46 Commits

Author SHA1 Message Date
Nicolas Vasilache 3f906c54a2 [mlir][Vector] Add 2-D vector contract lowering to ReduceOp
This new pattern mixes vector.transpose and direct lowering to vector.reduce.
This allows more progressive lowering than immediately going to insert/extract and
composes more nicely with other canonicalizations.
This has 2 use cases:
1. for very wide vectors the generated IR may be much smaller
2. when we have a custom lowering for transpose ops we can target it directly
rather than rely LLVM

Differential Revision: https://reviews.llvm.org/D85428
2020-08-07 06:17:48 -04:00
Nicolas Vasilache 1353cbc257 [mlir][Vector] NFC - Use matchAndRewrite in ContractionOp lowering patterns
Replace the use of separate match and rewrite which unnecessarily duplicates logic.

Differential Revision: https://reviews.llvm.org/D85421
2020-08-06 09:02:25 -04:00
Nicolas Vasilache 2d0b05969b [mlir][Vector] Relax condition for splitFullAndPartialTransferPrecondition
The `splitFullAndPartialTransferPrecondition` has a restrictive condition to
prevent the pattern to be applied recursively if it is nested under an scf.IfOp.
Relaxing the condition to the immediate parent op must not be an scf.IfOp lets
the pattern be applied more generally while still preventing recursion.

Differential Revision: https://reviews.llvm.org/D85209
2020-08-04 10:06:21 -04:00
Nicolas Vasilache 1a4263d394 [mlir][Vector] Add linalg.copy-based pattern for splitting vector.transfer_read into full and partial copies.
This revision adds a transformation and a pattern that rewrites a "maybe masked" `vector.transfer_read %view[...], %pad `into a pattern resembling:

```
   %1:3 = scf.if (%inBounds) {
      scf.yield %view : memref<A...>, index, index
    } else {
      %2 = linalg.fill(%extra_alloc, %pad)
      %3 = subview %view [...][...][...]
      linalg.copy(%3, %alloc)
      memref_cast %extra_alloc: memref<B...> to memref<A...>
      scf.yield %4 : memref<A...>, index, index
   }
   %res= vector.transfer_read %1#0[%1#1, %1#2] {masked = [false ... false]}
```
where `extra_alloc` is a top of the function alloca'ed buffer of one vector.

This rewrite makes it possible to realize the "always full tile" abstraction where vector.transfer_read operations are guaranteed to read from a padded full buffer.
The extra work only occurs on the boundary tiles.
2020-08-04 08:46:08 -04:00
Nicolas Vasilache d313e9c12e [mlir][Vector] Add transformation + pattern to split vector.transfer_read into full and partial copies.
This revision adds a transformation and a pattern that rewrites a "maybe masked" `vector.transfer_read %view[...], %pad `into a pattern resembling:

```
   %1:3 = scf.if (%inBounds) {
      scf.yield %view : memref<A...>, index, index
    } else {
      %2 = vector.transfer_read %view[...], %pad : memref<A...>, vector<...>
      %3 = vector.type_cast %extra_alloc : memref<...> to
      memref<vector<...>> store %2, %3[] : memref<vector<...>> %4 =
      memref_cast %extra_alloc: memref<B...> to memref<A...> scf.yield %4 :
      memref<A...>, index, index
   }
   %res= vector.transfer_read %1#0[%1#1, %1#2] {masked = [false ... false]}
```
where `extra_alloc` is a top of the function alloca'ed buffer of one vector.

This rewrite makes it possible to realize the "always full tile" abstraction where vector.transfer_read operations are guaranteed to read from a padded full buffer.
The extra work only occurs on the boundary tiles.

Differential Revision: https://reviews.llvm.org/D84631
2020-08-03 12:58:18 -04:00
Mehdi Amini 7ba82a7320 Revert "[mlir][Vector] Add transformation + pattern to split vector.transfer_read into full and partial copies."
This reverts commit 35b65be041.

Build is broken with -DBUILD_SHARED_LIBS=ON with some undefined
references like:

VectorTransforms.cpp:(.text._ZN4llvm12function_refIFvllEE11callback_fnIZL24createScopedInBoundsCondN4mlir25VectorTransferOpInterfaceEE3$_8EEvlll+0xa5): undefined reference to `mlir::edsc::op::operator+(mlir::Value, mlir::Value)'
2020-08-03 16:16:47 +00:00
Nicolas Vasilache 35b65be041 [mlir][Vector] Add transformation + pattern to split vector.transfer_read into full and partial copies.
This revision adds a transformation and a pattern that rewrites a "maybe masked" `vector.transfer_read %view[...], %pad `into a pattern resembling:

```
   %1:3 = scf.if (%inBounds) {
      scf.yield %view : memref<A...>, index, index
    } else {
      %2 = vector.transfer_read %view[...], %pad : memref<A...>, vector<...>
      %3 = vector.type_cast %extra_alloc : memref<...> to
      memref<vector<...>> store %2, %3[] : memref<vector<...>> %4 =
      memref_cast %extra_alloc: memref<B...> to memref<A...> scf.yield %4 :
      memref<A...>, index, index
   }
   %res= vector.transfer_read %1#0[%1#1, %1#2] {masked = [false ... false]}
```
where `extra_alloc` is a top of the function alloca'ed buffer of one vector.

