This is a reland of cf93071c91
Original change's description:
> [interpreter] Short Star bytecode
>
> Design doc:
> https://docs.google.com/document/d/1g_NExMT78II_KnIYNa9MvyPYIj23qAiFUEsyemY5KRk/edit
>
> This change adds 16 new interpreter opcodes, kStar0 through kStar15, so
> that we can use a single byte to represent the common operation of
> storing to a low-numbered register. This generally reduces the quantity
> of bytecode generated on web sites by 8-9%.
>
> In order to not degrade speed, a couple of other changes are required:
>
> The existing lookahead logic to check for Star after certain other
> bytecode handlers is updated to check for these new short Star codes
> instead. Furthermore, that lookahead logic is updated to contain its own
> copy of the dispatch jump rather than merging control flow with the
> lookahead-failed case, to improve branch prediction.
>
> A bunch of constants use bytecode size in bytes as a proxy for the size
> or complexity of a function, and are adjusted downward proportionally to
> the decrease in generated bytecode size.
>
> Other small drive-by fix: update generate-bytecode-expectations to emit
> \n instead of \r\n on Windows.
>
> Change-Id: I6307c2b0f5794a3a1088bb0fb94f6e1615441ed5
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2641180
> Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
> Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
> Cr-Commit-Position: refs/heads/master@{#72773}
Change-Id: I1afb670c25694498b3989de615858f984a8c7f6f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2698057
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Mythri Alle <mythria@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72821}
This reverts commit cf93071c91.
Reason for revert: Speculative revert because of Mac4 GC stress failure: https://ci.chromium.org/ui/p/v8/builders/ci/V8%20Mac64%20GC%20Stress/16697/overview
Original change's description:
> [interpreter] Short Star bytecode
>
> Design doc:
> https://docs.google.com/document/d/1g_NExMT78II_KnIYNa9MvyPYIj23qAiFUEsyemY5KRk/edit
>
> This change adds 16 new interpreter opcodes, kStar0 through kStar15, so
> that we can use a single byte to represent the common operation of
> storing to a low-numbered register. This generally reduces the quantity
> of bytecode generated on web sites by 8-9%.
>
> In order to not degrade speed, a couple of other changes are required:
>
> The existing lookahead logic to check for Star after certain other
> bytecode handlers is updated to check for these new short Star codes
> instead. Furthermore, that lookahead logic is updated to contain its own
> copy of the dispatch jump rather than merging control flow with the
> lookahead-failed case, to improve branch prediction.
>
> A bunch of constants use bytecode size in bytes as a proxy for the size
> or complexity of a function, and are adjusted downward proportionally to
> the decrease in generated bytecode size.
>
> Other small drive-by fix: update generate-bytecode-expectations to emit
> \n instead of \r\n on Windows.
>
> Change-Id: I6307c2b0f5794a3a1088bb0fb94f6e1615441ed5
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2641180
> Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
> Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
> Cr-Commit-Position: refs/heads/master@{#72773}
TBR=rmcilroy@chromium.org,mythria@chromium.org,seth.brenith@microsoft.com
Change-Id: I0162b9400861b90bacef27cca9aebc8ab9d74c10
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2697350
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72777}
Design doc:
https://docs.google.com/document/d/1g_NExMT78II_KnIYNa9MvyPYIj23qAiFUEsyemY5KRk/edit
This change adds 16 new interpreter opcodes, kStar0 through kStar15, so
that we can use a single byte to represent the common operation of
storing to a low-numbered register. This generally reduces the quantity
of bytecode generated on web sites by 8-9%.
In order to not degrade speed, a couple of other changes are required:
The existing lookahead logic to check for Star after certain other
bytecode handlers is updated to check for these new short Star codes
instead. Furthermore, that lookahead logic is updated to contain its own
copy of the dispatch jump rather than merging control flow with the
lookahead-failed case, to improve branch prediction.
