Collect type information for JavaScript variables and display it
in Chrome DevTools.
Design Doc: https://docs.google.com/a/google.com/document/d/1O1uepXZXBI6IwiawTrYC3ohhiNgzkyTdjn3R8ysbYgk/edit?usp=sharing
When debugging JavaScript, it’s helpful to know the type of
a variable, parameter, and return values. JavaScript is
dynamically typed, and for complex
source code it’s often hard to infer types. With type profiling, we
can provide type information to JavaScript developers.
This CL is a proof of concept. It collects type profile for
assignments and simply prints the types to stdout.
The output looks something like this:
#my_var1
#Object
#number
#string
#number
#undefined
#string
#Object
#Object
We use an extra slot in the feedback vector of assignments to
carry the list of types for that assignment. The extra slot is
only added when the flag --type-profile is given.
Missing work:
* Collect data for parameters and return values (currently only assignments).
* Remove duplicates from the list of collected types and use a common base class.
* Add line numbers or source position instead of the variable name.
BUG=v8:5935
Review-Url: https://codereview.chromium.org/2707873002
Cr-Original-Original-Commit-Position: refs/heads/master@{#43791}
Committed: 0332bebde9
Review-Url: https://codereview.chromium.org/2707873002
Cr-Original-Commit-Position: refs/heads/master@{#43804}
Committed: 6cf880f4b8
Review-Url: https://codereview.chromium.org/2707873002
Cr-Commit-Position: refs/heads/master@{#43846}
Adds a TestTypeof bytecode to deal with comparisons of the form:
typeof(object) === 'string';
Also adds support to Turbofan to perform these comparisons without
inserting checkpoints.
BUG=v8:4280,v8:5267
Change-Id: Ib5cc1c6816dfe70a4120838d8eada2fc0267750f
Reviewed-on: https://chromium-review.googlesource.com/454837
Reviewed-by: Mythri Alle <mythria@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#43832}
Reason for revert:
gcc bot is now flaky https://build.chromium.org/p/client.v8/builders/V8%20Linux%20gcc%204.8/builds/11863
Original issue's description:
> Collect type profile for DevTools
>
> Collect type information for JavaScript variables and display it
> in Chrome DevTools.
> Design Doc: https://docs.google.com/a/google.com/document/d/1O1uepXZXBI6IwiawTrYC3ohhiNgzkyTdjn3R8ysbYgk/edit?usp=sharing
>
> When debugging JavaScript, it’s helpful to know the type of
> a variable, parameter, and return values. JavaScript is
> dynamically typed, and for complex
> source code it’s often hard to infer types. With type profiling, we
> can provide type information to JavaScript developers.
>
> This CL is a proof of concept. It collects type profile for
> assignments and simply prints the types to stdout.
>
> The output looks something like this:
>
> #my_var1
> #Object
> #number
> #string
> #number
> #undefined
> #string
> #Object
> #Object
>
>
> We use an extra slot in the feedback vector of assignments to
> carry the list of types for that assignment. The extra slot is
> only added when the flag --type-profile is given.
>
>
> Missing work:
> * Collect data for parameters and return values (currently only assignments).
> * Remove duplicates from the list of collected types and use a common base class.
> * Add line numbers or source position instead of the variable name.
>
>
>
> BUG=v8:5935
>
> Review-Url: https://codereview.chromium.org/2707873002
> Cr-Original-Commit-Position: refs/heads/master@{#43791}
> Committed: 0332bebde9
> Review-Url: https://codereview.chromium.org/2707873002
> Cr-Commit-Position: refs/heads/master@{#43804}
> Committed: 6cf880f4b8TBR=yangguo@chromium.org,mvstanton@chromium.org,rmcilroy@chromium.org,mstarzinger@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:5935
Review-Url: https://codereview.chromium.org/2754573002
Cr-Commit-Position: refs/heads/master@{#43805}
Collect type information for JavaScript variables and display it
in Chrome DevTools.
Design Doc: https://docs.google.com/a/google.com/document/d/1O1uepXZXBI6IwiawTrYC3ohhiNgzkyTdjn3R8ysbYgk/edit?usp=sharing
When debugging JavaScript, it’s helpful to know the type of
a variable, parameter, and return values. JavaScript is
dynamically typed, and for complex
source code it’s often hard to infer types. With type profiling, we
can provide type information to JavaScript developers.
This CL is a proof of concept. It collects type profile for
assignments and simply prints the types to stdout.
The output looks something like this:
#my_var1
#Object
#number
#string
#number
#undefined
#string
#Object
#Object
We use an extra slot in the feedback vector of assignments to
carry the list of types for that assignment. The extra slot is
only added when the flag --type-profile is given.