This rewrite makes it possible to realize the "always full tile" abstraction where vector.transfer_read operations are guaranteed to read from a padded full buffer.
The extra work only occurs on the boundary tiles.

Differential Revision: https://reviews.llvm.org/D84631
2020-08-03 04:53:43 -04:00
Benjamin Kramer eb41f9edde [mlir][Vector] Simplify code a bit. NFCI. 2020-08-01 14:49:19 +02:00
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
Pierre Oechsel ec62e37c86 [mlir] [vector] Add an optional filter to vector contract lowering patterns.
Summary: Vector contract patterns were only parameterized by a `vectorTransformsOptions`. As a result, even if an mlir file was containing several occurrences of `vector.contract`, all of them would be lowered in the same way. More granularity might be required . This Diff adds a `constraint` argument to each of these patterns which allows the user to specify with more precision on which `vector.contract` should each of the lowering apply.

Differential Revision: https://reviews.llvm.org/D83960
2020-07-17 12:03:13 -04:00
aartbik 365434a584 [mlir] [VectorOps] Merge OUTER/AXPY vector.contract lowering into single case
We temporarily had separate OUTER lowering (for matmat flavors) and
AXPY lowering (for matvec flavors). With the new generalized
"vector.outerproduct" semantics, these cases can be merged into
a single lowering method. This refactoring will simplify future
decisions on cost models and lowering heuristics.

Reviewed By: nicolasvasilache

Differential Revision: https://reviews.llvm.org/D83585
2020-07-10 13:11:54 -07:00
aartbik 9bf6354301 [mlir] [VectorOps] Allow AXPY to be expressed as special case of OUTERPRODUCT
This specialization allows sharing more code where an AXPY follows naturally
in cases where an OUTERPRODUCT on a scalar would be generated.

Reviewed By: nicolasvasilache

Differential Revision: https://reviews.llvm.org/D83453
2020-07-10 12:23:24 -07:00
Benjamin Kramer cca4ac523e [mlir][VectorOps] Lower vector.outerproduct of int vectors
vector.fma and mulf don't work on integers. Use a muli/addi pair or
plain muli instead.

Differential Revision: https://reviews.llvm.org/D83292
2020-07-07 14:40:07 +02:00
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 05c65dc0fe [mlir][Vector] Add a VectorUnrollInterface and expose UnrollVectorPattern.
The UnrollVectorPattern is can be used in a programmable fashion by:
```
OwningRewritePatternList patterns;
    patterns.insert<UnrollVectorPattern<AddFOp>>(ArrayRef<int64_t>{2, 2}, ctx);
    patterns.insert<UnrollVectorPattern<vector::ContractionOp>>(
        ArrayRef<int64_t>{2, 2, 2}, ctx);
    ...
    applyPatternsAndFoldGreedily(getFunction(), patterns);
```

Differential revision: https://reviews.llvm.org/D83064
2020-07-06 08:09:06 -04:00
aartbik ee01c7a740 [mlir] [VectorOps] Add choice between dot and axpy lowering of vector.contract
Default vector.contract lowering essentially yields a series of sdot/ddot
operations. However, for some layouts a series of saxpy/daxpy operations,
chained through fma are more efficient. This CL introduces a choice between
the two lowering paths. A default heuristic is to follow.

Some preliminary avx2 performance numbers for matrix-times-vector.
Here, dot performs best for 64x64 A x b and saxpy for 64x64 A^T x b.

```
------------------------------------------------------------
            A x b                          A^T x b
------------------------------------------------------------
GFLOPS    sdot (reassoc)    saxpy    sdot (reassoc)    saxpy
------------------------------------------------------------
1x1        0.6               0.9       0.6             0.9
2x2        2.5               3.2       2.4             3.5
4x4        6.4               8.4       4.9             11.8
8x8       11.7               6.1       5.0             29.6
16x16     20.7              10.8       7.3             43.3
32x32     29.3               7.9       6.4             51.8
64x64     38.9                                         79.3
128x128   32.4                                         40.7
------------------------------------------------------------
```

Reviewed By: nicolasvasilache, ftynse

Differential Revision: https://reviews.llvm.org/D83012
2020-07-02 13:21:17 -07:00
aartbik 63b3933d0c [mlir] [VectorOps] Replace zero fma with mult for vector.contract
More efficient implementation of the multiply-reduce pair,
no need to add in a zero vector. Microbenchmarking on AVX2
yields the following difference in vector.contract speedup
(over strict-order scalar reduction).

