New code should use nullptr instead of NULL.
This patch updates existing use of NULL to nullptr where applicable,
making the code base more consistent.
BUG=v8:6928,v8:6921
Cq-Include-Trybots: master.tryserver.chromium.linux:linux_chromium_rel_ng;master.tryserver.v8:v8_linux_noi18n_rel_ng
Change-Id: I4687f5b96fcfd88b41fa970a2b937b4f6538777c
Reviewed-on: https://chromium-review.googlesource.com/718338
Commit-Queue: Mathias Bynens <mathias@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48557}
CCalls have significantly less overhead than runtime calls which will improve
runtime performance on programs that make lots of transitions between JS and
Wasm.
Bug: v8:5277
Change-Id: If09dea97f24eb43753847e2b894ebc1ba5168c23
Reviewed-on: https://chromium-review.googlesource.com/688481
Commit-Queue: Eric Holk <eholk@chromium.org>
Reviewed-by: Mircea Trofin <mtrofin@chromium.org>
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48297}
The WasmContext struct introduced in this CL is used to store the
mem_size and mem_start address of the wasm memory. These variables can
be accessed at C++ level at graph build time (e.g., initialized during
instance building). When the GrowMemory runtime is invoked, the context
variables can be changed in the WasmContext at C++ level so that the
generated code will load the correct values.
This requires to insert a relocatable pointer only in the
JSToWasmWrapper (and in the other wasm entry points), the value is then
passed from function to function as an automatically added additional
parameter. The WasmContext is then dropped when creating an Interpreter
Entry or when invoking a JavaScript function. This removes the need of
patching the generated code at runtime (i.e., when the memory grows)
with respect to WASM_MEMORY_REFERENCE and WASM_MEMORY_SIZE_REFERENCE.
However, we still need to patch the code at instance build time to patch
the JSToWasmWrappers; in fact the address of the WasmContext is not
known during compilation, but only when the instance is built.
The WasmContext address is passed as the first parameter. This has the
advantage of not having to move the WasmContext around if the function
does not use many registers. This CL also changes the wasm calling
convention so that the first parameter register is different from the
return value register. The WasmContext is attached to every
WasmMemoryObject, to share the same context with multiple instances
sharing the same memory. Moreover, the nodes representing the
WasmContext variables are cached in the SSA environment, similarly to
other local variables that might change during execution. The nodes are
created when initializing the SSA environment and refreshed every time a
grow_memory or a function call happens, so that we are sure that they
always represent the correct mem_size and mem_start variables.
This CL also removes the WasmMemorySize runtime (since it's now possible
to directly retrieve mem_size from the context) and simplifies the
GrowMemory runtime (since every instance now has a memory_object).
R=ahaas@chromium.org,clemensh@chromium.org
CC=gdeepti@chromium.org
Change-Id: I3f058e641284f5a1bbbfc35a64c88da6ff08e240
Reviewed-on: https://chromium-review.googlesource.com/671008
Commit-Queue: Enrico Bacis <enricobacis@google.com>
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48209}
Use operator== and operator!= instead.
Implemented for x64, ia32, arm, arm64, mips and mips64.
R=mstarzinger@chromium.org,ishell@chromium.org,jgruber@chromium.org
Change-Id: Iad0f03f7f442709dcaa12d6a49a8bc4b03b9cdae
Reviewed-on: https://chromium-review.googlesource.com/654857
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47889}
Up to now, each architecture defined all Register types as structs,
with lots of redundancy. An often found comment noted that they cannot
be classes due to initialization order problems. As these problems are
gone with C++11 constexpr constants, I now tried making Registers
classes again.
All register types now inherit from RegisterBase, which provides a
default set of methods and named constructors (like ::from_code,
code(), bit(), is_valid(), ...).
This design allows to guarantee an interesting property: Each register
is either valid, or it's the no_reg register. There are no other
invalid registers. This is guaranteed statically by the constexpr
constructor, and dynamically by ::from_code.
I decided to disallow the default constructor completely, so instead of
"Register reg;" you now need "Register reg = no_reg;". This makes
explicit how the Register is initialized.
I did this change to the x64, ia32, arm, arm64, mips and mips64 ports.
