... to OptimizedCompilationInfo, BytecodeGraphBuilder, and
JSHeapBroker.
Also add first uses of these flags in pipeline.cc by skipping certain
phases when nci is enabled. With this change, tests in the NCI variant
will start to fail since generic lowering is not fully implemented.
These implementations will follow incrementally in the next days.
Bug: v8:8888
Change-Id: I3f570fb92f09059d1f1f4015f88ffe80ccf746ad
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2239572
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68339}
Including but not limiting to removing:
* BitcastCompressedXXX
* CheckedCompressedXXX
* ChangeXXXToCompressedYYY
* ChangeCompressedXXX
As a note, ChangeTaggedToCompressed can't be removed just yet as it
is still in use.
Bug: v8:7703
Change-Id: I98cf88a32adfa976d419e69702d1cac4d3e811a5
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1903435
Commit-Queue: Santiago Aboy Solanes <solanes@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64880}
Replace all usages of VectorSlotPair with FeedbackSource.
Bug: v8:7790
Change-Id: I0ac6e9cd8f5730154cc1842e267ca1ebfdebc874
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1763536
Commit-Queue: Maya Lekova <mslekova@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63378}
This change implements lowering of speculative BigInt addition as well as
BigInt heap constants to corresponding int64 versions, if they are used in
a context where the result is truncated to the least significant 64 bits
(e.g. using asUintN). The JSHeapBroker is extended to provide access to the
BigInt's least significant digit during concurrent compilation. The BigInt
context (required to introduce correct conversions) is recognized in the
RepresentationChanger by either the output type propagated downward or the
TypeCheckKind propagated upward. This is necessary, because the TypeCheckKind
may only be set by nodes that may potentially deopt (and sit in the effect
chain). This is the case for SpeculativeBigIntAdd, but not for BigIntAsUintN.
This CL contains a simple fix to prevent int64-lowered BigInts to flow into
state values as the deoptimizer cannot handle them yet. A more sophisticated
solution to allow the deoptimizer to materialize truncated BigInts will be
added in a following CL.
Bug: v8:9407
Change-Id: I96a293e9077962f53e5f199857644f004e3ae56e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1684183
Commit-Queue: Nico Hartmann <nicohartmann@google.com>
Reviewed-by: Georg Neis <neis@chromium.org>
Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Reviewed-by: Maya Lekova <mslekova@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62665}
Reverse specialization of https://chromium-review.googlesource.com/c/v8/v8/+/1684075.
Again, it skips over Tagged to save some instructions.
Cq-Include-Trybots: luci.v8.try:v8_linux64_pointer_compression_rel_ng
Cq-Include-Trybots: luci.v8.try:v8_linux64_arm64_pointer_compression_rel_ng
Bug: v8:7703
Change-Id: I7fc50e0d8eebfef7a1ba02ce3d687ff808f30680
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1693007
Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Commit-Queue: Santiago Aboy Solanes <solanes@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62645}
This adds missing support when converting a Word32 value (either in
Signed32 or Unsigned32 range) to Word64 representation, for which the
type also includes MinusZero. This conversion is fine as long as the
difference between 0 and -0 is not observable (in other words, as long
as the truncation identifies zeros).
Bug: chromium:971782, chromium:225811, v8:4153, v8:7881, v8:8171, v8:8383
Change-Id: I9d350a25f57b1342eb7fd1279d55a8610bdaf7cd
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1664062
Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62235}
Truncation::Float64 is confusing; in reality, we mean that oddballs
and big-ints are identified with their ToNumber counterparts.
Bug: v8:9183
Change-Id: Ibcce990327ac7e01e36a2237ad39c374ac9922aa
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1632224
Commit-Queue: Jaroslav Sevcik <jarin@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61937}
TurboFan truncated null to +0 even in contexts such as -0 == null
because it was not handling the TypeCheck correctly. This restricts
the type conversion case to not apply truncation in this case (see
comment in patch).
Change-Id: Ia38ace9608800c8d61988de402a31dd863d9160a
Bug: chromium:961237
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1609538
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61446}
GraphBuilderTester was introduced at a time where RawMachineAssembler
was going to be deprecated (https://codereview.chromium.org/1423923003/).
