67 Commits

Author SHA1 Message Date
Matthias Springer
8c4bc1e75d
[mlir][Transforms] Merge 1:1 and 1:N type converters (#113032)
The 1:N type converter derived from the 1:1 type converter and extends
it with 1:N target materializations. This commit merges the two type
converters and stores 1:N target materializations in the 1:1 type
converter. This is in preparation of merging the 1:1 and 1:N dialect
conversion infrastructures.

1:1 target materializations (producing a single `Value`) will remain
valid. An additional API is added to the type converter to register 1:N
target materializations (producing a `SmallVector<Value>`). Internally,
all target materializations are stored as 1:N materializations.

The 1:N type converter is removed.

Note for LLVM integration: If you are using the `OneToNTypeConverter`,
simply switch all occurrences to `TypeConverter`.

---------

Co-authored-by: Markus Böck <markus.boeck02@gmail.com>
2024-10-25 11:44:20 -07:00
Frank Schlimbach
d5746d73ce
eliminating g++ warnings (#105520)
Eliminating g++ warnings. Mostly declaring "[[maybe_unused]]", adding
return statements where missing and fixing casts.

@rengolin

---------

Co-authored-by: Benjamin Maxwell <macdue@dueutil.tech>
Co-authored-by: Renato Golin <rengolin@systemcall.eu>
2024-10-18 21:20:47 +01:00
Benjamin Maxwell
fc4485bf98
Revert "[mlir][ArmSME] Pattern to swap shape_cast(tranpose) with transpose(shape_cast) (#100731)" (#102457)
This reverts commit 88accd9aaa20c6a30661c48cc2ca6dbbdf991ec0.

This change can be dropped in favor of just #102017.
2024-08-09 13:29:57 +01:00
Benjamin Maxwell
8a5f33fd12
[mlir][ArmSME] Update OuterProductFusion to account for recent changes (#102125)
- Use vector.interleave rather than the LLVM intrinsic
- Remove dependency on LLVM dialect
- Remove manual outerproduct erases (these are now trivially dead)
- Remove comment explaining issues with previous tile allocator
- Update pipeline in `multi-tile-matmul-mixed-types.mlir`

Recent changes: #90448, #80965
2024-08-07 13:10:10 +01:00
Andrzej Warzyński
fe07d9aa41
[mlir][vector] Switch to using getNumScalableDims (nfc) (#100806) 2024-07-27 08:11:00 +01:00
Benjamin Maxwell
88accd9aaa
[mlir][ArmSME] Pattern to swap shape_cast(tranpose) with transpose(shape_cast) (#100731)
This applies when the shape_cast is simply for dropping unit dims, and
the result rank is >= 2.

This simplifies the transpose making it possible for other ArmSME
legalization patterns to handle it.

Example:

```mlir
%0 = vector.transpose %vector, [3, 0, 1, 2]
       : vector<1x1x4x[4]xf32> to vector<[4]x1x1x4xf32>
%1 = vector.shape_cast %0 : vector<[4]x1x1x4xf32> to vector<[4]x4xf32>
```

```mlir
%0 = vector.shape_cast %arg0 : vector<1x1x4x[4]xf32> to vector<4x[4]xf32>
%1 = vector.transpose %0, [1, 0] : vector<4x[4]xf32> to vector<[4]x4xf32>
```
2024-07-26 14:45:51 +01:00
Benjamin Maxwell
c194bc77a2
[mlir][ArmSME] Add rewrite to handle unsupported SVE transposes via SME/ZA (#98620)
This adds a workaround rewrite that allows stores of unsupported SVE
transposes such as:

```mlir
%tr = vector.transpose %vec, [1, 0]
  : vector<2x[4]xf32> to vector<[4]x2xf32>
vector.transfer_write %tr, %dest[%i, %j] {in_bounds = [true, true]}
  : vector<[4]x2xf32>,  memref<?x?xf32>
```

To use SME tiles, which are possible to lower (when SME is available):

```mlir
// Insert vector<2x[4]xf32> into an SME tile:
%0 = arm_sme.get_tile : vector<[4]x[4]xf32>
%1 = vector.extract %vec[0] : vector<[4]xf32> from vector<2x[4]xf32>
%2 = vector.insert %1, %0 [0] : vector<[4]xf32> into vector<[4]x[4]xf32>
%3 = vector.extract %vec[1] : vector<[4]xf32> from vector<2x[4]xf32>
%4 = vector.insert %3, %2 [1] : vector<[4]xf32> into vector<[4]x[4]xf32>
// Store the tile with a transpose + mask:
%c4_vscale = arith.muli %vscale, %c4 : index
%mask = vector.create_mask %c4_vscale, %c2 : vector<[4]x[4]xi1>
vector.transfer_write %4, %arg1[%arg2, %arg3], %mask
   {permutation_map = affine_map<(d0, d1) -> (d1, d0)>}
   : vector<[4]x[4]xf32>, memref<?x?xf32>
```
2024-07-25 18:15:14 +01:00
Chenguang Wang
a41a4b8fed
Revert "[mlir][ArmSME] Suppress potential unused warning (#99573)" (#99578)
This reverts commit 05bce3f079b677edd0efd28e3923f4776ffb8b59.

