They have the same lifetime. It's a match!
Both structures are native context dependent and dealt with (creation,
clearing, gathering feedback) at the same time. By treating the spaces used
for literal boilerplates as feedback vector slots, we no longer have to keep
track of the materialized literal count elsewhere.
A follow-on CL removes even more parser infrastructure related to this count.
BUG=v8:5456
Review-Url: https://codereview.chromium.org/2655853010
Cr-Commit-Position: refs/heads/master@{#42771}
Since JumpLoop is always backwards, and other jumps are always forwards,
we can store the jump offset as an always positive integer and decide on
the jump direction based on the bytecode. This will save a small amount
of space for large-ish for loops (>128 bytecodes).
Review-Url: https://codereview.chromium.org/2641443002
Cr-Commit-Position: refs/heads/master@{#42638}
Atomics.wait is a function which may block, which is not allowed on the
main thread. Since V8 doesn't know whether a particular isolate is the
"main thread", this CL adds an option to Isolate::CreateParams to choose
whether this function is allowed.
Review-Url: https://codereview.chromium.org/2642293002
Cr-Commit-Position: refs/heads/master@{#42611}
The resume trampolin used to call the generator function with the context of the
last suspension rather than the closure's context. While that was fine for
Ignition, Turbofan got utterly confused. With this CL, the resume trampolin
always passes in the closure's context (like in the very first call of the
generator function). The generator function itself then restores its previously
current context by reading it from the generator object and doing a
PushContext.
BUG=chromium:681171
Review-Url: https://codereview.chromium.org/2639533002
Cr-Commit-Position: refs/heads/master@{#42407}
Most notably, the interpreter now calls this stub instead of the
runtime.
BUG=
Review-Url: https://codereview.chromium.org/2619163004
Cr-Commit-Position: refs/heads/master@{#42218}
ECMA 402 v2 made Intl constructors more strict in terms of how they would
initialize objects, refusing to initialize objects which have already
been constructed. However, when Chrome tried to ship these semantics,
we ran into web compatibility issues.
This patch tries to square the circle and implement the simpler v2 object
semantics while including a compatibility workaround to allow objects to
sort of be initialized later, storing the real underlying Intl object
in a symbol-named property.
The new semantics are described in this PR against the ECMA 402 spec:
https://github.com/tc39/ecma402/pull/84
BUG=v8:4360, v8:4870
LOG=Y
Review-Url: https://codereview.chromium.org/2582993002
Cr-Commit-Position: refs/heads/master@{#41943}
This is so that a NotSuperConstructor error is thrown before evaluating the
arguments to the super constructor. Besides updating the runtime function, a
new bytecode GetSuperConstructor is introduced.
BUG=v8:5336
Review-Url: https://codereview.chromium.org/2504553003
Cr-Commit-Position: refs/heads/master@{#41788}
This introduces an explicit struct for the communication channel between
the {ArrayLiteral} AST node and the corresponding runtime methods. Those
methods take a pair of {ElementsKind} as well as an array (can either be
a FixedArray or a FixedDoubleArray) of constant values.
For bonus points it also reduces the size of the involved heap object by
one word (i.e. length field of FixedArray not needed anymore).
R=mvstanton@chromium.org
Review-Url: https://codereview.chromium.org/2581683003
Cr-Commit-Position: refs/heads/master@{#41752}
Allocate the registers used as arguments to a call on-demand after visiting the
argument (or reciever). This means that the visited expression can use registers
that would otherwise have been allocated for arguments which haven't been
visited yet.
The reason for doing this is to avoid keeping things live in registers
unecessarily for chained function calls, which avoids a memory leak for
functions which chain a large number of calls with large temporary arguments /
recievers.
BUG=chromium:672027
Review-Url: https://codereview.chromium.org/2557173004
Cr-Commit-Position: refs/heads/master@{#41714}
Introduces:
- a new AST node representing the GetIterator() algorithm in the specification, to be used by ForOfStatement, YieldExpression (in the case of delegating yield*), and the future `for-await-of` loop proposed in http://tc39.github.io/proposal-async-iteration/#sec-async-iterator-value-unwrap-functions.