Overall, code got much more compact and more safe. In theory, it should
also increase performance (since the is_valid() check is simpler), but
this is probably not measurable.
R=mstarzinger@chromium.org
Change-Id: I5ccfa4050daf4e146a557970e9d37fd3d2788d4a
Reviewed-on: https://chromium-review.googlesource.com/650927
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47847}
This adds support for lazy deserialization of JS-linkage (TFJ) builtins,
still gated behind the --lazy-deserialization flag. If enabled, we
proceed as follows:
During isolate initialization, only eager builtins are deserialized. All
references to lazy builtins are replaced by the DeserializeLazy builtin.
In particular, this happens in the builtin table (Builtins::builtins_)
and in SharedFunctionInfo objects.
When calling into a not-yet deserialized function (i.e. the JSFunction's
code object is the DeserializeLazy builtin), the DeserializeLazy builtin
takes over. It checks the builtin table to see if the target builtin
(determined by looking at the builtin id stored on the
SharedFunctionInfo) has already been deserialized. If so, it simply
copies the builtin code object to the JSFunction and SharedFunctionInfo.
Otherwise, we enter Runtime::kDeserializeLazy to deserialize the
builtin.
With --lazy-deserialization, isolate deserialization is 11% faster
(1.5ms vs. 1.7ms), and code_space->Size() is 33% lower (984K vs.
1475K).
Moving relocation infos & handler tables out of the partial snapshot
cache would additionally let us save up to 30K per isolate. Adding code
stubs to that list increases further potential savings to 262K.
Bug: v8:6624
Change-Id: I0ac7d05d165d2466998269bd431ac076a311cbeb
Reviewed-on: https://chromium-review.googlesource.com/649166
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47818}
This change adapts the Call bytecode handlers such that they don't require
a stack frame. It does this by modifying the call bytecode handler to
tail-call the Call or InterpreterPushArgsAndCall builtins. As a result, the
callee function will return to the InterpreterEntryTrampoline when it returns
(since this is the return address on the interpreter frame), which is
adapted to dispatch to the next bytecode handler. The return bytecode
handler is modified to tail-call a new InterpreterExitTramoline instead
of returning to the InterpreterEntryTrampoline.
Overall this significanlty reduces the amount of stack space required for
interpreter frames, increasing the maximum depth of recursive calls from
around 6000 to around 12,500 on x64.
BUG=chromium:753705
Change-Id: I23328e4cef878df3aca4db763b47d72a2cce664c
Reviewed-on: https://chromium-review.googlesource.com/634364
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47617}
Code size in snapshot can be reduced ~41KB
Contributed by kanghua.yu@intel.com
Bug: None
Cq-Include-Trybots: master.tryserver.chromium.linux:linux_chromium_rel_ng
Change-Id: Ib73af39fe97cd38728affea40c593236f15bf6e5
Reviewed-on: https://chromium-review.googlesource.com/588751
Commit-Queue: Pan Deng <pan.deng@intel.com>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47531}
Code aging is no longer supported by any remaining compilers now
that full codegen has been removed. This CL removes all vestiges of
code aging.
BUG=v8:6409
Change-Id: I945ebcc20c7c55120550c8ee36188bfa042ea65e
Reviewed-on: https://chromium-review.googlesource.com/619153
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Marja Hölttä <marja@chromium.org>
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47501}
This reverts commit af37f6b970.
Reason for revert: Reverted dependency fixed.
Original change's description:
> Revert "[wasm] Reference indirect tables as addresses of global handles"
>
> This reverts commit 186099d49f.
>
> Reason for revert: Need to revert:
> https://chromium-review.googlesource.com/c/613880
>
> Original change's description:
> > [wasm] Reference indirect tables as addresses of global handles
> >
> > This sets us up for getting the wasm code generation off the GC heap.
> > We reference tables as global handles, which have a stable address. This
> > requires an extra instruction when attempting to make an indirect call,
> > per table (i.e. one for the signature table and one for the function
> > table).
