Now that all 'const' declarations are of the ES2015 variety, the only
use of CONST_LEGACY is for function name bindings in sloppy mode
named function expressions.

This patch aims to delete all code meant to handle other cases, which
mostly had to do with hole initialization/hole checks. Since function
name bindings are initialized at entry to a function, it's impossible
to ever observe one in an uninitialized state.

To simplify the patch further, it removes the `IMPORT` VariableMode,
as it's not likely to be needed (IMPORT is identical to CONST for
the purpose of VariableMode).

Review URL: https://codereview.chromium.org/1895973002

Cr-Commit-Position: refs/heads/master@{#35632}

  The CL #35139 (https://codereview.chromium.org/1775323002) added V8_TARGET_ARCH_IA32 macro in
  src/globals.h.

  X87 is almost same as IA32, So It needs the V8_TARGET_ARCH_X87 macro in src/globals.h too.

BUG=

Review URL: https://codereview.chromium.org/1886233002

Cr-Commit-Position: refs/heads/master@{#35464}

The previous code cache system required stubs to be marked with a StubType, causing them to be inserted either into a fixed array or into a dictionary-mode code cache. This could cause names to be in both cases, and lookup would just find the "fast" one first. Given that we clear out the caches on each GC, the memory overhead shouldn't be too bad. Additionally, the dictionary itself should just stay linear for small arrays; that's faster anyway.

This CL additionally deletes some dead IC code.

BUG=

Review URL: https://codereview.chromium.org/1846963002

Cr-Commit-Position: refs/heads/master@{#35291}

Removed Frame::needs_frame and the function-wide logic using it in
favor of FrameAccessState::has_frame, which can be set on a more
granular level, and driving it block by block.

BUG= v8:4533
LOG=N

Review URL: https://codereview.chromium.org/1775323002

Cr-Commit-Position: refs/heads/master@{#35139}

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}

Immortal immovable roots must be allocated on the first page of the space.
If serializing the root list exceeds the first page, immortal immovable root
objects might end up outside of the first page. That could cause missing
write barriers.

We now iterate the root list twice. The first time we only serialize immortal
immovable root objects. The second time we serialize the rest.

R=mstarzinger@chromium.org

Review URL: https://codereview.chromium.org/1811913002

Cr-Commit-Position: refs/heads/master@{#34859}

A startup snapshot is considered cold when it does not contain any
function code. We can now create a warm startup snapshot from a cold one
by running a warm-up script. Functions exercised by the warm-up script
are compiled and its code included in the warm startup snapshot. Side
effects caused by the warm-up script does not persist.

R=vogelheim@chromium.org
BUG=v8:4836
LOG=Y

Review URL: https://codereview.chromium.org/1805903002

Cr-Commit-Position: refs/heads/master@{#34849}

Add S390 platform specific \#includes across various common files.
Add S390 CPU features to enum.
Add S390 implementation to extract sp/fp/pc from signal context.

R=danno@chromium.org,jkummerow@chromium.org,jochen@chromium.org,jyan@ca.ibm.com,michael_dawson@ca.ibm.com,mbrandy@us.ibm.com
BUG=

Review URL: https://codereview.chromium.org/1777593003

Cr-Commit-Position: refs/heads/master@{#34674}

R=mstarzinger@chromium.org,bmeurer@chromium.org,adamk@chromium.org
BUG=v8:3956
LOG=Y

Review URL: https://codereview.chromium.org/1773653002

Cr-Commit-Position: refs/heads/master@{#34669}

The enum in question is (and should) no longer be used outside of the
compiler API and hence is being moved back into the Compiler class.

R=yangguo@chromium.org

Review URL: https://codereview.chromium.org/1762323002

Cr-Commit-Position: refs/heads/master@{#34526}

R=bmeurer@chromium.org
BUG=v8:3956
LOG=n

Review URL: https://codereview.chromium.org/1731063007

Cr-Commit-Position: refs/heads/master@{#34398}

Various syntactic forms now cause functions to have names where they
didn't before. Per the upcoming changes to the toString spec, only
a name that was literally part of a function's expression or declaration
is meant to be reflected in toString. This also happens to be the same
set of names that V8 currently outputs (without the --harmony-function-name
flag).

