Instead of counting profiler ticks on the shared function info (which is
shared between native contexts), count them on the feedback vector
(which is not). This allows us to continue pushing optimization
decisions off the SFI, onto the feedback vector.
Note that a side-effect of this is that ICs don't have to walk the stack
to reset profiler ticks, as they can access the feedback vector directly
from their feedback nexus.
Change-Id: I232ae9e759fca75cd89d393148a4ff42caa2646f
Reviewed-on: https://chromium-review.googlesource.com/544888
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46411}
Storing the boilerplate on the first run leads to memory ovehead for code
that is run only once. Hence we directly return the creating literal on the
first run and only start creating copies from the second run on.
Bug: v8:6211
Change-Id: I69b96d124a5b594b991fdbcc76dbf935d973ffad
Reviewed-on: https://chromium-review.googlesource.com/530688
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45975}
Since the feedback vector is itself a native context structure, why
not store optimized code for a function in there rather than in
a map from native context to code? This allows us to get rid of
the optimized code map in the SharedFunctionInfo, saving a pointer,
and making lookup of any optimized code quicker.
Original patch by Michael Stanton <mvstanton@chromium.org>
BUG=v8:6246,chromium:718891
TBR=yangguo@chromium.org,ulan@chromium.org
Change-Id: I3bb9ec0cfff32e667cca0e1403f964f33a6958a6
Reviewed-on: https://chromium-review.googlesource.com/500134
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45234}
This reverts commit 662aa425ba.
Reason for revert: Crashing on Canary
BUG=chromium:718891
Original change's description:
> Reland: [TypeFeedbackVector] Store optimized code in the vector
>
> Since the feedback vector is itself a native context structure, why
> not store optimized code for a function in there rather than in
> a map from native context to code? This allows us to get rid of
> the optimized code map in the SharedFunctionInfo, saving a pointer,
> and making lookup of any optimized code quicker.
>
> Original patch by Michael Stanton <mvstanton@chromium.org>
>
> BUG=v8:6246
> TBR=yangguo@chromium.org,ulan@chromium.org
>
> Change-Id: Ic83e4011148164ef080c63215a0c77f1dfb7f327
> Reviewed-on: https://chromium-review.googlesource.com/494487
> Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
> Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#45084}
TBR=ulan@chromium.org,rmcilroy@chromium.org,yangguo@chromium.org,jarin@chromium.org
# Not skipping CQ checks because original CL landed > 1 day ago.
BUG=v8:6246
Change-Id: Idab648d6fe260862c2a0e35366df19dcecf13a82
Reviewed-on: https://chromium-review.googlesource.com/498633
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45174}
Since the feedback vector is itself a native context structure, why
not store optimized code for a function in there rather than in
a map from native context to code? This allows us to get rid of
the optimized code map in the SharedFunctionInfo, saving a pointer,
and making lookup of any optimized code quicker.
Original patch by Michael Stanton <mvstanton@chromium.org>
BUG=v8:6246
TBR=yangguo@chromium.org,ulan@chromium.org
Change-Id: Ic83e4011148164ef080c63215a0c77f1dfb7f327
Reviewed-on: https://chromium-review.googlesource.com/494487
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45084}
We only need to materialize the existing output register for a given
register transfer if it is in a different equivalence set, otherwise we
already have the value we want in the output register.
BUG=v8:4280
Change-Id: Ic4966590ac10445180aff353940d2c93e6a818aa
Reviewed-on: https://chromium-review.googlesource.com/493168
Reviewed-by: Mythri Alle <mythria@chromium.org>
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45051}
This reverts commit c5ad9c6d8e.
Reason for revert: Fails on gc stress:
https://build.chromium.org/p/client.v8/builders/V8%20Linux64%20GC%20Stress%20-%20custom%20snapshot/builds/12661
Original change's description:
> [TypeFeedbackVector] Store optimized code in the vector
>
> Since the feedback vector is itself a native context structure, why
> not store optimized code for a function in there rather than in
> a map from native context to code? This allows us to get rid of
> the optimized code map in the SharedFunctionInfo, saving a pointer,
> and making lookup of any optimized code quicker.
