Commit Graph

29 Commits

Author SHA1 Message Date
aartbik
078776a679 [mlir] [VectorOps] Progressively lower vector.outerproduct to LLVM
Summary:
This replaces the direct lowering of vector.outerproduct to LLVM with progressive lowering into elementary vectors ops to avoid having the similar lowering logic at several places.

NOTE1: with the new progressive rule, the lowered llvm is slightly more elaborate than with the direct lowering, but the generated assembly is just as optimized; still if we want to stay closer to the original, we should add a "broadcast on extract" to shuffle rewrite (rather than special cases all the lowering steps)

NOTE2: the original outerproduct lowering code should now be removed but some linalg test work directly on vector and contain some dead code, so this requires another CL

Reviewers: nicolasvasilache, andydavis1

Reviewed By: nicolasvasilache, andydavis1

Subscribers: mehdi_amini, rriddle, jpienaar, burmako, shauheen, antiagainst, nicolasvasilache, arpith-jacob, mgester, lucyrfox, liufengdb, Joonsoo, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D75956
2020-03-12 13:45:42 -07:00
Nicolas Vasilache
63b683a816 [mlir][Vector] Add a vector.matrix_multiply op on 1-D vectors
Summary: This op mirrors the llvm.intr counterpart and allows lowering + type conversions in a progressive fashion.

Differential Revision: https://reviews.llvm.org/D75775
2020-03-09 13:34:03 -04:00
aartbik
e83b7b99da [mlir] [VectorOps] Implement vector.reduce operation
Summary:
This new operation operates on 1-D vectors and
forms the bridge between vector.contract and
llvm intrinsics for vector reductions.

Reviewers: nicolasvasilache, andydavis1, ftynse

Reviewed By: nicolasvasilache

Subscribers: mehdi_amini, rriddle, jpienaar, burmako, shauheen, antiagainst, nicolasvasilache, arpith-jacob, mgester, lucyrfox, liufengdb, Joonsoo, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D74370
2020-02-11 11:31:59 -08:00
Nicolas Vasilache
681f929f59 [mlir][VectorOps] Introduce a vector.fma op that works on n-D vectors and lowers to llvm.intrin.fmuladd
Summary:
The `vector.fma` operation is portable enough across targets that we do not want
to keep it wrapped under `vector.outerproduct` and `llvm.intrin.fmuladd`.
This revision lifts the op into the vector dialect and implements the lowering to LLVM by using two patterns:
1. a pattern that lowers from n-D to (n-1)-D by unrolling when n > 2
2. a pattern that converts from 1-D to the proper LLVM representation

Reviewers: ftynse, stellaraccident, aartbik, dcaballe, jsetoain, tetuante

Reviewed By: aartbik

Subscribers: fhahn, dcaballe, merge_guards_bot, mehdi_amini, rriddle, jpienaar, burmako, shauheen, antiagainst, arpith-jacob, mgester, lucyrfox, aartbik, liufengdb, Joonsoo, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D74075
2020-02-07 15:44:53 -05:00
Nicolas Vasilache
499ad45877 [mlir][VectorOps] Expose and use llvm.intrin.fma*
Summary:
This revision exposes the portable `llvm.fma` intrinsic in LLVMOps and uses it
in lieu of `llvm.fmuladd` when lowering the `vector.outerproduct` op to LLVM.
This guarantees proper `fma` instructions will be emitted if the target ISA
supports it.

`llvm.fmuladd` does not have this guarantee in its semantics, despite evidence
that the proper x86 instructions are emitted.

For more details, see https://llvm.org/docs/LangRef.html#llvm-fmuladd-intrinsic.

Reviewers: ftynse, aartbik, dcaballe, fhahn

Reviewed By: aartbik

Subscribers: mehdi_amini, rriddle, jpienaar, burmako, shauheen, antiagainst, arpith-jacob, mgester, lucyrfox, liufengdb, Joonsoo, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D74219
2020-02-07 15:38:40 -05:00
aartbik
e52414b1ae [mlir][VectorOps] Generalized vector.print to i32/i64
Summary:
Lowering to LLVM IR was restricted to float/double.
This CL also adds the integral values.