Now we know that it's not going to happen any time soon.
Since GraphBuilderTester it's only used in one test which can use
RawMachineAssembler, I updated it and removed the class.
Now the .h file had another class, which is now the only class in the file.
Therefore, I renamed it and updated the include calls to it.
Also updated the include commands: some were not necessary, and some others
could be moved to more aptly places.
Bug: v8:9183
Change-Id: I44bf16090c0515b1b9ff6cbded1bdb0adb4e44e2
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1594563
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Reviewed-by: Ben Titzer <titzer@chromium.org>
Commit-Queue: Santiago Aboy Solanes <solanes@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61269}
Includes both changing from compressed pointers and to compressed pointers.
Also added tests to the representation changer test
B
Cq-Include-Trybots: luci.v8.try:v8_linux64_pointer_compression_rel_ng,v8_linux64_arm64_pointer_compression_rel_ng
Bug: v8:8977
Change-Id: I8a13f6b7ec2208442aa354949173cc9061bce168
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1533866
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Santiago Aboy Solanes <solanes@chromium.org>
Cr-Commit-Position: refs/heads/master@{#60587}
This CL changes the usage pattern from
FOR_XXX_VALUES(i) { Use(*i); }
to
FOR_XXX_VALUES(i) { Use(i); }
which is way more intuitive.
Note that the replacement in the uses was done via regular expression,
so it's purely mechanical. In two locations I removed unneeded braces
around the macro, because they confused clang-format.
I plan to do more cleanups (remove redundant assignments within the
FOR_XXX_VALUES body) in a follow-up CL.
R=mstarzinger@chromium.org
Bug: v8:8562
Change-Id: I4329bfcf34e5b077d19b50f4204ceb3b4340fe61
Reviewed-on: https://chromium-review.googlesource.com/c/1449615
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59287}
Apart from being more in-line with the style guide, this allows to use
DEFINE_LAZY_LEAKY_OBJECT_GETTER for defining {TypeCache::Get}.
R=tebbi@chromium.org
Bug: v8:8562
Change-Id: I016b28624950ce9404180fc1ca1a232551f75cd0
Reviewed-on: https://chromium-review.googlesource.com/c/1392201
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58500}
Merging the temporary HeapObjectPtr back into HeapObject.
Bug: v8:3770
Change-Id: I5bcd23ca2f5ba862cf5b52955dca143e531c637b
Reviewed-on: https://chromium-review.googlesource.com/c/1386492
Commit-Queue: Jakob Kummerow <jkummerow@chromium.org>
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Michael Stanton <mvstanton@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58410}
This change ensures that we do not try to check the conversion of a floating
point constant, but insert the floating point constant instead.
Change-Id: I1c65e3a69acaea2ff805ba10317f64c0ac0ba098
Reviewed-on: https://chromium-review.googlesource.com/c/1340257
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
Cr-Commit-Position: refs/heads/master@{#57630}
This introduces Word64 support for the CheckBounds operator, which now
lowers to either CheckedUint32Bounds or CheckedUint64Bounds after the
representation selection. The right hand side of CheckBounds can now
be any positive safe integer on 64-bit architectures, whereas it remains
Unsigned31 for 32-bit architectures. We only use the extended Word64
support when the right hand side is outside the Unsigned31 range, so
for everything except DataViews this means that the performance should
remain the same. The typing rule for the CheckBounds operator was
updated to reflect this new behavior.
The CheckBounds with a right hand side outside the Unsigned31 range will
pass a new Signed64 feedback kind, which is handled with newly introduced
CheckedFloat64ToInt64 and CheckedTaggedToInt64 operators in representation
selection.
The JSCallReducer lowering for DataView getType()/setType() methods was
updated to not smi-check the [[ByteLength]] and [[ByteOffset]] anymore,
but instead just use the raw uintptr_t values and operate on any value
(for 64-bit architectures these fields can hold any positive safe
integer, for 32-bit architectures it's limited to Unsigned31 range as
before). This means that V8 can now handle huge DataViews fully, without
falling off a performance cliff.