> >
> > Bug:
> > Change-Id: I83743ba0f1dfdeba9aee5d27232f8823981288f8
> > Reviewed-on: https://chromium-review.googlesource.com/612322
> > Commit-Queue: Mircea Trofin <mtrofin@chromium.org>
> > Reviewed-by: Brad Nelson <bradnelson@chromium.org>
> > Cr-Commit-Position: refs/heads/master@{#47444}
>
> TBR=bradnelson@chromium.org,titzer@chromium.org,mtrofin@chromium.org
>
> Change-Id: Ic3dff87410a51a2072ddc16cfc83a230526d4c56
> No-Presubmit: true
> No-Tree-Checks: true
> No-Try: true
> Reviewed-on: https://chromium-review.googlesource.com/622568
> Reviewed-by: Michael Achenbach <machenbach@chromium.org>
> Commit-Queue: Michael Achenbach <machenbach@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#47450}
TBR=bradnelson@chromium.org,machenbach@chromium.org,titzer@chromium.org,mtrofin@chromium.org
Change-Id: I3dc5dc8be26b5462703edac954cbedbb8f504c1e
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/622035
Reviewed-by: Mircea Trofin <mtrofin@chromium.org>
Commit-Queue: Mircea Trofin <mtrofin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47455}
This reverts commit 186099d49f.
Reason for revert: Need to revert:
https://chromium-review.googlesource.com/c/613880
Original change's description:
> [wasm] Reference indirect tables as addresses of global handles
>
> This sets us up for getting the wasm code generation off the GC heap.
> We reference tables as global handles, which have a stable address. This
> requires an extra instruction when attempting to make an indirect call,
> per table (i.e. one for the signature table and one for the function
> table).
>
> Bug:
> Change-Id: I83743ba0f1dfdeba9aee5d27232f8823981288f8
> Reviewed-on: https://chromium-review.googlesource.com/612322
> Commit-Queue: Mircea Trofin <mtrofin@chromium.org>
> Reviewed-by: Brad Nelson <bradnelson@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#47444}
TBR=bradnelson@chromium.org,titzer@chromium.org,mtrofin@chromium.org
Change-Id: Ic3dff87410a51a2072ddc16cfc83a230526d4c56
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/622568
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47450}
This sets us up for getting the wasm code generation off the GC heap.
We reference tables as global handles, which have a stable address. This
requires an extra instruction when attempting to make an indirect call,
per table (i.e. one for the signature table and one for the function
table).
Bug:
Change-Id: I83743ba0f1dfdeba9aee5d27232f8823981288f8
Reviewed-on: https://chromium-review.googlesource.com/612322
Commit-Queue: Mircea Trofin <mtrofin@chromium.org>
Reviewed-by: Brad Nelson <bradnelson@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47444}
This removes:
- CodeBreakIterator for FCG code.
- RelocModes for debug breaks.
- Code generator for debug break slots.
- GC support for debug break slots.
- Code flag to indicate code with debug break slots.
- Builtin type DBG.
- Mechanisms to replace FCG code in the debugger and LiveEdit.
- Runtime entry to the debugger from debug break slots.
R=bmeurer@chromium.org, rmcilroy@chromium.org, ulan@chromium.org
Bug: v8:6409
Change-Id: I5662c8800e3ef1b1584ad107bfe0aae26c9d8abb
Reviewed-on: https://chromium-review.googlesource.com/613263
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Commit-Queue: Yang Guo <yangguo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47364}
The way we access wasm addresses or sizes is the same, on
a platform. We have 2 size parameters - memory and table - and
2 addresses - globals and memory.
The CL also renames for generality the address setting API.
Bug:
Change-Id: Ib66c3aff6a0ab4313391528cd2692749bb389559
Reviewed-on: https://chromium-review.googlesource.com/612597
Commit-Queue: Brad Nelson <bradnelson@chromium.org>
Reviewed-by: Brad Nelson <bradnelson@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47350}
Bug: 749486
The feature is off by default, and could be turned on via
`v8_enable_csa_write_barrier = true`. With this CL, only x64 uses this
feature
Change-Id: Ie024f08b7d796a4cc4d55285dc9fe796780f0e53
Reviewed-on: https://chromium-review.googlesource.com/588891
Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Albert Mingkun Yang <albertnetymk@google.com>
Cr-Commit-Position: refs/heads/master@{#47122}
Until now, when generating a builtin, it can only embed builtins
(as call targets) that have already been generated. This is either
achieved by reordering the builtins list, or by loading the call
target at runtime from the builtins list (see
MacroAssembler::TailCallBuiltin).
