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}
Since now the IterationBody StackChecks are implicit within JumpLoops,
we are able to eagerly deopt in them. If we do that, whenever we advance
to the next bytecode we don't have to advance to the next literal
bytecode, but instead "advance" in the sense of doing the JumpLoop.
Adding tests that test this advancing for wide and extra wide JumpLoops.
Also, marking JumpLoop as needing source positions since now it has
the ability of causing an interrupt.
Bug: v8:10149, v8:9960
Fixes: v8:10149
Change-Id: Ib0d9efdfb379e0dfbba7a7f67cba9262668813b0
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2064226
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Santiago Aboy Solanes <solanes@chromium.org>
Cr-Commit-Position: refs/heads/master@{#66809}
This CL is a step towards making StackChecks implicit. In a follow-up CL
said StackChecks will become implicit within JumpLoops.
Cq-Include-Trybots: luci.chromium.try:linux-rel
Bug: v8:10149, v8:9960
Change-Id: I5ae247be3f7a58ccdf86398cace30724715767a8
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2062391
Commit-Queue: Santiago Aboy Solanes <solanes@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#66668}
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}
This is a reland of 35269f77f8
Switches on an expression that unconditionally throws would have all their
case statements dead, causing a DCHECK error in the SwitchBuilder. This
fixes up the DCHECK to allow dead labels.
Original change's description:
> [ignition] Skip binding dead labels
>
> BytecodeLabels for forward jumps may create a dead basic block if their
> corresponding jump was elided (due to it dead code elimination). We can
> avoid generating such dead basic blocks by skipping the label bind when
> no corresponding jump has been observed. This works because all jumps
> except JumpLoop are forward jumps, so we only have to special case one
> Bind for loop headers to bind unconditionally.
>
> Since Binds are now conditional on a jump existing, we can no longer rely
> on using Bind to get the current offset (e.g. at the beginning of a try
> block). Instead, we now expose the current offset in the bytecode array
> writer. Conveniently, this means that we can be a bit smarter about basic
> blocks around these statements.
>
> As a drive-by, remove the unused Bind(target,label) function.
>
> Bug: chromium:934166
> Change-Id: I532aa452fb083560d07b90da99caca0b1d082aa3
> Reviewed-on: https://chromium-review.googlesource.com/c/1488763
> Commit-Queue: Leszek Swirski <leszeks@chromium.org>
> Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#59942}
TBR=rmcilroy@chromium.org
Bug: chromium:934166
Change-Id: If6eab4162106717ce64a2dc477000c6a76354cb4
Reviewed-on: https://chromium-review.googlesource.com/c/1494535
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59948}
This reverts commit 35269f77f8.
Reason for revert: Fuzzer unhappy: https://ci.chromium.org/p/v8/builders/ci/V8%20Fuzzer/29792
Original change's description:
> [ignition] Skip binding dead labels
>
> BytecodeLabels for forward jumps may create a dead basic block if their
> corresponding jump was elided (due to it dead code elimination). We can
> avoid generating such dead basic blocks by skipping the label bind when
> no corresponding jump has been observed. This works because all jumps
> except JumpLoop are forward jumps, so we only have to special case one
> Bind for loop headers to bind unconditionally.
>
> Since Binds are now conditional on a jump existing, we can no longer rely
> on using Bind to get the current offset (e.g. at the beginning of a try
> block). Instead, we now expose the current offset in the bytecode array
> writer. Conveniently, this means that we can be a bit smarter about basic
> blocks around these statements.
>
> As a drive-by, remove the unused Bind(target,label) function.