>
> Original patch by Michael Stanton <mvstanton@chromium.org>
>
> BUG=v8:6246
>
> Change-Id: I60ff8c408c3001bc272b4b198c9cbaea2872a9e5
> Reviewed-on: https://chromium-review.googlesource.com/476891
> Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
> Reviewed-by: Michael Stanton <mvstanton@chromium.org>
> Reviewed-by: Yang Guo <yangguo@chromium.org>
> Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#45022}
TBR=ulan@chromium.org,rmcilroy@chromium.org,yangguo@chromium.org,mvstanton@chromium.org,jarin@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:6246
Change-Id: I9cd5735b03898cae6ae7adea0f19d32fceb31619
Reviewed-on: https://chromium-review.googlesource.com/493287
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45027}
Since the feedback vector is itself a native context structure, why
not store optimized code for a function in there rather than in
a map from native context to code? This allows us to get rid of
the optimized code map in the SharedFunctionInfo, saving a pointer,
and making lookup of any optimized code quicker.
Original patch by Michael Stanton <mvstanton@chromium.org>
BUG=v8:6246
Change-Id: I60ff8c408c3001bc272b4b198c9cbaea2872a9e5
Reviewed-on: https://chromium-review.googlesource.com/476891
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Michael Stanton <mvstanton@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45022}
With this CL we reduce the difference between directly using a null prototype
in a literal or using Object.create(null).
- The EmitFastCloneShallowObject builtin now supports cloning slow
object boilerplates.
- Unified behavior to find the matching Map and instantiating it for
Object.create(null) and literals with a null prototype.
- Cleanup of literal type parameter of CompileTimeValue, now in sync with
ObjectLiteral flags.
Review-Url: https://codereview.chromium.org/2445333002
Cr-Commit-Position: refs/heads/master@{#44941}
This relands commit d3e9aade0f. The original CL was reverted speculatively but didn't cause the buildbot failure.
Original change's description:
> [Interpreter] Move BinaryOp Smi transformation into BytecodeGenerator.
>
> Perform the transformation to <BinaryOp>Smi for Binary ops which take Smi
> literals in the BytecodeGenerator. This enables us to perform the
> transformation for literals on either side for commutative operations, and
> Avoids having to do the check on every bytecode in the peephole optimizer.
>
> In the process, adds Smi bytecode variants for all binary operations, adding
> - MulSmi
> - DivSmi
> - ModSmi
> - BitwiseXorSmi
> - ShiftRightLogical
>
> BUG=v8:6194
>
> Change-Id: If1484252f5385c16957004b9cac8bfbb1f209219
> Reviewed-on: https://chromium-review.googlesource.com/466246
> Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
> Reviewed-by: Yang Guo <yangguo@chromium.org>
> Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
> Reviewed-by: Igor Sheludko <ishell@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#44477}
TBR=rmcilroy@chromium.org,machenbach@chromium.org,yangguo@chromium.org,mstarzinger@chromium.org,mythria@chromium.org,v8-reviews@googlegroups.com,ishell@chromium.org
# Not skipping CQ checks because original CL landed > 1 day ago.
BUG=v8:6194
Change-Id: I2ccaefa1ce58d3885f5c2648755985c06f25c1d8
Reviewed-on: https://chromium-review.googlesource.com/472746
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#44511}
This reverts commit d3e9aade0f.
Reason for revert: Speculative for:
https://build.chromium.org/p/client.v8.ports/builders/V8%20Linux%20-%20arm64%20-%20sim%20-%20nosnap%20-%20debug/builds/4449
Bisect points to this CL.
Original change's description:
> [Interpreter] Move BinaryOp Smi transformation into BytecodeGenerator.