This refactoring even gave us some performance improvements, on a simple
micro-benchmark just exercising different DataView accesses we go from
testDataViewGetUint8: 796 ms.
testDataViewGetUint16: 997 ms.
testDataViewGetInt32: 994 ms.
testDataViewGetFloat64: 997 ms.
to
testDataViewGetUint8: 895 ms.
testDataViewGetUint16: 889 ms.
testDataViewGetInt32: 888 ms.
testDataViewGetFloat64: 890 ms.
meaning we lost around 10% on the single byte case, but gained 10% across
the board for all the other element sizes.
Design-Document: http://bit.ly/turbofan-word64
Bug: chromium:225811, v8:4153, v8:7881, v8:8171, v8:8383
Change-Id: Ic9d1bf152e47802c04dcfd679372e5c85e4abc83
Reviewed-on: https://chromium-review.googlesource.com/c/1303732
Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#57095}
When converting a Signed32\/MinusZero value from Word32 to Float64
representation or just passing it through as Word32 (with potential
type checks on it) we don't need to worry about -0 as long as the uses
identify 0 and -0.
Drive-by-fix: Fix the CheckChange() helper in the representation
changer test to pass Truncation::Any() by default.
Bug: chromium:891639, chromium:891612, chromium:891627, v8:8015, v8:8178
Change-Id: I06948ec0cdb8e778cb3678124ef927277a5f40ee
Reviewed-on: https://chromium-review.googlesource.com/c/1258902
Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56369}
Teach TurboFan about representation changes from Float64 to Word64 where
the input value is already known to be within the Int64 or Uint64 range.
While not all of these values have representations in Float64, those
that do can be converted to Word64 without loss of precision.
Same is true for Tagged to Word64 conversions, although here we don't
(currently) need the case for Uint64 ranges, so we can skip adding an
operator for that until it becomes necessary (there's a hard check in
the code so it'll not silently cause trouble).
Bug: v8:8178
Change-Id: Ie99b0bc9af096bd927f63b26b0a61e66454bc4ae
Reviewed-on: https://chromium-review.googlesource.com/1231593
Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56022}
Word8 and Word16 representation is treated like Word32 for the sake of
TurboFan's representation selection, but this was missing from the
Word64 conversions.
Bug: chromium:884933, v8:4153, v8:7881, v8:8171, v8:8178
Change-Id: If7b69cdd02b12546d87bba0643e9ee9cb35cb299
Reviewed-on: https://chromium-review.googlesource.com/1229953
Reviewed-by: Georg Neis <neis@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#55983}
This change introduces the necessary conversion operators to convert
from Word64 to other representations (Tagged, Word32, Float64, etc.),
and plugs in the Word64 representation for NumberAdd/NumberSubtract,
such that TurboFan will go to Int64Add/Sub on 64-bit architectures
when the inputs and the output of the operation is in safe integer
range. This includes the necessary changes to the Deoptimizer to be
able to rematerialize Int64 values as Smi/HeapNumber when going back
to Ignition later.
This change might affect performance, although measurements indicate
that there should be no noticable performance impact.
The goal is to have TurboFan support Word64 representation to a degree
that changing the TypedArray length to an uint64_t (for 64-bit archs)
becomes viable and doesn't have any negative performance implications.
Independent of that we might get performance improvements in other areas
such as for crypto code later.
Bug: v8:4153, v8:7881, v8:8171, v8:8178
Design-Document: bit.ly/turbofan-word64
Change-Id: I29d56e2a31c1bae61d04a89d29ea73f21fd49c59
Cq-Include-Trybots: luci.chromium.try:linux_chromium_headless_rel
Reviewed-on: https://chromium-review.googlesource.com/1225709
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#55937}
This adds support to TurboFan's representation selection for the Word64
representation, and makes use of that to handle indices for memory access
and allocation instructions (i.e. LoadElement, StoreElement, Allocate,
etc.). These instructions had previously used Word32 as representation
for the indices / sizes, and then internally converted it to the correct
representation (aka Word64 on 64-bit architectures) later on, but that
was kind of brittle, and sometimes led to weird generated code.
