Commit Graph

280 Commits

Author SHA1 Message Date
Aart Bik
0b1764a3d7 [mlir][sparse] sparse tensor storage implementation
This revision connects the generated sparse code with an actual
sparse storage scheme, which can be initialized from a test file.
Lacking a first-class citizen SparseTensor type (with buffer),
the storage is hidden behind an opaque pointer with some "glue"
to bring the pointer back to tensor land. Rather than generating
sparse setup code for each different annotated tensor (viz. the
"pack" methods in TACO), a single "one-size-fits-all" implementation
has been added to the runtime support library.  Many details and
abstractions need to be refined in the future, but this revision
allows full end-to-end integration testing and performance
benchmarking (with on one end, an annotated Lingalg
op and, on the other end, a JIT/AOT executable).

Reviewed By: nicolasvasilache, bixia

Differential Revision: https://reviews.llvm.org/D95847
2021-02-10 11:57:24 -08:00
Nicolas Vasilache
bb69de3f41 [mlir][Linalg] Add a vectorization pattern for linalg::PadTensorOp
The new pattern is exercised from the TestLinalgTransforms pass.

Differential Revision: https://reviews.llvm.org/D96410
2021-02-10 14:13:49 +00:00
River Riddle
fe7c0d90b2 [mlir][IR] Remove the concept of OperationProperties
These properties were useful for a few things before traits had a better integration story, but don't really carry their weight well these days. Most of these properties are already checked via traits in most of the code. It is better to align the system around traits, and improve the performance/cost of traits in general.

Differential Revision: https://reviews.llvm.org/D96088
2021-02-09 12:00:15 -08:00
Nicolas Vasilache
d57a305fdf [mlir][Linalg] Fix padding related bugs.
This revision fixes the fact that the padding transformation did not have enough information to set the proper type for the padding value.
Additionally, the verifier for Yield in the presence of PadTensorOp is fixed to properly report incorrect number of results or operands. Previously, the error would be silently ignored which made the core issue difficult to debug.

Differential Revision: https://reviews.llvm.org/D96264
2021-02-08 18:59:24 +00:00
Lei Zhang
7630520ae3 [mlir][vector] Add pattern to shuffle bitcast ops
These patterns move vector.bitcast ops to be before
insert ops or after extract ops where suitable.
With them, bitcast will happen on smaller vectors
and there are more chances to share extract/insert
ops.

Reviewed By: ThomasRaoux

Differential Revision: https://reviews.llvm.org/D96040
2021-02-05 17:52:49 -05:00
Lei Zhang
874ce9b80f [mlir][vector] Add patterns to cast away leading 1-dim
This patch adds patterns to use vector.shape_cast to cast
away leading 1-dimensions from a few vector operations.
It allows exposing more canonical forms of vector.transfer_read,
vector.transfer_write, vector_extract_strided_slice, and
vector.insert_strided_slice. With this, we can have more
opportunity to cancelling extract/insert ops or forwarding
write/read ops.

Reviewed By: ThomasRaoux

Differential Revision: https://reviews.llvm.org/D95873
2021-02-05 09:02:15 -05:00
Nicolas Vasilache
ef9e1e5a59 [mlir][Linalg] Add option to anchor on func name in TestLinalgCodegenStrategy 2021-02-05 11:39:48 +00:00
River Riddle
e21adfa32d [mlir] Mark LogicalResult as LLVM_NODISCARD
This makes ignoring a result explicit by the user, and helps to prevent accidental errors with dropped results. Marking LogicalResult as no discard was always the intention from the beginning, but got lost along the way.

Differential Revision: https://reviews.llvm.org/D95841
2021-02-04 15:10:10 -08:00
Nicolas Vasilache
e4a503a26d [mlir][Linalg] Introduce a ContractionOpInterface
This revision takes advantage of recent extensions to vectorization to refactor contraction detection into a bona fide Linalg interface.
The mlit-linalg-ods-gen parser is extended to support adding such interfaces.
The detection that was originally enabling vectorization is refactored to serve as both a test on a generic LinalgOp as well as to verify ops that declare to conform to that interface.

This is plugged through Linalg transforms and strategies but it quickly becomes evident that the complexity and rigidity of the C++ class based templating does not pay for itself.
Therefore, this revision changes the API for vectorization patterns to get rid of templates as much as possible.
Variadic templates are relegated to the internals of LinalgTransformationFilter as much as possible and away from the user-facing APIs.

