This is a pure refactoring and renaming of methods in the compiler API
with the goal to increase readability. Also the compiler API is moved to
the top of the file, as it is the central piece in that file.
R=yangguo@chromium.org
Review URL: https://codereview.chromium.org/1766623004
Cr-Commit-Position: refs/heads/master@{#34579}
Instead of using CheckFloatEq and CheckDoubleEq directly, I introduced
a macro which first stores the expected result in a volatile variable.
Here are some comments of previous CLs:
The reason is same as the CL #31808 (issue 1430943002, X87: Change the test case for X87 float operations), please refer: https://codereview.chromium.org/1430943002/.
Here is the key comments from CL #31808
Some new test cases use CheckFloatEq(...) and CheckDoubleEq(...) function for result check. When GCC compiling the CheckFloatEq() and CheckDoubleEq() function,
those inlined functions has different behavior comparing with GCC ia32 build and x87 build.
The major difference is sse float register still has single precision rounding semantic. While X87 register has no such rounding precsion semantic when directly use register value.
The V8 turbofan JITTed has exactly same result in both X87 and IA32 port.
So we add the following sentence to do type cast to keep the same precision for RunCallInt64ToFloat32/RunCallInt64ToFloat64. Such as: volatile double expect = static_cast<float>(*i).
R=titzer@chromium.org, weiliang.lin@intel.com
Review URL: https://codereview.chromium.org/1773513002
Cr-Commit-Position: refs/heads/master@{#34534}
On 32-bit systems FXXXConvertI64 instructions are compiled to calls to
C functions. The TF node for the function call is already generated in
the wasm compiler, the lowering of the I64 parameter is done in the
Int64Lowering.
R=titzer@chromium.org, yangguo@chromium.org
Review URL: https://codereview.chromium.org/1738623003
Cr-Commit-Position: refs/heads/master@{#34487}
Add StringLessThanStub, StringLessThanOrEqualStub, StringGreaterThanStub
and StringGreaterThanOrEqualStub, based on the CodeStubAssembler, and
hook them up with TurboFan (and Ignition). The stubs are currently
essentially comparable with the StringCompareStub, which is now
obsolete. We can later extend these stubs to cover more interesting
cases (i.e. two byte sequential string comparisons, etc.).
R=epertoso@chromium.org
Review URL: https://codereview.chromium.org/1765823002
Cr-Commit-Position: refs/heads/master@{#34485}
These new stubs perform exactly the same job as the string equality case
for the CompareIC, but are platform independent and usable outside of
fullcodegen and Crankshaft. We use them in the StrictEqualStub and the
StrictNotEqualStub instead of falling back to the runtime immediately
for String comparisons, and we also use them in TurboFan to perform
String equality or inequality comparisons.
These stubs currently handle only internalized and one byte strings w/o
going to C++, but it should be easy to add support for more string cases
later, i.e. utilizing already flattened cons strings or comparing two
byte strings as well.
Review URL: https://codereview.chromium.org/1761823002
Cr-Commit-Position: refs/heads/master@{#34459}
The LoadBuffer operator that is used for asm.js heap access claims to
return only the appropriate typed array type, but out of bounds access
could make it return undefined. So far we tried to "repair" the graph
later if we see that our assumption was wrong, and for various reasons
that worked for some time. But now that wrong type information that is
propagated earlier is picked up appropriately and thus we generate wrong
code, i.e. we in the repro case we feed NaN into ChangeFloat64Uint32 and
thus get 2147483648 instead of 0 (with proper JS truncation).
This was always considered a temporary hack until we have a proper
asm.js pipeline, but since we still run asm.js through the generic
JavaScript pipeline, we have to address this now. Quickfix is to just
bailout from the pipeline when we see that the LoadBuffer type was
wrong, i.e. the result of LoadBuffer is not properly truncated and thus
undefined or NaN would be observable.
R=mstarzinger@chromium.org, jarin@chromium.org
BUG=chromium:589792
LOG=y
Review URL: https://codereview.chromium.org/1740123002
Cr-Commit-Position: refs/heads/master@{#34322}
Migrate Math.imul, Math.fround, Math.acos, Math.asin and Math.atan to
C++ builtins, as these ones call into C++ anyway and so there's no
need to have this extra wrapper around it.
R=yangguo@chromium.org
Review URL: https://codereview.chromium.org/1731543004
Cr-Commit-Position: refs/heads/master@{#34274}
Reason for revert:
It is not a good idea to call CallICStub from the builtin. It might be sensitive to the frame structure. Constructing a internal frame might cause problems. It is much better to inline the code related to the type feedback vector into the builtin.
Original issue's description:
> [Interpreter] Implements calls through CallICStub in the interpreter.
>
> Calls are implemented through CallICStub to collect type feedback. Adds
> a new builtin called InterpreterPushArgsAndCallIC that pushes the
> arguments onto stack and calls CallICStub.
>
> Also adds two new bytecodes CallIC and CallICWide to indicate calls have to
> go through CallICStub.
>
> MIPS port contributed by balazs.kilvady.
>
> BUG=v8:4280, v8:4680
> LOG=N
>
> Committed: https://crrev.com/20362a2214c11a0f2ea5141b6a79e09458939cec
> Cr-Commit-Position: refs/heads/master@{#34244}
TBR=rmcilroy@chromium.org,mvstanton@chromium.org,mstarzinger@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:4280, v8:4680
Review URL: https://codereview.chromium.org/1731253003
Cr-Commit-Position: refs/heads/master@{#34252}
Calls are implemented through CallICStub to collect type feedback. Adds
a new builtin called InterpreterPushArgsAndCallIC that pushes the
arguments onto stack and calls CallICStub.
Also adds two new bytecodes CallIC and CallICWide to indicate calls have to
go through CallICStub.
MIPS port contributed by balazs.kilvady.
BUG=v8:4280, v8:4680
LOG=N
Review URL: https://codereview.chromium.org/1688283003
Cr-Commit-Position: refs/heads/master@{#34244}
The CL #33796 (https://codereview.chromium.org/1628133002) added the RunRoundUint32ToFloat32 test case and X87 failed at it.
The reason is same as the CL #33630 (Issue 1649323002: X87: Change the test case for X87 RunRoundInt32ToFloat32), please refer: https://codereview.chromium.org/1649323002.
