This patch is part of a larger initiative aimed at fixing floating-point `max` and `min` operations in MLIR: https://discourse.llvm.org/t/rfc-fix-floating-point-max-and-min-operations-in-mlir/72671.
Within LLVM, there are no masked reduction counterparts for vector reductions such as `fmaximum` and `fminimum`.
More information can be found here: https://github.com/llvm/llvm-project/issues/64940#issuecomment-1690694156.
To address this issue in MLIR, where we need to generate appropriate lowerings for these cases, we employ regular non-masked intrinsics.
However, we modify the input vector using the `arith.select` operation to effectively deactivate undesired elements using a "neutral mask value".
The neutral mask value is the smallest possible value for the `fmaximum` reduction and the largest possible value for the `fminimum` reduction.
Depends on D158618
Reviewed By: dcaballe
Differential Revision: https://reviews.llvm.org/D158773
This patch is part of a larger initiative aimed at fixing floating-point `max` and `min` operations in MLIR: https://discourse.llvm.org/t/rfc-fix-floating-point-max-and-min-operations-in-mlir/72671.
This commit addresses Task 1.2 of the mentioned RFC. By renaming these operations, we align their names with LLVM intrinsics that have corresponding semantics.
This is a follow-on to D158753, and allows the lowering of a
transfer read/write of n-D vectors with a single trailing scalable dimension
to primitive vector ops.
The final conversion to LLVM depends on D158517 and D158752, without
these patches type conversion will fail (or an assert is hit in the LLVM
backend) if the final IR contains an array of scalable vectors.
This patch adds `transform.apply_patterns.vector.lower_create_mask`
which allows the lowering of vector.create_mask/constant_mask to be
tested independently of --convert-vector-to-llvm.
Reviewed By: c-rhodes, awarzynski, dcaballe
Differential Revision: https://reviews.llvm.org/D159482
Reland of the original patch after updating the Python binding tests,
a few CUDA/GPU MLIR tests, and ensuring the assembly format is
round-trippable.
This patch splits the lowering of vector.print into first converting
an n-D print into a loop of scalar prints of the elements, then a second
pass that converts those scalar prints into the runtime calls. The
former is done in VectorToSCF and the latter in VectorToLLVM.
The main reason for this is to allow printing scalable vector types,
which are not possible to fully unroll at compile time, though this
also avoids fully unrolling very large vectors.
To allow VectorToSCF to add the necessary punctuation between vectors
and elements, a "punctuation" attribute has been added to vector.print.
This abstracts calling the runtime functions such as printNewline(),
without leaking the LLVM details into the higher abstraction levels.
For example:
vector.print punctuation <comma>
lowers to
llvm.call @printComma() : () -> ()
The output format and runtime functions remain the same, which avoids
the need to alter a large number of tests (aside from the pipelines).
Reviewed By: awarzynski, c-rhodes, aartbik
Differential Revision: https://reviews.llvm.org/D156519
Reland of the original patch after updating the Python binding tests and
a few CUDA/GPU MLIR tests.
This patch splits the lowering of vector.print into first converting
an n-D print into a loop of scalar prints of the elements, then a second
pass that converts those scalar prints into the runtime calls. The
former is done in VectorToSCF and the latter in VectorToLLVM.
The main reason for this is to allow printing scalable vector types,
which are not possible to fully unroll at compile time, though this
also avoids fully unrolling very large vectors.
To allow VectorToSCF to add the necessary punctuation between vectors
and elements, a "punctuation" attribute has been added to vector.print.
This abstracts calling the runtime functions such as printNewline(),
without leaking the LLVM details into the higher abstraction levels.
For example:
vector.print <comma>
lowers to
llvm.call @printComma() : () -> ()
The output format and runtime functions remain the same, which avoids
the need to alter a large number of tests (aside from the pipelines).
Reviewed By: awarzynski, c-rhodes, aartbik
Differential Revision: https://reviews.llvm.org/D156519
This patch splits the lowering of vector.print into first converting
an n-D print into a loop of scalar prints of the elements, then a second
pass that converts those scalar prints into the runtime calls. The
former is done in VectorToSCF and the latter in VectorToLLVM.
The main reason for this is to allow printing scalable vector types,
which are not possible to fully unroll at compile time, though this
also avoids fully unrolling very large vectors.
To allow VectorToSCF to add the necessary punctuation between vectors
and elements, a "punctuation" attribute has been added to vector.print.
This abstracts calling the runtime functions such as printNewline(),
without leaking the LLVM details into the higher abstraction levels.
For example:
vector.print <comma>
lowers to
llvm.call @printComma() : () -> ()
The output format and runtime functions remain the same, which avoids
the need to alter a large number of tests (aside from the pipelines).
Reviewed By: awarzynski, c-rhodes, aartbik
Differential Revision: https://reviews.llvm.org/D156519
This patch improves the lowering by changing target LLVM intrinsics from
`reduce.fmax` and `reduce.fmin`,
which have different semantic for handling NaN,
to `reduce.fmaximum` and `reduce.fminimum` ones.