Reviewers: andydavis1, nicolasvasilache, ftynse

Reviewed By: nicolasvasilache, ftynse

Subscribers: mehdi_amini, rriddle, jpienaar, burmako, shauheen, antiagainst, nicolasvasilache, arpith-jacob, mgester, lucyrfox, liufengdb, Joonsoo, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D74179
2020-02-07 09:25:30 -08:00
aartbik
c8fc76a99b [mlir] [VectorOps] fixed bug in vector.insert_strided_slice lowering
Summary:
Rationale:
When lowering to LLVM for different rank insert (n vs k), the offset
arrays needs to drop one dimension (becomes n-1), but the strides
array needs to be preserved (remains k). With regression test.
Note that this example was actually in the documentation, so
extra important to do it right :-)

Reviewers: nicolasvasilache, andydavis1, ftynse

Reviewed By: nicolasvasilache, ftynse

Subscribers: Joonsoo, merge_guards_bot, mehdi_amini, rriddle, jpienaar, burmako, shauheen, antiagainst, arpith-jacob, mgester, lucyrfox, liufengdb, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D73733
2020-01-31 11:29:46 -08:00
aartbik
459cf6e500 [mlir] [VectorOps] Lowering of vector.extract/insert_slices to LLVM IR
Summary: Uses progressive lowering to convert vector.extract_slices and vector_insert_slices to equivalent vector operations that can be subsequently lowered into LLVM.

Reviewers: nicolasvasilache, andydavis1, rriddle

Reviewed By: nicolasvasilache, rriddle

Subscribers: merge_guards_bot, mehdi_amini, rriddle, jpienaar, burmako, shauheen, antiagainst, nicolasvasilache, arpith-jacob, mgester, lucyrfox, liufengdb, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D72808
2020-01-27 10:35:48 -08:00
Nicolas Vasilache
2d515e49d8 [mlir][VectorOps] Implement insert_strided_slice conversion
Summary:
This diff implements the progressive lowering of insert_strided_slice.
Two cases appear:
1. when the source and dest vectors have different ranks, extract the dest
subvector at the proper offset and reduce to case 2.
2. when they have the same rank N:
  a. if the source and dest type are the same, the insertion is trivial:
     just forward the source
  b. otherwise, iterate over all N-1 D subvectors and create an
     extract/insert_strided_slice/insert replacement, reducing the problem
     to vecotrs of the same N-1 rank.

This combines properly with the other conversion patterns to lower all the way to LLVM.

Reviewers: ftynse, rriddle, AlexEichenberger, andydavis1, tetuante, nicolasvasilache

Reviewed By: andydavis1

Subscribers: merge_guards_bot, mehdi_amini, jpienaar, burmako, shauheen, antiagainst, arpith-jacob, mgester, lucyrfox, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D72317
2020-01-09 03:13:01 -05:00
Nicolas Vasilache
65678d9384 [mlir][VectorOps] Implement strided_slice conversion
Summary:
This diff implements the progressive lowering of strided_slice to either:
  1. extractelement + insertelement for the 1-D case
  2. extract + optional strided_slice + insert for the n-D case.

This combines properly with the other conversion patterns to lower all the way to LLVM.

Appropriate tests are added.

Reviewers: ftynse, rriddle, AlexEichenberger, andydavis1, tetuante

Reviewed By: andydavis1

Subscribers: merge_guards_bot, mehdi_amini, jpienaar, burmako, shauheen, antiagainst, arpith-jacob, mgester, lucyrfox, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D72310
2020-01-09 03:03:51 -05:00
Aart Bik
1d47564a53 [VectorOps] unify vector dialect "subscripts"
PiperOrigin-RevId: 286650682
2019-12-20 15:33:04 -08:00
Aart Bik
15f800f4bc [VectorOps] minor cleanup: vector dialect "subscripts" are i32
Introduces some centralized methods to move towards
consistent use of i32 as vector subscripts.

Note: sizes/strides/offsets attributes are still i64
PiperOrigin-RevId: 286434133
2019-12-19 11:51:08 -08:00
Aart Bik
d9b500d3bb [VectorOps] Add vector.print definition, with lowering support
Examples:

  vector.print %f : f32
  vector.print %x : vector<4xf32>
  vector.print %y : vector<3x4xf32>
  vector.print %z : vector<2x3x4xf32>

LLVM lowering replaces these with fully unrolled calls
into a small runtime support library that provides some
basic printing operations (single value, opening closing
bracket, comma, newline).