This required distinguishing anonymous FunctionExpressions from other sorts
of function definitions (like methods and getters/setters) in the AST, parser,
and at runtime.

The patch also takes the opportunity to remove one more argument (and enum)
from FunctionLiteral, as well as adding a special factory method for the
case of a FunctionLiteral representing toplevel or eval'd code.

BUG=v8:4760
LOG=n

Review URL: https://codereview.chromium.org/1712833002

Cr-Commit-Position: refs/heads/master@{#34132}

This frees up one bit in FunctionKind, which I plan to make slightly
more syntactic info about functions available in SharedFunctionInfo
(needed for ES2015 Function.name support).

BUG=v8:3956, v8:4760
LOG=n

Review URL: https://codereview.chromium.org/1704223002

Cr-Commit-Position: refs/heads/master@{#34125}

Replace the somewhat awkward RestParamAccessStub, which would always
call into the runtime anyway with a proper FastNewRestParameterStub,
which is basically based on the code that was already there for strict
arguments object materialization. But for rest parameters we could
optimize even further (leading to 8-10x improvements for functions with
rest parameters), by fixing the internal formal parameter count:

Every SharedFunctionInfo has a formal_parameter_count field, which
specifies the number of formal parameters, and is used to decide whether
we need to create an arguments adaptor frame when calling a function
(i.e. if there's a mismatch between the actual and expected parameters).
Previously the formal_parameter_count included the rest parameter, which
was sort of unfortunate, as that meant that calling a function with only
the non-rest parameters still required an arguments adaptor (plus some
other oddities). Now with this CL we fix, so that we do no longer
include the rest parameter in that count. Thereby checking for rest
parameters is very efficient, as we only need to check whether there is
an arguments adaptor frame, and if not create an empty array, otherwise
check whether the arguments adaptor frame has more parameters than
specified by the formal_parameter_count.

The FastNewRestParameterStub is written in a way that it can be directly
used by Ignition as well, and with some tweaks to the TurboFan backends
and the CodeStubAssembler, we should be able to rewrite it as
TurboFanCodeStub in the near future.

Drive-by-fix: Refactor and unify the CreateArgumentsType which was
different in TurboFan and Ignition; now we have a single enum class
which is used in both TurboFan and Ignition.

R=jarin@chromium.org, rmcilroy@chromium.org
TBR=rossberg@chromium.org
BUG=v8:2159
LOG=n

Review URL: https://codereview.chromium.org/1676883002

Cr-Commit-Position: refs/heads/master@{#33809}

R=bmeurer@chromium.org, domenic@chromium.org

Review URL: https://codereview.chromium.org/1670923003

Cr-Commit-Position: refs/heads/master@{#33770}

This reverts commit 85ba94f2.

All parallelism can be turned off using --predictable, or --noparallel-compaction.

This patch completely parallelizes
 - semispace copy: from space -> to space (within newspace)
 - newspace evacuation: newspace -> oldspace
 - oldspace compaction: oldspace -> oldspace

Previously newspace has been handled sequentially (semispace copy, newspace
evacuation) before compacting oldspace in parallel. However, on a high level
there are no dependencies between those two actions, hence we parallelize them
altogether. We base the number of evacuation tasks on the overall set of
to-be-processed pages (newspace + oldspace compaction pages).

Some low-level details:
 - The hard cap on number of tasks has been lifted
 - We cache store buffer entries locally before merging them back into the global
   StoreBuffer in a finalization phase.
 - We cache AllocationSite operations locally before merging them back into the
   global pretenuring storage in a finalization phase.
 - AllocationSite might be compacted while they would be needed for newspace
   evacuation. To mitigate any problems we defer checking allocation sites for
   newspace till merging locally buffered data.