The work was already done in 99faa03.
2024-07-18 14:59:26 -07:00
Chenguang Wang
05bce3f079
[mlir][ArmSME] Suppress potential unused warning (#99573)
When building in release mode, the assert will be dropped, making
`remove` unused.
2024-07-18 14:55:22 -07:00
Kazu Hirata
99faa038c6 [mlir] Fix a warning
This patch fixes:

  mlir/lib/Dialect/ArmSME/Transforms/TileAllocation.cpp:621:16: error:
  unused variable 'removed' [-Werror,-Wunused-variable]
2024-07-18 14:41:15 -07:00
Benjamin Maxwell
eed72d4381
[mlir][ArmSME] Support filling liveness 'holes' in the tile allocator (#98350)
Holes in a live range are points where the corresponding value does not
need to be in a tile/register. If the tile allocator keeps track of
these holes it can reuse tiles for more values (avoiding spills).

Take this simple example:

```mlir
func.func @example(%cond: i1) {
  %tileA = arm_sme.get_tile : vector<[4]x[4]xf32>
  cf.cond_br %cond, ^bb2, ^bb1
^bb1:
  // If we end up here we never use %tileA again!
  "test.some_use"(%tileB) : (vector<[4]x[4]xf32>) -> ()
  cf.br ^bb3
^bb2:
  "test.some_use"(%tileA) : (vector<[4]x[4]xf32>) -> ()
  cf.br ^bb3
^bb3:
  return
}
```

If you were to calculate the liveness of %tileA and %tileB. You'd see
there is a hole in the liveness of %tileA in bb1:

```
      %tileA  %tileB
^bb0:  Live
^bb1:          Live
^bb2:  Live
```

The tile allocator can make use of that hole and reuse the tile ID it
assigned to %tileA for %tileB.
2024-07-18 20:13:45 +01:00
Benjamin Maxwell
5ed5d723db
[mlir][ArmSME] Lower multi-tile stores to a single loop (#96187)
This adds a new pattern that can legalize a multi-tile transfer_write as
a single store loop. This is done as part of type decomposition as at
this level we know each tile write is disjoint, but that information is
lost after decomposition (without analysis to reconstruct it).

Example (pseudo-MLIR):

```
vector.transfer_write %vector, %dest[%y, %x], %mask
  : vector<[16]x[8]xi16>, memref<?x?xi16>
```
Is rewritten to:
```
scf.for %slice_idx = %c0 to %c8_vscale step %c1 {
  %upper_slice_mask = vector.extract %mask[%slice_idx] ─┐
    : vector<[8]xi1> from vector<[16]x[8]xi1>           |
  %upper_slice = vector.extract %upper_tile[%slice_idx] |- Store upper tile
    : vector<[8]xi16> from vector<[8]x[8]xi16>          |
  vector.transfer_write %upper_slice,                   |
    %dest[%slice_idx + %y, %x], %upper_slice_mask       |
    : vector<[8]xi16>, memref<?x?xi16>                  ┘
  %lower_slice_idx = %slice_idx + %c8_vscale                 ─┐
  %lower_slice_mask = vector.extract %mask[%lower_slice_idx]  |
    : vector<[8]xi1> from vector<[16]x[8]xi1>                 |
  %lower_slice = vector.extract %lower_tile[%slice_idx]       |- Store lower
    : vector<[8]xi16> from vector<[8]x[8]xi16>                |  tile
  vector.transfer_write %lower_slice,                         |
    %dest[%lower_slice_idx + %y, %x], %lower_slice_mask       |
    : vector<[8]xi16>, memref<?x?xi16>                        ┘
}
```
2024-06-25 12:46:56 +01:00
Benjamin Maxwell
1b64ed0e0c
[mlir][ArmSME] Disallow streaming mode for gathers/scatters (#96209)
Ideally, this would be based on target information (but we don't really
have that), so this currently errs on the side of caution. If possible
gathers/scatters should be lowered regular vector loads/stores before
using invoking enable-arm-streaming.
2024-06-24 11:10:00 +01:00
Benjamin Maxwell
d319fc41d0
[mlir][ArmSME] Add option to only enable streaming mode for scalable code (#94759)
This adds a new option
`-enable-arm-streaming=if-contains-scalable-vectors`, which only applies
the selected streaming/ZA modes if the function contains scalable vector
types.

As a NFC this patch also removes the `only-` prefix from the
`if-required-by-ops` mode.
2024-06-10 12:02:16 +01:00
Christian Ulmann
b00e0c1671
[MLIR][Analysis] Consolidate topological sort utilities (#92563)
This PR attempts to consolidate the different topological sort utilities
into one place. It adds them to the analysis folder because the
`SliceAnalysis` uses some of these.