PiperOrigin-RevId: 286230325
2019-12-18 11:31:34 -08:00
Aart Bik
cd5dab8ad7 [VectorOps] Add [insert/extract]element definition together with lowering to LLVM
Similar to insert/extract vector instructions but
(1) work on 1-D vectors only
(2) allow for a dynamic index

  %c3 = constant 3 : index
  %0 = vector.insertelement %arg0, %arg1[%c : index] : vector<4xf32>
  %1 = vector.extractelement %arg0[%c3 : index] : vector<4xf32>

PiperOrigin-RevId: 285792205
2019-12-16 09:52:46 -08:00
Aart Bik
1c81adf362 [VectorOps] Add lowering of vector.shuffle to LLVM IR
For example, a shuffle

%1 = vector.shuffle %arg0, %arg1 [0 : i32, 1 : i32] : vector<2xf32>, vector<2xf32>

becomes a direct LLVM shuffle

0 = llvm.shufflevector %arg0, %arg1 [0 : i32, 1 : i32] : !llvm<"<2 x float>">, !llvm<"<2 x float>">

but

%1 = vector.shuffle %a, %b[1 : i32, 0 : i32, 2: i32] : vector<1x4xf32>, vector<2x4xf32>

becomes the more elaborate (note the index permutation that drives
argument selection for the extract operations)

%0 = llvm.mlir.undef : !llvm<"[3 x <4 x float>]">
%1 = llvm.extractvalue %arg1[0] : !llvm<"[2 x <4 x float>]">
%2 = llvm.insertvalue %1, %0[0] : !llvm<"[3 x <4 x float>]">
%3 = llvm.extractvalue %arg0[0] : !llvm<"[1 x <4 x float>]">
%4 = llvm.insertvalue %3, %2[1] : !llvm<"[3 x <4 x float>]">
%5 = llvm.extractvalue %arg1[1] : !llvm<"[2 x <4 x float>]">
%6 = llvm.insertvalue %5, %4[2] : !llvm<"[3 x <4 x float>]">

PiperOrigin-RevId: 285268164
2019-12-12 14:11:56 -08:00
Aart Bik
9826fe5c9f [VectorOps] Add lowering of vector.insert to LLVM IR
For example, an insert

  %0 = vector.insert %arg0, %arg1[3 : i32] : f32 into vector<4xf32>

becomes

  %0 = llvm.mlir.constant(3 : i32) : !llvm.i32
  %1 = llvm.insertelement %arg0, %arg1[%0 : !llvm.i32] : !llvm<"<4 x float>">

A more elaborate example, inserting an element in a higher dimension
vector

  %0 = vector.insert %arg0, %arg1[3 : i32, 7 : i32, 15 : i32] : f32 into vector<4x8x16xf32>

becomes

  %0 = llvm.extractvalue %arg1[3 : i32, 7 : i32] : !llvm<"[4 x [8 x <16 x float>]]">
  %1 = llvm.mlir.constant(15 : i32) : !llvm.i32
  %2 = llvm.insertelement %arg0, %0[%1 : !llvm.i32] : !llvm<"<16 x float>">
  %3 = llvm.insertvalue %2, %arg1[3 : i32, 7 : i32] : !llvm<"[4 x [8 x <16 x float>]]">

PiperOrigin-RevId: 284882443
2019-12-10 17:12:49 -08:00
Aart Bik
1fe65688d4 [VectorOps] Add a ShuffleOp to the VectorOps dialect
For example

 %0 = vector.shuffle %x, %y [3 : i32, 2 : i32, 1 : i32, 0 : i32] : vector<2xf32>, vector<2xf32>

yields a vector<4xf32> result with a permutation of the elements of %x and %y

PiperOrigin-RevId: 284657191
2019-12-09 16:15:41 -08:00
Aart Bik
d37f27251f [VecOps] Rename vector.[insert|extract]element to just vector.[insert|extract]
Since these operations lower to [insert|extract][element|value] at LLVM
dialect level, neither element nor value would correctly reflect the meaning.

PiperOrigin-RevId: 284240727
2019-12-06 12:39:25 -08:00
Aart Bik
b36aaeafb1 [VectorOps] Add lowering of vector.broadcast to LLVM IR
For example, a scalar broadcast

    %0 = vector.broadcast %x : f32 to vector<2xf32>
    return %0 : vector<2xf32>

which expands scalar x into vector [x,x] by lowering
to the following LLVM IR dialect to implement the
duplication over the leading dimension.

    %0 = llvm.mlir.undef : !llvm<"<2 x float>">
    %1 = llvm.mlir.constant(0 : index) : !llvm.i64
    %2 = llvm.insertelement %x, %0[%1 : !llvm.i64] : !llvm<"<2 x float>">
    %3 = llvm.shufflevector %2, %0 [0 : i32, 0 : i32] : !llvm<"<2 x float>">, !llvm<"<2 x float>">
    return %3 : vector<2xf32>

In the trailing dimensions, the operand is simply
"passed through", unless a more elaborate "stretch"
is required.

