Moves the feedback vector slot allocation out of ast-numbering and into
bytecode generation directly. This has a couple of benifits, including reduced
AST size, avoid code duplication and reduced feedback vector sizes in many cases
due to only allocating slots when needed. Also removes AstProperties since
this is no longer needed.
AstNumbering is now only used to allocate suspend ids for generators.
BUG=v8:6921
Change-Id: I103e8593c94ef5b2e56c34ef4f77bd6e7d64796f
Reviewed-on: https://chromium-review.googlesource.com/722959
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Michael Stanton <mvstanton@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48757}
This CL adds support to optimize for..in in fast enum-cache mode to the
same degree that it was optimized in Crankshaft, without adding the same
deoptimization loop that Crankshaft had with missing enum cache indices.
That means code like
for (var k in o) {
var v = o[k];
// ...
}
and code like
for (var k in o) {
if (Object.prototype.hasOwnProperty.call(o, k)) {
var v = o[k];
// ...
}
}
which follows the https://eslint.org/docs/rules/guard-for-in linter
rule, can now utilize the enum cache indices if o has only fast
properties on the receiver, which speeds up the access o[k]
significantly and reduces the pollution of the global megamorphic
stub cache.
For example the micro-benchmark in the tracking bug v8:6702 now runs
faster than ever before:
forIn: 1516 ms.
forInHasOwnProperty: 1674 ms.
forInHasOwnPropertySafe: 1595 ms.
forInSum: 2051 ms.
forInSumSafe: 2215 ms.
Compared to numbers from V8 5.8 which is the last version running with
Crankshaft
forIn: 1641 ms.
forInHasOwnProperty: 1719 ms.
forInHasOwnPropertySafe: 1802 ms.
forInSum: 2226 ms.
forInSumSafe: 2409 ms.
and V8 6.0 which is the current stable version with TurboFan:
forIn: 1713 ms.
forInHasOwnProperty: 5417 ms.
forInHasOwnPropertySafe: 5324 ms.
forInSum: 7556 ms.
forInSumSafe: 11067 ms.
It also improves the throughput on the string-fasta benchmark by
around 7-10%, and there seems to be a ~5% improvement on the
Speedometer/React benchmark locally.
For this to work, the ForInPrepare bytecode was split into
ForInEnumerate and ForInPrepare, which is very similar to how it was
handled in Fullcodegen initially. In TurboFan we introduce a new
operator LoadFieldByIndex that does the dynamic property load.
This also removes the CheckMapValue operator again in favor of
just using LoadField, ReferenceEqual and CheckIf, which work
automatically with the EscapeAnalysis and the
BranchConditionElimination.
Bug: v8:6702
Change-Id: I91235413eea478ba77ace7bd14bb2f62e155dd9a
Reviewed-on: https://chromium-review.googlesource.com/645949
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47768}
Removes handles from bytecode generation, instead storing
un-internalized AstValues (and other, similar values such as Scopes and
AstRawStrings) in the constant array builder.
This will allow us in the future to generate the bytecode before
internalizing the AST.
BUG=v8:5832
Change-Id: I3b8be8f7329a484eb1e5d12808b001d3475239da
Reviewed-on: https://chromium-review.googlesource.com/439326
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Marja Hölttä <marja@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#43115}
Downside: this adds all kinds of weird includes in the .cc files.
(See design doc linked in the bug.)
BUG=v8:5402
Review-Url: https://codereview.chromium.org/2622503002
Cr-Commit-Position: refs/heads/master@{#42140}
This allows us to optimise the bytecode liveness analysis to jump
directly to previously seen indices. The analysis is optimised to store
a stack of loop ends (JumpLoop bytecode indices), and iterate through
these indices directly rather than looping through the bytecode array to
find them.
Review-Url: https://codereview.chromium.org/2536653003
Cr-Commit-Position: refs/heads/master@{#41485}