There are now two different sorting strategies: 
1. Sort only according to SSA use-def chains
2. Sort while taking regions into account. This requires a much more
elaborate traversal and cannot be applied on graph regions that easily.

This additionally reimplements the region aware topological sorting
because the previous implementation had an exponential space complexity.

I'm open to suggestions on how to combine this further or how to fuse
the test passes.
2024-05-22 08:48:10 +02:00
Christian Ulmann
9e39a0c723 [MLIR][ArmSME] Fix for block sorting refactor
This commit fixes a breakage introduced by changing the name of the
block sorting function.

Related PR: https://github.com/llvm/llvm-project/pull/92558
2024-05-17 15:59:04 +00:00
Benjamin Maxwell
041baf2f60
[mlir][ArmSME] Use liveness information in the tile allocator (#90448)
This patch rewrites the ArmSME tile allocator to use liveness
information to make better tile allocation decisions and improve the
correctness of the ArmSME dialect. This algorithm used here is a linear
scan over live ranges, where live ranges are assigned to tiles as they
appear in the program (chronologically). Live ranges release their
assigned tile ID when the current program point is passed their end.
This is a greedy algorithm (which is mainly to keep the implementation
relatively straightforward), and because it seems to be sufficient for
most kernels (e.g. matmuls) that use ArmSME. The general steps of this
are roughly from
https://link.springer.com/content/pdf/10.1007/3-540-45937-5_17.pdf,
though there have been a few simplifications and assumptions made for
our use case.

Hopefully, the only changes needed for a user of the ArmSME dialect is
that:

- `-allocate-arm-sme-tiles` will no longer be a standalone pass 
  - `-test-arm-sme-tile-allocation` is only for unit tests 
- `-convert-arm-sme-to-llvm` must happen after `-convert-scf-to-cf` 
   - SME tile allocation is now part of the LLVM conversion

By integrating this into the `ArmSME -> LLVM` conversion we can allow
high-level (value-based) ArmSME operations to be side-effect-free, as we
can guarantee nothing will rearrange ArmSME operations before we emit
intrinsics (which could invalidate the tile allocation).

The hope is for ArmSME operations to have no hidden state/side effects
and allow easily lowering dialects such as `vector` and `arith` to SME,
without making assumptions about how the input IR looks, as the
semantics of the operations will be the same. That is no (new) side
effects and the IR follows the rules of SSA (a value will never change).

The aim is correctness, so we have a base for working on optimizations.
2024-05-14 14:59:01 +01:00
Maciej Gabka
bfc0317153
Move several vector intrinsics out of experimental namespace (#88748)
This patch is moving out following intrinsics:
* vector.interleave2/deinterleave2
* vector.reverse
* vector.splice

from the experimental namespace.

All these intrinsics exist in LLVM for more than a year now, and are
widely used, so should not be considered as experimental.
2024-04-29 10:16:45 +01:00
Benjamin Maxwell
dadcaf8227
[mlir][ArmSME] Support decomposing constant splats into ArmSME tiles (#88762)
This adds a simple rewrite/legalization to decompose constant splats
larger than a single ArmSME tile into multiple SME virtual tile sized
splats. E.g. a constant splat to `vector<[8]x[8]xi32>` would decompose
into four `vector<[4]x[4]xi32>` splats.
2024-04-16 12:54:01 +01:00
Benjamin Maxwell
d1fc59c3b5
[mlir][ArmSME] Rewrite illegal shape_casts to vector.transpose ops (#82985)
This adds a rewrite that converts illegal 2D unit-dim `shape_casts` into
`vector.transpose` ops.

E.g.

```mlir
// Case 1:
%a = vector.shape_cast %0 : vector<[4]x1xf32> to vector<1x[4]xf32>
// Case 2:
%b = vector.shape_cast %1 : vector<[4]x1xf32> to vector<[4]xf32>
```

Becomes:

```mlir
// Case 1:
%a = vector.transpose %0 : [1, 0] vector<[4]x1xf32> to vector<1x[4]xf32>
// Case 2:
%t = vector.transpose %1 : [1, 0] vector<[4]x1xf32> to vector<1x[4]xf32>
%b = vector.shape_cast %t : vector<1x[4]xf32> to vector<[4]xf32>
```

Various lowerings and drop unit-dims patterns add such shape_casts,
however, if they do not cancel out (which they likely won't if we've
reached the vector-legalization pass) they will prevent lowering the IR.

Rewriting them as a transpose gives `LiftIllegalVectorTransposeToMemory`
a chance to eliminate the illegal types.
2024-03-07 17:04:12 +00:00
Benjamin Maxwell
8cfb71613c
[mlir][ArmSME] Replace use of isa with isa_and_present (#82798)
`op` can be null here, in which case this should just return a null
value back.
2024-02-26 09:44:26 +00:00
Benjamin Maxwell
1408667fdd [mlir][ArmSME] Follow MLIR constant style in VectorLegalization.cpp (NFC) 2024-02-23 16:55:32 +00:00
Cullen Rhodes
fff86c6111
[mlir][ArmSME] Support 4-way widening outer products (#79288)
This patch introduces support for 4-way widening outer products. This
enables the fusion of 4 'arm_sme.outerproduct' operations that are
chained via the accumulator into single widened operations.