For example

    %0 = vector.broadcast %arg0 : vector<1xf32> to vector<4xf32>
    return %0 : vector<4xf32>

becomes

    %0 = llvm.mlir.undef : !llvm<"<4 x float>">
    %1 = llvm.mlir.constant(0 : index) : !llvm.i64
    %2 = llvm.extractelement %arg0[%1 : !llvm.i64] : !llvm<"<1 x float>">
    %3 = llvm.mlir.constant(0 : index) : !llvm.i64
    %4 = llvm.insertelement %2, %0[%3 : !llvm.i64] : !llvm<"<4 x float>">
    %5 = llvm.shufflevector %4, %0 [0 : i32, 0 : i32, 0 : i32, 0 : i32] : !llvm<"<4 x float>">, !llvm<"<4 x float>">
    llvm.return %5 : !llvm<"<4 x float>">

PiperOrigin-RevId: 284219926
2019-12-06 11:02:29 -08:00
Nicolas Vasilache
5c0c51a997 Refactor dependencies to expose Vector transformations as patterns - NFC
This CL refactors some of the MLIR vector dependencies to allow decoupling VectorOps, vector analysis, vector transformations and vector conversions from each other.
This makes the system more modular and allows extracting VectorToVector into VectorTransforms that do not depend on vector conversions.

This refactoring exhibited a bunch of cyclic library dependencies that have been cleaned up.

PiperOrigin-RevId: 283660308
2019-12-03 17:52:10 -08:00
Nicolas Vasilache
0b271b7dfe Refactor the LowerVectorTransfers pass to use the RewritePattern infra - NFC
This is step 1/n in refactoring infrastructure along the Vector dialect to make it ready for retargetability and composable progressive lowering.

PiperOrigin-RevId: 280529784
2019-11-14 15:40:07 -08:00
Alex Zinenko
bf5916e7a4 Use MemRefDescriptor in Vector-to-LLVM convresion
Following up on the consolidation of MemRef descriptor conversion, update
Vector-to-LLVM conversion to use the helper class that abstracts away the
implementation details of the MemRef descriptor. This also makes the types of
the attributes in emitted llvm.insert/extractelement operations consistently
i64 instead of a mix of index and i64.

PiperOrigin-RevId: 280441451
2019-11-14 09:05:42 -08:00
Nicolas Vasilache
f2b6ae9991 Move VectorOps to Tablegen - (almost) NFC
This CL moves VectorOps to Tablegen and cleans up the implementation.

This is almost NFC but 2 changes occur:
  1. an interface change occurs in the padding value specification in vector_transfer_read:
     the value becomes non-optional. As a shortcut we currently use %f0 for all paddings.
     This should become an OpInterface for vectorization in the future.
  2. the return type of vector.type_cast is trivial and simplified to `memref<vector<...>>`

Relevant roundtrip and invalid tests that used to sit in core are moved to the vector dialect.

The op documentation is moved to the .td file.

PiperOrigin-RevId: 280430869
2019-11-14 08:15:23 -08:00
Nicolas Vasilache
f51a155337 Add support for alignment attribute in std.alloc.
This CL adds an extra pointer to the memref descriptor to allow specifying alignment.

In a previous implementation, we used 2 types: `linalg.buffer` and `view` where the buffer type was the unit of allocation/deallocation/alignment and `view` was the unit of indexing.

After multiple discussions it was decided to use a single type, which conflates both, so the memref descriptor now needs to carry both pointers.

This is consistent with the [RFC-Proposed Changes to MemRef and Tensor MLIR Types](https://groups.google.com/a/tensorflow.org/forum/#!searchin/mlir/std.view%7Csort:date/mlir/-wKHANzDNTg/4K6nUAp8AAAJ).

PiperOrigin-RevId: 279959463
2019-11-12 07:06:54 -08:00
Nicolas Vasilache
2823b68580 Implement lowering of VectorTypeCastOp to LLVM
A VectorTypeCastOp can only be used to lower between statically sized contiguous memrefs of scalar and matching vector type. The sizes and strides are thus fully static and easy to determine.

A relevant test is added.

This is a step towards solving tensorflow/mlir#189.

