This change introduces new intrinsics used to desugar async functions
in the Parser and the BytecodeGenerator, namely we introduce a new
%_AsyncFunctionEnter intrinsic that constructs the generator object
for the async function (and in the future will also create the outer
promise for the async function). This generator object is internal
and never escapes to user code, plus since async functions don't have
a "prototype" property, we can just a single map here instead of tracking
the prototype/initial_map on every async function. This saves one word
per async function plus one initial_map per async function that was
invoked at least once.
We also introduce two new intrinsics %_AsyncFunctionReject, which
rejects the outer promise with the caught exception, and another
%_AsyncFunctionResolve, which resolves the outer promise with the
right hand side of the `return` statement. These functions also perform
the DevTools part of the job (aka popping from the promise stack and
sending the debug event). This allows us to get rid of the implicit
try-finally from async functions completely; because the finally
block only called to the %AsyncFunctionPromiseRelease builtin, which
was used to inform DevTools.
In essence we now turn an async function like
```js
async function f(x) { return await bar(x); }
```
into something like this (in Parser and BytecodeGenerator respectively):
```
function f(x) {
.generator_object = %_AsyncFunctionEnter(.closure, this);
.promise = %AsyncFunctionCreatePromise();
try {
.tmp = await bar(x);
return %_AsyncFunctionResolve(.promise, .tmp);
} catch (e) {
return %_AsyncFunctionReject(.promise, e);
}
}
```
Overall the bytecode for async functions gets significantly shorter
already (and will get even shorter once we put the outer promise into
the async function generator object). For example the bytecode for a
simple async function
```js
async function f(x) { return await x; }
```
goes from 175 bytes to 110 bytes (a ~38% reduction in size), which
is in particular due to the simplification around the try-finally
removal.
Overall this seems to improve the doxbee-async-es2017-native test by
around 2-3%. On the test case mentioned in v8:8276 we go from
1124ms to 441ms, which corresponds to a 60% reduction in total
execution time!
Tbr: marja@chromium.org
Bug: v8:7253, v8:7522, v8:8276
Cq-Include-Trybots: luci.chromium.try:linux_chromium_headless_rel;luci.chromium.try:linux_chromium_rel_ng;master.tryserver.blink:linux_trusty_blink_rel
Change-Id: Id29dc92de7490b387ff697860c900cee44c9a7a4
Reviewed-on: https://chromium-review.googlesource.com/c/1269041
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Reviewed-by: Maya Lekova <mslekova@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56502}
The test started flaking on almost every run since 1 day, disabling
until the root cause is triaged.
NOTRY=true
Bug: v8:8219
Change-Id: Id3cf219874e79cefc41bb63a9a4a04b6288d5350
Reviewed-on: https://chromium-review.googlesource.com/c/1270942
Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56488}
This fixes handling of two corner cases with catch-all blocks:
1) The catch-all blocks are conceptually outside the corresponding try.
2) Reachability of catch-all is determined by parent reachability.
R=clemensh@chromium.org
TEST=mjsunit/wasm/exceptions-catchall
BUG=v8:8091
Change-Id: Idfd8310bc232f3ce389763023c5a33f1ef90e0b5
Reviewed-on: https://chromium-review.googlesource.com/c/1270816
Reviewed-by: Ben Titzer <titzer@chromium.org>
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56486}
This adds support for multiple catch blocks being attached to a single
try block. The implemented semantics are that type checks are performed
in order from top to bottom.
Note that multiple catch blocks of the same type are not prohibited and
will be accepted, making the second such block essentially unreachable.
The current proposal neither explicitly allows nor prohibits it.
R=clemensh@chromium.org
TEST=mjsunit/wasm/exceptions
BUG=v8:8091
Change-Id: I31e7a07a7cffdd909a58342e00f05e52ed1a3182
Reviewed-on: https://chromium-review.googlesource.com/c/1270591
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56478}
This adds support to wire control flow of catch-all expressions into an
existing try-catch cascade. Note that multiple typed catch blocks are
not yet supported, only one typed catch block followed by one catch-all
block is supported.
In case the explicit catch-all block is missing, we emulate the correct
semantics by internally always emitting a catch-all containing a simple
rethrow instruction.
R=clemensh@chromium.org
TEST=mjsunit/wasm/exceptions-catchall
BUG=v8:8091
Change-Id: I6b29a98c4f1a558fabe6012f4ba6c7b7d43529bb
Reviewed-on: https://chromium-review.googlesource.com/c/1270585
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56476}
Now duplicate parameter detection depends on tracking of unresolved references.
