This patch implements "immutable prototype exotic objects" from the ECMAScript
spec, which are objects whose __proto__ cannot be changed, but are not otherwise
frozen. They are introduced in order to prevent a Proxy from being introduced
to the prototype chain of the global object.
The API is extended by a SetImmutablePrototype() call in ObjectTemplate, which
can be used to vend new immutable prototype objects. Additionally, Object.prototype
is an immutable prototype object.
In the implementation, a new bit is added to Maps to say whether the prototype is
immutable, which is read by SetPrototype. Map transitions to the immutable prototype
state are not saved in the transition tree because the main use case is just for
the prototype chain of the global object, which there will be only one of per
Context, so no need to take up the extra word for a pointer in each full transition
tree.
BUG=v8:5149
Review-Url: https://codereview.chromium.org/2108203002
Cr-Commit-Position: refs/heads/master@{#37482}
Make intrinsic ids a contiguous set of ids so that the switch statement can build
a table switch rather than doing a large if/else tree.
BUG=v8:4822
LOG=N
Review-Url: https://codereview.chromium.org/2084623002
Cr-Commit-Position: refs/heads/master@{#37135}
With this change the bytecode array builder only emits expression
positions for bytecodes that can throw. This allows more peephole
optimization opportunities and results in smaller code.
BUG=v8:4280,chromium:615979
LOG=N
Review-Url: https://codereview.chromium.org/2038323002
Cr-Commit-Position: refs/heads/master@{#36863}
This change requires a single pass over the register set during
bytecode pipeline flushes.
A few bytecode tests are updated too because the order of register
flushes is different.
BUG=v8:4280
LOG=N
Review-Url: https://codereview.chromium.org/2033013002
Cr-Commit-Position: refs/heads/master@{#36726}
Async functions are built out of generators, but the
SharedFunctionInfo returns false for is_generator. is_resumable is
the broader query. This patch fixes many parts of V8 to refer
to is_resumable as appropriate.
One incidental change is to remove a check for generators extending
classes. This is part of a general check for constructors being the
only thing which can extend classes, so it is removed here and the
error message for the general case is made more accurate.
BUG=v8:4483
Review-Url: https://codereview.chromium.org/1996943002
Cr-Commit-Position: refs/heads/master@{#36621}
One of the top runtime calls in many workloads is Runtime_Call. Add an
intrinsic for the interpreter to inline this runtime call.
BUG=v8:4280
LOG=N
Review-Url: https://codereview.chromium.org/2019433003
Cr-Commit-Position: refs/heads/master@{#36565}
This change introduces five fused bytecodes for common bytecode
sequences on popular websites. These are LdrNamedProperty,
LdrKeyedProperty, LdrGlobal, LdrContextSlot, and LdrUndefined. These
load values into a destination register operand instead of the
accumulator. They are emitted by the peephole optimizer.
BUG=v8:4280
LOG=N
Review-Url: https://codereview.chromium.org/1985753002
Cr-Commit-Position: refs/heads/master@{#36507}
Makes LogicalNot bytecode not do the ToBoolean operation, and add support in the
peephole optimizer to choose between the appropriate bytecode depending upon
whether the previous bytecode emitted a boolean or not.
BUG=v8:4280
LOG=N
Review-Url: https://codereview.chromium.org/1985033002
Cr-Commit-Position: refs/heads/master@{#36295}
This adds back the instanceof operator support in the backends and
introduces a @@hasInstance protector cell on the isolate that guards the
fast path for the InstanceOfStub. This way we recover the ~10%
regression on Octane EarleyBoyer in Crankshaft and greatly improve
TurboFan and Ignition performance of instanceof.
R=ishell@chromium.orgTBR=hpayer@chromium.org,rossberg@chromium.org
BUG=chromium:597249, v8:4447
LOG=n
Review-Url: https://codereview.chromium.org/1980483003
Cr-Commit-Position: refs/heads/master@{#36275}
Prints source position information alongside bytecode.
BUG=v8:4280
LOG=N
Review-Url: https://codereview.chromium.org/1963663002
Cr-Commit-Position: refs/heads/master@{#36171}
We sometimes used to continue by jumping _back_ to the condition check at the
top of the loop. After my recent generator-related changes, that check is no
longer at the loop header, so a continue could create an additional loop. In
order to avoid this, we now always set the continue target to be the first
instruction following the loop body.
BUG=
Review-Url: https://codereview.chromium.org/1943383003
Cr-Commit-Position: refs/heads/master@{#36029}
Adapts FastCloneShallowObjectStub to enable it to be used by the
CreateObjectLiteral bytecode.
BUG=v8:4280
LOG=N
Review-Url: https://codereview.chromium.org/1922523002
Cr-Commit-Position: refs/heads/master@{#35909}
These checks ensure that a TypeError is thrown, per spec, rather than
a runtime assert failure.
BUG=v8:4964
R=adamk
LOG=Y
Review-Url: https://codereview.chromium.org/1929123002
Cr-Commit-Position: refs/heads/master@{#35885}
The feature was deprecated in M49 and flagged off in M50.
This patch removes it entirely from the codebase.
Review URL: https://codereview.chromium.org/1909433003
Cr-Commit-Position: refs/heads/master@{#35714}
The parser uses a try-catch in order to record when the client of an iterator
throws. The exception then used to get rethrown via 'throw', which
unfortunately resulted in the original exception message object getting
overwritten.