It is expected other patterns / transformations will follow the same path and drop as much C++ templating as possible from the class definition.

Differential revision: https://reviews.llvm.org/D95973
2021-02-04 16:53:24 +00:00
Nicolas Vasilache
f245b7ad36 [mlir][Linalg] Generalize the definition of a Linalg contraction.
This revision defines a Linalg contraction in general terms:

  1. Has 2 input and 1 output shapes.
  2. Has at least one reduction dimension.
  3. Has only projected permutation indexing maps.
  4. its body computes `u5(u1(c) + u2(u3(a) * u4(b)))` on some field
    (AddOpType, MulOpType), where u1, u2, u3, u4 and u5 represent scalar unary
    operations that may change the type (e.g. for mixed-precision).

As a consequence, when vectorization of such an op occurs, the only special
behavior is that the (unique) MulOpType is vectorized into a
`vector.contract`. All other ops are handled in a generic fashion.

 In the future, we may wish to allow more input arguments and elementwise and
 constant operations that do not involve the reduction dimension(s).

A test is added to demonstrate the proper vectorization of matmul_i8_i8_i32.

Differential revision: https://reviews.llvm.org/D95939
2021-02-04 07:50:44 +00:00
Lei Zhang
b24e3cc542 [mlir] Put template specialization in the same namespace
This should address GCC 5 failure due to specialization of
runStrategy in different namespace.
2021-02-02 10:05:32 -05:00
Nicolas Vasilache
8fce22888b [mlir][Linalg] Fix and properly test CodegenStrategy API
Fix a bug that was introduced where calling the codegen strategy with actual concrete C++ Op types did not trigger the expected behavior.
Also introduce a test for the behavior that was missing.

Differential Revision: https://reviews.llvm.org/D95863
2021-02-02 13:01:12 +00:00
Hanhan Wang
b3f611bfe7 [mlir][Linalg] Replace SimplePad with PadTensor in hoist-padding
This is the last revision to migrate using SimplePadOp to PadTensorOp, and the
SimplePadOp is removed in the patch. Update a bit in SliceAnalysis because the
PadTensorOp takes a region different from SimplePadOp. This is not covered by
LinalgOp because it is not a structured op.

Also, remove a duplicated comment from cpp file, which is already described in a
header file. And update the pseudo-mlir in the comment.

This is as same as D95615 but fixing one dep in CMakeLists.txt

Different from D95671, the fix was applied to run target.

Reviewed By: mravishankar

Differential Revision: https://reviews.llvm.org/D95785
2021-02-01 11:38:43 -08:00
Tres Popp
2790cbedd0 Revert "[mlir][Linalg] Replace SimplePad with PadTensor in hoist-padding"
This reverts commit d9b953d84b.

This commit resulted in build bot failures and the author is away from a
computer, so I am reverting on their behalf until they have a chance to
look into this.
2021-02-01 09:43:55 +01:00
Hanhan Wang
d9b953d84b [mlir][Linalg] Replace SimplePad with PadTensor in hoist-padding
This is the last revision to migrate using SimplePadOp to PadTensorOp, and the
SimplePadOp is removed in the patch. Update a bit in SliceAnalysis because the
PadTensorOp takes a region different from SimplePadOp. This is not covered by
LinalgOp because it is not a structured op.

Also, remove a duplicated comment from cpp file, which is already described in a
header file. And update the pseudo-mlir in the comment.

Reviewed By: nicolasvasilache

Differential Revision: https://reviews.llvm.org/D95671
2021-02-01 00:02:37 -08:00
MaheshRavishankar
98835e3d98 [mlir][Linalg] Enable TileAndFusePattern to work with tensors.
Differential Revision: https://reviews.llvm.org/D94531
2021-01-28 14:13:01 -08:00
Hanhan Wang
2c7cc5fd20 Revert "[mlir][Linalg] Replace SimplePad with PadTensor in hoist-padding"
This reverts commit 1e790b745d.

Differential Revision: https://reviews.llvm.org/D95636
2021-01-28 11:25:02 -08:00
Hanhan Wang
1e790b745d [mlir][Linalg] Replace SimplePad with PadTensor in hoist-padding
This is the last revision to migrate using SimplePadOp to PadTensorOp, and the
SimplePadOp is removed in the patch. Update a bit in SliceAnalysis because the
PadTensorOp takes a region different from SimplePadOp. This is not covered by
LinalgOp because it is not a structured op.