A bunch of constants use bytecode size in bytes as a proxy for the size
or complexity of a function, and are adjusted downward proportionally to
the decrease in generated bytecode size.
Other small drive-by fix: update generate-bytecode-expectations to emit
\n instead of \r\n on Windows.
Change-Id: I6307c2b0f5794a3a1088bb0fb94f6e1615441ed5
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2641180
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#72773}
FunctionEntry StackChecks is one of the two cases where we generate a
StackCheck bytecode. In these cases, we do stack check against the js
limit (not to be confused with the real js limit). Their purpose is to
be able to interrupt the running code.
We can omit the FunctionEntry StackCheck by embedding its code into
the InterpreterEntryTrampoline builtin. We save one bytecode per
interpreted function.
This change has rippling effects for optimized code, as well as the
deoptimizer.
Bug: v8:10149, v8:9977, v8:9960
Change-Id: I6156de48b3bc0b519dd21190a8e6214fbe96c78d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1914218
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Commit-Queue: Santiago Aboy Solanes <solanes@chromium.org>
Cr-Commit-Position: refs/heads/master@{#66206}
The function-entry stack check should dominate all other
instructions in a function. Prior to this CL it was possible to create
paths not including a stack check due to SwitchOnGeneratorState: the
generator-creation branch had a stack check, while generator-resume
branches did not.
0 : af fb 00 01 SwitchOnGeneratorState r0, [0], [1] { 0: @22 }
4 : 27 fe fa Mov <closure>, r1
7 : 27 02 f9 Mov <this>, r2
10 : 64 0a fa 02 InvokeIntrinsic [_CreateJSGeneratorObject], r1-r2
14 : 26 fb Star r0
16 : a7 StackCheck
17 : b0 fb fb 01 00 SuspendGenerator r0, r0-r0, [0]
22 : b1 fb fb 01 ResumeGenerator r0, r0-r0
[... no stack check here ...]
This CL moves the stack check to the beginning of the bytecode array,
i.e. before SwitchOnGeneratorState.
Bug: chromium:1020031
Change-Id: I8ba8cba99611ddbe50c76023129d926cc84b1d5e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1903440
Reviewed-by: Georg Neis <neis@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64888}
Nop bytecodes are required only for break locations in debugger. Since nop bytecode doesn't change program state we can remove all of them.
There are at least two changes which this CL produce:
- we don't provide break position when we load local variable (still provide when load variable from global),
- we don't provide break position for statements without actual break positions (e.g. "a;") - these expressions should be super rare and user always can set breakpoint before or after this statement.
More details in one pager: https://docs.google.com/a/google.com/document/d/1JXlQpfMa9vRojbE272b6GMBbrfh6m_00135iAUOJEz8/edit?usp=sharing
Bug: v8:6425
Change-Id: I4aee73d497a84f7b5d89caa6dda6d3060567dfda
Reviewed-on: https://chromium-review.googlesource.com/543161
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46742}
Goal of this CL: explicit return from non-async function has position after
return expression as return position (will unblock [1]).
BytecodeArrayBuilder has SetStatementPosition and SetExpressionPosition methods.
If one of these methods is called then next generated bytecode will get passed
position. It's general treatment for most cases.
Unfortunately it doesn't work for Returns:
- debugger requires source positions exactly on kReturn bytecode in stepping
implementation,
- BytecodeGenerator::BuildReturn and BytecodeGenerator::BuildAsyncReturn
generates more then one bytecode and general solution will put return position
on first generated bytecode,
- it's not easy to split BuildReturn function into two parts to allow something
like following in BytecodeGenerator::VisitReturnStatement since generated
bytecodes are actually controlled by execution_control().
..->BuildReturnPrologue();
..->SetReturnPosition(stmt);
..->Return();
In this CL we pass ReturnStatement through ExecutionControl and use it for
position when we emit return bytecode right here.
So this CL only will improve return position for returns inside of non-async
functions, I'll address async functions later.