Changes:

- Adds the following operations:
  - smopa_4way, smops_4way
  - umopa_4way, umops_4way
  - sumopa_4way, sumops_4way
  - sumopa_4way, sumops_4way
- Implements conversions for the above ops to intrinsics in ArmSMEToLLVM.
- Extends 'arm-sme-outer-product' pass.

For a detailed description of these operations see the
'arm_sme.smopa_4way' description.
2024-02-07 08:17:47 +00:00
Benjamin Maxwell
0473e322f6
[mlir][ArmSME] Add rewrite to lift illegal vector.transposes to memory (#80170)
When unrolling the reduction dimension of something like a matmul for
SME, you can end up with transposed reads of illegal types, like so:

```mlir
%illegalRead = vector.transfer_read %memref[%a, %b]
                : memref<?x?xf32>, vector<[8]x4xf32>
%legalType = vector.transpose %illegalRead, [1, 0]
                : vector<[8]x4xf32> to vector<4x[8]xf32>
```

Here the `vector<[8]x4xf32>` is an illegal type, there's no way to lower
a scalable vector of fixed vectors. However, as the final type
`vector<4x[8]xf32>` is legal, we can instead lift the transpose to
memory (producing a strided memref), and eliminate all the illegal
types. This is shown below.

```mlir
%readSubview = memref.subview %memref[%a, %b] [%c8_vscale, %c4] [%c1, %c1]
                : memref<?x?xf32> to memref<?x?xf32>
%transpose = memref.transpose %readSubview (d0, d1) -> (d1, d0)
                : memref<?x?xf32> to memref<?x?xf32>
%legalType = vector.transfer_read %transpose[%c0, %c0]
                : memref<?x?xf32>, vector<4x[8]xf32>
```
2024-02-06 09:30:55 +00:00
Cullen Rhodes
5f5b3bb22b
[mlir][ArmSME] Add rewrites to swap extract of extend (#80407)
In mixed matmul lowering (e.g., i8 to i32) we're seeing the following
sequence:

  %0 = arith.extsi %src : vector<4x[8]xi8> to vector<4x[8]xi32>
  %1 = vector.extract %0[0] : vector<[8]xi32> from vector<4x[8]xi32>
%lhs = vector.scalable.extract %1[0] : vector<[4]xi32> from
vector<[8]xi32>

  ... (same for rhs)

%2 = vector.outerproduct %lhs, %rhs, %acc vector<[4]xi32>,
vector<[4]xi32>

  // x4 chained by accumulator

This chain of 4 outer products can be fused into a single 4-way widening
variant but the pass doesn't match on the IR, as it expects the source
of the inputs to be an extend and it can't look through the extracts.

This patch fixes this with two rewrites that swaps extract(extend) into
extend(extract).

Related to #78975, #79288.
2024-02-05 14:13:53 +00:00
Benjamin Maxwell
c2dea7122c
[mlir][ArmSME] Fold extracts from 3D create_masks of SME-like masks (#80148)
When unrolling the reduction dimension of something like a matmul for
SME, it is possible to get 3D masks, which are vectors of SME-like
masks. The 2D masks for individual operations are then extracted from
the 3D masks.

i.e.:

```mlir
%mask = vector.create_mask %nonConstantDim, %a, %b : vector<4x[4]x[4]xi1>
%subMask = vector.extract %mask[2]
        : vector<[4]x[4]xi1> from vector<4x[4]x[4]xi1>
```

ArmSME only supports lowering 2D create_masks, so we must fold the
extract into the create_mask. This can be done by checking if the
extraction index is within the true region, then using that select the
first dimension of the 2D mask. This is shown below.

```mlir
%extractionInTrueRegion = arith.cmpi slt, %c2, %nonConstantDim : index
%newMaskFrontDim = arith.select %extractionInTrueRegion, %a, %c0 : index
%subMask = vector.create_mask %newMaskFrontDim, %b : vector<[4]x[4]xi1>
```
2024-02-02 10:06:11 +00:00
Benjamin Maxwell
042800a4dd
[mlir][ArmSME] Add initial SME vector legalization pass (#79152)
This adds a new pass (`-arm-sme-vector-legalization`) which legalizes
vector operations so that they can be lowered to ArmSME. This initial
patch adds decomposition for `vector.outerproduct`,
`vector.transfer_read`, and `vector.transfer_write` when they operate on
vector types larger than a single SME tile. For example, a [8]x[8]xf32
outer product would be decomposed into four [4]x[4]xf32 outer products,
which could then be lowered to ArmSME. These three ops have been picked
as supporting them alone allows lowering matmuls that use all ZA
accumulators to ArmSME.