Here is the key comments from CL #33630:
Some new test cases use CheckFloatEq(...) and CheckDoubleEq(...) function for result check. When GCC compiling the CheckFloatEq() and CheckDoubleEq() function,
those inlined functions has different behavior comparing with GCC ia32 build and x87 build.
The major difference is sse float register still has single precision rounding semantic. While X87 register has no such rounding precsion semantic when directly use register value.
The V8 turbofan JITTed has exactly same result in both X87 and IA32 port.
For CHECK_EQ(a, b) function, if a and b are doubles, it will has similar behaviors like CheckFloatEq(...) and CheckDoubleEq(...) function when compiled by GCC and causes the test case
fail.
So we add the following sentence to do type case to keep the same precision for RunRoundUint32ToFloat32. Such as: volatile double expect = static_cast<float>(*i).
BUG=
Review URL: https://codereview.chromium.org/1714413002
Cr-Commit-Position: refs/heads/master@{#34202}
Reason for revert:
Tanks benchmarks (e.g., Octane box2d TF).
Original issue's description:
> [turbofan] Connect ObjectIsNumber to effect and control chains.
>
> In theory, we could connect the nodes when doing
> the schedule-in-the-middle pass, but that would require creating two
> versions of the operator (effectful and pure). I believe we do not
> lose anything by wiring the node up eagerly.
>
> Committed: https://crrev.com/2894e80a0a4a51a0d72e72aa48fcd01968f7949f
> Cr-Commit-Position: refs/heads/master@{#34141}
TBR=bmeurer@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
Review URL: https://codereview.chromium.org/1718483002
Cr-Commit-Position: refs/heads/master@{#34147}
In theory, we could connect the nodes when doing
the schedule-in-the-middle pass, but that would require creating two
versions of the operator (effectful and pure). I believe we do not
lose anything by wiring the node up eagerly.
Review URL: https://codereview.chromium.org/1709093002
Cr-Commit-Position: refs/heads/master@{#34141}
The BufferedRawMachineAssemblerTester caused problems for the
Int64Lowering. Instead we construct a TF graph now which is compiled by
Pipeline::GenerateCodeForTesting.
R=titzer@chromium.org
Review URL: https://codereview.chromium.org/1702023002
Cr-Commit-Position: refs/heads/master@{#34107}
This CL splits up some long-running bytecode graph builder tests.
There's a lot of working going on here that probably should be split
up into smaller tests and/or mjsunit tests once we have the full
ignition pipeline. This one just targets the top offenders for now.
R=rmcilroy@chromium.org, oth@chromium.org
BUG=
Review URL: https://codereview.chromium.org/1699113002
Cr-Commit-Position: refs/heads/master@{#34039}
Drive-by-fix: Remove the (now) unused %_SetValueOf and %_JSValueGetValue
intrinsics from the various compilers and the runtime.
R=jarin@chromium.org
Review URL: https://codereview.chromium.org/1698343002
Cr-Commit-Position: refs/heads/master@{#34037}
This functionality is useful for stubs that need to walk the stack. The new
machine operator, LoadParentFramePointer dosn't force the currently compiling
method to have a frame in contrast to LoadFramePointer. Instead, it adapts
accordingly when frame elision is possible, making efficient stack walks
possible without incurring a performance penalty for small stubs that can
benefit from frame elision.
R=bmeurer@chromium.org
LOG=N
Review URL: https://codereview.chromium.org/1695313002
Cr-Commit-Position: refs/heads/master@{#34014}
There are only two uses of %_ObjectEquals left, which should actually
use strict equality instead, so there's no need to keep this special
logic at all.
R=mvstanton@chromium.org
Review URL: https://codereview.chromium.org/1692193002
Cr-Commit-Position: refs/heads/master@{#33948}
The tests in question have been disabled because throwing into lazy
deoptimized code was borked. After recent fixes landed these tests
should now pass again.
R=jarin@chromium.org
TEST=cctest/test-run-deopt/DeoptExceptionHandler
BUG=v8:4195
LOG=n
Review URL: https://codereview.chromium.org/1692873002
Cr-Commit-Position: refs/heads/master@{#33937}
The field in question is only needed when the optimizing compiler is
triggered via OSR. All other paths (e.g. from bytecode stream) should
not rely on the unoptimized code being present.
R=yangguo@chromium.org
Review URL: https://codereview.chromium.org/1685633002
Cr-Commit-Position: refs/heads/master@{#33860}
This makes sure we can run through the TurboFan pipeline without having
to parse the source when using the bytecode stream as input. This path
is now being tested by the BytecodeGraphTester helper.
R=titzer@chromium.org,rmcilroy@chromium.org
Review URL: https://codereview.chromium.org/1679313002
Cr-Commit-Position: refs/heads/master@{#33856}
By now only the default %TypedArray%.prototype.sort compare function
and the JS implementation of SameValueZero were still using the odd
%_IsMinusZero intrinsic, whose semantics both included a number check
(actually HeapNumber test) plus testing if the heap number stores the
special -0 value. In both cases we already know that we deal with
number so we can reduce it to a simple number test for -0, which can
be expressed via dividing 1 by that value and checking the sign of
the result. In case of the compare function, we can be even smarter
and work with the reciprocal values in case x and y are equal to 0
(although long term we should probably rewrite the fast case for
the typed array sorting function in C++ anyway, which will be way,
way faster than our handwritten callback-style, type-feedback
polluted JS implementation).
R=yangguo@chromium.org
Review URL: https://codereview.chromium.org/1680783002
Cr-Commit-Position: refs/heads/master@{#33833}
Adds implementation and tests to support const/let variables in the
interpreter.
BUG=v8:4280,v8:4679
LOG=N
Review URL: https://codereview.chromium.org/1634153002
Cr-Commit-Position: refs/heads/master@{#33819}
Reason for revert:
Must revert for now due to chromium api natives issues.
Original issue's description:
> Type Feedback Vector lives in the closure
>
> (RELAND: the problem before was a missing write barrier for adding the code
> entry to the new closure. It's been addressed with a new macro instruction
> and test. The only change to this CL is the addition of two calls to
> __ RecordWriteCodeEntryField() in the platform CompileLazy builtin.)
>
> We get less "pollution" of type feedback if we have one vector per native
> context, rather than one for the whole system. This CL moves the vector
> appropriately.