This also fixes finding duplicate parameters of arrow functions nested in other
arrow functions.
Change-Id: I644bfdc513244637345c1069e5c7e5fde713da63
Reviewed-on: https://chromium-review.googlesource.com/c/1270578
Commit-Queue: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56467}
This adds support to the escape analysis to allow scalar replacement
of (small) FixedArrays with element accesses where the index is not a
compile time constant. This happens quite often when inlining functions
that operate on variable number of arguments. For example consider this
little piece of code:
```js
function sum(...args) {
let s = 0;
for (let i = 0; i < args.length; ++i) s += args[i];
return s;
}
function sum2(x, y) {
return sum(x, y);
}
```
This example is made up, of course, but it shows the problem. Let's
assume that TurboFan inlines the function `sum` into it's call site
at `sum2`. Now it has to materialize the `args` array with the two
values `x` and `y`, and iterate through these `args` to sum them up.
The escape analysis pass figures out that `args` doesn't escape (aka
doesn't outlive) the optimized code for `sum2` now, but TurboFan still
needs to materialize the elements backing store for `args` since there's
a `LoadElement(args.elements,i)` in the graph now, and `i` is not a
compile time constant.
However the escape analysis has more information than just that. In
particular the escape analysis knows exactly how many elements a non
escaping object has, based on the fact that the allocation must be
local to the function and that we only track objects with known size.
So in the case above when we get to `args[i]` in the escape analysis
the relevant part of the graph looks something like this:
```
elements = LoadField[elements](args)
length = LoadField[length](args)
index = CheckBounds(i, length)
value = LoadElement(elements, index)
```
In particular the contract here is that `LoadElement(elements,index)`
is guaranteed to have an `index` that is within the valid bounds for
the `elements` (there must be a preceeding `CheckBounds` or some other
guard in optimized code before it). And since `elements` is allocated
inside of the optimized code object, the escape analysis also knows
that `elements` has exactly two elements inside (namely the values of
`x` and `y`). So we can use that information and replace the access
with a `Select(index===0,x,y)` operation instead, which allows us to
scalar replace the `elements`, since there's no escaping use anymore
in the graph.
We do this for the case that the number of elements is 2, as described
above, but also for the case where elements length is one. In case
of 0, we know that the `LoadElement` must be in dead code, but we can't
just mark it for deletion from the graph (to make sure it doesn't block
scalar replacement of non-dead code), so we don't handle this for now.
And for one element it's even easier, since the `LoadElement` has to
yield exactly said element.
We could generalize this to handle arbitrary lengths, but since there's
a cost to arbitrary decision trees here, it's unclear when this is still
beneficial. Another possible solution for length > 2 would be to have
special stack allocation for these backing stores and do variable index
accesses to these stack areas. But that's way beyond the scope of this
isolated change.
This change shows a ~2% improvement on the EarleyBoyer benchmark in
JetStream, since it benefits a lot from not having to materialize these
small arguments backing stores.
Drive-by-fix: Fix JSCreateLowering to properly initialize "elements"
with StoreElement instead of StoreField (which violates the invariant
in TurboFan that fields and elements never alias).
Bug: v8:5267, v8:6200
Change-Id: Idd464a15a81e7c9653c48c814b406eb859841428
Reviewed-on: https://chromium-review.googlesource.com/c/1267935
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56442}
This change adds predicates to check whether a given JavaScript operator
needs the "current context" or if any surrounding context (including the
"native context") does it. For example JSAdd doesn't ever need the
current context, but actually only the native context. In the
BytecodeGraphBuilder we use this predicate to check whether a given
operator needs the current context, and if not, we just pass in the
native context.
Doing so we improve the performance on the benchmarks given in the
tracking bug significantly, and go from something around
arrayMap: 476 ms.
arrayFilter: 312 ms.
arrayEvery: 241 ms.
arraySome: 152 ms.
to
arrayMap: 377 ms.
arrayFilter: 296 ms.
arrayEvery: 191 ms.
arraySome: 91 ms.
which is an up to 40% improvement. So for idiomatic modern JavaScript
which uses higher order functions quite a lot, not just the builtins
provided by the JSVM, this is going to improve peak performance
noticably.