- a new opcode (JumpIfJSReceiver), which is useful for `if Type(object) is not Object` checks which are common throughout the specification. This node is easily eliminated by TurboFan.
The AST node is desugared specially in bytecode, rather than manually when building the AST. The benefit of this is that desugaring in the BytecodeGenerator is much simpler and easier to understand than desugaring the AST.
This also reduces parse time very slightly, and allows us to use LoadIC rather than KeyedLoadIC, which seems to have better baseline performance. This results in a ~20% improvement in test/js-perf-test/Iterators micro-benchmarks, which I believe owes to the use of the slightly faster LoadIC as opposed to the KeyedLoadIC in the baseline case. Both produce identical optimized code via TurboFan when the type check can be eliminated, and the load can be replaced with a constant value.
BUG=v8:4280
R=bmeurer@chromium.org, rmcilroy@chromium.org, adamk@chromium.org, neis@chromium.org, jarin@chromium.orgTBR=rossberg@chromium.org
Review-Url: https://codereview.chromium.org/2557593004
Cr-Commit-Position: refs/heads/master@{#41555}
Equality with null/undefined is equivalent to a check on the undetectable bit
on the map of the object. This would be more efficient than performing the entire
comparison operation.
This cl introduces:
1. A new bytecode called TestUndetectable that checks if the object is null/undefined.
2. Updates peeophole optimizer to emit TestUndetectable when a LdaNull/Undefined
precedes equality check.
4. TestUndetectable is transformed to ObjectIsUndetectable operator when building
turbofan graph.
BUG=v8:4280
Review-Url: https://codereview.chromium.org/2547043002
Cr-Commit-Position: refs/heads/master@{#41514}
Removed a redundant check: If completion is not normal, then #iterator cannot be undefined.
Review-Url: https://codereview.chromium.org/2533803002
Cr-Commit-Position: refs/heads/master@{#41321}
Adds a bytecode to set and retrieve the pending message. This avoids a
runtime call in finally blocks, and also ensures that TurboFan builds a
graph using the SetMessage / LoadMessage nodes instead of inserting a
runtime call.
BUG=chromium:662334
Review-Url: https://codereview.chromium.org/2501503005
Cr-Commit-Position: refs/heads/master@{#41023}
We seem to get some small wins from avoiding the Ldr bytecodes, probably due
to reduced icache pressure since there are less bytecode handlers. Replace
the Ldr bytecodes with Star lookahead inlined into the Lda versions.
Also fixes IsAccumulatorLoadWithoutEffects to include LdaContextSlot and
LdaCurrentContextSlot
BUG=v8:4280
Review-Url: https://codereview.chromium.org/2489513005
Cr-Commit-Position: refs/heads/master@{#40883}
The Ldr[Named/Keyed]Property bytecodes are problematic for the deoptimizer when
inlining accessors in TurboFan. Remove them and replace with a Star lookahead
in the bytecode handlers for Lda[Named/Keyed]Property.
BUG=v8:4280
Review-Url: https://codereview.chromium.org/2485383002
Cr-Commit-Position: refs/heads/master@{#40860}
The majority of context slot accesses are to the local context (current context
register and depth 0), so this adds bytecodes to optimise for that case.
This cuts down bytecode size by roughly 1% (measured on Octane and Top25).
Review-Url: https://codereview.chromium.org/2459513002
Cr-Commit-Position: refs/heads/master@{#40641}
This is a new bytecode which behaves (for now) exactly like Call,
except that in turbofan graph building we can set the
ConvertReceiverMode to NotNullOrUndefined.
I observe a 1% improvement on Box2D, I'd expect a similar improvement on
other OOP heavy code.
Review-Url: https://codereview.chromium.org/2450243002
Cr-Commit-Position: refs/heads/master@{#40610}
Move hole check logic from full-codegen into scope analysis, and store the
"needs hole check" bit on VariableProxy. This makes it easy to re-use in
any backend: it will be trivial to extend the use of this logic in, e.g.,
full-codegen variable stores.