>
> Perform the transformation to <BinaryOp>Smi for Binary ops which take Smi
> literals in the BytecodeGenerator. This enables us to perform the
> transformation for literals on either side for commutative operations, and
> Avoids having to do the check on every bytecode in the peephole optimizer.
>
> In the process, adds Smi bytecode variants for all binary operations, adding
> - MulSmi
> - DivSmi
> - ModSmi
> - BitwiseXorSmi
> - ShiftRightLogical
>
> BUG=v8:6194
>
> Change-Id: If1484252f5385c16957004b9cac8bfbb1f209219
> Reviewed-on: https://chromium-review.googlesource.com/466246
> Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
> Reviewed-by: Yang Guo <yangguo@chromium.org>
> Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
> Reviewed-by: Igor Sheludko <ishell@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#44477}
TBR=rmcilroy@chromium.org,yangguo@chromium.org,mstarzinger@chromium.org,mythria@chromium.org,ishell@chromium.org,v8-reviews@googlegroups.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:6194
Change-Id: If57dbdbe40be77804bf437463b855d3167e2d473
Reviewed-on: https://chromium-review.googlesource.com/471308
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#44488}
Perform the transformation to <BinaryOp>Smi for Binary ops which take Smi
literals in the BytecodeGenerator. This enables us to perform the
transformation for literals on either side for commutative operations, and
Avoids having to do the check on every bytecode in the peephole optimizer.
In the process, adds Smi bytecode variants for all binary operations, adding
- MulSmi
- DivSmi
- ModSmi
- BitwiseXorSmi
- ShiftRightLogical
BUG=v8:6194
Change-Id: If1484252f5385c16957004b9cac8bfbb1f209219
Reviewed-on: https://chromium-review.googlesource.com/466246
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#44477}
Moves the ToName elision out of the peephole optimizer and into the
BytecodeGenerator.
BUG=v8:6194
Change-Id: Ic355adbe21f967dc5d52babdd37100a260c62c26
Reviewed-on: https://chromium-review.googlesource.com/467466
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#44427}
... 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}
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}
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}
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}
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}
Add bytecode for defining data properties, which initially just calls the runtime function.
BUG=v8:5624
Review-Url: https://codereview.chromium.org/2510743002
Cr-Commit-Position: refs/heads/master@{#41101}
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}
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}
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}
Drive-by fix: the order of parameters in the BinaryOpWithFeedback TurboFan code stubs now reflects the convention of having the context at the end.
BUG=v8:5273
Review-Url: https://codereview.chromium.org/2263253002
Cr-Commit-Position: refs/heads/master@{#38832}
This optimization required access to the heap which we can't do off-thread.
There doesn't seem to be a regression without this optmization in anycase,
so just rip it out.
BUG=v8:5203
Review-Url: https://codereview.chromium.org/2238853002
Cr-Commit-Position: refs/heads/master@{#38585}
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}
Assign feedback slots in the type feedback vector for binary operations.
Update bytecode-generator to use these slots and add them as an operand
to binary operations.
BUG=v8:4280
LOG=N
Review-Url: https://codereview.chromium.org/2209633002
Cr-Commit-Position: refs/heads/master@{#38408}
ToName was always generated with a subsequent Star, fuse them.
Requires a few changes in the peephole optimizer as ToName cannot be
elided as easily, but must be replaced by Star.
BUG=v8:4280
LOG=n
Review-Url: https://codereview.chromium.org/2169813002
Cr-Commit-Position: refs/heads/master@{#38019}
Introduces fused bytecodes for fusing LdaSmi followed by a binary op bytecode.
The chosen bytecodes are used frequently in Octane: AddSmi, SubSmi,
BitwiseOrSmi, BitwiseAndSmi, ShiftLeftSmi, ShiftRightSmi.
There are additional code stubs for these operations that are biased towards
both the left hand and right hand operands being Smis.
BUG=v8:4280
LOG=N
Review-Url: https://codereview.chromium.org/2111923002
Cr-Commit-Position: refs/heads/master@{#37531}
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}
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}