This also makes it possible to completely eliminate all the allocations
in the aliased sloppy arguments example
```js
function foo(a) { return arguments.length; }
```
concretely we don't allocate the function context anymore and we also
don't allocate the arguments object anymore (the JSStackCheck was the
reason why we did this in the past, because it was holding on to the
current context, which also kept the allocation for the arguments
alive).
Bug: v8:6200, v8:8060
Change-Id: I1db56d00d6b510ce6337608c0fff16af96e95eef
Design-Document: bit.ly/v8-turbofan-context-sensitive-js-operators
Reviewed-on: https://chromium-review.googlesource.com/c/1267176
Reviewed-by: Georg Neis <neis@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56441}
This is a reland of ef2a19a211.
Use AllocateJSArray to avoid allocating an empty fixed array.
Original change's description:
> Add fast path for spreading primitive strings.
>
> This improves the performance on primitive strings of
> IterableToListWithSymbolLookup, which implements the
> CreateArrayFromIterable bytecode. The fast path is only
> taken if the string iterator protector is valid (that is,
> String.prototype[Symbol.iterator] and
> String.prototype[Symbol.iterator]().next are untouched).
>
> This brings spreading of primitive strings closer to the
> performance of the string iterator optimizations.
> (see https://docs.google.com/document/d/13z1fvRVpe_oEroplXEEX0a3WK94fhXorHjcOMsDmR-8/).
>
> Bug: chromium:881273, v8:7980
> Change-Id: Ic8d8619da2f2afcc9346203613a844f62653fd7a
> Reviewed-on: https://chromium-review.googlesource.com/1243110
> Commit-Queue: Hai Dang <dhai@google.com>
> Reviewed-by: Georg Neis <neis@chromium.org>
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
> Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#56329}
Bug: chromium:881273, v8:7980
Change-Id: I746c57ddfc300e1032057b5125bc824adf5c2cd3
Reviewed-on: https://chromium-review.googlesource.com/c/1267497
Commit-Queue: Georg Neis <neis@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56438}
As identified in the web-tooling-benchmark, there are specific code
patterns involving array indexed property accesses and subsequent
comparisons of those indices that lead to repeated Smi checks in the
optimized code, which in turn leads to high register pressure and
generally bad register allocation. An example of this pattern is
code like this:
```js
function f(a, n) {
const i = a[n];
if (n >= 1) return i;
}
```
The `a[n]` property access introduces a CheckBounds on `n`, which
later lowers to a `CheckedTaggedToInt32[dont-check-minus-zero]`,
however the `n >= 1` comparison has collected `SignedSmall` feedback
and so it introduces a `CheckedTaggedToTaggedSigned` operation. This
second Smi check is redundant and cannot easily be combined with the
earlier tagged->int32 conversion, since that also deals with heap
numbers and even truncates -0 to 0.
So we teach the RedundancyElimination to look at the inputs of these
speculative number comparisons and if there's a leading bounds check
on either of these inputs, we change the input to the result of the
bounds check. This avoids the redundant Smi checks later and generally
allows the SimplifiedLowering to do a significantly better job on the
number comparisons. We only do this in case of SignedSmall feedback
and only for inputs that are not already known to be in UnsignedSmall
range, to avoid doing too many (unnecessary) expensive lookups during
RedundancyElimination.
All of this is safe despite the fact that CheckBounds truncates -0
to 0, since the regular number comparisons in JavaScript identify
0 and -0 (unlike Object.is()). This also adds appropriate tests,
especially for the interesting cases where -0 is used only after
the code was optimized.
Bug: v8:6936, v8:7094
Change-Id: Ie37114fb6192e941ae1a4f0bfe00e9c0a8305c07
Reviewed-on: https://chromium-review.googlesource.com/c/1246181
Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56428}
This reverts commit 4fd92b252b.
Reason for revert: Significant tankage on the no-mitigations bots (bad timing on the regular bots)
Original change's description:
> [turbofan] Do not consume SignedSmall feedback in TurboFan anymore.
>
> This changes TurboFan to treat SignedSmall feedback similar to Signed32
> feedback for binary and compare operations, in order to simplify and
> unify the machinery.
>
> This is an experiment. If this turns out to tank performance, we will
> need to revisit and ideally revert this change.