>
> We rely more heavily on the Optimized Code Map in the SharedFunctionInfo. The
> vector actually lives in the first slot of the literals array (indeed there is
> great commonality between those arrays, they can be thought of as the same
> thing). So we make greater effort to ensure there is a valid literals array
> after compilation.
>
> This meant, for performance reasons, that we needed to extend
> FastNewClosureStub to support creating closures with literals. And ultimately,
> it drove us to move the optimized code map lookup out of FastNewClosureStub
> and into the compile lazy builtin.
>
> The heap change is trivial so I TBR Hannes for it...
> Also, Yang has had a look at the debugger changes already and approved 'em. So he is TBR style too.
> And Benedikt reviewed it as well.
>
> TBR=hpayer@chromium.org, yangguo@chromium.org, bmeurer@chromium.org
>
> BUG=
>
> Committed: https://crrev.com/bb31db3ad6de16f86a61f6c7bbfd3274e3d957b5
> Cr-Commit-Position: refs/heads/master@{#33741}
TBR=bmeurer@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=
Review URL: https://codereview.chromium.org/1670813005
Cr-Commit-Position: refs/heads/master@{#33766}
(RELAND: the problem before was a missing write barrier for adding the code
entry to the new closure. It's been addressed with a new macro instruction
and test. The only change to this CL is the addition of two calls to
__ RecordWriteCodeEntryField() in the platform CompileLazy builtin.)
We get less "pollution" of type feedback if we have one vector per native
context, rather than one for the whole system. This CL moves the vector
appropriately.
We rely more heavily on the Optimized Code Map in the SharedFunctionInfo. The
vector actually lives in the first slot of the literals array (indeed there is
great commonality between those arrays, they can be thought of as the same
thing). So we make greater effort to ensure there is a valid literals array
after compilation.
This meant, for performance reasons, that we needed to extend
FastNewClosureStub to support creating closures with literals. And ultimately,
it drove us to move the optimized code map lookup out of FastNewClosureStub
and into the compile lazy builtin.
The heap change is trivial so I TBR Hannes for it...
Also, Yang has had a look at the debugger changes already and approved 'em. So he is TBR style too.
And Benedikt reviewed it as well.
TBR=hpayer@chromium.org, yangguo@chromium.org, bmeurer@chromium.org
BUG=
Review URL: https://codereview.chromium.org/1668103002
Cr-Commit-Position: refs/heads/master@{#33741}
Adds implementation and tests for with statement to interprter.
BUG=v8:4280,v8:4684
LOG=N
Review URL: https://codereview.chromium.org/1656863002
Cr-Commit-Position: refs/heads/master@{#33705}
Moves the temporary register allocator out of the bytecode array
builder into TemporaryRegisterAllocator class and adds unittests.
Particular must be taken around the translation window boundary
motivating the addition of tests.
Also adds a Clear() method to IdentityMap() which is called by
the destructor. This allows classes to hold an IdentityMap if
they are zone allocated. Classes must call Clear() before the zone
is re-cycled or face v8 heap corruption.
BUG=v8:4280,v8:4675
LOG=N
Review URL: https://codereview.chromium.org/1651133002
Cr-Commit-Position: refs/heads/master@{#33686}
If the architecture does not provide rounding instructions, then C
implementations of these rounding instructions are called. The C
implementations from math.h are used, function pointers are registered
as external references so that they can be call from the simulator.
R=titzer@chromium.org
BUG=575379
LOG=Y
Review URL: https://codereview.chromium.org/1661463002
Cr-Commit-Position: refs/heads/master@{#33677}
After this change, the functionality of the CodeStubAssembler should be
sufficient to generate non-trivial stubs (e.g. the KeyedLoadIC) with control
flow, variables and probing of internal meta data structures.
Specifically this patch:
* introduces a Label class, which allows stubs to construct graphs that don't
have linear control graphs.
* introduces a Variable class. Variables can be bound to Node* values at
different points in a non-linear control flow graph. In conjunction with the
Label machinery, the CodeStubAssembler ensures that Phi nodes are inserted at
the "minimal" set of merge points.
* adds Tail calling support to other Stubs and to any arbitrary code whose
interface can be described by a CallInterfaceDescriptor.
* provides new macros for accessing FixedArray elements that are optimized for
use with Smi values.
Review URL: https://codereview.chromium.org/1649723002
Cr-Commit-Position: refs/heads/master@{#33664}
The runtime call to Runtime::kReThrow does not need a frame-state node
attached, the frame-state input count is zero. This restructures the
graph builder to not instantiate a FrameStateBeforeAndAfter for it.
R=jarin@chromium.org
TEST=cctest/test-run-bytecode-graph-builder
BUG=v8:4674
LOG=n
Review URL: https://codereview.chromium.org/1654833002
Cr-Commit-Position: refs/heads/master@{#33641}
Although x87 has 8 registers, it use only 1 double register in TurboFan code generation for some limitations.
So for TestStackSlot() function, use the num_allocatable_double_registers() to check the avaliable double registers
of TurboFan is more suitable than num_double_registers().
BUG=
Review URL: https://codereview.chromium.org/1653913002
Cr-Commit-Position: refs/heads/master@{#33636}
The reachability of a bytecode is implied by a live environment reaching
the bytecode during the abstract control flow simulation of the bytecode
iteration perfromed by the graph builder. There is no need to compute it
upfront anymore.
Also, the upfront computation was only an approximation when it came to
the reachability of an exception handler. This is why several tests for
translation of exception handlers can now be enabled.
R=oth@chromium.org
Review URL: https://codereview.chromium.org/1645293003
Cr-Commit-Position: refs/heads/master@{#33634}
The CL #33347 (https://codereview.chromium.org/1589363002) added the RunRoundInt32ToFloat32 test case and X87 failed at it.
The reason is same as the CL #31808 (issue 1430943002, X87: Change the test case for X87 float operations), please refer: https://codereview.chromium.org/1430943002/.
Here is the key comments from CL #31808
Some new test cases use CheckFloatEq(...) and CheckDoubleEq(...) function for result check. When GCC compiling the CheckFloatEq() and CheckDoubleEq() function,
those inlined functions has different behavior comparing with GCC ia32 build and x87 build.