Also, remove a duplicated comment from cpp file, which is already described in a
header file. And update the pseudo-mlir in the comment.

Reviewed By: nicolasvasilache

Differential Revision: https://reviews.llvm.org/D95615
2021-01-28 11:09:57 -08:00
Nicolas Vasilache
299cc5da6d [mlir][Linalg] Further improve codegen strategy and add a linalg.matmul_i8_i8_i32
This revision adds a layer of SFINAE to the composable codegen strategy so it does
not have to require statically defined ops but instead can also be used with OpInterfaces, Operation* and an op name string.

A linalg.matmul_i8_i8_i32 is added to the .tc spec to demonstrate how all this works end to end.

Differential Revision: https://reviews.llvm.org/D95600
2021-01-28 13:02:42 +00:00
Nicolas Vasilache
d0c9fb1b8e [mlir][Linalg] Improve codegen strategy
This revision improves the usage of the codegen strategy by adding a few flags that
make it easier to control for the CLI.
Usage of ModuleOp is replaced by FuncOp as this created issues in multi-threaded mode.

A simple benchmarking capability is added for linalg.matmul as well as linalg.matmul_column_major.
This latter op is also added to linalg.

Now obsolete linalg integration tests that also take too long are deleted.

Correctness checks are still missing at this point.

Differential revision: https://reviews.llvm.org/D95531
2021-01-28 10:59:16 +00:00
Nicolas Vasilache
dbf9bedf40 [mlir][Linalg] Add a hoistPaddingOnTensors transformation
This transformation anchors on a padding op whose result is only used as an input
to a Linalg op and pulls it out of a given number of loops.
The result is a packing of padded tailes of ops that is amortized just before
the outermost loop from which the pad operation is hoisted.

Differential revision: https://reviews.llvm.org/D95243
2021-01-25 12:41:18 +00:00
Nicolas Vasilache
3747eb9c85 [mlir][Linalg] Add a padding option to Linalg tiling
This revision allows the base Linalg tiling pattern to optionally require padding to
a constant bounding shape.
When requested, a simple analysis is performed, similar to buffer promotion.
A temporary `linalg.simple_pad` op is added to model padding for the purpose of
connecting the dots. This will be replaced by a more fleshed out `linalg.pad_tensor`
op when it is available.
In the meantime, this temporary op serves the purpose of exhibiting the necessary
properties required from a more fleshed out pad op, to compose with transformations
properly.

Reviewed By: ftynse

Differential Revision: https://reviews.llvm.org/D95149
2021-01-25 09:17:30 +00:00
MaheshRavishankar
01defcc8d7 [mlir][Linalg] Extend tile+fuse to work on Linalg operation on tensors.
Differential Revision: https://reviews.llvm.org/D93086
2021-01-22 11:33:35 -08:00
Aart Bik
b5c542d64b [mlir][sparse] add narrower choices for pointers/indices
Use cases with 16- or even 8-bit pointer/index structures have been identified.

Reviewed By: penpornk

Differential Revision: https://reviews.llvm.org/D95015
2021-01-19 20:20:38 -08:00
Aart Bik
f4f158b2f8 [mlir][sparse] add vectorization strategies to sparse compiler
Similar to the parallelization strategies, the vectorization strategies
provide control on what loops should be vectorize. Unlike the parallel
strategies, only innermost loops are considered, but including reductions,
with the control of vectorizing dense loops only or dense and sparse loops.

The vectorized loops are always controlled by a vector mask to avoid
overrunning the iterations, but subsequent vector operation folding removes
redundant masks and replaces the operations with more efficient counterparts.
Similarly, we will rely on subsequent loop optimizations to further optimize
masking, e.g. using an unconditional full vector loop and scalar cleanup loop.

The current strategy already demonstrates a nice interaction between the
sparse compiler and all prior optimizations that went into the vector dialect.

Ongoing discussion at:
https://llvm.discourse.group/t/mlir-support-for-sparse-tensors/2020/10

Reviewed By: penpornk

Differential Revision: https://reviews.llvm.org/D94551
2021-01-13 11:55:23 -08:00
Nicolas Vasilache
80f0785488 [mlir][Linalg] NFC - Refactor fusion APIs
This revision uniformizes fusion APIs to allow passing OpOperand, OpResult and adds a finer level of control fusion.

