Commit Graph

77 Commits

Author SHA1 Message Date
Nicolas Vasilache 8d64df9f13 [mlir][Vector] Revisit VectorToSCF.
Vector to SCF conversion still had issues due to the interaction with the natural alignment derived by the LLVM data layout. One traditional workaround is to allocate aligned. However, this does not always work for vector sizes that are non-powers of 2.

This revision implements a more portable mechanism where the intermediate allocation is always a memref of elemental vector type. AllocOp is extended to use the natural LLVM DataLayout alignment for non-scalar types, when the alignment is not specified in the first place.

An integration test is added that exercises the transfer to scf.for + scalar lowering with a 5x5 transposition.

Differential Revision: https://reviews.llvm.org/D87150
2020-09-07 05:19:43 -04:00
Benjamin Kramer dfb7b3fe02 [mlir][VectorOps] Fall back to a loop when accessing a vector from a strided memref
The scalar loop is slow but correct.

Differential Revision: https://reviews.llvm.org/D87082
2020-09-03 16:05:38 +02:00
Jakub Lichman f5ed22f09d [mlir][VectorToSCF] 128 byte alignment of alloc ops
Added 128 byte alignment to alloc ops created in VectorToSCF pass.
128b alignment was already introduced to this pass but not to all alloc
ops. This commit changes that by adding 128b alignment to the remaining ops.
The point of specifying alignment is to prevent possible memory alignment errors
on weakly tested architectures.

Differential Revision: https://reviews.llvm.org/D86454
2020-09-02 12:37:35 +00:00
Jakub Lichman aeb338cc3e [mlir][VectorToSCF] Fix of broken build - missing link to MLIRLinalgUtils 2020-08-19 17:28:49 +00:00
Jakub Lichman 8dace28f92 [mlir][VectorToSCF] Bug in TransferRead lowering fixed
If Memref has rank > 1 this pass emits N-1 loops around
TransferRead op and transforms the op itself to 1D read. Since vectors
must have static shape while memrefs don't the pass emits if condition
to prevent out of bounds accesses in case some memref dimension is smaller
than the corresponding dimension of targeted vector. This logic is fine
but authors forgot to apply `permutation_map` on loops upper bounds and
thus if condition compares induction variable to incorrect loop upper bound
(dimension of the memref) in case `permutation_map` is not identity map.
This commit aims to fix that.
2020-08-19 15:34:34 +00:00
Jakub Lichman a4b8c2de1d [mlir] VectorToSCF bug in setAllocAtFunctionEntry fixed.
The function makes too strong assumption regarding parent FuncOp
which gets broken when FuncOp is first lowered to llvm function.
In this fix we generalize the assumption to allocation scope and
add assertion to produce user friendly message in case our assumption
is broken.

Differential Revision: https://reviews.llvm.org/D86086
2020-08-18 07:12:40 +00:00
Nicolas Vasilache 47cbd9f922 [mlir][Vector] NFC - Improve VectorInterfaces
This revision improves and makes better use of OpInterfaces for the Vector dialect.

Differential Revision: https://reviews.llvm.org/D84053
2020-07-20 08:24:22 -04:00
Nicolas Vasilache cc0a58d7cd [mlir][Vector] Fix masking logic in VectorToSCF
Summary: The logic was conservative but inverted: cases that should remain unmasked became 1-D masked.

Differential Revision: https://reviews.llvm.org/D84051
2020-07-17 13:24:07 -04:00
Nicolas Vasilache ec2f2cec76 [mlir][Vector] Add folding for vector.transfer ops
This revision folds vector.transfer operations by updating the `masked` bool array attribute when more unmasked dimensions can be discovered.

Differential revision: https://reviews.llvm.org/D83586
2020-07-10 16:49:12 -04:00
River Riddle 9db53a1827 [mlir][NFC] Remove usernames and google bug numbers from TODO comments.
These were largely leftover from when MLIR was a google project, and don't really follow LLVM guidelines.
2020-07-07 01:40:52 -07:00
Nicolas Vasilache bd87c6bce1 [mlir][Vector] Add custom slt / SCF.if folding to VectorToSCF
scf.if currently lacks folding on true / false conditionals.
Such foldings are a bit more involved than can be addressed immediately.
This revision introduces an eager folding  for lowering vector.transfer operations in the presence of unrolling.