>
> Bug: v8:7094
> Change-Id: I885769c2fe93d8413e59838fbe844650c848c3f1
> Reviewed-on: https://chromium-review.googlesource.com/c/1261442
> Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
> Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#56411}
TBR=jarin@chromium.org,bmeurer@chromium.org
# Not skipping CQ checks because original CL landed > 1 day ago.
Bug: v8:7094
Change-Id: I9fff3b40e6dc0ceb7611b55e1ca9940089470404
Reviewed-on: https://chromium-review.googlesource.com/c/1267175
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56427}
The RNG state is initialized with random_seed parameter that usually
has lots of zeros. Each random generation iteration shuffles bits with
xor operation over the state. It takes a while before the state is populated
with enough 1s and starts generating uniformly distributed numbers.
The patch warms up the state with 32 iterations when --random_seed is used.
BUG=v8:8265
Change-Id: I7a4e8c842962bea0f2935c7b3673494367d8580f
Reviewed-on: https://chromium-review.googlesource.com/c/1263816
Commit-Queue: Alexei Filippov <alph@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56418}
This forces .generator_object variable to stack slot 0 for async
generator functions so that the stack trace construction logic
can extract the JSAsyncGeneratorObject appropriately.
Bug: v8:7522
Change-Id: I37b52836bb512bcf5cd7e10e1738c8e7895b06ea
Ref: nodejs/node#11865
Design-Document: http://bit.ly/v8-zero-cost-async-stack-traces
Reviewed-on: https://chromium-review.googlesource.com/c/1264556
Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56415}
For each intrinsic/runtime function we define in runtime.h, an inline
version is automatically declared. We only ever use 24 of the inline
functions. Even though we don't call the other ones, macro magic means
they still take up space by existing in various arrays and tables like
kIntrinsicFunctions. They also create code in switch statements.
Some drive-by cleanups:
- Remove the switch in NameForRuntimeId() and just use the table of
runtime functions to lookup the name directly.
- Remove tests for IsFunction, ClassOf and StringAdd intrinsics as
they are the last users of the inline versions of these.
- Remove the MaxSmi inline version as it is only used in tests.
Saves 64 KiB binary size.
Change-Id: I4c870ddacd2655ffcffa97d93200ed8f853752f5
Reviewed-on: https://chromium-review.googlesource.com/c/1261939
Commit-Queue: Peter Marshall <petermarshall@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56412}
This changes TurboFan to treat SignedSmall feedback similar to Signed32
feedback for binary and compare operations, in order to simplify and
unify the machinery.
This is an experiment. If this turns out to tank performance, we will
need to revisit and ideally revert this change.
Bug: v8:7094
Change-Id: I885769c2fe93d8413e59838fbe844650c848c3f1
Reviewed-on: https://chromium-review.googlesource.com/c/1261442
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56411}
For --async-stack-traces don't try to peak into frames that don't belong
to async functions/generators, specifically don't try to peak into some
arbitrary builtin frames (the FrameInspector doesn't support that).
Bug: chromium:892472, chromium:892473, v8:7522
Change-Id: Idcdee26ff958c03b24dd2910bb92fc51cbc14e3c
Ref: nodejs/node#11865
Design-Document: http://bit.ly/v8-zero-cost-async-stack-traces
Reviewed-on: https://chromium-review.googlesource.com/c/1264276
Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56396}
The CheckSmi in String.fromCodePoint() is unnecessary and even leads to
unnecessary deoptimizations, since the CheckBounds already does the
right thing, plus it also handles HeapNumbers (in Signed32 range) and
properly identifies zeros.
Bug: v8:8238
Change-Id: I73bf7a70c3cd718c987f112ceb928188c0534cd5
Reviewed-on: https://chromium-review.googlesource.com/c/1262675
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56395}
For NumberModulus and SpeculativeNumberModulus there's no observable
difference between 0 and -0 for the right hand side, since both of them
result in NaN (in general the sign of the right hand side is ignored
for modulus in JavaScript). For the left hand side we can just propagate
the zero identification part of the truncation, since we only care about
-0 on the left hand side if the use nodes care about -0 too.
This further improves the Kraken/audio-oscillator test from around 67ms
to 64ms.
Bug: v8:8015, v8:8178
Change-Id: I1f51d42f7df08aaa28a9b0ddd3177df6b76be98c
Reviewed-on: https://chromium-review.googlesource.com/c/1260024
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56372}
This is a follow-up cleanup to treat NumberRound like the other rounding
operations (NumberFloor, NumberCeil and NumberTrunc).