For it to be possible to legalize a vector type it has to be a multiple
of an SME tile size, but other than that any shape can be used. E.g.
`vector<[8]x[8]xf32>`, `vector<[4]x[16]xf32>`, `vector<[16]x[4]xf32>`
can all be lowered to four `vector<[4]x[4]xf32>` operations.

In future, this pass will be extended with more SME-specific rewrites to
legalize unrolling the reduction dimension of matmuls (which is not
type-decomposition), which is why the pass has quite a general name.
2024-01-31 11:55:22 +00:00
Cullen Rhodes
95ef8e3868
[mlir][ArmSME] Support 2-way widening outer products (#78975)
This patch introduces support for 2-way widening outer products. This
enables the fusion of 2 'arm_sme.outerproduct' operations that are
chained via the accumulator into a 2-way widening outer product
operation.

Changes:

- Add 'llvm.aarch64.sme.[us]mop[as].za32' intrinsics for 2-way variants.
  These map to instruction variants added in SME2 and use different
  intrinsics. Intrinsics are already implemented for widening variants
  from SME1.
- Adds the following operations:
  - fmopa_2way, fmops_2way
  - smopa_2way, smops_2way
  - umopa_2way, umops_2way
- Implements conversions for the above ops to intrinsics in
ArmSMEToLLVM.
- Adds a pass 'arm-sme-outer-product-fusion'  that fuses
  'arm_sme.outerproduct' operations.

For a detailed description of these operations see the
'arm_sme.fmopa_2way' description.

The reason for introducing many operations rather than one is the
signed/unsigned variants can't be distinguished with types (e.g., ui16,
si16) since 'arith.extui' and 'arith.extsi' only support signless
integers. A single operation would require this information and an
attribute (for example) for the sign doesn't feel right if
floating-point types are also supported where this wouldn't apply.
Furthermore, the SME FP8 extensions (FEAT_SME_F8F16, FEAT_SME_F8F32)
introduce FMOPA 2-way (FP8 to FP16) and 4-way (FP8 to FP32) variants but
no subtract variant. Whilst these are not supported in this patch, it
felt simpler to have separate ops for add/subtract given this.
2024-01-31 09:13:18 +00:00
Matthias Springer
5fcf907b34
[mlir][IR] Rename "update root" to "modify op" in rewriter API (#78260)
This commit renames 4 pattern rewriter API functions:
* `updateRootInPlace` -> `modifyOpInPlace`
* `startRootUpdate` -> `startOpModification`
* `finalizeRootUpdate` -> `finalizeOpModification`
* `cancelRootUpdate` -> `cancelOpModification`

The term "root" is a misnomer. The root is the op that a rewrite pattern
matches against
(https://mlir.llvm.org/docs/PatternRewriter/#root-operation-name-optional).
A rewriter must be notified of all in-place op modifications, not just
in-place modifications of the root
(https://mlir.llvm.org/docs/PatternRewriter/#pattern-rewriter). The old
function names were confusing and have contributed to various broken
rewrite patterns.

Note: The new function names use the term "modify" instead of "update"
for consistency with the `RewriterBase::Listener` terminology
(`notifyOperationModified`).
2024-01-17 11:08:59 +01:00
Matthias Springer
e2bb47caa6
[mlir][Arm] Fix invalid rewrite pattern API violations (#78246)
This commit fixes rewrite pattern API violations:
* Rewrite pattern must return "failure" if the IR was not modified.
* In-place op modifications must be communicated to the rewriter
(`updateRootInPlace`).

This commit fixes `test/Dialect/ArmSVE/legalize-vector-storage.mlir`,
`test/Dialect/ArmSME/vector-ops-to-llvm.mlir`,
`test/Dialect/ArmSME/tile-allocation-invalid.mlir`,
`test/Conversion/ArmSMEToLLVM/arm-sme-to-llvm.mlir`,
`test/Conversion/ArmSMEToLLVM/tile-spills-and-fills.mlir`,
`test/Conversion/ArmSMEToLLVM/unsupported.mlir` when running with
`MLIR_ENABLE_EXPENSIVE_PATTERN_API_CHECKS`.

---------

Co-authored-by: Benjamin Maxwell <macdue@dueutil.tech>
2024-01-16 13:26:39 +01:00
Benjamin Maxwell
5417a5fed6
[mlir][ArmSME] Add rudimentary support for tile spills to the stack (#76086)
This adds very basic (and inelegant) support for something like spilling
and reloading tiles, if you use more SME tiles than physically exist.

This is purely implemented to prevent the compiler from aborting if a
function uses too many tiles (i.e. due to bad unrolling), but is
expected to perform very poorly.