The major difference is sse float register still has single precision rounding semantic. While X87 register has no such rounding precsion semantic when directly use register value.
The V8 turbofan JITTed has exactly same result in both X87 and IA32 port.
For CHECK_EQ(a, b) function, if a and b are doubles, it will has similar behaviors like CheckFloatEq(...) and CheckDoubleEq(...) function when compiled by GCC and causes the test case
fail.
So we add the following sentence to do type case to keep the same precision for RunRoundInt32ToFloat32. Such as: volatile double expect = static_cast<float>(*i).
BUG=
Review URL: https://codereview.chromium.org/1649323002
Cr-Commit-Position: refs/heads/master@{#33630}
Reason for revert:
problems on Mac64
Original issue's description:
> [turbofan] Add the StackSlot operator to turbofan.
>
> The StackSlot operator allows to allocate a spill slot on the stack. We
> are going to use this operator to pass floats through pointers to c
> functions, which we need for floating point rounding in the case where
> the architecture does not provide rounding instructions.
>
> R=titzer@chromium.org, v8-arm-ports@googlegroups.com, v8-ppc-ports@googlegroups.com, v8-mips-ports@googlegroups.com
>
> Committed: https://crrev.com/7a693437787090d62d937b862e29521debcc5223
> Cr-Commit-Position: refs/heads/master@{#33600}
TBR=titzer@chromium.org,v8-arm-ports@googlegroups.com,v8-mips-ports@googlegroups.com,v8-ppc-ports@googlegroups.com
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
Review URL: https://codereview.chromium.org/1644283002
Cr-Commit-Position: refs/heads/master@{#33601}
This is to fix a bug in the bytecode graph builder. This cl adds a new merge
node before we copy the environment on conditional/unconditional jumps. Since
these environments could be merged later, we add a place holder merge so that
the control dependencies are correctly merged. If we do not have a merge node
we may incorrectly merge the dependencies into the previous block.
For ex: test-run-variables/ContextStoreVariables in cctests.
BUG=v8:4280
LOG=N
Review URL: https://codereview.chromium.org/1641143002
Cr-Commit-Position: refs/heads/master@{#33591}
avoid jump threading erasing the reconstruction of a frame, if the
frame was elided.
BUG=
Review URL: https://codereview.chromium.org/1642823002
Cr-Commit-Position: refs/heads/master@{#33590}
This translates the exception handler table attached to a bytecode array
correctly into exceptional projections within the TurboFan graph. We
perform an abstract simulation of handlers that are being entered and
exited by the bytecode iteration to track the correct handler for each
node.
R=oth@chromium.org
BUG=v8:4674
LOG=n
Review URL: https://codereview.chromium.org/1641723002
Cr-Commit-Position: refs/heads/master@{#33580}
Reason for revert:
Bug: failing to use write barrier when writing code entry into closure.
Original issue's description:
> Reland of Type Feedback Vector lives in the closure
>
> (Fixed a bug found by nosnap builds.)
>
> We get less "pollution" of type feedback if we have one vector per native
> context, rather than one for the whole system. This CL moves the vector
> appropriately.
>
> We rely more heavily on the Optimized Code Map in the SharedFunctionInfo. The
> vector actually lives in the first slot of the literals array (indeed there is
> great commonality between those arrays, they can be thought of as the same
> thing). So we make greater effort to ensure there is a valid literals array
> after compilation.
>
> This meant, for performance reasons, that we needed to extend
> FastNewClosureStub to support creating closures with literals. And ultimately,
> it drove us to move the optimized code map lookup out of FastNewClosureStub
> and into the compile lazy builtin.
>
> The heap change is trivial so I TBR Hannes for it...
>
> TBR=hpayer@chromium.org
> BUG=
>
> Committed: https://crrev.com/d984b3b0ce91e55800f5323b4bb32a06f8a5aab1
> Cr-Commit-Position: refs/heads/master@{#33548}
TBR=bmeurer@chromium.org,yangguo@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=
Review URL: https://codereview.chromium.org/1643533003
Cr-Commit-Position: refs/heads/master@{#33556}
(Fixed a bug found by nosnap builds.)
We get less "pollution" of type feedback if we have one vector per native
context, rather than one for the whole system. This CL moves the vector
appropriately.
We rely more heavily on the Optimized Code Map in the SharedFunctionInfo. The
vector actually lives in the first slot of the literals array (indeed there is
great commonality between those arrays, they can be thought of as the same
thing). So we make greater effort to ensure there is a valid literals array
after compilation.
This meant, for performance reasons, that we needed to extend
FastNewClosureStub to support creating closures with literals. And ultimately,
it drove us to move the optimized code map lookup out of FastNewClosureStub
and into the compile lazy builtin.
The heap change is trivial so I TBR Hannes for it...
TBR=hpayer@chromium.org
BUG=
Review URL: https://codereview.chromium.org/1642613002
Cr-Commit-Position: refs/heads/master@{#33548}
Reason for revert:
FAilure on win32 bot, need to investigate webkit failures.
Original issue's description:
> Type Feedback Vector lives in the closure
>
> We get less "pollution" of type feedback if we have one vector per native
> context, rather than one for the whole system. This CL moves the vector
> appropriately.
>
> We rely more heavily on the Optimized Code Map in the SharedFunctionInfo. The
> vector actually lives in the first slot of the literals array (indeed there is
> great commonality between those arrays, they can be thought of as the same
> thing). So we make greater effort to ensure there is a valid literals array
> after compilation.
>
> This meant, for performance reasons, that we needed to extend
> FastNewClosureStub to support creating closures with literals. And ultimately,
> it drove us to move the optimized code map lookup out of FastNewClosureStub
> and into the compile lazy builtin.
>
> The heap change is trivial so I TBR Hannes for it...
>
> TBR=hpayer@chromium.org
>
> BUG=
>
> Committed: https://crrev.com/a5200f7ed4d11c6b882fa667da7a1864226544b4
> Cr-Commit-Position: refs/heads/master@{#33518}
TBR=bmeurer@chromium.org,akos.palfi@imgtec.com
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=
Review URL: https://codereview.chromium.org/1632993003
Cr-Commit-Position: refs/heads/master@{#33520}
We get less "pollution" of type feedback if we have one vector per native
context, rather than one for the whole system. This CL moves the vector
appropriately.