Differential Revision: https://reviews.llvm.org/D94493
2021-01-12 14:27:15 +00:00
Aart Bik
a57def30f5 [mlir][vector] generalized masked l/s and compressed l/s with indices
Adding the ability to index the base address brings these operations closer
to the transfer read and write semantics (with lowering advantages), ensures
more consistent use in vector MLIR code (easier to read), and reduces the
amount of code duplication to lower memrefs into base addresses considerably
(making codegen less error-prone).

Reviewed By: ThomasRaoux

Differential Revision: https://reviews.llvm.org/D94278
2021-01-08 13:59:34 -08:00
Alex Zinenko
2230bf99c7 [mlir] replace LLVMIntegerType with built-in integer type
The LLVM dialect type system has been closed until now, i.e. did not support
types from other dialects inside containers. While this has had obvious
benefits of deriving from a common base class, it has led to some simple types
being almost identical with the built-in types, namely integer and floating
point types. This in turn has led to a lot of larger-scale complexity: simple
types must still be converted, numerous operations that correspond to LLVM IR
intrinsics are replicated to produce versions operating on either LLVM dialect
or built-in types leading to quasi-duplicate dialects, lowering to the LLVM
dialect is essentially required to be one-shot because of type conversion, etc.
In this light, it is reasonable to trade off some local complexity in the
internal implementation of LLVM dialect types for removing larger-scale system
complexity. Previous commits to the LLVM dialect type system have adapted the
API to support types from other dialects.

Replace LLVMIntegerType with the built-in IntegerType plus additional checks
that such types are signless (these are isolated in a utility function that
replaced `isa<LLVMType>` and in the parser). Temporarily keep the possibility
to parse `!llvm.i32` as a synonym for `i32`, but add a deprecation notice.

Reviewed By: mehdi_amini, silvas, antiagainst

Differential Revision: https://reviews.llvm.org/D94178
2021-01-07 19:48:31 +01:00
Thomas Raoux
efd05040e1 [mlir] Add hoisting transformation for transfer ops on tensor
Add same hoisting transformation existing for transfer ops on buffers for
transfer_ops on tensor. The logic is significantly different so this is done as
a separate transformation and it is expect that user would know which
transformation to use based on the flow.

Differential Revision: https://reviews.llvm.org/D94115
2021-01-06 14:23:59 -08:00
Thomas Raoux
f9190c8681 [mlir][vector] Support unrolling for transfer ops using tensors
Differential Revision: https://reviews.llvm.org/D93904
2021-01-06 13:28:04 -08:00
Kazuaki Ishizaki
2b638ed5a1 [mlir] NFC: fix trivial typos
fix typos under docs, test, and tools directories

Reviewed By: ftynse

Differential Revision: https://reviews.llvm.org/D94158
2021-01-07 02:36:02 +09:00
Alex Zinenko
7ed9cfc7b1 [mlir] Remove static constructors from LLVMType
LLVMType contains numerous static constructors that were initially introduced
for API compatibility with LLVM. Most of these merely forward to arguments to
`SpecificType::get` (MLIR defines classes for all types, unlike LLVM IR), while
some introduce subtle semantics differences due to different modeling of MLIR
types (e.g., structs are not auto-renamed in case of conflicts). Furthermore,
these constructors don't match MLIR idioms and actively prevent us from making
the LLVM dialect type system more open. Remove them and use `SpecificType::get`
instead.

Depends On D93680

Reviewed By: mehdi_amini

Differential Revision: https://reviews.llvm.org/D93681
2020-12-23 13:12:47 +01:00
Thomas Raoux
7c7b55b985 [mlir][vector] Extend vector unroll to all element-wise ops
Extend unroll to support all element-wise ops and allow unrolling for ops with
vector operands of with the same shape as the destination but different element
type (like Cmp or Select).

Differential Revision: https://reviews.llvm.org/D93121
2020-12-21 13:31:22 -08:00
River Riddle
1b97cdf885 [mlir][IR][NFC] Move context/location parameters of builtin Type::get methods to the start of the parameter list
This better matches the rest of the infrastructure, is much simpler, and makes it easier to move these types to being declaratively specified.