CQ_EXTRA_TRYBOTS=tryserver.v8:v8_linux_arm64_gc_stress_dbg,v8_linux_gc_stress_dbg,v8_mac_gc_stress_dbg,v8_linux64_asan_rel,v8_linux64_tsan_rel,v8_mac64_asan_rel
BUG=chromium:524425
LOG=N
R=hpayer@chromium.org, ulan@chromium.org

Review URL: https://codereview.chromium.org/1640563004

Cr-Commit-Position: refs/heads/master@{#33552}

Revert of [heap] Parallel newspace evacuation, semispace copy, and compaction \o/ (patchset #16 id:620001 of https://codereview.chromium.org/1577853007/ )

Reason for revert:
[Sheriff] Leads to crashes on all webrtc chromium testers, e.g.:
https://build.chromium.org/p/chromium.webrtc/builders/Mac%20Tester/builds/49664

Original issue's description:
> [heap] Parallel newspace evacuation, semispace copy, and compaction \o/
>
> All parallelism can be turned off using --predictable, or --noparallel-compaction.
>
> This patch completely parallelizes
>  - semispace copy: from space -> to space (within newspace)
>  - newspace evacuation: newspace -> oldspace
>  - oldspace compaction: oldspace -> oldspace
>
> Previously newspace has been handled sequentially (semispace copy, newspace
> evacuation) before compacting oldspace in parallel. However, on a high level
> there are no dependencies between those two actions, hence we parallelize them
> altogether. We base the number of evacuation tasks on the overall set of
> to-be-processed pages (newspace + oldspace compaction pages).
>
> Some low-level details:
>  - The hard cap on number of tasks has been lifted
>  - We cache store buffer entries locally before merging them back into the global
>    StoreBuffer in a finalization phase.
>  - We cache AllocationSite operations locally before merging them back into the
>    global pretenuring storage in a finalization phase.
>  - AllocationSite might be compacted while they would be needed for newspace
>    evacuation. To mitigate any problems we defer checking allocation sites for
>    newspace till merging locally buffered data.
>
> CQ_EXTRA_TRYBOTS=tryserver.v8:v8_linux_arm64_gc_stress_dbg,v8_linux_gc_stress_dbg,v8_mac_gc_stress_dbg,v8_linux64_asan_rel,v8_linux64_tsan_rel,v8_mac64_asan_rel
> BUG=chromium:524425
> LOG=N
> R=hpayer@chromium.org, ulan@chromium.org
>
> Committed: https://crrev.com/8f0fd8c0370ae8c5aab56491b879d7e30c329062
> Cr-Commit-Position: refs/heads/master@{#33523}

TBR=hpayer@chromium.org,ulan@chromium.org,mlippautz@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=chromium:524425

Review URL: https://codereview.chromium.org/1643473002

Cr-Commit-Position: refs/heads/master@{#33539}

All parallelism can be turned off using --predictable, or --noparallel-compaction.

This patch completely parallelizes
 - semispace copy: from space -> to space (within newspace)
 - newspace evacuation: newspace -> oldspace
 - oldspace compaction: oldspace -> oldspace

Previously newspace has been handled sequentially (semispace copy, newspace
evacuation) before compacting oldspace in parallel. However, on a high level
there are no dependencies between those two actions, hence we parallelize them
altogether. We base the number of evacuation tasks on the overall set of
to-be-processed pages (newspace + oldspace compaction pages).

Some low-level details:
 - The hard cap on number of tasks has been lifted
 - We cache store buffer entries locally before merging them back into the global
   StoreBuffer in a finalization phase.
 - We cache AllocationSite operations locally before merging them back into the
   global pretenuring storage in a finalization phase.
 - AllocationSite might be compacted while they would be needed for newspace
   evacuation. To mitigate any problems we defer checking allocation sites for
   newspace till merging locally buffered data.

CQ_EXTRA_TRYBOTS=tryserver.v8:v8_linux_arm64_gc_stress_dbg,v8_linux_gc_stress_dbg,v8_mac_gc_stress_dbg,v8_linux64_asan_rel,v8_linux64_tsan_rel,v8_mac64_asan_rel
BUG=chromium:524425
LOG=N
R=hpayer@chromium.org, ulan@chromium.org

Review URL: https://codereview.chromium.org/1577853007

Cr-Commit-Position: refs/heads/master@{#33523}

This CL implements PrepareForTailCall() mentioned in ES6 spec for full codegen, Crankshaft and Turbofan.
When debugger is active tail calls are disabled.