This patch works around this issue by filling the builtins list
with dummy code objects, which are later replaced with the completed
actual builtins. In release mode, this adds around 3ms to 140ms we
previously needed to populate the builtins list.
Change-Id: I7d451b3c09a1db4b9e755548102a80c7f0dfada2
Reviewed-on: https://chromium-review.googlesource.com/586531
Commit-Queue: Yang Guo <yangguo@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47062}
Register configuration data is not the same as frame configuration data.
This CL moves the last remnants of register configuration into
the assembler files, to be with the other register configuration
macros.
Next step: extract this register configuration data into
platform-specific files that can be included independent of the
assembler.
R=mstarzinger@chromium.org
Bug:
Change-Id: I10933b5090be94e90e2a1442197528dfe30bb566
Reviewed-on: https://chromium-review.googlesource.com/595590
Commit-Queue: Ben Titzer <titzer@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47044}
This switches the "code entry" field on JSFunction to no longer be an
inner pointer into a Code object (i.e. to the start of the instruction
stream), but a properly tagged pointer instead.
Motivation behind this is the ability to treat this field regularly as
part of escape analysis in the optimizing compiler. Also simplifies the
object visitation for JSFunction objects.
R=bmeurer@chromium.org
Change-Id: Ib53a3fc5f3d783a6fed06dbcab319f5568632acc
Reviewed-on: https://chromium-review.googlesource.com/577890
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46844}
This makes {NeedsDebugHookCheck} the default for all invocations, as
there is no call-site left that doesn't perform said check. All other
pieces of the {CallWrapper} are dead since Crankshafts removal.
R=jgruber@chromium.org
Change-Id: I158b816c089ede42972e8a7bdfc6ef0c02053a6b
Reviewed-on: https://chromium-review.googlesource.com/577531
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46758}
The tail call implementation is hidden behind the --harmony-tailcalls
flag, which is off-by-default (and has been unstaged since February).
It is known to be broken in a variety of cases, including clusterfuzz
security issues (see sample Chromium issues below). To avoid letting
the implementation bitrot further on trunk, this patch removes it.
Bug: v8:4698, chromium:636914, chromium:724746
Cq-Include-Trybots: master.tryserver.chromium.linux:linux_chromium_rel_ng;master.tryserver.v8:v8_linux_noi18n_rel_ng
Change-Id: I9cb547101456a582374fdf7b1a3f044a9ef33e5c
Reviewed-on: https://chromium-review.googlesource.com/569069
Commit-Queue: Adam Klein <adamk@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46651}
TF will instantiate the Assembler when we're already on a background
thread, so it's not safe to read out the heap's max_old_generation_size
(it can change). This CL simply removes the use of that value from the
assembler. If the buffer gets too large we will fail when creating the
actual code object.
Bug: v8:6048
Change-Id: Ifb8a64c90222e4516117d237b001779fae060d28
Reviewed-on: https://chromium-review.googlesource.com/567921
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Commit-Queue: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46581}
The use of double variables to store bit patterns may lead to bit flips
when the stored bit pattern is a signaling NaN (sNaN). Operations on a
sNaN variable (even just returning the variable from a function) may
turn it into a quiet NaN (qNaN), flipping the signaling bit and
affecting the information stored in the variable.
We observed this behaviour on ia32 architectures and therefore in the
simulator builds for other platforms. The use of the wrapper class
Double should prevent this behaviour.
R=ahaas@chromium.org
Change-Id: Ibd1119924a59db771fd4c250689ad9c2a35fff75
Reviewed-on: https://chromium-review.googlesource.com/562771
Reviewed-by: Jaideep Bajwa <bjaideep@ca.ibm.com>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Commit-Queue: Enrico Bacis <enricobacis@google.com>
Cr-Commit-Position: refs/heads/master@{#46533}
This introduces a new builtin (MapLookupHashIndex) and uses it
in Turbofan to compute Map.p.get and Map.p.has.