Differential Revision: https://reviews.llvm.org/D93432
2020-12-17 13:01:36 -08:00
Lei Zhang
0117865412 [mlir][spirv] NFC: Shuffle code around to better follow convention
This commit shuffles SPIR-V code around to better follow MLIR
convention. Specifically,

* Created IR/, Transforms/, Linking/, and Utils/ subdirectories and
  moved suitable code inside.
* Created SPIRVEnums.{h|cpp} for SPIR-V C/C++ enums generated from
  SPIR-V spec. Previously they are cluttered inside SPIRVTypes.{h|cpp}.
* Fixed include guards in various header files (both .h and .td).
* Moved serialization tests under test/Target/SPIRV.
* Renamed TableGen backend -gen-spirv-op-utils into -gen-spirv-attr-utils
  as it is only generating utility functions for attributes.

Reviewed By: mravishankar

Differential Revision: https://reviews.llvm.org/D93407
2020-12-17 11:03:26 -05:00
River Riddle
d7eba20052 [mlir][Inliner] Refactor the inliner to use nested pass pipelines instead of just canonicalization
Now that passes have support for running nested pipelines, the inliner can now allow for users to provide proper nested pipelines to use for optimization during inlining. This revision also changes the behavior of optimization during inlining to optimize before attempting to inline, which should lead to a more accurate cost model and prevents the need for users to schedule additional duplicate cleanup passes before/after the inliner that would already be run during inlining.

Differential Revision: https://reviews.llvm.org/D91211
2020-12-14 18:09:47 -08:00
Christian Sigg
1ffc1aaa09 [mlir] Use mlir::OpState::operator->() to get to methods of mlir::Operation.
This is a preparation step to remove those methods from OpState.

Reviewed By: mehdi_amini

Differential Revision: https://reviews.llvm.org/D93098
2020-12-13 09:58:16 +01:00
Christian Sigg
0bf4a82a5a [mlir] Use mlir::OpState::operator->() to get to methods of mlir::Operation. This is a preparation step to remove the corresponding methods from OpState.
Reviewed By: silvas, rriddle

Differential Revision: https://reviews.llvm.org/D92878
2020-12-09 12:11:32 +01:00
Thomas Raoux
3e3e276d22 [mlir][vector][NFC] Change UnrollVectorPattern to not be statically dependent on an op type
Make UnrollVectorPattern inherit from RewritePattern instead of
OpRewritePattern so that we don't need to create many patterns when applying to
many different type of ops. Since we may want to apply the pattern to all
arithmetic op, it is more convenient to filter dynamically.

Differential Revision: https://reviews.llvm.org/D92635
2020-12-04 09:53:01 -08:00
Nicolas Vasilache
a1cd559ce5 [mlir][Linalg] Properly use distribution options.
Let tiling to scf.for actually use the distribution method.
For now only Cyclic is supported.

Differential Revision: https://reviews.llvm.org/D92653
2020-12-04 14:00:54 +00:00
River Riddle
09f7a55fad [mlir][Types][NFC] Move all of the builtin Type classes to BuiltinTypes.h
This is part of a larger refactoring the better congregates the builtin structures under the BuiltinDialect. This also removes the problematic "standard" naming that clashes with the "standard" dialect, which is not defined within IR/. A temporary forward is placed in StandardTypes.h to allow time for downstream users to replaced references.

Differential Revision: https://reviews.llvm.org/D92435
2020-12-03 18:02:10 -08:00
Thomas Raoux
c503dc1b8a [mlir][linalg] Add vectorization for element-wise linalg ops
Add support for vectorization for linalg.generic representing element-wise ops.
Those are converted to transfer_read + vector ops + transfer_write.
Also re-organize the vectorization tests to be together.

Implementation derived from the work of @burmako, @agrue and
@fedelebron.

Differential Revision: https://reviews.llvm.org/D92540
2020-12-03 15:31:13 -08:00
Christian Sigg
c4a0405902 Add Operation* OpState::operator->() to provide more convenient access to members of Operation.
Given that OpState already implicit converts to Operator*, this seems reasonable.

The alternative would be to add more functions to OpState which forward to Operation.