Bug: v8:8015
Change-Id: I2b2fbc7f0319497d16ccb7472595eeb68be1f51d
Reviewed-on: https://chromium-review.googlesource.com/c/1260403
Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56371}
The slow-path of CheckedInt32Mod(x,y) when x is found to be negative
still had the power of two right hand side optimization, and thus would
perform a dynamic check on y. Now the same dynamic check was done for
the fast-path, and the word operations for this check were pure, leading
to weird bit materialization in TurboFan (due to sea of nodes). But
there's not really a point to be clever for the slow-path, so we just
insert the Uint32Mod operation directly here, which completely avoids
the problem.
This improves the Kraken/audio-oscillator test from around 73ms to 69ms.
Bug: v8:8069
Change-Id: Ie8ea667136c95df2bd8c5ba56ebbc6bd2442ff23
Reviewed-on: https://chromium-review.googlesource.com/c/1259063
Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56370}
When converting a Signed32\/MinusZero value from Word32 to Float64
representation or just passing it through as Word32 (with potential
type checks on it) we don't need to worry about -0 as long as the uses
identify 0 and -0.
Drive-by-fix: Fix the CheckChange() helper in the representation
changer test to pass Truncation::Any() by default.
Bug: chromium:891639, chromium:891612, chromium:891627, v8:8015, v8:8178
Change-Id: I06948ec0cdb8e778cb3678124ef927277a5f40ee
Reviewed-on: https://chromium-review.googlesource.com/c/1258902
Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56369}
This introduces a new flag --async-stack-traces, which enables zero-cost
async stack traces. This enriches the non-standard Error.stack property
with async stack frames computed from walking up the promise chains and
collecting all the await suspension points along the way. In Error.stack
these async frames are marked with "async" to make it possible to
distinguish them from regular frames, for example:
```
Error: Some error message
at bar (<anonymous>)
at async foo (<anonymous>)
```
It's zero-cost because no additional information is collected during the
execution of the program, but only the information already present in the
promise chains is used to reconstruct an approximation of the async stack
in case of an exception. But this approximation is limited to suspension
points at await's in async functions. This depends on a recent ECMAScript
specification change, flagged behind --harmony-await-optimization and
implied the --async-stack-traces flag. Without this change there's no
way to get from the outer promise of an async function to the rest of
the promise chain, since the link is broken by the indirection introduced
by await.
For async functions the special outer promise, named .promise in the
Parser desugaring, is now forcible allocated to stack slot 0 during
scope resolution, to make it accessible to the stack frame construction
logic. Note that this first prototype doesn't yet work fully support
async generators and might have other limitations.
Bug: v8:7522
Ref: nodejs/node#11865
Change-Id: I0cc8e3cdfe45dab56d3d506be2d25907409b01a9
Design-Document: http://bit.ly/v8-zero-cost-async-stack-traces
Reviewed-on: https://chromium-review.googlesource.com/c/1256762
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Adam Klein <adamk@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56363}
By moving the block range end to left of closing bracket,
we can avoid ambiguity where an open-ended singleton range
could be both interpreted as inside the parent range, or
next to it.
R=verwaest@chromium.org
Bug: v8:8237
Change-Id: Ibc9412b31efe900b6d8bff0d8fa8c52ddfbf460a
Reviewed-on: https://chromium-review.googlesource.com/1254127
Reviewed-by: Georg Neis <neis@chromium.org>
Commit-Queue: Yang Guo <yangguo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56347}
Following up on the earlier work regarding redundant Smi checks in
https://chromium-review.googlesource.com/c/v8/v8/+/1246181, it was
noticed that the handling of the 0 and -0 and how some operations
identify these is not really consistent, but was still rather ad-hoc.
This change tries to unify the handling a bit by making sure that all
number comparisons generally pass truncations that identify zeros, since
for the number comparisons in JavaScript there's no difference between
0 and -0. In the same spirit NumberAbs and NumberToBoolean should also
pass these truncations, since they also don't care about the differences
between 0 and -0.
Adjust NumberCeil, NumberFloor, NumberTrunc, NumberMin and NumberMax
to pass along any incoming kIdentifiesZeros truncation, since these
operations also don't really care whether the inputs can be -0 if the
use nodes don't care.
Also utilize the kIdentifiesZeros truncation for NumberModulus with
Signed32 inputs, because it's kind of common to do something like
`x % 2 === 0`, where it doesn't really matter whether `x % 2` would
eventually produce a negative zero (since that would still be considered
true for the sake of the comparison).