Currently, this works in two stages:

During tile allocation, if we run out of tiles instead of giving up, we
switch to allocating 'in-memory' tile IDs. These are tile IDs that start
at 16 (which is higher than any real tile ID). A warning will also be
emitted for each (root) tile op assigned an in-memory tile ID:

```
warning: failed to allocate SME virtual tile to operation, all tile operations will go through memory, expect degraded performance
```

Everything after this works like normal until `-convert-arm-sme-to-llvm`

Here the in-memory tile op:

```mlir
arm_sme.tile_op { tile_id = <IN MEMORY TILE> }
```

Is lowered to:

```mlir
// At function entry:
%alloca = memref.alloca ... : memref<?x?xty>

// Around the op:
// Swap the contents of %alloca and tile 0.
scf.for %slice_idx {
  %current_slice = "arm_sme.intr.read.horiz" ... <{tile_id = 0 : i32}>
  "arm_sme.intr.ld1h.horiz"(%alloca, %slice_idx)  <{tile_id = 0 : i32}>
  vector.store %current_slice, %alloca[%slice_idx, %c0]
}
// Execute op using tile 0.
arm_sme.tile_op { tile_id = 0 }
// Swap the contents of %alloca and tile 0.
// This restores tile 0 to its original state.
scf.for %slice_idx {
  %current_slice = "arm_sme.intr.read.horiz" ... <{tile_id = 0 : i32}>
  "arm_sme.intr.ld1h.horiz"(%alloca, %slice_idx)  <{tile_id = 0 : i32}>
  vector.store %current_slice, %alloca[%slice_idx, %c0]
}
```

This is inserted during the lowering to LLVM as spilling/reloading
registers is a very low-level concept, that can't really be modeled
correctly at a high level in MLIR.

Note: This is always doing the worst case full-tile swap. This could be
optimized to only spill/load data the tile op will use, which could be
just a slice. It's also not making any use of liveness, which could
allow reusing tiles. But these is not seen as important as correct code
should only use the available number of tiles.
2024-01-12 14:51:47 +00:00
Matthias Springer
db8a119e8f
[mlir][ArmSME] Fix invalid rewriter API usage (#76123)
When operations are modified in-place, the rewriter must be notified.
This commit fixes `mlir/test/Conversion/ArmSMEToLLVM/unsupported.mlir`,
`mlir/test/Dialect/ArmSME/tile-zero-masks.mlir` and
`mlir/test/Dialect/ArmSME/vector-ops-to-llvm.mlir` when running with
`MLIR_ENABLE_EXPENSIVE_PATTERN_API_CHECKS` enabled.
2023-12-21 17:39:36 +09:00
Benjamin Maxwell
01e40a8a3d
[mlir][ArmSME] Remove ArmSMETypeConverter (and configure LLVM one instead) (#73639)
This patch removes the ArmSMETypeConverter, and instead updates
`populateArmSMEToLLVMConversionPatterns()` to add an ArmSME vector type
conversion to the existing LLVMTypeConverter. This makes it easier to
add these patterns to an existing `-to-llvm` lowering pass.
2023-12-04 17:02:48 +00:00
Benjamin Maxwell
f7d91faa79
[mlir][ArmSME] Add option to only enable streaming mode/ZA if required (#73931)
This adds a `only-if-required-by-ops` flag to the `enable-arm-streaming`
pass. This flag defaults to `false` (which preserves the original
behaviour), however, if set to `true` the pass will only add the
selected ZA/streaming mode to functions that contain ops that implement
`ArmSMETileOpInterface`.

This simplifies enabling these modes, as we can now first try lowering
ops to ArmSME, then only if we succeed, add the relevant function
attributes.
2023-12-01 10:39:01 +00:00
Benjamin Maxwell
eaff02f28e
[mlir][ArmSME] Switch to an attribute-based tile allocation scheme (#73253)
This reworks the ArmSME dialect to use attributes for tile allocation.
This has a number of advantages and corrects some issues with the
previous approach:

* Tile allocation can now be done ASAP (i.e. immediately after
`-convert-vector-to-arm-sme`)
* SSA form for control flow is now supported (e.g.`scf.for` loops that
yield tiles)
* ArmSME ops can be converted to intrinsics very late (i.e. after
lowering to control flow)
 * Tests are simplified by removing constants and casts
* Avoids correctness issues with representing LLVM `immargs` as MLIR
values
- The tile ID on the SME intrinsics is an `immarg` (so is required to be
a compile-time constant), `immargs` should be mapped to MLIR attributes
(this is already the case for intrinsics in the LLVM dialect)
- Using MLIR values for `immargs` can lead to invalid LLVM IR being
generated (and passes such as -cse making incorrect optimizations)

As part of this patch we bid farewell to the following operations:

```mlir
arm_sme.get_tile_id : i32
arm_sme.cast_tile_to_vector : i32 to vector<[4]x[4]xi32>
arm_sme.cast_vector_to_tile : vector<[4]x[4]xi32> to i32
```

These are now replaced with:
```mlir
// Allocates a new tile with (indeterminate) state:
arm_sme.get_tile : vector<[4]x[4]xi32>
// A placeholder operation for lowering ArmSME ops to intrinsics:
arm_sme.materialize_ssa_tile : vector<[4]x[4]xi32>
```

The new tile allocation works by operations implementing the
`ArmSMETileOpInterface`. This interface says that an operation needs to
be assigned a tile ID, and may conditionally allocate a new SME tile.