Fixes#63969
Depends on D155869
Reviewed By: dcaballe
Differential Revision: https://reviews.llvm.org/D155877
Rationale:
The LLVM dialect supports passing fastmath flags from floating point ops to LLVMIR instructions. However, not all LLVM ops have the required attribute. This change adds support for fastmath flags to `llvm.intr.vector.reduce.{fmin,fmax}`. One scenario where this is useful is in lowering llvm.intr.vector.reduce.{fmax,fmin} to LLVMIR with `nnan` (NoNans) flag so it may be [[ 115c7beda7/llvm/lib/CodeGen/ExpandReductions.cpp (L159) | lowered to a shuffle reduction ]].
Changes:
- Make `LLVM_VecReductionF` implement the `FastmathFlagsInterface`; change is modeled on `LLVM_UnaryIntrOpF`
- Add an assembly format for `LLVM_VecReductionF` ops. The purpose is to keep existing functionality: avoid printing the fastmath flags attribute when it has its default value (`none`). Change is modeled on `LLVM_UnaryIntrOpBase`
Reviewed By: gysit
Differential Revision: https://reviews.llvm.org/D145692
This patch adds masking support for more contraction flavors including those
with any combiner operation (add, mul, min, max, and, or, etc.) and
regular matmul contractions.
Combiner operations that are performing vertical reductions (and,
therefore, they are not represented with a horizontal reduction
operation) can be executed unmasked. However, the previous value of
the accumulator must be propagated for lanes that shouldn't accumulate.
We achieve this goal by introducing a select operation after the
accumulator to choose between the combined and the previous accumulator
value. This design decision is made to avoid introducing masking support
to all the arithmetic and logical operations in the Arith dialect. VP
intrinsics do not support pass-thru values either so we would have to
generate the same sequence when lowering to LLVM. The op + select
pattern is peepholed by some backend with native masking support for those
operations.
Consequently, this patch removes masking support from the vector.fma
operation to follow the same approach for all the combiner operations.
Reviewed By: ThomasRaoux
Differential Revision: https://reviews.llvm.org/D144239
This patch adds support for masking vector.contract ops with the
vector.mask approach. This also includes the lowering of vector.contract
through the vector.outerproduct path to LLVM. For now, this only adds
support for one of the many potential flavors of
vector.contract/vector.outerproduct but unsupported cases will fail
gratefully.
Reviewed By: ThomasRaoux
Differential Revision: https://reviews.llvm.org/D143965
This patch adds the conversion patterns to lower masked reduction
operations to the corresponding vp intrinsics in LLVM.
Reviewed By: ftynse
Differential Revision: https://reviews.llvm.org/D142177
This is generated by running
```
sed --in-place 's/[[:space:]]\+$//' mlir/**/*.td
sed --in-place 's/[[:space:]]\+$//' mlir/**/*.mlir
```
Reviewed By: rriddle, dcaballe
Differential Revision: https://reviews.llvm.org/D138866
This is required for D126305 code to propagate fastmath attributes
for Arith operations that are converted to LLVM IR intrinsics
operations.
LLVM IR intrinsic operations are using custom assembly format now
to avoid printing {fastmathFlags = #llvm.fastmath<none>}, which
is too verbose.
Reviewed By: rriddle
Differential Revision: https://reviews.llvm.org/D136225
Currently vector.gather only supports reading memory into a 1-D result vector.
This patch extends it to support an n-D result vector with the indices, masks,
and passthroughs in n-D vectors.
As we are trying to vectorize tensor.extract with vector.gather
(https://github.com/iree-org/iree/issues/9198), it will need to gather the
elements into an n-D vector. Having vector.gather with n-D results allows us
to avoid flatten and reshape at the vectorization stage. The backends can then
decide the optimal ways to lower the vector.gather op.
Note that this is different from n-D gathering, which is about reading n-D
memory with the n-D indices. The indices here are still only 1-D offsets on
the base.
Reviewed By: dcaballe
Differential Revision: https://reviews.llvm.org/D131905
This patch moves `LLVM::ShuffleVectorOp` to assembly format and in the
process drops the extra type that can be inferred (both operand types
are required to be the same) and switches to a dense integer array.
The syntax change:
```
// Before
%0 = llvm.shufflevector %0, %1 [0 : i32, 0 : i32, 0 : i32, 0 : i32] : vector<4xf32>, vector<4xf32>
// After
%0 = llvm.shufflevector %0, %1 [0, 0, 0, 0] : vector<4xf32>
```
Reviewed By: dcaballe
Differential Revision: https://reviews.llvm.org/D132038
This commit adds support for 0-D vectors in ReductionOp.