Differential revision: https://reviews.llvm.org/D83146
2020-07-06 08:21:21 -04:00
Adam D Straw 25055a4fb9 [mlir] add unsigned comparison builders to Affine EDSC
Current Affine comparison builders, which use operator overload, default to signed comparison.  This creates the possibility of misuse of these builders and potential correctness issues when dealing with unsigned integers.  This change makes the distinction between signed and unsigned comparison builders and forces the caller to make a choice between the two.

Differential Revision: https://reviews.llvm.org/D82323
2020-06-29 23:30:49 +02:00
Alex Zinenko 3f5bd53eb1 [mlir] Introduce callback-based builders for AffineForOp
Similarly to `scf::ForOp`, introduce additional `function_ref` arguments to
`AffineForOp::build` that can be used to populate the body of the loop during
its construction. Provide compatibility functions for constructing affine loop
nests using `edsc::ScopedContext`.

`edsc::AffineLoopNestBuilder` and reletad functionality is now deprecated and
will be removed soon, users are expected to switch to `affineLoopNestBuilder`
that provides similar functionality with a simpler OpBuilder-based
implementation.

Differential Revision: https://reviews.llvm.org/D81754
2020-06-15 17:55:49 +02:00
Alexander Belyaev e9ac792748 [mlir] Fix some of the warnings in MLIR code.
Summary:
* extra ';' in the following files:
    mlir/lib/Dialect/Linalg/Transforms/Transforms.cpp
    mlir/lib/Dialect/Shape/IR/Shape.cpp

* base class ‘mlir::ConvertVectorToSCFBase<ConvertVectorToSCFPass>’
  should be explicitly initialized in the copy constructor [-Wextra] in
    mlir/lib/Conversion/VectorToSCF/VectorToSCF.cpp

* warning: ‘bool Expression::operator==(const Expression&) const’
  defined but not used [-Wunused-function] in
    mlir/tools/mlir-linalg-ods-gen/mlir-linalg-ods-gen.cpp

Differential Revision: https://reviews.llvm.org/D81673
2020-06-11 22:18:32 +02:00
Nicolas Vasilache 247e185dd5 [mlir][Vector] Move temporary alloc to top of the function alloca when lowering vector_transfers
Recently introduced allocation hoisting is quite conservative on the cases when it triggers.
This revision makes it such that the allocations for vector transfer lowerings are hoisted
to the top of the function.
This should be revisited in the context of parallelism and is a temporary workaround.

Differential Revision: https://reviews.llvm.org/D81253
2020-06-05 08:45:52 -04:00
Nicolas Vasilache 5f9e0466f2 [mlir][Vector] Fix vector.transfer alignment calculation
https://reviews.llvm.org/D79246 introduces alignment propagation for vector transfer operations. Unfortunately, the alignment calculation is incorrect and can result in crashes.

This revision fixes the calculation by using the natural alignment of the memref elemental type, instead of the resulting vector type.

If more alignment is desired, it can be done in 2 ways:
1. use a proper vector.type_cast to transform a memref<axbxcxdxf32> into a memref<axbxvector<cxdxf32>> giving a natural alignment of vector<cxdxf32>
2. add an alignment attribute to vector transfer operations and propagate it.

With this change the alignment in the relevant tests goes down from 128 to 4.

Lastly, a few minor cleanups are performed and the custom `isMinorIdentityMap` is deprecated.

Differential Revision: https://reviews.llvm.org/D80734
2020-05-28 17:58:51 -04:00
Alex Zinenko cadb7ccf2c [mlir] SCF: provide function_ref builders for IfOp
Now that OpBuilder is available in `build` functions, it becomes possible to
populate the "then" and "else" regions directly when building the "if"
operation. This is desirable in more structured forms of builders, especially
in when conditionals are mixed with loops. Provide new `build` APIs taking
callbacks for body constructors, similarly to scf::ForOp, and replace more
clunky edsc::BlockBuilder uses with these. The original APIs remain available
and go through the new implementation.