We rely more heavily on the Optimized Code Map in the SharedFunctionInfo. The
vector actually lives in the first slot of the literals array (indeed there is
great commonality between those arrays, they can be thought of as the same
thing). So we make greater effort to ensure there is a valid literals array
after compilation.
This meant, for performance reasons, that we needed to extend
FastNewClosureStub to support creating closures with literals. And ultimately,
it drove us to move the optimized code map lookup out of FastNewClosureStub
and into the compile lazy builtin.
The heap change is trivial so I TBR Hannes for it...
TBR=hpayer@chromium.org
BUG=
Review URL: https://codereview.chromium.org/1563213002
Cr-Commit-Position: refs/heads/master@{#33518}
The current support for try-catch in the interpreter can handle most of
the cases appearing in our test suite. Also the flag in question did not
detect try-finally constructs. This removes the flag and instead extends
the test expectations.
R=rmcilroy@chromium.org
BUG=v8:4674
LOG=n
Review URL: https://codereview.chromium.org/1631593003
Cr-Commit-Position: refs/heads/master@{#33494}
The motivation for this is that CompilationInfo really shouldn't
explicitly know anything about CodeStubs. This is evident in
the TurboFan stubs pipeline, which only needs to pass down
information about Code::Flags to the code generator and not
any of the CallInterfaceDescriptor silliness that Hydrogen has
to push around, since TF has the Linkage class that
encapsulates everything that is needed for the stub ABI. So,
instead of threading CodeStub machinery through the TF stub
pipeline, it is now removed from CompilationInfo and replaced
by only the explicit bits needed both by the Crankshaft and
TF pipelines in code generation.
Review URL: https://codereview.chromium.org/1604543002
Cr-Commit-Position: refs/heads/master@{#33410}
Now that we support eval in Ignition, remove the fallback for eval checks
and make the flag only fallback on catch blocks.
BUG=v8:4280,v8:4676
LOG=N
Review URL: https://codereview.chromium.org/1595223004
Cr-Commit-Position: refs/heads/master@{#33384}
Reason for revert:
Code is incorrect for -0.
Original issue's description:
> [turbofan] Implement rounding of floats on x64 and ia32 without sse4.1.
>
> The implementation sets the rounding mode flag and then uses the
> cvtsd2si and cvtsi2sd instructions (convert between float and int) to do
> the rounding. Input values outside int range either don't have to be
> rounded anyways, or are rounded by calculating input + 2^52 - 2^52 for
> positive inputs, or input -2^52 + 2^52 for negative inputs. The original
> rounding mode is restored afterwards.
>
> R=titzer@chromium.org
>
> B=575379
>
> Committed: https://crrev.com/fa5d09e547abe79a8c82f780deb980c53ad78beb
> Cr-Commit-Position: refs/heads/master@{#33367}
TBR=titzer@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
Review URL: https://codereview.chromium.org/1593313010
Cr-Commit-Position: refs/heads/master@{#33369}
The implementation sets the rounding mode flag and then uses the
cvtsd2si and cvtsi2sd instructions (convert between float and int) to do
the rounding. Input values outside int range either don't have to be
rounded anyways, or are rounded by calculating input + 2^52 - 2^52 for
positive inputs, or input -2^52 + 2^52 for negative inputs. The original
rounding mode is restored afterwards.
R=titzer@chromium.org
B=575379
Review URL: https://codereview.chromium.org/1584663007
Cr-Commit-Position: refs/heads/master@{#33367}
Once we use type feedback, we need to reflect the feedback in the types, propagate
the new narrower types forward and use them in the subsequent
representation inference. This CL propagates and uses the recomputed types
for Phi and Select nodes (rather than using the types from the typer).
Review URL: https://codereview.chromium.org/1580353003
Cr-Commit-Position: refs/heads/master@{#33268}
Adds support for LOOKUP_SLOT_CALL calls to the interpreter. Also changes
VisitCall to keep callee and reciever consecutive to avoid register
shuffles when performing LOOKUP_SLOT_CALL calls. Adds tests for the
interpreter and bytecode graph generator.
BUG=v8:4280
LOG=N
Review URL: https://codereview.chromium.org/1568323002
Cr-Commit-Position: refs/heads/master@{#33237}
This patch moves the semantics of 'const' in sloppy mode to match those
in strict mode, that is, const makes lexical (let-like) bindings, must
have an initializer, and does not create properties of the global object.
R=adamk
LOG=Y
BUG=v8:3305
CQ_INCLUDE_TRYBOTS=tryserver.chromium.linux:linux_chromium_rel_ng;tryserver.blink:linux_blink_rel
Review URL: https://codereview.chromium.org/1571873004
Cr-Commit-Position: refs/heads/master@{#33218}
Adds support for the CallRuntimeForPair bytecode to the Bytecode Graph
Builder. Modifies the FrameState support to allow updating of output
registers.
Also adds Eval tests to test-run-bytecode-graph-builder since these are
enabled by CallRuntimeForPair support.
BUG=v8:4280
LOG=N
Review URL: https://codereview.chromium.org/1570623007
Cr-Commit-Position: refs/heads/master@{#33186}
This increases the size of addressable constant pool entries for jumps
to match other bytecodes using operands indexing the constant pool.
This change also introduces reservations for constant pool entries.
Reservations are used for forward jumps to ensure a constant pool entry
will be available when the jump target (label) is bound and the jump is
patched up in the bytecode array.
BUG=v8:4280
LOG=N
Review URL: https://codereview.chromium.org/1546683002
Cr-Commit-Position: refs/heads/master@{#33125}
Adds support for loads and stores to lookup slots to BytecodeGraphBuilder.
Also adds tests for them.
BUG=v8:4280
LOG=N
Review URL: https://codereview.chromium.org/1541143003
Cr-Commit-Position: refs/heads/master@{#33075}
We'll be able to optimize rest parameters in TurboFan similarly to the arguments array. This CL restores the previous behavior, and a follow-on will enable TurboFan optimization.
(TBR for rossberg since we discussed the revert beforehand. The only changes are a few lines related to tests and rebasing.)
TBR=rossberg@chromium.org
BUG=
Review URL: https://codereview.chromium.org/1537683002
Cr-Commit-Position: refs/heads/master@{#33024}
Adds support for deleting a variable in a lookup slot. Adds a new bytecode,
its implementation and tests. Also adds support for this bytecode to the
bytecode graph builder.