The change thus only adds support to convert integer values in the safe
integer range from all kinds of representations to Word64 (on 64-bit
architectures). We don't yet handle the opposite direction and none of
the representation selection heuristics for the numeric operations were
changed so far. This will be done in follow-up CLs.
This CL itself is supposed to be neutral wrt. functionality, and only
serves as a starting point, and a cleanup for the (weird) implicit
Word64 index/size handling.
Bug: v8:7881, v8:8015, v8:8171
Design-Document: http://bit.ly/turbofan-word64
Change-Id: I3c6961a0e96cbc3fb8ac9d3e1be8f2e5c89bfd25
Cq-Include-Trybots: luci.chromium.try:linux_chromium_headless_rel
Reviewed-on: https://chromium-review.googlesource.com/1224932
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#55886}
This removes Type::operator-> which was used to split the change that
removed undefined misuse of Type* to represent integers.
Bug: v8:3770
Change-Id: I9a5bce5ccdc75461a7b939b4070cb58fe6040d99
Reviewed-on: https://chromium-review.googlesource.com/1033736
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Commit-Queue: Jaroslav Sevcik <jarin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#52878}
This is part of the effort to decrease the amount of undefined behavior.
that v8 relies on.
The main change here is to represent types with class Type rather than
with pointer Type*. To make the CL smaller, I used an operator overload
hack to separate the change from `->` to `.`. I am working on a CL that
will remove the operator and change all those arrows to dots.
Bug: v8:3770
Change-Id: I71a197cb739a1467937bc95c2a757fab0469aa22
Reviewed-on: https://chromium-review.googlesource.com/1032551
Commit-Queue: Jaroslav Sevcik <jarin@chromium.org>
Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Cr-Commit-Position: refs/heads/master@{#52872}
Simplified lowering may loose feedback by inserting Checked
conversions for BoundsChecks in case the bounds check gets
optimized away later on.
Bug: v8:7127
Change-Id: I254a29ba4e578d653d1dee2d70582ce0a4b57789
Reviewed-on: https://chromium-review.googlesource.com/878743
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
Cr-Commit-Position: refs/heads/master@{#50783}
This change is quite invasive, because CheckSmi is lowered
through representation change depending on UseInfo to several
different checked conversion operators. This CL adds feedback
to every checked conversion operator to Int32.
Bug: v8:7127, v8:7204
Change-Id: Icb780e5a69d321c2ec161c3c2a32984bdcf101f1
Reviewed-on: https://chromium-review.googlesource.com/831521
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
Cr-Commit-Position: refs/heads/master@{#50167}
This introduces a new truncation bit for truncation of minus-zero to zero.
At the moment it is only used to handle the limit cases of deopt, such as the
one in the Google maps workload (see simplified version below), where the -q
(which is desugared to q * -1.0) currently deoptimizes because the result would
produce minus zero. To handle this situation, we exploit the knowledge that
righthand side of + cannot be -0, so even if lefthand side was -0, the result
would still be 0 (so the + operation cannot distinguish between left hand side
0 and -0).
function f(q) {
q -= 4;
return (-q) + q;
}
f(10);
f(10);
%OptimizeFunctionOnNextCall(f);
f(4);
Review-Url: https://codereview.chromium.org/2734253002
Cr-Commit-Position: refs/heads/master@{#43661}
Don't unconditionally assume that Tagged->Word32 changes are always
truncating independent of the type of the input. Work-around the
remaining issues with for-in by properly renaming the index if it's
not already of appropriate type (happens with generators or OSR).
R=jarin@chromium.org
Review-Url: https://codereview.chromium.org/2545393002
Cr-Commit-Position: refs/heads/master@{#41484}
This is preparation for using TF to create builtins that handle variable number of
arguments and have to remove these arguments dynamically from the stack upon
return.
The gist of the changes:
- Added a second argument to the Return node which specifies the number of stack
slots to pop upon return in addition to those specified by the Linkage of the
compiled function.