Differential Revision: https://reviews.llvm.org/D80527
2020-05-27 16:12:58 +02:00
Benjamin Kramer a9b5edc5e2 Make mlir::Value's bool conversion operator explicit
This still allows `if (value)` while requiring an explicit cast when not
in a boolean context. This means things like `std::set<Value>` will no
longer compile.

Differential Revision: https://reviews.llvm.org/D80497
2020-05-25 18:22:00 +02:00
Nicolas Vasilache 3393cc4ceb [mlir] NFC - Appease GCC 5 again.. 2020-05-20 17:58:18 -04:00
Nicolas Vasilache ebf14d9b6d [mlir] NFC - Appease GCC 5 again.. 2020-05-20 16:47:45 -04:00
Nicolas Vasilache 7c3c5b11b1 [mlir][Vector] Add option to fully unroll for VectorTransfer to SCF lowering
Summary:
Previously, the only support partial lowering from vector transfers to SCF was
going through loops. This requires a dedicated allocation and extra memory
roundtrips because LLVM aggregates cannot be indexed dynamically (for more
details see the [deep-dive](https://mlir.llvm.org/docs/Dialects/Vector/#deeperdive)).

This revision allows specifying full unrolling which removes this additional roundtrip.
This should be used carefully though because full unrolling will spill, negating the
benefits of removing the interim alloc in the first place.

Proper heuristics are left for a later time.

Differential Revision: https://reviews.llvm.org/D80100
2020-05-20 11:02:13 -04:00
Nicolas Vasilache da95a0d8cc [mlir] NFC - Appease gcc 5
This should fix the error ```
VectorToSCF.cpp:238:62: error: specialization of 'template<class
ConcreteOp> mlir::LogicalResult
{anonymous}::NDTransferOpHelper<ConcreteOp>::doReplace()' in different
namespace
```
2020-05-19 22:47:51 -04:00
Benjamin Kramer 350dadaa8a Give helpers internal linkage. NFC. 2020-05-19 22:16:37 +02:00
Alex Zinenko d1560f3956 [mlir] scf::ForOp: provide builders with callbacks for loop body
Thanks to a recent change that made `::build` functions take an instance of
`OpBuilder`, it is now possible to build operations within a region attached to
the operation about to be created. Exercise this on `scf::ForOp` by taking a
callback that populates the loop body while the loop is being created.

Additionally, provide helper functions to build perfect nests of `ForOp`s,
with support for iteration arguments. These functions provide the same
functionality as EDSC LoopNestBuilder with simpler implementation, without
relying on edsc::ScopedContext, and using `OpBuilder` in an unambiguous way.
Compatibility functions for EDSC are provided, but may be removed in the
future.

Differential Revision: https://reviews.llvm.org/D79688
2020-05-19 16:26:29 +02:00
Nicolas Vasilache 1870e787af [mlir][Vector] Add an optional "masked" boolean array attribute to vector transfer operations
Summary:
Vector transfer ops semantic is extended to allow specifying a per-dimension `masked`
attribute. When the attribute is false on a particular dimension, lowering to LLVM emits
unmasked load and store operations.

Differential Revision: https://reviews.llvm.org/D80098
2020-05-18 11:52:08 -04:00
Nicolas Vasilache 36cdc17f8c [mlir][Vector] Make minor identity permutation map optional in transfer op printing and parsing
Summary:
This revision makes the use of vector transfer operatons more idiomatic by
allowing to omit and inferring the permutation_map.

Differential Revision: https://reviews.llvm.org/D80092
2020-05-18 11:41:27 -04:00
Alex Zinenko 4ead2cf76c [mlir] Rename conversions involving ex-Loop dialect to mention SCF
The following Conversions are affected: LoopToStandard -> SCFToStandard,
LoopsToGPU -> SCFToGPU, VectorToLoops -> VectorToSCF. Full file paths are
affected. Additionally, drop the 'Convert' prefix from filenames living under
lib/Conversion where applicable.

API names and CLI options for pass testing are also renamed when applicable. In
particular, LoopsToGPU contains several passes that apply to different kinds of
loops (`for` or `parallel`), for which the original names are preserved.

Differential Revision: https://reviews.llvm.org/D79940
2020-05-15 10:45:11 +02:00