While the `gpu.launch` Op allows setting the size via the
`dynamic_shared_memory_size` argument, accessing the dynamic shared
memory is very convoluted. This PR implements the proposed Op,
`gpu.dynamic_shared_memory` that aims to simplify the utilization of
dynamic shared memory.
RFC:
https://discourse.llvm.org/t/rfc-simplifying-dynamic-shared-memory-access-in-gpu/
**Proposal from RFC**
This PR `gpu.dynamic.shared.memory` Op to use dynamic shared memory
feature efficiently. It is is a powerful feature that enables the
allocation of shared memory at runtime with the kernel launch on the
host. Afterwards, the memory can be accessed directly from the device. I
believe similar story exists for AMDGPU.
**Current way Using Dynamic Shared Memory with MLIR**
Let me illustrate the challenges of using dynamic shared memory in MLIR
with an example below. The process involves several steps:
- memref.global 0-sized array LLVM's NVPTX backend expects
- dynamic_shared_memory_size Set the size of dynamic shared memory
- memref.get_global Access the global symbol
- reinterpret_cast and subview Many OPs for pointer arithmetic
```
// Step 1. Create 0-sized global symbol. Manually set the alignment
memref.global "private" @dynamicShmem : memref<0xf16, 3> { alignment = 16 }
func.func @main() {
// Step 2. Allocate shared memory
gpu.launch blocks(...) threads(...)
dynamic_shared_memory_size %c10000 {
// Step 3. Access the global object
%shmem = memref.get_global @dynamicShmem : memref<0xf16, 3>
// Step 4. A sequence of `memref.reinterpret_cast` and `memref.subview` operations.
%4 = memref.reinterpret_cast %shmem to offset: [0], sizes: [14, 64, 128], strides: [8192,128,1] : memref<0xf16, 3> to memref<14x64x128xf16,3>
%5 = memref.subview %4[7, 0, 0][7, 64, 128][1,1,1] : memref<14x64x128xf16,3> to memref<7x64x128xf16, strided<[8192, 128, 1], offset: 57344>, 3>
%6 = memref.subview %5[2, 0, 0][1, 64, 128][1,1,1] : memref<7x64x128xf16, strided<[8192, 128, 1], offset: 57344>, 3> to memref<64x128xf16, strided<[128, 1], offset: 73728>, 3>
%7 = memref.subview %6[0, 0][64, 64][1,1] : memref<64x128xf16, strided<[128, 1], offset: 73728>, 3> to memref<64x64xf16, strided<[128, 1], offset: 73728>, 3>
%8 = memref.subview %6[32, 0][64, 64][1,1] : memref<64x128xf16, strided<[128, 1], offset: 73728>, 3> to memref<64x64xf16, strided<[128, 1], offset: 77824>, 3>
// Step.5 Use
"test.use.shared.memory"(%7) : (memref<64x64xf16, strided<[128, 1], offset: 73728>, 3>) -> (index)
"test.use.shared.memory"(%8) : (memref<64x64xf16, strided<[128, 1], offset: 77824>, 3>) -> (index)
gpu.terminator
}
```
Let’s write the program above with that:
```
func.func @main() {
gpu.launch blocks(...) threads(...) dynamic_shared_memory_size %c10000 {
%i = arith.constant 18 : index
// Step 1: Obtain shared memory directly
%shmem = gpu.dynamic_shared_memory : memref<?xi8, 3>
%c147456 = arith.constant 147456 : index
%c155648 = arith.constant 155648 : index
%7 = memref.view %shmem[%c147456][] : memref<?xi8, 3> to memref<64x64xf16, 3>
%8 = memref.view %shmem[%c155648][] : memref<?xi8, 3> to memref<64x64xf16, 3>
// Step 2: Utilize the shared memory
"test.use.shared.memory"(%7) : (memref<64x64xf16, 3>) -> (index)
"test.use.shared.memory"(%8) : (memref<64x64xf16, 3>) -> (index)
}
}
```
This PR resolves#72513
This function has several overloads that allow to specify the symbol
that should be renamed and the scope for that renaming in different
ways. The overloads were inconsistent in the following way (quoted
strings are `StringAttr`s, other variables are `Operation *`):
* `replaceAllSymbolUses(symbolOp, "new_symbol", scopeOp)` would traverse
into the nested regions of `scopeOp` and hence rename the symbol inside
of `scopeOp`.
* `replaceAllSymbolUses("symbol", "new_symbol", scopeOp)` would *not*
traverse into the nested regions of `scopeOp` and hence *not* rename the
symbol.
The underlying behavior was spread over different places and is somewhat
hard to understand. The two overloads above mainly differed by what
`collectSymbolScopes` computed, which is itself overloaded. If `scopeOp`
is a top-level module, then the overload on `(Operation *, Operation
*)`, which is used in the first of the above cases, computes a scope
where the body region of the module is the `limit`; however, the
overload on `(StringAttr, Operation *)` computed the module op itself as
the `limit`. Later, `walkSymbolTable` would walk the body of the module
if it was given as a region but it would *not* enter the regions of the
module op because that op has a symbol table (which was assumed to be a
*different* scope).