- Removed Tail -> Non-Tail fallback in the instruction selector. Since TF now should
handles all tail-call cases except where the return value type differs, this fallback
was not really useful and in fact caused unexpected behavior with variable
sized argument popping, since it wasn't possible to materialize a Return node
with the right pop count from the TailCall without additional context.
- Modified existing Return generation to pass a constant zero as the additional
pop argument since the variable pop functionality
LOG=N
Review-Url: https://codereview.chromium.org/2446543002
Cr-Commit-Position: refs/heads/master@{#40699}
Reason for revert:
Seems to break arm64 sim debug and blocks roll:
https://build.chromium.org/p/client.v8.ports/builders/V8%20Linux%20-%20arm64%20-%20sim%20-%20debug/builds/3294
Original issue's description:
> [turbofan] Support variable size argument removal in TF-generated functions
>
> This is preparation for using TF to create builtins that handle variable number of
> arguments and have to remove these arguments dynamically from the stack upon
> return.
>
> The gist of the changes:
> - Added a second argument to the Return node which specifies the number of stack
> slots to pop upon return in addition to those specified by the Linkage of the
> compiled function.
> - Removed Tail -> Non-Tail fallback in the instruction selector. Since TF now should
> handles all tail-call cases except where the return value type differs, this fallback
> was not really useful and in fact caused unexpected behavior with variable
> sized argument popping, since it wasn't possible to materialize a Return node
> with the right pop count from the TailCall without additional context.
> - Modified existing Return generation to pass a constant zero as the additional
> pop argument since the variable pop functionality
>
> LOG=N
TBR=bmeurer@chromium.org,mstarzinger@chromium.org,epertoso@chromium.org,danno@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
NOPRESUBMIT=true
Review-Url: https://codereview.chromium.org/2473643002
Cr-Commit-Position: refs/heads/master@{#40691}
This is preparation for using TF to create builtins that handle variable number of
arguments and have to remove these arguments dynamically from the stack upon
return.
The gist of the changes:
- Added a second argument to the Return node which specifies the number of stack
slots to pop upon return in addition to those specified by the Linkage of the
compiled function.
- Removed Tail -> Non-Tail fallback in the instruction selector. Since TF now should
handles all tail-call cases except where the return value type differs, this fallback
was not really useful and in fact caused unexpected behavior with variable
sized argument popping, since it wasn't possible to materialize a Return node
with the right pop count from the TailCall without additional context.
- Modified existing Return generation to pass a constant zero as the additional
pop argument since the variable pop functionality
LOG=N
Review-Url: https://codereview.chromium.org/2446543002
Cr-Commit-Position: refs/heads/master@{#40678}
The only way to get a minus zero result from subtraction is
(-0) - (+0) = -0, hence checking for minus zero on the RHS is
redundant. This is causing some unnecessary deoptimisations
in Box2D from Octane on 32-bit platforms.
BUG=
Review-Url: https://codereview.chromium.org/2410883003
Cr-Commit-Position: refs/heads/master@{#40207}
Add a dedicated simplified operator to inline the general case for the
ToBoolean conversion. In a follow up CL we will also use the ToBoolean
hints gathered by the baseline compiler.
CQ_INCLUDE_TRYBOTS=master.tryserver.v8:v8_linux_arm64_gc_stress_dbg
R=jarin@chromium.org
BUG=v8:5267
Committed: https://crrev.com/8c50b51ab3d21efcd2f6900d83962159f21e1590
Review-Url: https://codereview.chromium.org/2167593002
Cr-Original-Commit-Position: refs/heads/master@{#37882}
Cr-Commit-Position: refs/heads/master@{#39420}
Reason for revert:
Octane/Mandreel aborts with an exception now:
TypeError: __FUNCTION_TABLE__[(r2 >> 2)] is not a function
Original issue's description:
> [turbofan] Insert dummy values when changing from None type.
>
> Currently we choose the MachineRepresentation::kNone representation for
> values of Type::None, and when converting values from the kNone representation
> we use "impossible" conversions that will crash at runtime. This
> assumes that the impossible conversions should never be hit (the only
> way to produce the impossible values is to perform an always-failing
> runtime check on a value, such as Smi-checking a string). Note that
> this assumes that the runtime check is executed before the impossible
> convesrion.