[1] https://chromium-review.googlesource.com/c/543161/
Change-Id: Iede512c120b00c209990bf50c20e7d23dc0d65db
Reviewed-on: https://chromium-review.googlesource.com/560738
Commit-Queue: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
Reviewed-by: Adam Klein <adamk@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46687}
Move bytecode array writing logic into the array builder, allowing us to
remove the bytecode array writer and bytecode node, and convert runtime
operand writing to compile-time bytecode operand writing using the
information statically known at compile time.
Bug: v8:6474
Change-Id: I210cd9897fd41293745614e4a253c7c251dfffc9
Reviewed-on: https://chromium-review.googlesource.com/533055
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46183}
Introduces ThrowReferenceErrorIfHole / ThrowSuperNotCalledIfHole
/ ThrowSuperAlreadyCalledIfNotHole bytecodes to handle hole checks.
In the bytecode-graph builder they are handled by introducing a deopt point
instead of adding explicit control flow. JumpIfNotHole / JumpIfNotHoleConstant
bytecodes are removed since they are no longer required.
Bug: v8:4280, v8:6383
Change-Id: I58b70c556b0ffa30e41a0cd44016874c3e9c5fe1
Reviewed-on: https://chromium-review.googlesource.com/509613
Commit-Queue: Mythri Alle <mythria@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45720}
This CL improves break locations for expressions like 'var a = <expr>'. Without CL we use <expr> position as break location for initialization statement, with this CL we use position of first character after '=' as position.
Benefits (see test for details):
- only one break in expressions which includes mix of property lookup and calls, e.g. var p = Promise.resolve().then(x => x * 2),
- removed redundant break location for expressions like: let { x, y } = { x: 1, y: 2}.
TBR=dgozman@chromium.org,rmcilroy@chromium.org,machenbach@chromium.org,marja@chromium.org,kozyatinskiy@chromium.org,devtools-reviews@chromium.org,v8-reviews@googlegroups.com
# Not skipping CQ checks because original CL landed > 1 day ago.
Bug: v8:5909
Change-Id: Ie84fa79afeed09e28cf8478ba610a0cfbfdfc294
Reviewed-on: https://chromium-review.googlesource.com/518116
Commit-Queue: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
Reviewed-by: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45598}
This reverts commit 7a9cc70492.
Reason for revert: Changes layout tests:
https://build.chromium.org/p/client.v8.fyi/builders/V8-Blink%20Linux%2064/builds/15882
This is about:
inspector/sources/debugger/source-frame-inline-breakpoint-decorations.html
Original change's description:
> [inspector] moved var initialization break location before init expression
>
> This CL improves break locations for expressions like 'var a = <expr>'. Without CL we use <expr> position as break location for initialization statement, with this CL we use position of first character after '=' as position.
> Benefits (see test for details):
> - only one break in expressions which includes mix of property lookup and calls, e.g. var p = Promise.resolve().then(x => x * 2),
> - removed redundant break location for expressions like: let { x, y } = { x: 1, y: 2}.
>
> Bug: v8:5909
> Change-Id: I039d911903a2826c9859710a63ab0462c992e11b
> Reviewed-on: https://chromium-review.googlesource.com/513926
> Commit-Queue: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
> Reviewed-by: Marja Hölttä <marja@chromium.org>
> Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#45530}
TBR=dgozman@chromium.org,marja@chromium.org,kozyatinskiy@chromium.org
# Not skipping CQ checks because original CL landed > 1 day ago.
Bug: v8:5909
Change-Id: Ibf84401e8050d3c84db219d983de2c6bba0f697f
Reviewed-on: https://chromium-review.googlesource.com/518102
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45547}
This CL improves break locations for expressions like 'var a = <expr>'. Without CL we use <expr> position as break location for initialization statement, with this CL we use position of first character after '=' as position.