Missing work:
* Collect data for parameters and return values (currently only assignments).
* Remove duplicates from the list of collected types and use a common base class.
* Add line numbers or source position instead of the variable name.
BUG=v8:5935
Review-Url: https://codereview.chromium.org/2707873002
Cr-Original-Commit-Position: refs/heads/master@{#43791}
Committed: 0332bebde9
Review-Url: https://codereview.chromium.org/2707873002
Cr-Commit-Position: refs/heads/master@{#43804}
Reason for revert:
gcc bot has problems with this: https://build.chromium.org/p/client.v8/builders/V8%20Linux%20gcc%204.8/builds/11858
Original issue's description:
> Collect type profile for DevTools
>
> Collect type information for JavaScript variables and display it
> in Chrome DevTools.
> Design Doc: https://docs.google.com/a/google.com/document/d/1O1uepXZXBI6IwiawTrYC3ohhiNgzkyTdjn3R8ysbYgk/edit?usp=sharing
>
> When debugging JavaScript, it’s helpful to know the type of
> a variable, parameter, and return values. JavaScript is
> dynamically typed, and for complex
> source code it’s often hard to infer types. With type profiling, we
> can provide type information to JavaScript developers.
>
> This CL is a proof of concept. It collects type profile for
> assignments and simply prints the types to stdout.
>
> The output looks something like this:
>
> #my_var1
> #Object
> #number
> #string
> #number
> #undefined
> #string
> #Object
> #Object
>
>
> We use an extra slot in the feedback vector of assignments to
> carry the list of types for that assignment. The extra slot is
> only added when the flag --type-profile is given.
>
>
> Missing work:
> * Collect data for parameters and return values (currently only assignments).
> * Remove duplicates from the list of collected types and use a common base class.
> * Add line numbers or source position instead of the variable name.
>
>
>
> BUG=v8:5935
>
> Review-Url: https://codereview.chromium.org/2707873002
> Cr-Commit-Position: refs/heads/master@{#43791}
> Committed: 0332bebde9TBR=yangguo@chromium.org,mvstanton@chromium.org,rmcilroy@chromium.org,mstarzinger@chromium.org,franzih@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:5935
Review-Url: https://codereview.chromium.org/2749673003
Cr-Commit-Position: refs/heads/master@{#43798}
Collect type information for JavaScript variables and display it
in Chrome DevTools.
Design Doc: https://docs.google.com/a/google.com/document/d/1O1uepXZXBI6IwiawTrYC3ohhiNgzkyTdjn3R8ysbYgk/edit?usp=sharing
When debugging JavaScript, it’s helpful to know the type of
a variable, parameter, and return values. JavaScript is
dynamically typed, and for complex
source code it’s often hard to infer types. With type profiling, we
can provide type information to JavaScript developers.
This CL is a proof of concept. It collects type profile for
assignments and simply prints the types to stdout.
The output looks something like this:
#my_var1
#Object
#number
#string
#number
#undefined
#string
#Object
#Object
We use an extra slot in the feedback vector of assignments to
carry the list of types for that assignment. The extra slot is
only added when the flag --type-profile is given.
Missing work:
* Collect data for parameters and return values (currently only assignments).
* Remove duplicates from the list of collected types and use a common base class.
* Add line numbers or source position instead of the variable name.
BUG=v8:5935
Review-Url: https://codereview.chromium.org/2707873002
Cr-Commit-Position: refs/heads/master@{#43791}
Specifically, add bytecodes for Call0, Call1, Call2, CallProperty0, CallProperty1,
and CallProperty2. Also share the bytecode handler code between between
equivalent CallX and CallPropertyX handlers.
Review-Url: https://codereview.chromium.org/2684993002
Cr-Original-Commit-Position: refs/heads/master@{#43290}
Committed: 00d6f1f80a
Review-Url: https://codereview.chromium.org/2684993002
Cr-Commit-Position: refs/heads/master@{#43700}
The parser already changes all negative equality comparison operations
to their positive pendants in {ParserBase::ParseBinaryExpression}. No
other source of the Token::NE exists in the system. We can remove all
handling from the compiler and interpreter backends.
R=bmeurer@chromium.org
Change-Id: I58722c08dd8e498f20c65886fce86b8172737b10
Reviewed-on: https://chromium-review.googlesource.com/449716
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#43627}
Reason for revert:
Due to arm64 failures
Original issue's description:
> [interpreter] Create custom call opcodes for specific argument counts
>
> Specifically, add bytecodes for Call0, Call1, Call2, CallProperty0, CallProperty1,
> and CallProperty2. Also share the bytecode handler code between between
> equivalent CallX and CallPropertyX handlers.