Operations allocate a new tile by implementing...
```c++
std::optional<arm_sme::ArmSMETileType> getAllocatedTileType()
```
...and returning what type of tile the op allocates (ZAB, ZAH, etc).

Operations that don't allocate a tile return `std::nullopt` (which is
the default behaviour).

Currently the following ops are defined as allocating:
```mlir
arm_sme.get_tile
arm_sme.zero
arm_sme.tile_load
arm_sme.outerproduct // (if no accumulator is specified)
```

Allocating operations become the roots for the tile allocation pass,
which currently just (naively) assigns all transitive uses of a root
operation the same tile ID. However, this is enough to handle current
use cases.

Once tile IDs have been allocated subsequent rewrites can forward the
tile IDs to any newly created operations.
2023-11-30 10:22:22 +00:00
Benjamin Maxwell
dff97c1e4c
[mlir][ArmSME] Move ArmSME -> intrinsics lowerings to convert-arm-sme-to-llvm pass (#72890)
This gives more flexibility with when these lowerings are performed,
without also lowering unrelated vector ops.

This is a NFC (other than adding a new `-convert-arm-sme-to-llvm` pass)
2023-11-22 13:36:36 +00:00
Benjamin Maxwell
c4c52d4199
[mlir][ArmSME] Move vector.extract/insert lowerings to vector-to-arm-sme (NFC) (#72852)
These were placed in LegalizeForLLVMExport.cpp, which is the wrong stage
for these, as these lower to high-level ArmSME ops, not intrinsics.
2023-11-20 14:04:59 +00:00
Benjamin Maxwell
783ac3b6fb
[mlir][ArmSME] Make use of backend function attributes for enabling ZA storage (#71044)
Previously, we were inserting za.enable/disable intrinsics for functions
with the "arm_za" attribute (at the MLIR level), rather than using the
backend attributes. This was done to avoid a dependency on the SME ABI
functions from compiler-rt (which have only recently been implemented).

Doing things this way did have correctness issues, for example, calling
a streaming-mode function from another streaming-mode function (both
with ZA enabled) would lead to ZA being disabled after returning to the
caller (where it should still be enabled). Fixing issues like this would
require re-doing the ABI work already done in the backend within MLIR.

Instead, this patch switches to use the "arm_new_za" (backend) attribute
for enabling ZA for an MLIR function. For the integration tests, this
requires some way of linking the SME ABI functions. This is done via the
`%arm_sme_abi_shlib` lit substitution. By default, this expands to a
stub implementation of the SME ABI functions, but this can be overridden
by providing the `ARM_SME_ABI_ROUTINES_SHLIB` CMake cache variable
(pointing it at an alternative implementation). For now, the ArmSME
integration tests pass with just stubs, as we don't make use of nested
ZA-enabled calls.

A future patch may add an option to compiler-rt to build the SME
builtins into a standalone shared library to allow easily
building/testing with the actual implementation.
2023-11-14 12:50:38 +00:00
Cullen Rhodes
8f564e014e
[mlir][ArmSME] Add mask operand to store_tile_slice (#70838) 2023-11-02 08:43:37 +00:00
Cullen Rhodes
8ea260a093
[mlir][ArmSME] Add mask operand to load_tile_slice (#70655) 2023-10-31 13:08:55 +00:00
Benjamin Maxwell
e666295011
[mlir][ArmSME] Support lowering masked vector.outerproduct ops to SME (#69604)
This patch adds support for lowering masked outer products to SME. This
is done in two stages. First, vector.outerproducts (both masked and
non-masked) are rewritten to arm_sme.outerproducts. The
arm_sme.outerproduct op is close to vector.outerproduct, but supports
masking on the operands rather than the result. It also limits the cases
it handles to things that could be (directly) lowered to SME.

This currently requires that the source of the mask is a
vector.create_mask op. E.g.:

```mlir
%mask = vector.create_mask %dimA, %dimB : vector<[4]x[4]xi1>
%result = vector.mask %mask {
             vector.outerproduct %vecA, %vecB
              : vector<[4]xf32>, vector<[4]xf32>
          } : vector<[4]x[4]xi1> -> vector<[4]x[4]xf32>
```
Is rewritten to:
```
%maskA = vector.create_mask %dimA : vector<[4]xi1>
%maskB = vector.create_mask %dimB : vector<[4]xi1>
%result = arm_sme.outerproduct %vecA, %vecB masks(%maskA, %maskB)
              : vector<[4]xf32>, vector<[4]xf32>
```
(The same rewrite works for non-masked vector.outerproducts too)

The arm_sme.outerproduct can then be directly lowered to SME intrinsics.
2023-10-31 09:06:21 +00:00
Cullen Rhodes
2f055ddca3
[mlir][ArmSME] Add tile slice layout attr to vector <-> tile ops (#69186)
This is used in #69148 when lowering masked tile_store with non-zero
pad, see #69148

This updates:
 * `arm_sme.move_vector_to_tile_slice`
 * `arm_sme.move_tile_slice_to_vector`
2023-10-25 14:44:31 +01:00
Benjamin Maxwell
496318ad8d
[mlir][ArmSME] Lower vector.extract/insert on SME tiles to MOVA intrinsics (#67786)
This patch adds support for lowering vector.insert/extract of tile
slices or elements to ArmSME MOVA intrinsics.