This also adds a whole lot of tests to ensure that not only are these
optimizations correct, but also that we do indeed perform them.
Drive-by-fix: The `NumberAbs(x)` would incorrectly lower to just `x` for
PositiveIntegerOrMinusZeroOrNaN inputs, which was obviously wrong in
case of -0. This was fixed as well, and an appropriate test was added.
The reason for the unification is that with the introduction of Word64
for CheckBounds (which is necessary to support large TypedArrays and
DataViews) we can no longer safely pass Word32 truncations for the
interesting cases, since the index might be outside the Signed32 or
Unsigned32 ranges, but we still identify 0 and -0 for the sake of the
bounds check, and so it's important that this is handled consistently
to not regress performance on TypedArrays and DataViews accesses.
Bug: v8:8015, v8:8178
Change-Id: Ia1d32f1b726754cea1e5793105d9423d84a6393a
Reviewed-on: https://chromium-review.googlesource.com/1246172
Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56325}
The protector is useful for follow-up optimizations on string iterator.
Tests are also added.
Change-Id: I416037c742628c4d4d3b878d0df727a9ae7162f7
Reviewed-on: https://chromium-review.googlesource.com/1251122
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Commit-Queue: Hai Dang <dhai@google.com>
Cr-Commit-Position: refs/heads/master@{#56315}
Delay the creation of FunctionNameVariables until we validated the
FormalParameters. This is needed so we don't declare them in cases where
we later get an error, have to reset, and reparse.
Bug: chromium:890553, v8:7926
Change-Id: I742e6f7f71158e3903843bd583dc7943468c18f6
Reviewed-on: https://chromium-review.googlesource.com/1254061
Reviewed-by: Marja Hölttä <marja@chromium.org>
Commit-Queue: Florian Sattler <sattlerf@google.com>
Cr-Commit-Position: refs/heads/master@{#56314}
It was shipped in Chrome 67.
Bug: v8:6791, v8:8238
Cq-Include-Trybots: luci.chromium.try:linux_chromium_headless_rel;luci.chromium.try:linux_chromium_rel_ng;luci.v8.try:v8_linux_noi18n_rel_ng;master.tryserver.blink:linux_trusty_blink_rel
Change-Id: I94d8f0aa18570452403a35dea270b18f155c970a
Reviewed-on: https://chromium-review.googlesource.com/1253604
Reviewed-by: Georg Neis <neis@chromium.org>
Commit-Queue: Mathias Bynens <mathias@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56310}
Currently, we call the MapRef::AsElementsKind method on an initial
map multiple times (from JSCreateLowering::ReduceJSCreateArray).
However, this does not does not play well with the heap copier/broker,
which only expectes AsElementsKind to be called on initial maps.
This CL makes sure we only call AsElementsKind once (on the initial map).
Bug: chromium:890620
Change-Id: If44421d3900abb7629ea8f789a005b8d8ebaf881
Reviewed-on: https://chromium-review.googlesource.com/1253105
Reviewed-by: Georg Neis <neis@chromium.org>
Commit-Queue: Jaroslav Sevcik <jarin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56307}
The representation changer was lacking support for directly converting
Word64 values to Bit representation.
Bug: chromium:890243, v8:4153, v8:7881, v8:8171, v8:8178
Change-Id: I5fa31716c7b2b10ad00dc31d5035a1ada152661c
Reviewed-on: https://chromium-review.googlesource.com/1251551
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56304}
Bug: chromium:890057
Change-Id: I98bc278ebc202c3d8f6417367bd1c592e4824011
Reviewed-on: https://chromium-review.googlesource.com/1250481
Commit-Queue: Georg Neis <neis@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56279}
This adds a stress test for the I64 variants of the
AtomicCompareExchange opcodes.
Bug: v8:6532
Change-Id: Iaba4f31f944a71393e5c3222d364d214ff482b9e
Reviewed-on: https://chromium-review.googlesource.com/1235913
Commit-Queue: Stephan Herhut <herhut@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56261}
- Add a new broker mode kRetired, in which the heap can
again be accessed.
- Change the way modes work. We now always start in kDisabled.
If FLAG_concurrent_compiler_frontend is on, we eventually move
to kSerializing, then to kSerialized, then to kRetired.
- Add an ObjectDataKind to ObjectData that indicates whether the
data is just a dummy (i.e. created while broker was in kDisabled
mode).
This also happens to fix a bug found by clusterfuzz.