>
> Review-Url: https://codereview.chromium.org/2684993002
> Cr-Commit-Position: refs/heads/master@{#43290}
> Committed: 00d6f1f80aTBR=rmcilroy@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
Review-Url: https://codereview.chromium.org/2709533002
Cr-Commit-Position: refs/heads/master@{#43308}
Specifically, add bytecodes for Call0, Call1, Call2, CallProperty0, CallProperty1,
and CallProperty2. Also share the bytecode handler code between between
equivalent CallX and CallPropertyX handlers.
Review-Url: https://codereview.chromium.org/2684993002
Cr-Commit-Position: refs/heads/master@{#43290}
... which is used for initializing properties with non compile time values.
Currently we use StoreOwnIC only for storing properties that already exist
in the boilerplate therefore we can reuse StoreIC dispatcher.
The proper StoreOwnIC dispatcher will be implemented in a separate CL.
BUG=v8:5495, v8:4414
Change-Id: I9c33fdb8499ec5be2c7fce1ecb6ce7aa285e5844
Reviewed-on: https://chromium-review.googlesource.com/443588
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#43285}
Before this patch, the registers needed for bytecode dispatch in interpreter
handlers were inconsistently stored in the interpreter frame and/or kept in
values that remained live across calls.
After this patch, these registers are explicitly reloaded after calls, making it
possible to elide the spills of those registers before the call in many cases.
Some highlights from the CL:
* Added methods to the CSA and InterpreterAssembler to efficiently store and
load Smis values and Smi interpreter registers on x64 without explicit
tagging/untagging.
* Created Variables for all of the interpreter-internal values that need to be
reloaded before bytecode dispatch at the end of an interpreter handler.
* The bytecode offset can be written out early in a handler by marking it
has having a call along it's critical path. By moving this early in a
handler, it becomes possible to use memory operands for pushes used to
marshall parameters when making calls.
Change-Id: Icf8d7798789f88a4489e06a7092616bbbb881577
Reviewed-on: https://chromium-review.googlesource.com/442566
Commit-Queue: Daniel Clifford <danno@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#43260}
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}
Reason for revert:
False alarm, bot hiccup
Original issue's description:
> Revert of Thread maybe-assigned through the bytecodes. (patchset #5 id:80001 of https://codereview.chromium.org/2655733003/ )
>
> Reason for revert:
> needed for properly reverting f3ae5ccf57
>
> Original issue's description:
> > Thread maybe-assigned through the bytecodes.
> >
> > This introduces LoadImmutableContextSlot and LoadImmutableCurrentContextSlot
> > bytecodes, which are emitted when reading from never-assigned context slot.
> >
> > There is a subtlety here: the slot are not immutable, the meaning is
> > actually undefined-or-hole-or-immutable.
> >
> > Review-Url: https://codereview.chromium.org/2655733003
> > Cr-Commit-Position: refs/heads/master@{#43000}
> > Committed: 17c2dd3886
>
> TBR=rmcilroy@chromium.org,bmeurer@chromium.org,neis@chromium.org,jarin@chromium.org
> # Skipping CQ checks because original CL landed less than 1 days ago.
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
>
> Review-Url: https://codereview.chromium.org/2680923003
> Cr-Commit-Position: refs/heads/master@{#43011}
> Committed: ece4e54a31TBR=rmcilroy@chromium.org,bmeurer@chromium.org,neis@chromium.org,jarin@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
Review-Url: https://codereview.chromium.org/2679953003
Cr-Commit-Position: refs/heads/master@{#43012}
Reason for revert:
needed for properly reverting f3ae5ccf57
Original issue's description:
> Thread maybe-assigned through the bytecodes.
>
> This introduces LoadImmutableContextSlot and LoadImmutableCurrentContextSlot
> bytecodes, which are emitted when reading from never-assigned context slot.
>
> There is a subtlety here: the slot are not immutable, the meaning is
> actually undefined-or-hole-or-immutable.
>
> Review-Url: https://codereview.chromium.org/2655733003
> Cr-Commit-Position: refs/heads/master@{#43000}
> Committed: 17c2dd3886TBR=rmcilroy@chromium.org,bmeurer@chromium.org,neis@chromium.org,jarin@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
Review-Url: https://codereview.chromium.org/2680923003
Cr-Commit-Position: refs/heads/master@{#43011}
This introduces LoadImmutableContextSlot and LoadImmutableCurrentContextSlot
bytecodes, which are emitted when reading from never-assigned context slot.
