED FIXED

(Core :: JavaScript: WebAssembly, enhancement, P3)

Description

[Lars T Hansen [:lth]]

Implement all instructions with basic explicit bounds checking, memories still being limited to 4GB but pointers and offsets being 64 bits. (Initially we'll limit the offsets to 32 bits, as they are now.)

Comment 1

[Lars T Hansen [:lth]]

Attachment: Bug 1727084 - Memory64 - Preliminaries. r?yury

Scaffolding: Add assertions everywhere execution currently depends on
a memory being a memory32. These assertions will disappear by and by.

Add some useful predicates and guard memory64 on !huge-memory.

Depends on D124808

Comment 2

[Lars T Hansen [:lth]]

Attachment: Bug 1727084 - Memory64 - Bulk memory operations. r?yury

Implement 64-bit memory.grow and memory.size.

Introduce the suffixes M32 and M64 on instance call signatures to
disambiguate them properly. Rewrite existing ad-hoc suffixes
(typically just '32') to use the new ones.

Differentiate 64-bit instance call methods from ditto 32-bit with the
'_m32' and '_m64' syntax. Rewrite some existing '_i32' and '_i64'
cases to use the new syntax.

Depends on D124887

Comment 3

[Lars T Hansen [:lth]]

Bulk memory operations need better / more test cases but are otherwise considered done.

Comment 4

[Lars T Hansen [:lth]]

Attachment: Bug 1727084 - Memory64 - Non-atomic-RMW baseline operations. r?yury

Depends on D124888

Comment 5

[Lars T Hansen [:lth]]

Attachment: WIP: Bug 1727084 - Misc bugfixes, to be rolled in

Depends on D124888

Comment 6

[Lars T Hansen [:lth]]

Attachment: Bug 1727084 - Memory64 - Atomic-rmw baseline operations. r?yury

Comment 7

[Lars T Hansen [:lth]]

Attachment: Bug 1727084 - Memory64 - Ion operations. r?yury

Depends on D125524

Comment 8

[Lars T Hansen [:lth]]

Attachment: Bug 1727084 - Memory64 - Huge-memory status depends on index type. r?yury

Whether a memory is huge depends not just on whether huge memory
has been enabled in the process, but whether the memory's index
type allows the use of huge-memory optimization. (And in the
future it may depend on eg whether the memory, if it is i64,
has a declared maximum.) This fundamentally means that the
is-huge-memory attribute cannot be computed before compilation
starts but must be computed once the memory has been declared.

To make this simple, we parameterize IsHugeMemoryEnabled() by
the index type, and plumb the index type through the code where
we need it (not too many places). Features::hugeMemory can now
be removed.

The main issue with this is that IsHugeMemoryEnabled() becomes
fairly hot, yet it takes a multi-reader / single-writer lock
(that is never contended for writes, so should be fairly close
to optimal). If this becomes a bottleneck, we can read and
cache the value, or we can turn the lock into some relaxed
atomic, since the lock only controls a couple of bools and
everything would fit in a single word.

Comment 9

[Lars T Hansen [:lth]]

Attachment: Bug 1727084 - Memory64 - Allow larger-than-4GB allocations. r?yury

Depends on D124887

Comment 10

[Lars T Hansen [:lth]]

Attachment: Bug 1727084 - Memory64 - Expose the index type via js-types. r?yury

Depends on D126187

Comment 11

[Lars T Hansen [:lth]]

Attachment: Bug 1727084 - Memory64 - Test cases and testing code. r?yury

Depends on D125524

Comment 12

[Lars T Hansen [:lth]]

Status as of latest queue: Functionally complete and passes all tests on x64 + arm64. Missing Ion support for memory instructions on x86 and arm32.

Comment 13

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/5315e548b651
Memory64 - Huge-memory status depends on index type. r=yury
https://hg.mozilla.org/integration/autoland/rev/63ce829d63b4
Memory64 - Preliminaries. r=yury
https://hg.mozilla.org/integration/autoland/rev/d13d8c76693a
Memory64 - Allow larger-than-4GB allocations. r=yury
https://hg.mozilla.org/integration/autoland/rev/359e414a1d7f
Memory64 - Expose the index type via js-types. r=yury
https://hg.mozilla.org/integration/autoland/rev/b9d32ef0ad83
Memory64 - Bulk memory operations. r=yury
https://hg.mozilla.org/integration/autoland/rev/6089b4360edc
Memory64 - Non-atomic-RMW baseline operations. r=yury
https://hg.mozilla.org/integration/autoland/rev/1ab8383d17ee
Memory64 - Atomic-rmw baseline operations. r=yury
https://hg.mozilla.org/integration/autoland/rev/27db0e6a7010
Memory64 - Ion operations. r=yury
https://hg.mozilla.org/integration/autoland/rev/25456db35c17
Memory64 - Test cases and testing code. r=yury

Comment 14

[Cristina Cozmuta (:CrissCozmuta)]

Backed our for causing spidermonkey bustages on WasmMemory.cpp. CLOSED TREE

Backout link : https://hg.mozilla.org/integration/autoland/rev/b01a275e79a1d6b0ad5cc23a8ea96a539b0d451e

Push with failures : https://treeherder.mozilla.org/jobs?repo=autoland&selectedTaskRun=Efx2eK3bScyMvPlq65F8RQ.0&resultStatus=testfailed%2Cbusted%2Cexception%2Crunnable&revision=25456db35c176fcc71aaa73229da993a8aec5ec2&searchStr=SM

Link to failure log : https://treeherder.mozilla.org/logviewer?job_id=355128092&repo=autoland&lineNumber=8987

Comment 15

[Lars T Hansen [:lth]]

That was a weird bug after so many try runs, but just a header file missing.

Comment 16

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/83e52246d0ea
Memory64 - Huge-memory status depends on index type. r=yury
https://hg.mozilla.org/integration/autoland/rev/339e37a04ca1
Memory64 - Preliminaries. r=yury
https://hg.mozilla.org/integration/autoland/rev/caca657178e4
Memory64 - Allow larger-than-4GB allocations. r=yury
https://hg.mozilla.org/integration/autoland/rev/b658cfe4b173
Memory64 - Expose the index type via js-types. r=yury
https://hg.mozilla.org/integration/autoland/rev/13ee9674ee35
Memory64 - Bulk memory operations. r=yury
https://hg.mozilla.org/integration/autoland/rev/fb02656bb788
Memory64 - Non-atomic-RMW baseline operations. r=yury
https://hg.mozilla.org/integration/autoland/rev/44b0c0bed8a6
Memory64 - Atomic-rmw baseline operations. r=yury
https://hg.mozilla.org/integration/autoland/rev/3e40bdd11ab5
Memory64 - Ion operations. r=yury
https://hg.mozilla.org/integration/autoland/rev/80388e7f335c
Memory64 - Test cases and testing code. r=yury

Comment 17

[Natalia Csoregi [:nataliaCs]]

https://hg.mozilla.org/mozilla-central/rev/83e52246d0ea
https://hg.mozilla.org/mozilla-central/rev/339e37a04ca1
https://hg.mozilla.org/mozilla-central/rev/caca657178e4
https://hg.mozilla.org/mozilla-central/rev/b658cfe4b173
https://hg.mozilla.org/mozilla-central/rev/13ee9674ee35
https://hg.mozilla.org/mozilla-central/rev/fb02656bb788
https://hg.mozilla.org/mozilla-central/rev/44b0c0bed8a6
https://hg.mozilla.org/mozilla-central/rev/3e40bdd11ab5
https://hg.mozilla.org/mozilla-central/rev/80388e7f335c