BUG=v8:4280
LOG=N
Review URL: https://codereview.chromium.org/1542083002
Cr-Commit-Position: refs/heads/master@{#33019}
Adds implementation and tests for CreateMappedArguments and
CreateUnmappedArguments to bytecode graph builder.
BUG=v8:4280
LOG=N
Review URL: https://codereview.chromium.org/1490283003
Cr-Commit-Position: refs/heads/master@{#33004}
The CL #32908 (https://codereview.chromium.org/1526293002) updated the Float64 test data and cause the RunFloat64Add and RunFloat64Sub test cases failed.
The reason is same as the CL #31808 (issue 1430943002, X87: Change the test case for X87 float operations), please refer: https://codereview.chromium.org/1430943002/
Here is the key comments from CL #31808
Some new test cases use CheckFloatEq(...) and CheckDoubleEq(...) function for result check. When GCC compiling the CheckFloatEq() and CheckDoubleEq() function,
those inlined functions has different behavior comparing with GCC ia32 build and x87 build.
The major difference is sse float register still has single precision rounding semantic. While X87 register has no such rounding precsion semantic when directly use register value.
The V8 turbofan JITTed has exactly same result in both X87 and IA32 port.
So we add the following sentence to do type case to keep the same precision for RunFloat64Add and RunFloat64Sub.
Such as: volatile double expect = *i +/- *j; // *i +/- *j, etc.
BUG=
Review URL: https://codereview.chromium.org/1533593003
Cr-Commit-Position: refs/heads/master@{#32988}
A pre-requisite for this change was changing the interpreter to use
Runtime::ForInStep to bring the interpreter implementation closer
to the turbofan implementation. Also required to flatten out the
cache parameters into the interpreter frame for de-opt.
BUG=v8:4280
LOG=N
Review URL: https://codereview.chromium.org/1531693002
Cr-Commit-Position: refs/heads/master@{#32986}
Adds FrameState nodes to graphs built by the Bytecode Graph Builder, in
preparation for adding deopt support. Also adds a new
FrameStateType::kInterpretedFunction to allow for specialized deopt
stack translation for interpreted frames. Finally adds support for
disabling typed lowering of binary ops, since the current approach
relies on a FrameState hack which does not apply to interpreted frames
BUG=v8:4280
LOG=N
Review URL: https://codereview.chromium.org/1514413002
Cr-Commit-Position: refs/heads/master@{#32964}
This change adds support for local control flow when building graphs
from bytecode. The change ensures loop emitted from the bytecode
generator are in natural order so the only back branches are for loops.
BUG=v8:4280
LOG=N
Review URL: https://codereview.chromium.org/1502243002
Cr-Commit-Position: refs/heads/master@{#32911}
TryTruncateFloat32ToUint64 converts a float32 to a uint64. Additionally it
provides an optional second return value which indicates whether the conversion
succeeded (i.e. float32 value was within uint64 range) or not.
I implemented the new operator on x64, arm64, and mips64. @v8-ppc-ports, can you
please take care of the ppc64 implementation of the second output?
Additionally I fixed a bug on x64 and mips64 in the implementation of
TryTruncateFloat64ToUint64. Cases where the input value was between -1 and 0
were handled incorrectly.
R=titzer@chromium.org, v8-arm-ports@googlegroups.com, v8-mips-ports@googlegroups.com
Review URL: https://codereview.chromium.org/1512023002
Cr-Commit-Position: refs/heads/master@{#32796}
MachineType is now a class with two enum fields:
- MachineRepresentation
- MachineSemantic
Both enums are usable on their own, and this change switches some places from using MachineType to use just MachineRepresentation. Most notably:
- register allocator now uses just the representation.
- Phi and Select nodes only refer to representations.
Review URL: https://codereview.chromium.org/1513543003
Cr-Commit-Position: refs/heads/master@{#32738}
This operator now provides a second output which indicates whether the
conversion from float32 to int64 was successful or not. The second output
returns 0 if the conversion fails, or something else if the conversion succeeds.
The second output can be ignored, which means that the operator can be used the
same as the original operator.
I implement the new operator on x64, arm64, and mips64. @v8-ppc-ports, can you
please take care of the ppc64 implementation of the second output?
R=titzer@chromium.org, v8-arm-ports@googlegroups.com, v8-mips-ports@googlegroups.com
Review URL: https://codereview.chromium.org/1504363002
Cr-Commit-Position: refs/heads/master@{#32737}
Adds implementation and tests for CreateObjectLiteral, CreateArrayLiteral and CreateRegExpLiteral
to bytecode graph builder. Also changes these bytecodes to expect three operands instead of using
accumulator to pass one of the operands. This is done to avoid looking into the earlier nodes to
fetch operands in the bytecode graph builder. Also adds support for wide variant of these
bytecodes to bytecode generator and bytecode graph builder.
BUG=v8:4280
LOG=N
Review URL: https://codereview.chromium.org/1503963002
Cr-Commit-Position: refs/heads/master@{#32710}
This operator now provides a second output which indicates whether the conversion from float64 to uint64 was successful or not. The second output returns 0 if the conversion fails, or something else if the conversion succeeds.
The second output can be ignored, which means that the operator can be used the same as the original operator.
I implement the new operator on x64 and arm64. @v8-mips-ports and @v8-ppc-ports, can you please take care of the mips64 and ppc64 implementation of the second output?
R=titzer@chromium.org, v8-arm-ports@googlegroups.com
Review URL: https://codereview.chromium.org/1507703002
Cr-Commit-Position: refs/heads/master@{#32705}
The new operator provides a second output which indicates whether the
conversion from float64 to int64 was successful or not. The second
output returns 0 if the conversion fails. If the conversion succeeds,
then the second output is differs from 0.
The second output can be ignored, which means that the operator can be
used the same way as the original operator.
I implemented the new operator on x64 and arm64. @v8-mips-ports and
@v8-ppc-ports, can you please take care of the mips64 and ppc64
implementation of the second output?
R=titzer@chromium.org, v8-arm-ports@googlegroups.com
Review URL: https://codereview.chromium.org/1495213003
Cr-Commit-Position: refs/heads/master@{#32653}
The test expectations should fail consistently in both release and debug
builds. DCHECK is only meant for debug-only checks in production code.