>
> Bug: chromium:934166
> Change-Id: I532aa452fb083560d07b90da99caca0b1d082aa3
> Reviewed-on: https://chromium-review.googlesource.com/c/1488763
> Commit-Queue: Leszek Swirski <leszeks@chromium.org>
> Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#59942}
TBR=rmcilroy@chromium.org,leszeks@chromium.org
Change-Id: I8118e54e0afa5e08b0a0a874c952f8a01f1c3242
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: chromium:934166
Reviewed-on: https://chromium-review.googlesource.com/c/1494534
Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59947}
BytecodeLabels for forward jumps may create a dead basic block if their
corresponding jump was elided (due to it dead code elimination). We can
avoid generating such dead basic blocks by skipping the label bind when
no corresponding jump has been observed. This works because all jumps
except JumpLoop are forward jumps, so we only have to special case one
Bind for loop headers to bind unconditionally.
Since Binds are now conditional on a jump existing, we can no longer rely
on using Bind to get the current offset (e.g. at the beginning of a try
block). Instead, we now expose the current offset in the bytecode array
writer. Conveniently, this means that we can be a bit smarter about basic
blocks around these statements.
As a drive-by, remove the unused Bind(target,label) function.
Bug: chromium:934166
Change-Id: I532aa452fb083560d07b90da99caca0b1d082aa3
Reviewed-on: https://chromium-review.googlesource.com/c/1488763
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59942}
Moves the feedback vector slot allocation out of ast-numbering and into
bytecode generation directly. This has a couple of benifits, including reduced
AST size, avoid code duplication and reduced feedback vector sizes in many cases
due to only allocating slots when needed. Also removes AstProperties since
this is no longer needed.
AstNumbering is now only used to allocate suspend ids for generators.
BUG=v8:6921
Change-Id: I103e8593c94ef5b2e56c34ef4f77bd6e7d64796f
Reviewed-on: https://chromium-review.googlesource.com/722959
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Michael Stanton <mvstanton@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48757}
Instead of having feedback vector as a subtype of FixedArray with
reserved slots, make it a first-class variable-sized object with a
fixed-size header. This allows us to compress counters to ints in the
header, rather than forcing them to be Smis.
Cq-Include-Trybots: master.tryserver.chromium.linux:linux_chromium_rel_ng
Change-Id: Icc5f088ffbc2e2651b845bc71ea42060639e3e48
Reviewed-on: https://chromium-review.googlesource.com/585129
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Michael Stanton <mvstanton@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46935}
Reland of https://chromium-review.googlesource.com/c/544888/.
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: I7aa6baed03f726843d1b62629c72b74f05114b48
Reviewed-on: https://chromium-review.googlesource.com/579051
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46868}
This reverts commit a2fcdc7cc8.
Reason for revert: Large regressions in RCS (https://chromeperf.appspot.com/group_report?bug_id=740126)
Original change's description:
> [runtime] Move profiler ticks from SFI to feedback vector
>
> 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}
TBR=rmcilroy@chromium.org,leszeks@chromium.org,ishell@chromium.org
# Not skipping CQ checks because original CL landed > 1 day ago.
Change-Id: Id587e4172e300c420f93c49744a2a0e66696edf8
Reviewed-on: https://chromium-review.googlesource.com/574227
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46702}
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}
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}
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}
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}
Move the ToBoolean elision in the BytecodeGenerator instead of the
peephole optimizer. Adds a TypeHint mechanism to the ExpressionResult
to enable passing of type hints through the ast visitor.
BUG=v8:6194
Change-Id: Ic55506ba11b213f7459250004d3f18cab04ee9b3
Reviewed-on: https://chromium-review.googlesource.com/467208
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#44415}
Translates code of the form 'if (x === undefined)' into the JumpIfUndefined
bytecode, and similarly for comparisons with null. Also adds bytecodes for
JumpIfNotUndefined / Null.
Moves the peephole optimization for CompareUndefined out of the peephole
optimizer and into the BytecodeGenerator, having the side-effect of enabling
it for comparisons with undefined on both side of the compare operation.
BUG=v8:6107
Review-Url: https://codereview.chromium.org/2793923002
Cr-Commit-Position: refs/heads/master@{#44341}