PiperOrigin-RevId: 275538981
2019-10-18 14:00:06 -07:00
Alex Zinenko
c335d9d313 LLVM dialect: prefix auxiliary operations with "mlir."
Some of the operations in the LLVM dialect are required to model the LLVM IR in
MLIR, for example "constant" operations are needed to declare a constant value
since MLIR, unlike LLVM, does not support immediate values as operands.  To
avoid confusion with actual LLVM operations, we prefix such axuiliary
operations with "mlir.".

PiperOrigin-RevId: 266942838
2019-09-03 09:10:56 -07:00
Alex Zinenko
0f974817b5 LLVM dialect: prefix operations that correspond to intrinsics with "intr."
LLVM intrinsics have an open name space and their names can potentially overlap
with names of LLVM instructions (LLVM intrinsics are functions, not
instructions).  In MLIR, LLVM intrinsics are modeled as operations, so it needs
to make sure their names cannot clash with the instructions.  Use the "intr."
prefix for intrinsics in the LLVM dialect.

PiperOrigin-RevId: 264372173
2019-08-20 06:38:52 -07:00
Nicolas Vasilache
f826ceef3c Extend vector.outerproduct with an optional 3rd argument
This CL adds an optional third argument to the vector.outerproduct instruction.
When such a third argument is specified, it is added to the result of the outerproduct and  is lowered to FMA intrinsic when the lowering supports it.

In the future, we can add an attribute on the `vector.outerproduct` instruction to modify the operations for which to emit code (e.g. "+/*", "max/+", "min/+", "log/exp" ...).

This CL additionally performs minor cleanups in the vector lowering and adds tests to improve coverage.

This has been independently verified to result in proper fma instructions for haswell as follows.

Input:
```
func @outerproduct_add(%arg0: vector<17xf32>, %arg1: vector<8xf32>, %arg2: vector<17x8xf32>) -> vector<17x8xf32> {
  %2 = vector.outerproduct %arg0, %arg1, %arg2 : vector<17xf32>, vector<8xf32>
  return %2 : vector<17x8xf32>
}
}
```

Command:
```
mlir-opt vector-to-llvm.mlir -vector-lower-to-llvm-dialect --disable-pass-threading | mlir-opt -lower-to-cfg -lower-to-llvm | mlir-translate --mlir-to-llvmir | opt -O3 | llc -O3 -march=x86-64 -mcpu=haswell -mattr=fma,avx2
```

Output:
```
outerproduct_add:                       # @outerproduct_add
# %bb.0:
        ...
        vmovaps 112(%rbp), %ymm8
        vbroadcastss    %xmm0, %ymm0
        ...
        vbroadcastss    64(%rbp), %ymm15
        vfmadd213ps     144(%rbp), %ymm8, %ymm0 # ymm0 = (ymm8 * ymm0) + mem
        ...
        vfmadd213ps     400(%rbp), %ymm8, %ymm9 # ymm9 = (ymm8 * ymm9) + mem
        ...
```
PiperOrigin-RevId: 263743359
2019-08-16 03:53:26 -07:00
Nicolas Vasilache
252ada4932 Add lowering of vector dialect to LLVM dialect.
This CL is step 3/n towards building a simple, programmable and portable vector abstraction in MLIR that can go all the way down to generating assembly vector code via LLVM's opt and llc tools.

This CL adds support for converting MLIR n-D vector types to (n-1)-D arrays of 1-D LLVM vectors and a conversion VectorToLLVM that lowers the `vector.extractelement` and `vector.outerproduct` instructions to the proper mix of `llvm.vectorshuffle`, `llvm.extractelement` and `llvm.mulf`.

This has been independently verified to produce proper avx2 code.

Input:
```
func @vec_1d(%arg0: vector<4xf32>, %arg1: vector<8xf32>) -> vector<8xf32> {
  %2 = vector.outerproduct %arg0, %arg1 : vector<4xf32>, vector<8xf32>
  %3 = vector.extractelement %2[0 : i32]: vector<4x8xf32>
  return %3 : vector<8xf32>
}
```

Command:
```
mlir-opt vector-to-llvm.mlir -vector-lower-to-llvm-dialect --disable-pass-threading | mlir-opt -lower-to-cfg -lower-to-llvm | mlir-translate --mlir-to-llvmir | opt -O3 | llc -O3 -march=x86-64 -mcpu=haswell -mattr=fma,avx2
```

Output:
```
vec_1d:                                 # @vec_1d
# %bb.0:
        vbroadcastss    %xmm0, %ymm0
        vmulps  %ymm1, %ymm0, %ymm0
        retq
```
PiperOrigin-RevId: 262895929
2019-08-12 04:08:57 -07:00