R=yangguo@chromium.org
Review URL: https://codereview.chromium.org/1506753002
Cr-Commit-Position: refs/heads/master@{#32639}
I added a flag to the CallDescriptor which indicates that the native
stack should be used for a CallObject instead of the js stack on arm64.
Additionally I removed the use of EmitPrepareArguments because the
current implementation does not work when float and int parameters are
mixed. I plan to fix it in a future CL, because currently I have a
problem figuring out the type of a parameter.
R=titzer@chromium.org, v8-arm-ports@googlegroups.com
Review URL: https://codereview.chromium.org/1494123002
Cr-Commit-Position: refs/heads/master@{#32577}
Adds implementation and tests for Inc and Dec to bytecode graph builder.
BUG=v8:4280
LOG=N
Review URL: https://codereview.chromium.org/1499593002
Cr-Commit-Position: refs/heads/master@{#32562}
* Add a sibling interface to InterpreterAssembler called
CodeStubAssembler which provides a wrapper around the
RawMachineAssembler and is intented to make it easy to build
efficient cross-platform code stubs. Much of the implementation
of CodeStubAssembler is shamelessly stolen from the
InterpreterAssembler, and the idea is to eventually merge the
two interfaces somehow, probably moving the
InterpreterAssembler interface over to use the
CodeStubAssembler. Short-term, however, the two interfaces
shall remain decoupled to increase our velocity developing the
two systems in parallel.
* Implement the StringLength stub in TurboFan with the new
CodeStubAssembler. Replace and remove the old Hydrogen-stub
version.
* Remove a whole slew of machinery to support JavaScript-style
code stub generation, since it ultimately proved unwieldy,
brittle and baroque. This cleanup includes removing the shared
code stub context, several example stubs and a tangle of build
file changes.
BUG=v8:4587
LOG=n
Review URL: https://codereview.chromium.org/1475953002
Cr-Commit-Position: refs/heads/master@{#32508}
This is the initial support for binary operation hints on javascript
binary operators, i.e. JSAdd, JSSubtract and so on. The hints are
extracted from the fullcodegen code object before graph building and the
AstGraphBuilder puts those hints on the operators if available.
R=jarin@chromium.org
BUG=v8:4583
LOG=n
Review URL: https://codereview.chromium.org/1487973002
Cr-Commit-Position: refs/heads/master@{#32443}
an optomization to remove redundant cast operations.
1. Adds an optimization to remove redundant ToBoolean and ToName operations.
2. Adds implementation and tests for cast operatorts to bytecode graph builder.
BUG=v8:4280
LOG=N
Review URL: https://codereview.chromium.org/1468003002
Cr-Commit-Position: refs/heads/master@{#32408}
Adds support and tests for throw to bytecode graph builder.
BUG=v8:4280
LOG=N
Review URL: https://codereview.chromium.org/1481763002
Cr-Commit-Position: refs/heads/master@{#32399}
Previously all contexts had a link to the global object, but what is
required in most cases (except for the global load, store and delete
case) is the native context.
This also removes the second dummy global object that was still linked
to every native context. We will add a different mechanism to ensure
that builtins do not pollute the actual global object during
bootstrapping.
Drive-by-fix: Unify some MacroAssembler magic and drop obsolete stuff.
CQ_INCLUDE_TRYBOTS=tryserver.v8:v8_linux_nosnap_rel
R=yangguo@chromium.org,mstarzinger@chromium.org
Committed: https://crrev.com/d290f204938295bfecc5c8e645ccfcff6e80ddb8
Cr-Commit-Position: refs/heads/master@{#32375}
Review URL: https://codereview.chromium.org/1480003002
Cr-Commit-Position: refs/heads/master@{#32381}
The TruncateFloat32ToUint64 operator converts a float32 to an uint64 using
round-to-zero rounding mode. If the input value is outside uint64 range, then
the result depends on the architecture. I provide an implementation for x64 and
arm64.
R=titzer@chromium.org
Review URL: https://codereview.chromium.org/1479713003
Cr-Commit-Position: refs/heads/master@{#32379}
Reason for revert:
[Sheriff] Breaks:
https://build.chromium.org/p/client.v8/builders/V8%20Linux%20-%20nosnap/builds/5472
Original issue's description:
> [runtime] Replace global object link with native context link in all contexts.
>
> Previously all contexts had a link to the global object, but what is
> required in most cases (except for the global load, store and delete
> case) is the native context.
>
> This also removes the second dummy global object that was still linked
> to every native context. We will add a different mechanism to ensure
> that builtins do not pollute the actual global object during
> bootstrapping.
>
> Drive-by-fix: Unify some MacroAssembler magic and drop obsolete stuff.
>
> R=yangguo@chromium.org
>
> Committed: https://crrev.com/d290f204938295bfecc5c8e645ccfcff6e80ddb8
> Cr-Commit-Position: refs/heads/master@{#32375}
TBR=yangguo@chromium.org,mstarzinger@chromium.org,bmeurer@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
Review URL: https://codereview.chromium.org/1478303002
Cr-Commit-Position: refs/heads/master@{#32377}
Previously all contexts had a link to the global object, but what is
required in most cases (except for the global load, store and delete
case) is the native context.
This also removes the second dummy global object that was still linked
to every native context. We will add a different mechanism to ensure
that builtins do not pollute the actual global object during
bootstrapping.
Drive-by-fix: Unify some MacroAssembler magic and drop obsolete stuff.
R=yangguo@chromium.org
Review URL: https://codereview.chromium.org/1480003002
Cr-Commit-Position: refs/heads/master@{#32375}
Moves all files related to AST and scopes into ast/,
and all files related to scanner & parser to parsing/.
Also eliminates a couple of spurious dependencies.
R=mstarzinger@chromium.org
BUG=
Review URL: https://codereview.chromium.org/1481613002
Cr-Commit-Position: refs/heads/master@{#32351}
For a * b with only truncated word32 uses (or result known to be in
signed32 range), we can use Int32Mul if we know for sure that the
intermediate result is inside the safe integer range, and a and b are
in signed32 range.
Drive-by-fix: Also use TypeCache in SimplifiedLowering.
R=jarin@chromium.org
Review URL: https://codereview.chromium.org/1478953002
Cr-Commit-Position: refs/heads/master@{#32330}
Reason for revert:
Unexpected error occurred.