Tail calling can be enabled by --harmony-tailcalls flag.

BUG=v8:4698
LOG=Y
TBR=rossberg@chromium.org

Review URL: https://codereview.chromium.org/1609893003

Cr-Commit-Position: refs/heads/master@{#33509}

BUG=v8:4163,v8:4630
LOG=y

R=rossberg

Review URL: https://codereview.chromium.org/1590873002

Cr-Commit-Position: refs/heads/master@{#33360}

BUG=

Review URL: https://codereview.chromium.org/1467473002

Cr-Commit-Position: refs/heads/master@{#32223}

There's no point in collecting feedback for super constructor calls,
because in all (interesting) cases we can gather (better) feedback from
other sources (i.e. via inlining or via using a LOAD_IC to get to the
[[Prototype]] of the target).  So CallConstructStub is now only used
for new Foo(...args) sites where we want to collect feedback in the
baseline compiler.  The optimizing compilers, Reflect.construct and
super constructor calls use the Construct builtin directly, which allows
us to remove some weird code from the CallConstructStub (and opens the
possibility for more code sharing with the CallICStub, maybe even going
for a ConstructICStub).

Also remove the 100% redundant HCallNew instruction, which is just a
wrapper for the Construct builtin anyway (indirectly via the
CallConstructStub).

Drive-by-fix: Drop unused has_function_cache bit on Code objects.

R=mstarzinger@chromium.org, yangguo@chromium.org
BUG=v8:4413, v8:4430
LOG=n

Review URL: https://codereview.chromium.org/1469793002

Cr-Commit-Position: refs/heads/master@{#32172}

Introduce receiver conversion mode specialization for the Call and
CallFunction builtins, so we can specialize the builtin functionality
(actually an optimization only) based on static information from the
callsite (this is basically a superset of the optimizations that were
available with the CallFunctionStub and CallICStub, except that these
optimizations are correct now).

This fixes a regression introduced by the removal of CallFunctionStub,
for programs that call a lot.

R=yangguo@chromium.org
BUG=chromium:552244
LOG=n

Review URL: https://codereview.chromium.org/1436493002

Cr-Commit-Position: refs/heads/master@{#31871}

This fixes receiver conversion since the Call builtin does it correctly.

BUG=v8:4526
LOG=n

Review URL: https://codereview.chromium.org/1407373007

Cr-Commit-Position: refs/heads/master@{#31823}

The current implementation of classes throws the TypeError at the wrong
point, after activating a new context when directly calling a class
constructor. According to the spec, the TypeError has to be thrown
in the caller context.

LOG=N
BUG=v8:4428

Committed: https://crrev.com/6a06bc0a774933719f62009d81b3f1686d83bb90
Cr-Commit-Position: refs/heads/master@{#31786}

Review URL: https://codereview.chromium.org/1418623007

Cr-Commit-Position: refs/heads/master@{#31790}

Revert of [runtime] Fix ES6 9.2.1 [[Call]] when encountering a classConstructor. (patchset #20 id:370001 of https://codereview.chromium.org/1418623007/ )

Reason for revert:
failing build bot

Original issue's description:
> [runtime] Fix ES6 9.2.1 [[Call]] when encountering a classConstructor.
>
> The current implementation of classes throws the TypeError at the wrong
> point, after activating a new context when directly calling a class
> constructor. According to the spec, the TypeError has to be thrown
> in the caller context.
>
> LOG=N
> BUG=v8:4428
>
> Committed: https://crrev.com/6a06bc0a774933719f62009d81b3f1686d83bb90
> Cr-Commit-Position: refs/heads/master@{#31786}

TBR=bmeurer@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:4428

Review URL: https://codereview.chromium.org/1415783006

Cr-Commit-Position: refs/heads/master@{#31787}

The current implementation of classes throws the TypeError at the wrong
point, after activating a new context when directly calling a class
constructor. According to the spec, the TypeError has to be thrown
in the caller context.

