At the moment, loads introduced by multiply fusion may be placed after
an objects lifetime has been terminated by lifetime.end. This introduces
reads to dead objects.
To avoid this, first collect all lifetime.end calls in the function.
During fusion, we deal with any lifetime.end calls that may alias any of
the loads.
Such lifetime.end calls are either moved when possible (both the
lifetime.end and the store are in the same block) or deleted.
PR: https://github.com/llvm/llvm-project/pull/84914
Row and column arguments for matrix_transpose indicate the shape of the
operand. When hoisting the transpose to the result of the add, the add
operates on the original operand's shape, and so does the hoisted
transpose.
This patch also adds an assert that the shape for the original add and
the transpose match, as well as the shape of the new add matches the
cached shape for it.
The assert could potentially be moved to
updateShapeAndReplaceAllUsesWith.
extract subvector.
Many targets do not have cost for extractsubvector shuffle kind, but
have the costs for single source permute. If there are no costs
estimation for extractsubvector, better to switchto single source
permute for better cost estimation.
Reviewers: RKSimon, davemgreen, arsenm
Reviewed By: RKSimon
Pull Request: https://github.com/llvm/llvm-project/pull/79837
Generalize the logic used to convert column-vector ops to row-vectors to
support converting chains of operations.
A potential next step is to further generalize this to convert
column-vector ops to row-vector ops in general, not just for operands of
dot products. Dot-product handling would then be driven by the general
conversion, rather than the other way around.
PR: https://github.com/llvm/llvm-project/pull/72647
This patch canonicalizes getelementptr instructions with constant
indices to use the `i8` source element type. This makes it easier for
optimizations to recognize that two GEPs are identical, because they
don't need to see past many different ways to express the same offset.
This is a first step towards
https://discourse.llvm.org/t/rfc-replacing-getelementptr-with-ptradd/68699.
This is limited to constant GEPs only for now, as they have a clear
canonical form, while we're not yet sure how exactly to deal with
variable indices.
The test llvm/test/Transforms/PhaseOrdering/switch_with_geps.ll gives
two representative examples of the kind of optimization improvement we
expect from this change. In the first test SimplifyCFG can now realize
that all switch branches are actually the same. In the second test it
can convert it into simple arithmetic. These are representative of
common optimization failures we see in Rust.
Fixes https://github.com/llvm/llvm-project/issues/69841.
The cost of vector instructions has always been high under AArch64, in order to
add a high cost for inserts/extracts, shuffles and scalarization. This is a
conservative approach to limit the scope of unusual SLP vectorization where the
codegen ends up being quite poor, but has always been higher than the correct
costs would be for any specific core.
This relaxes that, reducing the vector insert/extract cost from 3 to 2. It is a
generalization of D142359 to all AArch64 cpus. The ScalarizationOverhead is
also overridden for integer vector at the same time, to remove the effect of
lane 0 being considered free for integer vectors (something that should only be
true for float when scalarizing).
The lower insert/extract cost will reduce the cost of insert, extracts,
shuffling and scalarization. The adjustments of ScalaizationOverhead will
increase the cost on integer, especially for small vectors. The end result will
be lower cost for float and long-integer types, some higher cost for some
smaller vectors. This, along with the raw insert/extract cost being lower, will
generally mean more vectorization from the Loop and SLP vectorizer.
We may end up regretting this, as that vectorization is not always profitable.
In all the benchmarking I have done this is generally an improvement in the
overall performance, and I've attempted to address the places where it wasn't
with other costmodel adjustments.
Differential Revision: https://reviews.llvm.org/D155459
These values don't propagate to the output; they are always replaced with a subsequent shuffle
or insertelement.
Tested equivalence with Alive2, e.g., https://alive2.llvm.org/ce/z/fj4s78.
The dot product lowering will use the left operand as row vector.
If the operand is a binary op, convert it to operate on a row vector
instead of a column vector.
Depends on D148428.
Reviewed By: thegameg
Differential Revision: https://reviews.llvm.org/D148429
Extend dot-product handling to skip transposes of the first operand. As
this is a vector, the conversion between column and row vector via the
transpose isn't needed.
Reviewed By: thegameg
Differential Revision: https://reviews.llvm.org/D148428
At the moment, lower-matrix-intrinsics accepts mis-matches between
shapes for operations. See shape-verification.ll for an example where
@llvm.matrix.column.major.load specifies 6x1 and then the use
(@llvm.matrix.multiply) specifies the operand to have 1x6.
This patch adds verification for shapes to check if shapes match.
Reviewed By: thegameg
Differential Revision: https://reviews.llvm.org/D147438
With this patch an undefined mask in a shufflevector will be printed as poison.
This change is done to support the new shufflevector semantics
for undefined mask elements.
Differential Revision: https://reviews.llvm.org/D149210
The current code did not properly account for integer matrixes. Check
if the operands are floating point or integer matrixes and use FAdd/Add
accordingly.
This is already done for other cases, like multiplies.
Fixes#62281.
