This reached consensus in the March 2020 TC39.
https://github.com/tc39/ecma262/pull/1908
This aligns JS with wasm, which allows atomics operations on non-shared
linear memory.
Bug: v8:10687, v8:9921
Change-Id: I7b60473b271cee6bccb342e97a4fd3781aedddb4
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2330802
Commit-Queue: Shu-yu Guo <syg@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69392}
This cl makes IsLockFree return true for 8 bytes on x64 platforms.
The standard is unfortunately a bit vague on what exactly 'lock free' means.
As a result, we err on the side of caution. We can revisit this, but first
we need the specification to nail down exactly what 'lock free' in this
context.
Bug: v8:8100
Change-Id: I0a6099c6cb95a5581f3e71d0267857b88b4a2f0a
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1735592
Commit-Queue: Joshua Litt <joshualitt@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63099}
It's required by the spec -- and observable -- that the index be validated
before the conversion of the value(s) via ToInteger.
The previous implementation also had an old test for validating the atomic
index, which has now been switched to ToIndex.
This also exposed an issue in the ia32 code generator: cmpxchg_b requires a
byte register, but the ia32 instruction selector was ensuring that the
new_value was a byte register, not the TempRegister. This change forces the
temp register to use edx, which always can be used as a byte register (dl).
This is the same behavior as currently used in UseByteRegister.
BUG=v8:4614
R=jarin@chromium.org,jkummerow@chromium.org
Review-Url: https://codereview.chromium.org/2814753003
Cr-Commit-Position: refs/heads/master@{#44626}
Reland of (https://codereview.chromium.org/1617503003)
* New atomic code stubs for x64, ia32, arm, arm64
* Add convenience functions JumpIfNotValidSmiValue, JumpIfUintNotValidSmiValue
to macro-assembler-ia32 (API based on x64 macro assembler)
* Remove runtime implementation of Atomics.load, the code stub should always be
called instead
* Add new test to mjsunit atomics test; check that Smi values of different
sizes are supported when possible, else fall back to HeapNumbers
These changes were needed to add another codestub:
* Bump kStubMajorKeyBits from 7 to 8
* Reduce ScriptContextFieldStub::kSlotIndexBits from 13 to 12
BUG=v8:4614
LOG=y
TBR=jarin@chromium.org,bmeurer@chromium.org,rodolph.perfetta@gmail.com,machenbach@chromium.org
Review URL: https://codereview.chromium.org/1617503003
Cr-Commit-Position: refs/heads/master@{#35427}
Review URL: https://codereview.chromium.org/1881383003
Cr-Commit-Position: refs/heads/master@{#35453}
Reason for revert:
[Sheriff] Roll was reverted. Please fix unused methods, see:
https://codereview.chromium.org/1884913002/https://build.chromium.org/p/tryserver.chromium.win/builders/win_clang/builds/5585/steps/compile%20%28with%20patch%29/logs/stdio
Original issue's description:
> [Atomics] code stubs for atomic operations
>
> * New atomic code stubs for x64, ia32, arm, arm64
> * Add convenience functions JumpIfNotValidSmiValue, JumpIfUintNotValidSmiValue
> to macro-assembler-ia32 (API based on x64 macro assembler)
> * Remove runtime implementation of Atomics.load, the code stub should always be
> called instead
> * Add new test to mjsunit atomics test; check that Smi values of different
> sizes are supported when possible, else fall back to HeapNumbers
>
> These changes were needed to add another codestub:
> * Bump kStubMajorKeyBits from 7 to 8
> * Reduce ScriptContextFieldStub::kSlotIndexBits from 13 to 12
>
> BUG=v8:4614
> LOG=y
>
> Committed: https://crrev.com/10b5febe11b318cfef130abae343183ac862e60d
> Cr-Commit-Position: refs/heads/master@{#35427}
TBR=jarin@chromium.org,bmeurer@chromium.org,rodolph.perfetta@gmail.com,binji@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:4614
Review URL: https://codereview.chromium.org/1884883003
Cr-Commit-Position: refs/heads/master@{#35443}
* New atomic code stubs for x64, ia32, arm, arm64
* Add convenience functions JumpIfNotValidSmiValue, JumpIfUintNotValidSmiValue
to macro-assembler-ia32 (API based on x64 macro assembler)
* Remove runtime implementation of Atomics.load, the code stub should always be
called instead
* Add new test to mjsunit atomics test; check that Smi values of different
sizes are supported when possible, else fall back to HeapNumbers
These changes were needed to add another codestub:
* Bump kStubMajorKeyBits from 7 to 8
* Reduce ScriptContextFieldStub::kSlotIndexBits from 13 to 12
BUG=v8:4614
LOG=y
Review URL: https://codereview.chromium.org/1617503003
Cr-Commit-Position: refs/heads/master@{#35427}