This CL solves this as follows:
- add a clear_pending_message flag to TryCatchStatement (set to true in normal
cases),
- set clear_pending_message to false for the TryCatchStatement used in iterator
finalization
- change full-codegen, turbofan, and the interpreter to emit the ClearPendingMessage call
only when the flag is set,
- replace 'throw' with '%ReThrow' in the iterator finalization code, thus
reusing the (not-cleared) pending message
R=littledan@chromium.org, mstarzinger@chromium.org, yangguo@chromium.org
BUG=v8:4875
LOG=n
Review URL: https://codereview.chromium.org/1842953003
Cr-Commit-Position: refs/heads/master@{#35226}
A bug in error printing meant that we failed to do proper type checks
before calling into C++ code, which could lead to RUNTIME_ASSERT
failures if methods are called on alternative receivers. This patch
adds the right type checks.
BUG=chromium:596718
LOG=Y
R=adamk
Review URL: https://codereview.chromium.org/1831053003
Cr-Commit-Position: refs/heads/master@{#35069}
This patch implements ES2015 RegExp subclassing semantics, namely the
hardest part where RegExp.prototype.exec and certain flag getters can
be overridden in order to provide different behavior. This change is
hidden behind a new flag, --harmony-regexp-exec. The flag guards the
behavior by installing entirely different implementations of the
methods which follow the new semantics.
Preliminary performance tests show a 3-4x regression in the Octane
RegExp benchmark. The new code doesn't call out into several fast
paths that the old code supported, so this is expected.
The patch is tested mostly by test262, where most RegExp tests are fixed,
with the exception of deliberate spec violations for web compatibility,
and for the 'sticky' flag, which is not dynamically read by this patch
in all cases but rather statically compiled into the RegExp. The latter
will require a follow-on patch to implement. A small additional set of
tests verifies one particular case, mostly to check whether the flag
mechanism works.
R=adamk,yangguo@chromium.org
LOG=Y
BUG=v8:4602
Review URL: https://codereview.chromium.org/1596483005
Cr-Commit-Position: refs/heads/master@{#35068}
Introduces a bytecode whose handler executes the equivalent of %_IsArray and %_IsJSReceiver without a runtime call.
BUG=v8:4822
LOG=y
Review URL: https://codereview.chromium.org/1645763003
Cr-Commit-Position: refs/heads/master@{#34983}
This change introduces wide prefix bytecodes to support wide (16-bit)
and extra-wide (32-bit) operands. It retires the previous
wide-bytecodes and reduces the number of operand types.
Operands are now either scalable or fixed size. Scalable operands
increase in width when a bytecode is prefixed with wide or extra-wide.
The bytecode handler table is extended to 256*3 entries. The
first 256 entries are used for bytecodes with 8-bit operands,
the second 256 entries are used for bytecodes with operands that
scale to 16-bits, and the third group of 256 entries are used for
bytecodes with operands that scale to 32-bits.
LOG=N
BUG=v8:4747,v8:4280
Review URL: https://codereview.chromium.org/1783483002
Cr-Commit-Position: refs/heads/master@{#34955}
We must close the iterator whenever the destructuring didn't exhaust it, unless an iterator operation (eg. next) threw. We do this by wrapping the iterator use in a try-catch-finally similar to the desugaring of for-of.
This is behind --harmony-iterator-close.
R=adamk@chromium.org
BUG=v8:3566
LOG=Y
Review URL: https://codereview.chromium.org/1772793002
Cr-Commit-Position: refs/heads/master@{#34654}
This mechanism was used to ensure that functions ended up as constants on the map of prototypes defined using object literals, e.g.,:
function.prototype = {
method: function() { ... }
}
Nowadays we treat prototypes specially, and make all their functions constants when an object turns prototype. Hence this special custom code isn't necessary anymore.
This also affects boilerplates that do not become prototypes. Their functions will not be constants but fields instead. Calling their methods will slow down. However, multiple instances of the same boilerplate will stay monomorphic. We'll have to see what the impact is for such objects, but preliminary benchmarks do not show this as an important regression.
BUG=chromium:593008
LOG=n
Review URL: https://codereview.chromium.org/1772423002
Cr-Commit-Position: refs/heads/master@{#34602}
Bytecode expectations have been moved to external (.golden) files,
one per test. Each test in the suite builds a representation of the
the compiled bytecode using BytecodeExpectationsPrinter. The output is
then compared to the golden file. If the comparision fails, a textual
diff can be used to identify the discrepancies.
Only the test snippets are left in the cc file, which also allows to
make it more compact and meaningful. Leaving the snippets in the cc
file was a deliberate choice to allow keeping the "truth" about the
tests in the cc file, which will rarely change, as opposed to golden
files.
Golden files can be generated and kept up to date using
generate-bytecode-expectations, which also means that the test suite
can be batch updated whenever the bytecode or golden format changes.
The golden format has been slightly amended (no more comments about
`void*`, add size of the bytecode array) following the consideration
made while converting the tests.
There is also a fix: BytecodeExpectationsPrinter::top_level_ was left
uninitialized, leading to undefined behaviour.
BUG=v8:4280
LOG=N
Review URL: https://codereview.chromium.org/1717293002
Cr-Commit-Position: refs/heads/master@{#34285}