This enables the following operations for ArmSME:
```
// Extract slice from tile:
%slice = vector.extract %tile[%row] 
                 : vector<[4]xi32> from vector<[4]x[4]xi32>
```
```
// Extract element from tile:
%el = vector.extract %tile[%row, %col]
                 : i32 from vector<[4]x[4]xi32>
```
```
// Insert slice into tile:
%new_tile = vector.insert %slice, %tile[%row]
                    : vector<[4]xi32> into vector<[4]x[4]xi32>
```
```
// Insert element into tile;
%new_tile = vector.insert %el, %tile[%row, %col]
                    : i32 into vector<[4]x[4]xi32>
```
2023-10-04 09:28:39 +01:00
Andrzej Warzynski
23b5f92c97 [mlir][SME] Re-order patterns alphabetically (nfc) 2023-09-29 16:54:47 +00:00
Benjamin Maxwell
b34f15df55
[mlir][ArmSME] Add arm_sme.move_tile_slice_to_vector op (#67652)
This adds a simple higher-level op for the tile slice to vector
intrinsics (and updates the existing vector.print lowering to use it).
This op will be used a few more times to implement vector.insert/extract
lowerings in later patches.
2023-09-29 10:33:09 +01:00
Benjamin Maxwell
174cd6145b
[mlir][ArmSME] Add custom vector.print lowering for SME tiles (#66691)
This adds a custom lowering for SME that loops over each row of the
tile, extracting it via an SME MOVA, then printing with a normal 1D
vector.print.

This makes writing SME integration tests easier and less verbose.

Depends on: #66910, #66911
2023-09-26 17:09:57 +01:00
Cullen Rhodes
75a71c27c1
[mlir][ArmSME] Support vertical layout in load and store ops (#66758)
In SME a ZA tile slice is a one-dimensional set of horizontally or
vertically contiguous elements within a ZA tile. Currently the load and
store ops only support horizontal tile slices. This patch adds a tile
slice layout attribute to the load and store ops to support both
horizontal and vertical tile slices.

When lowering from Vector dialect horizontal layout is the default.
2023-09-25 09:34:23 +01:00
Benjamin Maxwell
06f22c9ae5
[mlir][ArmSME] Add enable_arm_streaming_ignore attribute (#66911)
This attribute makes the `enable_arm_streaming` pass ignore a function
(i.e. not add the enable streaming/za attributes). The main use case for
this is to prevent helper functions within tests being made streaming
functions.
2023-09-22 11:27:55 +01:00
Cullen Rhodes
f75d46a7ec
[mlir][ArmSME] Lower vector.outerproduct to FMOPA/BFMOPA (#65621)
This patch adds support for lowering vector.outerproduct to the ArmSME
MOPA intrinsic for the following types:

  vector<[8]xf16>,  vector<[8]xf16>  -> vector<[8]x[8]xf16>
  vector<[8]xbf16>, vector<[8]xbf16> -> vector<[8]x[8]xbf16>
  vector<[4]xf32>,  vector<[4]xf32>  -> vector<[4]x[4]xf32>
  vector<[2]xf64>,  vector<[2]xf64>  -> vector<[2]x[2]xf64>

The FP variants are lowered to FMOPA (non-widening) [1] and BFloat to
BFMOPA
(non-widening) [2].

Note at the ISA level these variants are implemented by different
architecture features, these are listed below:

  FMOPA (non-widening)
    * half-precision   - +sme2p1,+sme-f16f16
    * single-precision - +sme
    * double-precision - +sme-f64f64
  BFMOPA (non-widening)
    * half-precision   - +sme2p1,+b16b16

There's currently no way to target different features when lowering to
ArmSME. Integration tests are added for F32 and F64. We use QEMU to run
the integration tests but SME2 support isn't available yet, it's
targeted for 9.0, so integration tests for these variants excluded.

Masking is currently unsupported.

Depends on #65450.

[1] https://developer.arm.com/documentation/ddi0602/2023-06/SME-Instructions/FMOPA--non-widening---Floating-point-outer-product-and-accumulate-
[2] https://developer.arm.com/documentation/ddi0602/2023-06/SME-Instructions/BFMOPA--non-widening---BFloat16-floating-point-outer-product-and-accumulate-
2023-09-14 08:31:52 +01:00
Cullen Rhodes
834cdc8b64 [mlir][ArmSME] Fix get_tile_id type in zero lowering
The arm_sme.get_tile_id op returns a scalar integer but the arm_sme.zero
op lowering incorrectly uses the element type, which could be
floating-point.

Reviewed By: awarzynski, benmxwl-arm

Differential Revision: https://reviews.llvm.org/D159080
2023-08-30 07:16:35 +00:00