>
> Introducing BitwiseOr type feedback broke this in two ways:
>
> - we always pick Word32 representation for bitwise-or, so the
> impossible conversion does not trigger (it only triggers with
> None representation), and we could end up with unsupported
> conversions from Word32.
>
> - even if we inserted impossible conversions, they are pure conversions.
> Since untagging, bitwise-or operations are also pure, we could hoist
> all these before the smi check of the inputs and we could hit the
> impossible conversions before we get to the smi check.
>
> This CL addresses this by just providing dummy values for conversions
> from the Type::None type. It also removes the impossible-to-* conversions.
>
> BUG=chromium:638132
>
> Committed: https://crrev.com/c83b21ab755f1420b6da85b3ff43d7e96ead9bbe
> Cr-Commit-Position: refs/heads/master@{#38883}
TBR=mstarzinger@chromium.org,jarin@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=chromium:638132
Review-Url: https://codereview.chromium.org/2280613002
Cr-Commit-Position: refs/heads/master@{#38893}
Currently we choose the MachineRepresentation::kNone representation for
values of Type::None, and when converting values from the kNone representation
we use "impossible" conversions that will crash at runtime. This
assumes that the impossible conversions should never be hit (the only
way to produce the impossible values is to perform an always-failing
runtime check on a value, such as Smi-checking a string). Note that
this assumes that the runtime check is executed before the impossible
convesrion.
Introducing BitwiseOr type feedback broke this in two ways:
- we always pick Word32 representation for bitwise-or, so the
impossible conversion does not trigger (it only triggers with
None representation), and we could end up with unsupported
conversions from Word32.
- even if we inserted impossible conversions, they are pure conversions.
Since untagging, bitwise-or operations are also pure, we could hoist
all these before the smi check of the inputs and we could hit the
impossible conversions before we get to the smi check.
This CL addresses this by just providing dummy values for conversions
from the Type::None type. It also removes the impossible-to-* conversions.
BUG=chromium:638132
Review-Url: https://codereview.chromium.org/2266823002
Cr-Commit-Position: refs/heads/master@{#38883}
This leads to a better handling of the Smi case when we introduce a checked truncation from a number or oddbal to a 32 bit word, which we were previously doing by concatenating a Smi to float64 conversion with a float64 to word32 truncation.
BUG=
Review-Url: https://codereview.chromium.org/2191503002
Cr-Commit-Position: refs/heads/master@{#38091}
Add a dedicated simplified operator to inline the general case for the
ToBoolean conversion. In a follow up CL we will also use the ToBoolean
hints gathered by the baseline compiler.
Review-Url: https://codereview.chromium.org/2167593002
Cr-Commit-Position: refs/heads/master@{#37882}
This introduces optimized number operations based on type feedback.
Summary of changes:
1. Typed lowering produces SpeculativeNumberAdd/Subtract for JSAdd/Subtract if
there is suitable feedback. The speculative nodes are connected to both the
effect chain and the control chain and they retain the eager frame state.
2. Simplified lowering now executes in three phases:
a. Propagation phase computes truncations by traversing the graph from uses to
definitions until checkpoint is reached. It also records type-check decisions
for later typing phase, and computes representation.
b. The typing phase computes more precise types base on the speculative types (and recomputes
representation for affected nodes).
c. The lowering phase performs lowering and inserts representation changes and/or checks.
3. Effect-control linearization lowers the checks to machine graphs.
Notes:
- SimplifiedLowering will be refactored to have handling of each operation one place and
with clearer input/output protocol for each sub-phase. I would prefer to do this once
we have more operations implemented, and the pattern is clearer.
- The check operations (Checked<A>To<B>) should have some flags that would affect
the kind of truncations that they can handle. E.g., if we know that a node produces
a number, we can omit the oddball check in the CheckedTaggedToFloat64 lowering.
- In future, we want the typer to reuse the logic from OperationTyper.
BUG=v8:4583
LOG=n
Review-Url: https://codereview.chromium.org/1921563002
Cr-Commit-Position: refs/heads/master@{#36674}