Reviewed By: rriddle, ftynse

Differential Revision: https://reviews.llvm.org/D92266
2020-12-02 15:46:20 +01:00
River Riddle
abfd1a8b3b [mlir][PDL] Add support for PDL bytecode and expose PDL support to OwningRewritePatternList
PDL patterns are now supported via a new `PDLPatternModule` class. This class contains a ModuleOp with the pdl::PatternOp operations representing the patterns, as well as a collection of registered C++ functions for native constraints/creations/rewrites/etc. that may be invoked via the pdl patterns. Instances of this class are added to an OwningRewritePatternList in the same fashion as C++ RewritePatterns, i.e. via the `insert` method.

The PDL bytecode is an in-memory representation of the PDL interpreter dialect that can be efficiently interpreted/executed. The representation of the bytecode boils down to a code array(for opcodes/memory locations/etc) and a memory buffer(for storing attributes/operations/values/any other data necessary). The bytecode operations are effectively a 1-1 mapping to the PDLInterp dialect operations, with a few exceptions in cases where the in-memory representation of the bytecode can be more efficient than the MLIR representation. For example, a generic `AreEqual` bytecode op can be used to represent AreEqualOp, CheckAttributeOp, and CheckTypeOp.

The execution of the bytecode is split into two phases: matching and rewriting. When matching, all of the matched patterns are collected to avoid the overhead of re-running parts of the matcher. These matched patterns are then considered alongside the native C++ patterns, which rewrite immediately in-place via `RewritePattern::matchAndRewrite`,  for the given root operation. When a PDL pattern is matched and has the highest benefit, it is passed back to the bytecode to execute its rewriter.

Differential Revision: https://reviews.llvm.org/D89107
2020-12-01 15:05:50 -08:00
Christian Sigg
acb69f3b7c [mlir] Change ConvertOpToLLVMPattern::matchAndRewrite argument to concrete operand type.
Reviewed By: herhut, ftynse

Differential Revision: https://reviews.llvm.org/D92111
2020-11-28 13:09:25 +01:00
Aart Bik
d5f0d0c0c4 [mlir][sparse] add ability to select pointer/index storage type
This change gives sparse compiler clients more control over selecting
individual types for the pointers and indices in the sparse storage schemes.
Narrower width obviously results in smaller memory footprints, but the
range should always suffice for the maximum number of entries or index value.

Reviewed By: penpornk

Differential Revision: https://reviews.llvm.org/D92126
2020-11-25 17:32:44 -08:00
Aart Bik
5c4e397e6c [mlir][sparse] add parallelization strategies to sparse compiler
This CL adds the ability to request different parallelization strategies
for the generate code. Every "parallel" loop is a candidate, and converted
to a parallel op if it is an actual for-loop (not a while) and the strategy
allows dense/sparse outer/inner parallelization.

This will connect directly with the work of @ezhulenev on parallel loops.

Still TBD: vectorization strategy

Reviewed By: penpornk

Differential Revision: https://reviews.llvm.org/D91978
2020-11-24 17:17:13 -08:00
MaheshRavishankar
e65a5e5b00 [mlir][Linalg] Fuse sequence of Linalg operation (on buffers)
Enhance the tile+fuse logic to allow fusing a sequence of operations.

Make sure the value used to obtain tile shape is a
SubViewOp/SubTensorOp. Current logic used to get the bounds of loop
depends on the use of `getOrCreateRange` method on `SubViewOp` and
`SubTensorOp`. Make sure that the value/dim used to compute the range
is from such ops.  This fix is a reasonable WAR, but a btter fix would
be to make `getOrCreateRange` method be a method of `ViewInterface`.

Differential Revision: https://reviews.llvm.org/D90991
2020-11-23 10:30:51 -08:00
Thomas Raoux
369c51a74b [mlir][vector] Add transfer_op LoadToStore forwarding and deadStore optimizations
Add transformation to be able to forward transfer_write into transfer_read
operation and to be able to remove dead transfer_write when a transfer_write is
overwritten before being read.

Differential Revision: https://reviews.llvm.org/D91321
2020-11-20 11:59:01 -08:00
Mikhail Goncharov
0caa82e2ac Revert "[mlir][Linalg] Fuse sequence of Linalg operation (on buffers)"
This reverts commit f8284d21a8.

Revert "[mlir][Linalg] NFC: Expose some utility functions used for promotion."

This reverts commit 0c59f51592.

Revert "Remove unused isZero function"

This reverts commit 0f9f0a4046.

Change f8284d21 led to multiple failures in IREE compilation.
2020-11-20 13:12:54 +01:00