Benefits (see test for details):
- only one break in expressions which includes mix of property lookup and calls, e.g. var p = Promise.resolve().then(x => x * 2),
- removed redundant break location for expressions like: let { x, y } = { x: 1, y: 2}.
Bug: v8:5909
Change-Id: I039d911903a2826c9859710a63ab0462c992e11b
Reviewed-on: https://chromium-review.googlesource.com/513926
Commit-Queue: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
Reviewed-by: Marja Hölttä <marja@chromium.org>
Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45530}
This patch expands scope analysis to skip hole initialization
when it can be determined statically that no hole checks will
be generated at runtime.
Two conditions must be met to safely eliminate hole initialization:
- There must not exist a VariableProxy referencing this Variable
whose HoleCheckMode is kRequired
- The Variable must be stack allocated; any other allocation implies
that it may be accessed from not-yet-analyzed scopes (other modules,
inner functions, or eval code) and that code may require
hole checks.
The new logic required removing debug code in full-codegen which is
now incorrect in some cases.
Also fixed Variable's bitfield helpers to take no more space than needed.
Bug: chromium:651637
Change-Id: Ie5ac326af4e05b7a5c3c37cd4d0afba6a51a504d
Reviewed-on: https://chromium-review.googlesource.com/494006
Commit-Queue: Adam Klein <adamk@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45170}
Move hole check logic from full-codegen into scope analysis, and store the
"needs hole check" bit on VariableProxy. This makes it easy to re-use in
any backend: it will be trivial to extend the use of this logic in, e.g.,
full-codegen variable stores.
While changing the signatures of the variable loading/storing methods in
Ignition, I took the liberty of replacing the verb "Visit" with "Build", since these
are not part of AST visiting.
BUG=v8:5460
Review-Url: https://chromiumcodereview.appspot.com/2411873004
Cr-Commit-Position: refs/heads/master@{#40479}
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}
In addition, make use of Variable::binding_needs_init() in addition to
VariableMode when deciding whether to do hole checking in variable assignment.
R=rmcilroy@chromium.org
Review-Url: https://codereview.chromium.org/2227203002
Cr-Commit-Position: refs/heads/master@{#38555}
Original issue's description:
> [interpeter] Move to table based peephole optimizer.
>
> Introduces a lookup table for peephole optimizations.
>
> Fixes some tests using BytecodePeepholeOptimizer::Write() that should
> have been update to use BytecodePeepholeOptimizer::WriteJump().
>
> BUG=v8:4280
> LOG=N
>
> Committed: https://crrev.com/f4234422b93b21a286b0f31799009bcbe8b90b9e
> Cr-Commit-Position: refs/heads/master@{#37819}
BUG=v8:4280
LOG=N
Review-Url: https://codereview.chromium.org/2164583002
Cr-Commit-Position: refs/heads/master@{#37866}
Reason for revert:
Break MIPS port.
Original issue's description:
> [interpeter] Move to table based peephole optimizer.
>
> Introduces a lookup table for peephole optimizations.
>
> Fixes some tests using BytecodePeepholeOptimizer::Write() that should
> have been update to use BytecodePeepholeOptimizer::WriteJump().
>
> BUG=v8:4280
> LOG=N
>
> Committed: https://crrev.com/f4234422b93b21a286b0f31799009bcbe8b90b9e
> Cr-Commit-Position: refs/heads/master@{#37819}
TBR=rmcilroy@chromium.org,machenbach@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:4280
Review-Url: https://codereview.chromium.org/2161563002
Cr-Commit-Position: refs/heads/master@{#37821}
Introduces a lookup table for peephole optimizations.
Fixes some tests using BytecodePeepholeOptimizer::Write() that should
have been update to use BytecodePeepholeOptimizer::WriteJump().
BUG=v8:4280
LOG=N
Review-Url: https://codereview.chromium.org/2118183002
Cr-Commit-Position: refs/heads/master@{#37819}
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}
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}
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}