LOG=N
BUG=v8:4428

Review URL: https://codereview.chromium.org/1418623007

Cr-Commit-Position: refs/heads/master@{#31786}

We have plans to create more ICs, and we are out of bits to represent the Kind
in the flags field of the code object. The InlineCacheState can lose a bit
because it no longer needs the DEFAULT state. That state existed as a way to
detect errors where code incorrectly looked at a vector IC stub's
InlineCacheState instead of correctly determining said state from a glance at
the vector. This really isn't a danger anymore.

So, with the horse trading, we could now represent up to 32 code kinds.

BUG=

Review URL: https://codereview.chromium.org/1427803003

Cr-Commit-Position: refs/heads/master@{#31666}

For platforms that use function descriptors (currently AIX and
PPC64BE), log an external callback's entrypoint address rather than
its function descriptor address.  This allows proper lookup in the
tick processor's symbol table.

R=jkummerow@chromium.org, michael_dawson@ca.ibm.com
BUG=

Review URL: https://codereview.chromium.org/1409993006

Cr-Commit-Position: refs/heads/master@{#31633}

Previously, arrow function scopes had a separate ScopeType. However,
Scope::DeserializeScopeChain() erroneously deserialized ARROW_SCOPE
ScopeInfos as FUNCTION_SCOPE. This could lead to bugs such as the
attached one, where "super" was disallowed where it should have
been allowed.

This patch utilizes the Scope's FunctionKind to distinguish arrow
functions from others. Besides fixing the above bug, this also
simplifies code in various places that had to deal with two different
ScopeTypes both of which meant "function".

BUG=v8:4466
LOG=n

Review URL: https://codereview.chromium.org/1386253002

Cr-Commit-Position: refs/heads/master@{#31154}

This CL also allows to use arbitrary number of feedback vector elements for particular slot kind.

Review URL: https://codereview.chromium.org/1370303004

Cr-Commit-Position: refs/heads/master@{#31050}

This enables linter checking for "readability/namespace" violations
during presubmit and instead marks the few known exceptions that we
allow explicitly.

R=bmeurer@chromium.org

Review URL: https://codereview.chromium.org/1371083003

Cr-Commit-Position: refs/heads/master@{#31019}

This adds ES6 compliant Object::ToInteger, Object::ToInt32,
Object::ToUint32 and Object::ToLength, and replaces the old
Execution wrappers of those abstract operations (which were
not using the correct ToPrimitive).

This also introduces proper %ToInteger and %ToLength runtime
entries, with a fast path %_ToInteger supported in fullcodegen
and Crankshaft (for now). Internal JavaScript code should use
TO_INTEGER and TO_LENGTH respectively.

CQ_INCLUDE_TRYBOTS=tryserver.v8:v8_linux_layout_dbg,v8_linux_nosnap_dbg
BUG=v8:4307
LOG=n

Review URL: https://codereview.chromium.org/1378533002

Cr-Commit-Position: refs/heads/master@{#30993}

There was already a bit on the Map named "function with prototype",
which basically meant that the Map was a map for a JSFunction that could
be used as a constructor. Now this CL generalizes that bit to
IsConstructor, which says that whatever (Heap)Object you are looking at
can be used as a constructor (i.e. the bit is also set for bound
functions that can be used as constructors and proxies that have a
[[Construct]] internal method).

This way we have a single chokepoint for IsConstructor checking, which
allows us to get rid of the various ways in which we tried to guess
whether something could be used as a constructor or not.

Drive-by-fix: Renamed IsConstructor on FunctionKind to
IsClassConstructor to resolve the weird name clash, and the
IsClassConstructor name also matches the spec.

CQ_INCLUDE_TRYBOTS=tryserver.v8:v8_linux_layout_dbg,v8_linux_nosnap_dbg
R=jarin@chromium.org, rossberg@chromium.org
BUG=v8:4413, v8:4430
LOG=n

Committed: https://crrev.com/8de4d9351df4cf66c8a128d561a6e331d196be54
Cr-Commit-Position: refs/heads/master@{#30900}

Review URL: https://codereview.chromium.org/1358423002

Cr-Commit-Position: refs/heads/master@{#30902}

Revert of [es6] Introduce spec compliant IsConstructor. (patchset #2 id:20001 of https://codereview.chromium.org/1358423002/ )

Reason for revert:
Failed on Fuzzer and MIPS bot.