Bug: v8:7790, chromium:889722
Change-Id: I38833fe7ad26d2d3efb15ba560576defb82f673a
Reviewed-on: https://chromium-review.googlesource.com/1245425
Commit-Queue: Georg Neis <neis@chromium.org>
Reviewed-by: Maya Lekova <mslekova@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56260}
I moved AnalyzePartially from ParseFunctionLiteral to SkipFunction, but arrow
functions only used the ResetAfterPreparsing part.
Bug: chromium:888825
Change-Id: I08de99af128b28031df6ed86a725e4dc918078f8
Reviewed-on: https://chromium-review.googlesource.com/1243383
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Commit-Queue: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56218}
When constructing a TypedArray by length, only actually setup the
JSTypedArray instance once the buffer is allocated, as only at that
time it's known whether the byte length is fine. Otherwise we confuse
the heap verifier.
Bug: chromium:887891
Change-Id: I407ff9a2a053dd11ef764e4e32f482abb27eb0a8
Reviewed-on: https://chromium-review.googlesource.com/1238494
Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56131}
Remove %ToPrimitive, %ToPrimitive_Number, %SameValue and %SameValueZero,
as these runtime functions were only used from tests. For the %SameValue
we use Object.is() to test the internal algorithm (the actual one even),
and for %SameValueZero we use Set#has() - this was already the case for
most uses anyways.
Also drop %IsDate and %ValueOf, which didn't have uses at all.
Bug: v8:8015
Change-Id: Ice26d25e68aed4d5d8adac0547c56aedf9826b13
Reviewed-on: https://chromium-review.googlesource.com/1237677
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56127}
The order in which ToNumber(left) and ToPrimitive(right,hint Number)
is called when performing an abstract relational comparison is
observable, and we need to make sure to trigger the conversions in
the correct order.
Bug: chromium:687063
Change-Id: Idc9edb99643c4cf1774b89dcdc319ed5dc7cdc8a
Reviewed-on: https://chromium-review.googlesource.com/1236557
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56125}
Properly test the abstract equality - both JSEqual and JSNotEqual - for
the case of symbols. Also add tests for the corner cases of the
JSObjectIsArray operator, which is used to implement Array.isArray()
builtin.
Bug: v8:8015
Change-Id: Ib008e85553d04527a5992a904ec77774761f872e
Reviewed-on: https://chromium-review.googlesource.com/1238237
Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56121}
Improve the lowering of CheckedInt32Div and CheckedUint32Div for the
case that the right hand side is a known (positive) power of two, as
in that case it's sufficient to just check the relevant bits on the
left hand side and then shift by the appropriate amount of bits.
This is significantly faster than what TurboFan is able to generate
from the general lowering, even with all the MachineOperatorReducer
magic (it even shows as a steady ~1.5% overall improvement on the
Kraken crypto ccm benchmark).
Also turn the general CheckedInt32Div lowering into readable code again,
and make sure that all the bailout cases are properly covered by mjsunit
tests (i.e. the "division by zero" bailout was not covered properly).
Bug: v8:8015
Change-Id: Ibfdd367a6ee5d70dcaa48801858042c5029b7004
Reviewed-on: https://chromium-review.googlesource.com/1236954
Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56115}
The previous tests didn't cover the case Number.isSafeInteger(x)
where TurboFan was unable to tell that `x` is always a Number and
thus had to use the ObjectIsSafeInteger operator instead.
Bug: v8:8015
Change-Id: I9bdbfa602fe0bf8c5fb2bc6c160ace7ab0bc0aaa
Reviewed-on: https://chromium-review.googlesource.com/1238234
Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56114}
Again in the spirit of https://chromium-review.googlesource.com/1226033
we can simplify the handling of NumberDivide and decide the lowering
based on the feedback type.
Drive-by-fix: Add test coverage for the relevant corner cases of the
NumberDivide handling in SimplifiedLowering.
Bug: v8:8015
Change-Id: I0edaca0fddb31d64d2c269268e87a32a687a0b26
Reviewed-on: https://chromium-review.googlesource.com/1236262
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56113}
The ObjectIsArrayBuffer simplified operator, which is used to implement
the ArrayBuffer.isView() builtin, didn't have any test coverage.
Bug: v8:8015
Change-Id: Ia15e35bc4ae61627137f7a89976560a8d3db771f
Reviewed-on: https://chromium-review.googlesource.com/1238215
Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56112}
