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}
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}
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}
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}
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 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}
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}
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}
Avoids the always generated Star bytecodes after ObjectLiteral.
BUG=v4:4820
LOG=n
Review-Url: https://codereview.chromium.org/2216023003
Cr-Commit-Position: refs/heads/master@{#38480}
Add a new bytecode to create a function context. The handler inlines
FastNewFunctionContextStub.
BUG=v8:4280
LOG=n
Review-Url: https://codereview.chromium.org/2187523002
Cr-Commit-Position: refs/heads/master@{#38301}
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}
The original peephole optimizer logic in the BytecodeArrayBuilder did
not respect source positions as it was written before there were
bytecode source positions. This led to some minor differences to
FCG and was problematic when combined with pending bytecode
optimizations. This change makes the new peephole optimizer fully
respect source positions.
BUG=v8:4280
LOG=N
Review-Url: https://codereview.chromium.org/1998203002
Cr-Commit-Position: refs/heads/master@{#36439}
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}
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}
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}
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}