While changing the signatures of the variable loading/storing methods in
Ignition, I took the liberty of replacing the verb "Visit" with "Build", since these
are not part of AST visiting.
BUG=v8:5460
Review-Url: https://chromiumcodereview.appspot.com/2411873004
Cr-Commit-Position: refs/heads/master@{#40479}
This makes optimization of all class constructors (i.e. both base and
derived) go through TurboFan. Note some class constructors containing
Harmony language features (e.g. super constructor calls or accesses to
the new.target value) were already going through TurboFan before.
R=bmeurer@chromium.org
BUG=v8:5458
Review-Url: https://codereview.chromium.org/2397723002
Cr-Commit-Position: refs/heads/master@{#40342}
There are only a few occasions where we allocate a register in an outer
expression allocation scope, which makes the costly free-list approach
of the BytecodeRegisterAllocator unecessary. This CL replaces all
occurrences with moves to the accumulator and stores to a register
allocated in the correct scope. By doing this, we can simplify the
BytecodeRegisterAllocator to be a simple bump-pointer allocator
with registers released in the same order as allocated.
The following changes are also made:
- Make BytecodeRegisterOptimizer able to use registers which have been
unallocated, but not yet reused
- Remove RegisterExpressionResultScope and rename
AccumulatorExpressionResultScope to ValueExpressionResultScope
- Introduce RegisterList to represent consecutive register
allocations, and use this for operands to call bytecodes.
By avoiding the free-list handling, this gives another couple of
percent on CodeLoad.
BUG=v8:4280
Review-Url: https://codereview.chromium.org/2369873002
Cr-Commit-Position: refs/heads/master@{#39905}
Use an unordered_map<Module, unordered_set<String>> to keep track
of visited Module/ExportName pairs during ResolveExport.
This required adding a Hash() method to Module, which is accomplished
by allocating a Symbol and storing it in the SharedFunctionInfo::name
slot, then delegating the hash to that Symbol.
Also added a helper method Module::shared() to easily get ahold of
the SharedFunctionInfo and call it in the appropriate places instead
of re-doing the ternary operator.
BUG=v8:1569
Review-Url: https://codereview.chromium.org/2367623004
Cr-Commit-Position: refs/heads/master@{#39743}
The CreateArrayLiteral bytecode handler now directly inlines the FastCloneShallowArrayStub.
BUG=v8:4280
Review-Url: https://codereview.chromium.org/2341743003
Cr-Commit-Position: refs/heads/master@{#39562}
Add a notion of "invocation count" to the baseline compilers, which
increment a special slot in the TypeFeedbackVector for each invocation
of a given function (the optimized code doesn't currently collect this
information).
Use this invocation count to relativize the call counts on the call
sites within the function, so that the inlining heuristic has a view
of relative importance of a call site rather than some absolute numbers
with unclear meaning for the current function. Also apply the call site
frequency as a factor to all frequencies in the inlinee by passing this
to the graph builders so that the importance of a call site in an
inlinee is relative to the topmost optimized function.
Note that all functions that neither have literals nor need type
feedback slots will share a single invocation count cell in the
canonical empty type feedback vector, so their invocation count is
meaningless, but that doesn't matter since we only use the invocation
count to relativize call counts within the function, which we only have
if we have at least one type feedback vector (the CallIC slot).
See the design document for additional details on this change:
https://docs.google.com/document/d/1VoYBhpDhJC4VlqMXCKvae-8IGuheBGxy32EOgC2LnT8
BUG=v8:5267,v8:5372
R=mvstanton@chromium.org,rmcilroy@chromium.org,mstarzinger@chromium.org
Review-Url: https://codereview.chromium.org/2337123003
Cr-Commit-Position: refs/heads/master@{#39410}
This introduces a new {JumpLoop} bytecode to combine the OSR polling
mechanism modeled by {OsrPoll} with the actual {Jump} performing the
backwards branch. This reduces the overall size and also avoids one
additional dispatch. It also makes sure that OSR polling is only done
within real loops.