There is a subtlety here: the slot are not immutable, the meaning is
actually undefined-or-hole-or-immutable.
Review-Url: https://codereview.chromium.org/2655733003
Cr-Commit-Position: refs/heads/master@{#43000}
... and TypeFeedbackMetadata to FeedbackMetadata.
BUG=
Change-Id: I2556d1c2a8f37b8cf3d532cc98d973b6dc7e9e6c
Reviewed-on: https://chromium-review.googlesource.com/439244
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Michael Stanton <mvstanton@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Hannes Payer <hpayer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#42999}
TypeFeedbackVectors are strongly rooted by a closure. However, in modern
JavaScript closures are created and abandoned more freely. An important
closure may not be present in the root-set at time of garbage collection,
even though we've cached optimized code and use it regularly. For
example, consider leaf functions in an event dispatching system. They may
well be "hot," but tragically non-present when we collect the heap.
Until now, we've relied on a weak root to cache the feedback vector in
this case. Since there is no way to signal intent or relative importance,
this weak root is as susceptible to clearing as any other weak root at
garbage collection time.
Meanwhile, the feedback vector has become more important. All of our
ICs store their data there. Literal and regex boilerplates are stored there.
If we lose the vector, then we not only lose optimized code built from
it, we also lose the very feedback which allowed us to create that optimized
code. Therefore it's vital to express that dependency through the root
set.
This CL does this by creating a strong link to a feedback
vector at the instantiation site of the function closure.
This instantiation site is in the code and feedback vector
of the outer closure.
BUG=v8:5456
Review-Url: https://codereview.chromium.org/2674593003
Cr-Commit-Position: refs/heads/master@{#42953}
Rename to Construct and ConstructWithSpread, to match the names of
the JSOperators used.
Unfortunately, I can't find a way for auto-formatting to stay happy unless we
change the indentation for the whole BYTECODE_LIST macro.
Review-Url: https://codereview.chromium.org/2663963003
Cr-Commit-Position: refs/heads/master@{#42840}
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}
We can share almost all of the architecture-specific builtin code with super-call-with-spread.
Info to port-writers: The code in CheckSpreadAndPushToStack has changed slightly from what was in Generate_ConstructWithSpread, in that we take the length of the spreaded parameters from the JSArray rather than the FixedArray backing store.
BUG=v8:5511
Review-Url: https://codereview.chromium.org/2649143002
Cr-Commit-Position: refs/heads/master@{#42632}
Reason for revert:
Causes a few bugs caught by clusterfuzz.
Original issue's description:
> [Ignition/turbo] Add a CallWithSpread bytecode.
>
> Also, emit a NewWithSpread bytecode for CallNew AST nodes where possible, rather than desugaring in the parser.
>
> BUG=v8:5511
>
> Review-Url: https://codereview.chromium.org/2629363002
> Cr-Commit-Position: refs/heads/master@{#42455}
> Committed: 4bae43471dTBR=bmeurer@chromium.org,rmcilroy@chromium.org,verwaest@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:5511
Review-Url: https://codereview.chromium.org/2642843002
Cr-Commit-Position: refs/heads/master@{#42470}
Also, emit a NewWithSpread bytecode for CallNew AST nodes where possible, rather than desugaring in the parser.
BUG=v8:5511
Review-Url: https://codereview.chromium.org/2629363002
Cr-Commit-Position: refs/heads/master@{#42455}
Moves constant element/property array building to be deferred for
igition and on-demand for the other compilers, and splits off the
object/array literal depth/flag initialisation from the array building.
BUG=v8:5832
Review-Url: https://codereview.chromium.org/2625873009
Cr-Commit-Position: refs/heads/master@{#42362}
This changes the NewClosure interface descriptor, but ignores
the additional vector/slot arguments for now. The feedback vector
gets larger, as it holds a space for each literal array. A follow-on
CL will constructively use this space.
BUG=v8:5456
Review-Url: https://codereview.chromium.org/2614373002
Cr-Commit-Position: refs/heads/master@{#42146}
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}
Add a feedback vector slot for computed property names in object
and class literals. Introduce new slot kind for storing
computed property names.
Change StaDataPropertyInLiteral to use the accumulator (again), so
we don't exceed Bytecodes::kMaxOperands.
We assume that most computed property names are
symbols. Therefore we should see performance
improvements, even if we deal with monomorphic ICs only.
This CL only collects feedback but does not use
it in Reduce() yet.