I have also refactored the existing CSA builtins for Map.p.get and
Map.p.has to use the new builtin under the hood.
The code for the lookup has been also improved.
- Specialized lookups for smis, strings, heap numbers and everything else.
- the advantage is that we can use fast equalities for the lookup.
- strings can likely be optimized further if we care about the
internalized string fast case.
- Instead of a call to runtime to get the hash code, we now call C directly.
In the Turbofan implementation itself, there are no special optimizations yet.
The next step is to teach load elimination to reuse the indexes from
previous calls of MapLookupHashIndex.
BUG=v8:6410
Change-Id: I0b1a70493eb031d444e51002f6b2cc1f30ea2b68
Reviewed-on: https://chromium-review.googlesource.com/560169
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Jaroslav Sevcik <jarin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46510}
On x86, signalling NaNs get converted to quiet NaNs when they get push
on the stack and popped again. This happens in the code generation for
arm, specifically for the vmov instruction with the immediate parameter.
This CL replaces the vmov function in assembler-arm to take the
immediate as a uint64_t instead of a double, to guarantee that the bit
pattern does not change even if the parameter is a signalling NaN.
BUG=v8:6564
Change-Id: I062559f9a7ba8b0f560628e5c39621ca578c3e7d
Reviewed-on: https://chromium-review.googlesource.com/558964
Commit-Queue: Andreas Haas <ahaas@chromium.org>
Reviewed-by: Ben Titzer <titzer@chromium.org>
Reviewed-by: Martyn Capewell <martyn.capewell@arm.com>
Cr-Commit-Position: refs/heads/master@{#46418}
OrderedHashSet doesn't need a ::Get, so we can move it to
OrderedHashMap.
Bug: v8:5717
Change-Id: I9606d8c4608473f9daecf8a87b4dd2e3b9570246
Reviewed-on: https://chromium-review.googlesource.com/522348
Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Commit-Queue: Sathya Gunasekaran <gsathya@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45740}
Instead of allocating and embedding certain heap numbers into the code
during code assembly, emit dummies but record the allocation requests.
Later then, in Assembler::GetCode, allocate the heap numbers and patch
the code by replacing the dummies with the actual objects. The
RelocInfos for the embedded objects are already recorded correctly when
emitting the dummies.
R=jarin@chromium.org
BUG=v8:6048
Review-Url: https://codereview.chromium.org/2900683002
Cr-Commit-Position: refs/heads/master@{#45635}
This patch also adds sharing of code target entries, which requires
sharing the RelocInfo for those entries as well. The disassembler
is also modified in order to print comments for the RelocInfo that
is now shared.
This improves the snapshot size for arm by about 4%.
BUG=
Review-Url: https://codereview.chromium.org/2869683004
Cr-Commit-Position: refs/heads/master@{#45497}
This CL migrates the CPP builtin to CSA with fast paths for strings
that can be unpacked to direct one-byte strings. Short strings are
handled directly in CSA, others need to call into C for conversion.
Microbenchmarks for "abcd".toLowerCase() show speedups of 2.5x.
BUG=v8:6353,v8:6344
Review-Url: https://codereview.chromium.org/2859203002
Cr-Commit-Position: refs/heads/master@{#45141}
In the simulators, the ExternalReference constructor rewrites external
addresses, which involves mutating a linked list rooted in the isolate.
We already construct external references concurrently (at least in Turbofan),
but the list mutation was not thread-safe (though no crashes are known). This
CL adds the necessary locking.
BUG=v8:6048
Review-Url: https://codereview.chromium.org/2852983002
Cr-Commit-Position: refs/heads/master@{#45014}
The StringIndexOf fast path used to be very narrow, only allowing
one-byte single-char search strings (and a one-byte subject string).
This changes the CSA fast path to call into our internal SearchString C++
function instead (after attempting to unpack both Strings), and can handle
strings of arbitrary length and encoding. The only remaining runtime call is
when either string needs to be flattened.
BUG=
Review-Url: https://codereview.chromium.org/2814373002
Cr-Commit-Position: refs/heads/master@{#44718}