R=rmcilroy@chromium.org
BUG=v8:4764
Review-Url: https://codereview.chromium.org/2331033002
Cr-Commit-Position: refs/heads/master@{#39384}
Moves the context chain search loop out of generated bytecode, and into
the (Lda|Ldr|Sda)ContextSlot handler, by passing the context depth in as
an additional operand. This should decrease the bytecode size and
increase performance for deep context chain searches, at the cost of
slightly increasing bytecode size for shallow context access.
Review-Url: https://codereview.chromium.org/2336643002
Cr-Commit-Position: refs/heads/master@{#39378}
In ignition, allocation site mementos were disabled when creating array
literals. Enabled them in this cl.
BUG=v8:4280
LOG=N
Review-Url: https://codereview.chromium.org/2294913006
Cr-Commit-Position: refs/heads/master@{#39234}
For historical reasons, the interpreter's bytecode expectations tests
required a type for the constant pool. This had two disadvantages:
1. Strings and numbers were not visible in mixed pools, and
2. Mismatches of pool types (e.g. when rebaselining) would cause parser
errors
This removes the pool types, making everything 'mixed', but appending
the values to string and number valued constants. Specifying a pool type
in the *.golden header now prints a warning (for backwards compatibility).
BUG=v8:5350
Review-Url: https://codereview.chromium.org/2310103002
Cr-Commit-Position: refs/heads/master@{#39216}
Reason for revert:
Performance regressions: crbug.com/644087
Clusterfuzz: crbug.com/644074
We'll reland all regexp changes at once when the port is complete and at least performance-neutral, since the partial port requires slow workarounds.
Original issue's description:
> [regexp] Port RegExp getters and setters
>
> BUG=v8:5339
>
> Committed: https://crrev.com/ac0eb5e05af40e16ae9402bb8a62600b32cc2ec9
> Committed: https://crrev.com/7711b1a16f864ed6ea56fa40274ff3f6287bbe34
> Cr-Original-Commit-Position: refs/heads/master@{#39076}
> Cr-Commit-Position: refs/heads/master@{#39088}
TBR=bmeurer@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=v8:5339
Review-Url: https://codereview.chromium.org/2313713002
Cr-Commit-Position: refs/heads/master@{#39176}
Since the extension field is already used for the catch name, store a
ContextExtension there instead.
In the future, this will allow for chaining ScopeInfos together, so we
no longer need a context chain for lazy parsing / compilation.
BUG=v8:5215
R=bmeurer@chromium.org,neis@chromium.org,marja@chromium.org
Review-Url: https://codereview.chromium.org/2302013002
Cr-Commit-Position: refs/heads/master@{#39164}
One more bytecode to pass info through to TurboFan.
BUG=v8:4280
LOG=n
Review-Url: https://codereview.chromium.org/2260473003
Cr-Commit-Position: refs/heads/master@{#38726}
Async functions are implemented via special generator functions; special in the
sense that they generally do not immediately yield. However, our generators
implementation still assumed that every generator function initially yields
(concretely: before doing the state dispatch in a loop header). This CL fixes
that.
R=littledan@chromium.org, rmcilroy@chromium.org
BUG=chromium:638019
Review-Url: https://codereview.chromium.org/2253033002
Cr-Commit-Position: refs/heads/master@{#38684}
Allows us to create a corresponding TurboFan node, so TF can
optimize it.
BUG=v8:4280
LOG=n
Review-Url: https://codereview.chromium.org/2248633002
Cr-Commit-Position: refs/heads/master@{#38651}
Adds TestResultScope and uses it to directly jump/fall through to the
correct branch in expressions used as branch conditions.
Should enable nicer TurboFan-graphs for easier control-flow
transformations in the future.
BUG=v8:4280
LOG=n
Review-Url: https://codereview.chromium.org/2242463002
Cr-Commit-Position: refs/heads/master@{#38634}
ForInPrepare checked whether the receiver object was null, undefined or
converted to a JSObject. This is already done by the generated bytecode.
BUG=v8:4820
LOG=n
Review-Url: https://codereview.chromium.org/2208043002
Cr-Commit-Position: refs/heads/master@{#38394}