Original issue's description:
> [es6] Introduce spec compliant IsConstructor.
>
> There was already a bit on the Map named "function with prototype",
> which basically meant that the Map was a map for a JSFunction that could
> be used as a constructor. Now this CL generalizes that bit to
> IsConstructor, which says that whatever (Heap)Object you are looking at
> can be used as a constructor (i.e. the bit is also set for bound
> functions that can be used as constructors and proxies that have a
> [[Construct]] internal method).
>
> This way we have a single chokepoint for IsConstructor checking, which
> allows us to get rid of the various ways in which we tried to guess
> whether something could be used as a constructor or not.
>
> Drive-by-fix: Renamed IsConstructor on FunctionKind to
> IsClassConstructor to resolve the weird name clash, and the
> IsClassConstructor name also matches the spec.
>
> R=jarin@chromium.org, rossberg@chromium.org
> BUG=v8:4430
> LOG=n
>
> Committed: https://crrev.com/8de4d9351df4cf66c8a128d561a6e331d196be54
> Cr-Commit-Position: refs/heads/master@{#30900}

TBR=jarin@chromium.org,rossberg@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:4430

Review URL: https://codereview.chromium.org/1360403002

Cr-Commit-Position: refs/heads/master@{#30901}

There was already a bit on the Map named "function with prototype",
which basically meant that the Map was a map for a JSFunction that could
be used as a constructor. Now this CL generalizes that bit to
IsConstructor, which says that whatever (Heap)Object you are looking at
can be used as a constructor (i.e. the bit is also set for bound
functions that can be used as constructors and proxies that have a
[[Construct]] internal method).

This way we have a single chokepoint for IsConstructor checking, which
allows us to get rid of the various ways in which we tried to guess
whether something could be used as a constructor or not.

Drive-by-fix: Renamed IsConstructor on FunctionKind to
IsClassConstructor to resolve the weird name clash, and the
IsClassConstructor name also matches the spec.

R=jarin@chromium.org, rossberg@chromium.org
BUG=v8:4430
LOG=n

Review URL: https://codereview.chromium.org/1358423002

Cr-Commit-Position: refs/heads/master@{#30900}

Introduce new builtins Construct and ConstructFunction (in line
with the Call and CallFunction builtins that we already have) as
proper bottleneck for Construct and [[Construct]] on JSFunctions.
Use these builtins to support passing NewTarget from C++ to
JavaScript land.

Long-term we want the CallConstructStub to be used for
gathering feedback on entry to construction chain (i.e. the
initial new Foo), and use the Construct builtins to do the
actual work inside the construction chain (i.e. calling into
super and stuff).

MIPS and MIPS64 ports contributed by akos.palfi@imgtec.com.

R=jarin@chromium.org
BUG=v8:4430
LOG=n

Review URL: https://codereview.chromium.org/1359583002

Cr-Commit-Position: refs/heads/master@{#30857}

R=machenbach@chromium.org

Review URL: https://codereview.chromium.org/1302413007

Cr-Commit-Position: refs/heads/master@{#30514}

R=bmeurer@chromium.org

Review URL: https://codereview.chromium.org/1302293002

Cr-Commit-Position: refs/heads/master@{#30291}

This is the first step of turning the v8.h file into a normal header
instead of an include-the-world header. The new rule is that no other
header files are allowed to include v8.h, which is enforced by DEPS.

Also the number of includes inside the v8.h file has been drastically
reduced. Basically the last missing piece is the inclusion of the big
objects-inl.h file.

This in turn makes many headers follow the IWYU principle.

R=bmeurer@chromium.org,hpayer@chromium.org,titzer@chromium.org

Review URL: https://codereview.chromium.org/1282503003

Cr-Commit-Position: refs/heads/master@{#30102}