SPEEDUP     SIMD-fma SIMD-mul
4x4	    1.45 	 2.00
8x8	    1.40 	 1.90
32x32    	5.32 	 5.80

Reviewed By: ftynse

Differential Revision: https://reviews.llvm.org/D82833
2020-06-30 09:04:20 -07:00
aartbik 55d09dfc7b [mlir] [VectorOps] Improve vector.create_mask lowering
Use vector compares for the 1-D case. This approach scales much better
than generating insertion operations, and exposes SIMD directly to backend.

Reviewed By: ftynse

Differential Revision: https://reviews.llvm.org/D82402
2020-06-23 14:33:41 -07:00
Thomas Raoux e4bc08f012 [mlir] Allow vector.contract to have mixed types operands
Allow lhs and rhs to have different type than accumulator/destination. Some
hardware like GPUs support natively operations like uint8xuint8xuint32.

Differential Revision: https://reviews.llvm.org/D82069
2020-06-19 17:08:57 -07:00
aartbik 0d82ab7885 [mlir] [VectorOps] Improve vector.constant_mask lowering
Use direct vector constants for the 1-D case. This approach
scales much better than generating elaborate insertion operations
that are eventually folded into a constant. We could of course
generalize the 1-D case to higher ranks, but this simplification
already helps in scaling some microbenchmarks that would formerly
crash on the intermediate IR length.

Reviewed By: reidtatge

Differential Revision: https://reviews.llvm.org/D82144
2020-06-19 10:40:08 -07:00
aartbik 1e45b55dcc [mlir] [VectorOps] Handle 'vector.shape_cast' lowering for all cases
Summary:
Even though this operation is intended for 1d/2d conversions currently,
leaving a semantic hole in the lowering prohibits proper testing of this
operation. This CL adds a straightforward reference implementation for the
missing cases.

Reviewers: nicolasvasilache, mehdi_amini, ftynse, reidtatge

Reviewed By: reidtatge

Subscribers: mehdi_amini, rriddle, jpienaar, shauheen, antiagainst, nicolasvasilache, arpith-jacob, mgester, lucyrfox, liufengdb, stephenneuendorffer, Joonsoo, grosul1, frgossen, Kayjukh, jurahul, msifontes

Tags: #mlir

Differential Revision: https://reviews.llvm.org/D81503
2020-06-09 16:08:45 -07:00
aartbik c19fae507e [mlir] [VectorOps] Add missing comments to CreateMaskOp lowering
Summary: Add missing comment to CreateMask. Fixed typo in ConstantMask comment.

Reviewers: nicolasvasilache, rriddle, reidtatge, ftynse

Reviewed By: ftynse

Subscribers: mehdi_amini, rriddle, jpienaar, shauheen, antiagainst, nicolasvasilache, arpith-jacob, mgester, lucyrfox, liufengdb, stephenneuendorffer, Joonsoo, grosul1, frgossen, Kayjukh, jurahul

Tags: #mlir

Differential Revision: https://reviews.llvm.org/D81125
2020-06-04 12:50:47 -07:00
aartbik 6391da98f4 [mlir] [VectorOps] Use 'vector.flat_transpose' for 2-D 'vector.tranpose'
Summary:
Progressive lowering of vector.transpose into an operation that
is closer to an intrinsic, and thus the hardware ISA. Currently
under the common vector transform testing flag, as we prepare
deploying this transformation in the LLVM lowering pipeline.

Reviewers: nicolasvasilache, reidtatge, andydavis1, ftynse

Reviewed By: nicolasvasilache, ftynse

Subscribers: mehdi_amini, rriddle, jpienaar, shauheen, antiagainst, nicolasvasilache, arpith-jacob, mgester, lucyrfox, liufengdb, stephenneuendorffer, Joonsoo, grosul1, frgossen, Kayjukh, jurahul, llvm-commits

Tags: #llvm, #mlir

Differential Revision: https://reviews.llvm.org/D80772
2020-06-03 14:55:50 -07:00
Nicolas Vasilache ba10daa820 [mlir][Vector] Add more vector.contract -> outerproduct lowerings and fix vector.contract type inference.
This revision expands the types of vector contractions that can be lowered to vector.outerproduct.
All 8 permutation cases are support.
The idiomatic manipulation of AffineMap written declaratively makes this straightforward.

In the process a bug with the vector.contract verifier was uncovered.
The vector shape verification part of the contract op is rewritten to use AffineMap composition.
One bug in the vector `ops.mlir` test is fixed and a new case not yet captured is added
to the vector`invalid.mlir` test.

Differential Revision: https://reviews.llvm.org/D80393
2020-05-26 15:40:55 -04:00
Nicolas Vasilache 9578a54f50 [mlir][Vector] Add vector contraction to outerproduct lowering
This revision adds the additional lowering and exposes the patterns at a finer granularity for better programmatic reuse. The unit test makes use of the finer grained pattern for simpler checks.

As the ContractionOpLowering is exposed programmatically, cleanup opportunities appear and static class methods are turned into free functions with static visibility.

Differential Revision: https://reviews.llvm.org/D80375
2020-05-26 09:31:26 -04:00