Reviewed By: nicolasvasilache, dcaballe
Differential Revision: https://reviews.llvm.org/D131896
Adding the accumulator value after the `vector.contract` changes the
precision of the operation. This makes sure the accumulator is carried
through to `vector.reduce` (and down to LLVM).
Differential Revision: https://reviews.llvm.org/D128674
For example, we could do the following eliminations:
fold vector.shuffle V1, V2, [0, 1, 2, 3] : <4xi32>, <2xi32> -> V1
fold vector.shuffle V1, V2, [4, 5] : <4xi32>, <2xi32> -> V2
Differential Revision: https://reviews.llvm.org/D122706
We are using "enable-index-optimizations" and "indexOptimizations" as
names for an optimization that consists of using i32 for indices within
a vector. For instance, when building a vector comparison for mask
generation. The name is confusing and suggests a scope beyond these
vector indices. This change makes the function of the option explicit
in its name.
Differential Revision: https://reviews.llvm.org/D122415
The way vector.create_mask is currently lowered is
vector-length-dependent, and therefore incompatible with scalable vector
types. This patch adds an alternative lowering path for create_mask
operations that return a scalable vector mask.
Differential Revision: https://reviews.llvm.org/D118248
Currently, the transfer mask is materialized by generating the vector
comparison: [offset + 0, .., offset + length - 1] < [dim, .., dim]
A better alternative is to materialize the transfer mask by using the
operation: `vector.create_mask (dim - offset)`, which will generate
simpler code and compose better with scalable vectors.
Differential Revision: https://reviews.llvm.org/D120487
This is part of the larger effort to split the standard dialect. This will also allow for pruning some
additional dependencies on Standard (done in a followup).
Differential Revision: https://reviews.llvm.org/D118202
The 0-D case gets lowered in almost the same way that the 1-D case does
in VectorCreateMaskOpConversion. I also had to slightly update the
verifier for the op to always require exactly 1 operand in the 0-D case.
Depends On D115220
Reviewed by: ftynse
Differential revision: https://reviews.llvm.org/D115221
To support creating both a mask with just a single `true` and `false` values,
I had to relax the restriction in the verifier that the rank is always equal to
the length of the attribute array, in other words, we now allow:
- `vector.constant_mask [0] : vector<i1>` which gets lowered to
`arith.constant dense<false> : vector<i1>`
- `vector.constant_mask [1] : vector<i1>` which gets lowered to
`arith.constant dense<true> : vector<i1>`
(the attribute list for the 0-D case must be a singleton containing
either `0` or `1`)
Reviewed By: nicolasvasilache
Differential Revision: https://reviews.llvm.org/D115023
The implementation only allows to bit-cast between two 0-D vectors. We could
probably support casting from/to vectors like `vector<1xf32>`, but I wasn't
convinced that this would be important and it would require breaking the
invariant that `BitCastOp` works only on vectors with equal rank.
Reviewed By: nicolasvasilache
Differential Revision: https://reviews.llvm.org/D114854
This reverts commit 29a50c5864.
After LLVM lowering, the original patch incorrectly moved alignment
information across an unconstrained GEP operation. This is only correct
for some index offsets in the GEP. It seems that the best approach is,
in fact, to rely on LLVM to propagate information from the llvm.assume()
to users.
Thanks to Thomas Raoux for catching this.
This changes the op to produce `AnyVectorOfAnyRank` following mostly the code for 1-D vectors.
Depends On D114598
Reviewed By: nicolasvasilache
Differential Revision: https://reviews.llvm.org/D114550
This revision makes concrete use of 0-d vectors to extend the semantics of
InsertElementOp.
Reviewed By: dcaballe, pifon2a
Differential Revision: https://reviews.llvm.org/D114388
This revision starts making concrete use of 0-d vectors to extend the semantics of
ExtractElementOp.
In the process a new VectorOfAnyRank Tablegen OpBase.td is added to allow progressive transition to supporting 0-d vectors by gradually opting in.
Differential Revision: https://reviews.llvm.org/D114387
`vector::InsertElementOp` and `vector::ExtractElementOp` have had their `position`
operand changed to accept `AnySignlessIntegerOrIndex` for better operability with
operations that use `index`, such as affine loops.
LLVM's `extractelement` and `insertelement` can also accept `i64`, so lowering
directly to these operations without explicitly inserting casts is allowed. SPIRV's
equivalent ops can also accept `i64`.
Reviewed By: nicolasvasilache, jpienaar
Differential Revision: https://reviews.llvm.org/D114139
FMAOp -> LLVM conversion is done progressively by peeling off 1 dimension from FMAOp at each pattern iteration. Add the recursively bounded property declaration to the pattern so that the rewriter can apply it multiple times.
Without this, FMAOps with 3+D do not lower to LLVM.
Differential Revision: https://reviews.llvm.org/D113886
This also fixes the vector.shuffle C++ builder which had an incorrect type assumption that triggers with this new rewrite.
The vector.shuffle semantics were correct though.
Differential revision: https://reviews.llvm.org/D112578