Original issue's description:
> [turbofan] Implemented the TruncateFloat32ToInt64 TurboFan operator.
>
> The TruncateFloat32ToInt64 operator converts a float32 to an int64 using
> the round-to-zero rounding mode (truncate). If the input value is
> outside the int64 range, then the result depends on the architecture. I
> implemented the operator on x64, arm64, and mips64.
>
> R=titzer@chromium.org, jacob.bramley@arm.com
>
> Committed: https://crrev.com/1df1066c3c77464d2a68d7c8d501a5a0f3ad195a
> Cr-Commit-Position: refs/heads/master@{#32315}
TBR=jacob.bramley@arm.com,titzer@chromium.org,v8-mips-ports@googlegroups.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
Review URL: https://codereview.chromium.org/1475343002
Cr-Commit-Position: refs/heads/master@{#32316}
The TruncateFloat32ToInt64 operator converts a float32 to an int64 using
the round-to-zero rounding mode (truncate). If the input value is
outside the int64 range, then the result depends on the architecture. I
implemented the operator on x64, arm64, and mips64.
R=titzer@chromium.org, jacob.bramley@arm.com
Review URL: https://codereview.chromium.org/1476063002
Cr-Commit-Position: refs/heads/master@{#32315}
The Float32RoundTiesEven operator rounds float32 numbers towards the nearest
integer. If the distance to two integers is the same, then the result is
the even integer. This is the default rounding mode of the ieee 754 floating
point standard.
I implemented the optional Float32RoundTiesEven operator on x64, ia32, arm, and arm64.
R=titzer@chromium.org
Review URL: https://codereview.chromium.org/1477753002
Cr-Commit-Position: refs/heads/master@{#32308}
The Float32RoundTruncate operator rounds float32 numbers towards zero.
The operator is currently implemented on x64, ia32, arm, and arm64.
Additionally I added support for the float32 vrintz, vrintn, and vrinta
instructions to the arm simulator.
R=titzer@chromium.org
Review URL: https://codereview.chromium.org/1468303005
Cr-Commit-Position: refs/heads/master@{#32301}
The Float32RoundUp operator rounds float32 numbers towards infinity.
The operator is currently implemented on x64, ia32, arm, and arm64.
R=titzer@chromium.org
Review URL: https://codereview.chromium.org/1474963002
Cr-Commit-Position: refs/heads/master@{#32262}
This change replaces the bitwise masking of uses by storing the most general truncation for all uses.
Review URL: https://codereview.chromium.org/1464763003
Cr-Commit-Position: refs/heads/master@{#32248}
Adds code and tests to support CreateClosure bytecode when building
graphs.
BUG=v8:4280
LOG=N
Review URL: https://codereview.chromium.org/1458603012
Cr-Commit-Position: refs/heads/master@{#32224}
Adds support for the New, CallRuntime and CallJSRuntime bytecodes in
BytecodeGraphBuilder. Also adds BuildLoadObjectField,
BuildLoadGlobalObject and BuildLoadNativeContextField helpers.
Landed on behalf of rmcilroy.
BUG=v8:4280
LOG=N
Review URL: https://codereview.chromium.org/1456483002
Cr-Commit-Position: refs/heads/master@{#32136}
The TruncateFloat64ToUint64 operator converts a float64 to an uint64 using
round-to-zero rounding mode (truncate). If the input value is outside uint64
range, then the result depends on the architecture. I provide an implementation for x64 and arm64.
@v8-ppc-ports and @v8-mips-ports, can you do the implementations for ppc64 and mips64?
R=titzer@chromium.org
Review URL: https://codereview.chromium.org/1457373002
Cr-Commit-Position: refs/heads/master@{#32127}
The ChangeFloat64ToInt64 operator changes the representation of a
float64 input value to int64 if the input value can be represented
exactly on int64. Otherwise the result is currently undefined.
R=titzer@chromium.org
Review URL: https://codereview.chromium.org/1455983002
Cr-Commit-Position: refs/heads/master@{#32102}
If the input type does not help us, we are conservative and truncate (rather than guessing signed).
Review URL: https://codereview.chromium.org/1455103002
Cr-Commit-Position: refs/heads/master@{#32075}
Adds support for the LdaGlobal and StaGlobal bytecodes to the
BytecodeGraphBuilder. Also fixes a bug in the context node's parameter
index and start node inputs.
Landed on behalf of rmcilroy.
TBR=bmeuer@chromium.org,mythria@chromium.org
BUG=v8:4280
LOG=N
Review URL: https://codereview.chromium.org/1449373002
Cr-Commit-Position: refs/heads/master@{#32049}
Adds support for visiting the Call bytecode to the bytecode graph builder.
This change also adds the call type feedback slot to the Call bytecode.
This is not currently used by the interpreter, but is used by the
graph builder.
Also adds a CallWide varient of the Call bytecode, and adds the kCount16
operand type.
Landed on behalf of rmcilroy.
BUG=v8:4280
LOG=N
Review URL: https://codereview.chromium.org/1456453002
Cr-Commit-Position: refs/heads/master@{#32033}
Adds implementation and tests for following operators in bytecode graph builder:
-VisitLoadICSloppy
-VisitLoadICStrict
-VisitLoadICSloppyWide
-VisitLoadICStrictWide
The current implementation introduces empty frame states for frame state inputs expected by these operations.
BUG=v8:4280
LOG=N
Review URL: https://codereview.chromium.org/1419373007
Cr-Commit-Position: refs/heads/master@{#32026}
The TiesEven rounding mode rounds float64 numbers to the nearest
integer. If there are two nearest integers, then the number is rounded
to the even one. This is the default rounding mode according to
IEEE~754.
I implemented the operator on ia32, x64, arm, arm64, mips, and mips64.
I think there is a bug in the current implementation of the ppc
simulator, which kept me from implementing the operator on ppc.
According to my understanding of the ppc instruction manual, the FRIN
instruction provides the right behavior for Float64RoundTiesEven. In the
simulator, however, FRIN provides a different semantics. If there are
two nearest integers, then the simulator returns the one which is
further away form 0.
Review URL: https://codereview.chromium.org/1440293002
Cr-Commit-Position: refs/heads/master@{#32005}