BUG=v8:5624
Review-Url: https://codereview.chromium.org/2587393006
Cr-Commit-Position: refs/heads/master@{#42082}
... and add explicit CallPrologue/CallEpilogue callbacks to CodeAssemblerState instead.
This will allow IntepreterAssembler to use any other helper assembler.
TBR=rmcilroy@chromium.org
BUG=
Review-Url: https://codereview.chromium.org/2600183004
Cr-Commit-Position: refs/heads/master@{#41973}
Reason for revert:
Speculative revert because of blocked roll: https://codereview.chromium.org/2596013002/
Original issue's description:
> [TypeFeedbackVector] Root literal arrays in function literals slots
>
> Literal arrays and feedback vectors for a function can be garbage
> collected if we don't have a rooted closure for the function, which
> happens often. It's expensive to come back from this (recreating
> boilerplates and gathering feedback again), and the cost is
> disproportionate if the function was inlined into optimized code.
>
> To guard against losing these arrays when we need them, we'll now
> create literal arrays when creating the feedback vector for the outer
> closure, and root them strongly in that vector.
>
> BUG=v8:5456
>
> Review-Url: https://codereview.chromium.org/2504153002
> Cr-Commit-Position: refs/heads/master@{#41893}
> Committed: 93df094081TBR=bmeurer@chromium.org,mlippautz@chromium.org,mvstanton@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:5456
Review-Url: https://codereview.chromium.org/2597163002
Cr-Commit-Position: refs/heads/master@{#41917}
Literal arrays and feedback vectors for a function can be garbage
collected if we don't have a rooted closure for the function, which
happens often. It's expensive to come back from this (recreating
boilerplates and gathering feedback again), and the cost is
disproportionate if the function was inlined into optimized code.
To guard against losing these arrays when we need them, we'll now
create literal arrays when creating the feedback vector for the outer
closure, and root them strongly in that vector.
BUG=v8:5456
Review-Url: https://codereview.chromium.org/2504153002
Cr-Commit-Position: refs/heads/master@{#41893}
eval() may introduce a scope which needs to be represented as a context at
runtime, e.g.,
eval('var x; let y; ()=>y')
introduces a variable y which needs to have a context allocated for it. However,
when traversing upwards to find the declaration context for a variable which leaks,
as the declaration of x does above, this context has to be understood to not be
a declaration context in sloppy mode.
This patch makes that distinction by introducing a different map for eval-introduced
contexts. A dynamic search for the appropriate context will continue past an eval
context to find the appropriate context. Marking contexts as eval contexts rather
than function contexts required updates in each compiler backend.
BUG=v8:5295, chromium:648719
Review-Url: https://codereview.chromium.org/2435023002
Cr-Commit-Position: refs/heads/master@{#41869}
Encode the PropertyAttribute and whether the function
names must be set as a flag instead of setting two registers.
BUG=v8:5624
Review-Url: https://codereview.chromium.org/2586463002
Cr-Commit-Position: refs/heads/master@{#41812}
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}
Transform LdaNull/LdaUndefined followed by StrictEquality to TestNull/TestUndefined.
This would avoid a call to the compare IC. In the bytecode-graph builder these are
mapped to StrictEqual javascript operator. When reducing this operator, we already
optimize the cases for null/undefined.
BUG=v8:4280
Review-Url: https://codereview.chromium.org/2554723004
Cr-Commit-Position: refs/heads/master@{#41768}
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}
Templatizes the AccumulatorUsage and OperandType for BytecodeNode creation and
BytecodeRegisterOptimizer::PrepareForBytecode. This allows the compiler to
statically know whether the bytecode being created accesses the accumulator
and what operand types need scaling, avoiding runtime checks in the code.
Also removes BytecodeNode::set_bytecode methods.
Review-Url: https://codereview.chromium.org/2542903003
Cr-Commit-Position: refs/heads/master@{#41706}
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}
This just calls into a runtime function for implementation currently.
Intermediate step in speeding up constructor calls containing a spread.
The NewWithSpread bytecode will probably end up having different arguments with future CLs - the constructor and the new.target should have their own regs. For now we are calling into the runtime function, so we need the regs together.
BUG=v8:5659
Review-Url: https://codereview.chromium.org/2541113004
Cr-Commit-Position: refs/heads/master@{#41542}
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}
Reorders the jump bytecodes so that the majority of jump checks can be
implemented as range checks (rather than a list of comparisons that get
compiled to a bunch of jumps).
Review-Url: https://codereview.chromium.org/2537123002
Cr-Commit-Position: refs/heads/master@{#41498}
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}