Perform dot-product lowering before instruction fusion to avoid crash in
newly added test. Also update lowerDotProduct to properly mark optimized
matmul as fused.
Limit to dot product lowering to column major matrixes for now. This
simplifies the code and reasoning for upcoming planned improvements.
Support for row-major matrixes can be added later as extension.
Add special case to matrix lowering for dot products. Normal matrix lowering if optimized for either row-major or column-major, which results in many `shufflevector` instructions being generated for one vector. We work around this in our special case. We can also use vector-reduce adds instead of sequential adds to sum the result of the element-wise multiplication, which takes advantage of SIMD instructions.
Reviewed By: fhahn, thegameg
Differential Revision: https://reviews.llvm.org/D131125
Update dot-product-int.ll tests to use mostly i32 instead of i64;
there's no mul.2d instruction, so vector versions of v2i64 cannot be
lowered efficiently.
The method DataLayout::getGEPIndexForOffset(Type *&ElemTy, APInt &Offset)
allows to generate GEP indices for a given byte-based offset.
This allows to generate "natural" GEPs using the given type structure
if the byte offset happens to match a nested element object.
With opaque pointers and a general move towards byte-based GEPs [1],
this function may be questionable in the future.
This patch avoids creation of GEPs into vectors in routines that use
DataLayout::getGEPIndexForOffset by not returning indices in that case.
The reason is that A) GEPs into vectors have been discouraged for a long
time [2], and B) that GEPs into vectors are currently broken if the element
type is overaligned [1]. This is also demonstrated by a lit test where
previously InstCombine replaced valid loads by poison. Note that
the result of InstCombine on that test is *still* invalid, because
padding bytes are assumed.
Moreover, GEPs into vectors may be outright forbidden in the future [1].
[1]: https://discourse.llvm.org/t/67497
[2]: https://llvm.org/docs/GetElementPtr.html
The test case is new. It will be precommitted if this patch is accepted.
Differential Revision: https://reviews.llvm.org/D142146
First, sink the transposes to the operands to simplify redudant
ones. Then, lift them to reduce the number of realized transposes.
```
(A + B)^T -> A^T + B^T -> (A + B)^T
```
See tests for more examples.
Differential Revision: https://reviews.llvm.org/D133657
Instcombine prefers this canonical form (see getPreferredVectorIndex),
as does IRBuilder when passing the index as an integer so we may as
well use the prefered form from creation.
NOTE: All test changes are mechanical with nothing else expected
beyond a change of index type from i32 to i64.
Differential Revision: https://reviews.llvm.org/D140983
store-align-volatile.ll needed manually updated check lines for a
-NEXT check after a deleted bitcast.
Also avoided breaking the example C++ comment in remarks-inlining.ll
This switches everything to use the memory attribute proposed in
https://discourse.llvm.org/t/rfc-unify-memory-effect-attributes/65579.
The old argmemonly, inaccessiblememonly and inaccessiblemem_or_argmemonly
attributes are dropped. The readnone, readonly and writeonly attributes
are restricted to parameters only.
The old attributes are auto-upgraded both in bitcode and IR.
The bitcode upgrade is a policy requirement that has to be retained
indefinitely. The IR upgrade is mainly there so it's not necessary
to update all tests using memory attributes in this patch, which
is already large enough. We could drop that part after migrating
tests, or retain it longer term, to make it easier to import IR
from older LLVM versions.
High-level Function/CallBase APIs like doesNotAccessMemory() or
setDoesNotAccessMemory() are mapped transparently to the memory
attribute. Code that directly manipulates attributes (e.g. via
AttributeList) on the other hand needs to switch to working with
the memory attribute instead.
Differential Revision: https://reviews.llvm.org/D135780
If one of the operands is a transposed splat, the transpose can be
removed.
This is useful to simplify when transposes are distributed to operands
of a matmul:
* k^T -> k
* (A * k)^t -> A^t * k
Differential Revision: https://reviews.llvm.org/D130177
If an instruction at the beginning of a block is erased, this may
trigger crash due to dereferencing an invalid iterator.
Check if II is at the end before dereferencing it.
Reviewed By: thegameg
Differential Revision: https://reviews.llvm.org/D127736
This patch tries to sink instructions when they are only used in a successor block.
This is a further enhancement patch based on Anna's commit:
D109700, which allows sinking an instruction having multiple uses in a single user.
In this patch, sink instructions with multiple users in a single successor block will be supported.
It could fix a known issue from rust:
https://github.com/rust-lang/rust/issues/51346#issuecomment-394443610
Reviewed By: nikic, reames
Differential Revision: https://reviews.llvm.org/D121585
When creating an alloca to copy a matrix due to memory conflicts, those
allocas used to use VectorTypes, which forced them to have huge
alignments for large vectors.
This patch updates LowerMatrixIntrinsics to use a corresponding array
type, like Clang already does, to get more manageable alignments.
Reviewed By: anemet, thegameg
Differential Revision: https://reviews.llvm.org/D118239