The fix in this commit is change the behavior of `collectSymbolScopes`
such that the `(StringAttr, Operation *)` overload returns a scope for
each region in the `limit` argument.
Until now, the interpreter would only load those symbols from the
provided library files that were declared in the main transform module.
However, sequences in the library may include other sequences on their
own. Until now, if such sequences were not *also* declared in the main
transform module, the interpreter would fail to resolve them. Forward
declaring all of them is undesirable as it defeats the purpose of
encapsulation into library modules.
This PR implements a kind of linker for transform scripts to solve this
problem. The linker merges all symbols of the library module into the
main module before interpreting the latter. Symbols whose names collide
are handled as follows: (1) if they are both functions (in the sense of
`FunctionOpInterface`) with compatible signatures, one is external, and
the other one is public, then they are merged; (2) of one of them is
private, that one is renamed; and (3) an error is raised otherwise.
One consequence of this change is that the loading of the library files
in the interpreter pass is not idempotent anymore, i.e., subsequent
interpreter passes cannot (and need not) load the same library files again
since would lead to doubly defined symbols.
The MLIR classes Type/Attribute/Operation/Op/Value support
cast/dyn_cast/isa/dyn_cast_or_null functionality through llvm's doCast
functionality in addition to defining methods with the same name.
This change begins the migration of uses of the method to the
corresponding function call as has been decided as more consistent.
Note that there still exist classes that only define methods directly,
such as AffineExpr, and this does not include work currently to support
a functional cast/isa call.
Context:
- https://mlir.llvm.org/deprecation/ at "Use the free function variants
for dyn_cast/cast/isa/…"
- Original discussion at https://discourse.llvm.org/t/preferred-casting-style-going-forward/68443
Implementation:
This patch updates all remaining uses of the deprecated functionality in
mlir/. This was done with clang-tidy as described below and further
modifications to GPUBase.td and OpenMPOpsInterfaces.td.
Steps are described per line, as comments are removed by git:
0. Retrieve the change from the following to build clang-tidy with an
additional check:
main...tpopp:llvm-project:tidy-cast-check
1. Build clang-tidy
2. Run clang-tidy over your entire codebase while disabling all checks
and enabling the one relevant one. Run on all header files also.
3. Delete .inc files that were also modified, so the next build rebuilds
them to a pure state.
```
ninja -C $BUILD_DIR clang-tidy
run-clang-tidy -clang-tidy-binary=$BUILD_DIR/bin/clang-tidy -checks='-*,misc-cast-functions'\
-header-filter=mlir/ mlir/* -fix
rm -rf $BUILD_DIR/tools/mlir/**/*.inc
```
Differential Revision: https://reviews.llvm.org/D151542
The MLIR classes Type/Attribute/Operation/Op/Value support
cast/dyn_cast/isa/dyn_cast_or_null functionality through llvm's doCast
functionality in addition to defining methods with the same name.
This change begins the migration of uses of the method to the
corresponding function call as has been decided as more consistent.
Note that there still exist classes that only define methods directly,
such as AffineExpr, and this does not include work currently to support
a functional cast/isa call.
Context:
* https://mlir.llvm.org/deprecation/ at "Use the free function variants for dyn_cast/cast/isa/…"
* Original discussion at https://discourse.llvm.org/t/preferred-casting-style-going-forward/68443
Implementation:
This follows a previous patch that updated calls
`op.cast<T>()-> cast<T>(op)`. However some cases could not handle an
unprefixed `cast` call due to occurrences of variables named cast, or
occurring inside of class definitions which would resolve to the method.
All C++ files that did not work automatically with `cast<T>()` are
updated here to `llvm::cast` and similar with the intention that they
can be easily updated after the methods are removed through a
find-replace.
See https://github.com/llvm/llvm-project/compare/main...tpopp:llvm-project:tidy-cast-check
for the clang-tidy check that is used and then update printed
occurrences of the function to include `llvm::` before.
One can then run the following:
```
ninja -C $BUILD_DIR clang-tidy
run-clang-tidy -clang-tidy-binary=$BUILD_DIR/bin/clang-tidy -checks='-*,misc-cast-functions'\
-export-fixes /tmp/cast/casts.yaml mlir/*\
-header-filter=mlir/ -fix
rm -rf $BUILD_DIR/tools/mlir/**/*.inc
```
Differential Revision: https://reviews.llvm.org/D150348
This class wraps a `SymbolTableCollection` to allow shared access to the
collection of symbol tables (but not the individual symbol tables). This
can be used, for example, in a pass that shards work among symbols that
requires symbol lookups.
Reviewed By: rriddle
Differential Revision: https://reviews.llvm.org/D144507
This commit restructures the sub element infrastructure to be a core part
of attributes and types, instead of being relegated to an interface. This
establishes sub element walking/replacement as something "always there",
which makes it easier to rely on for correctness/etc (which various bits of
infrastructure want, such as Symbols).
Attribute/Type now have `walk` and `replace` methods directly
accessible, which provide power API for interacting with sub elements. As
part of this, a new AttrTypeWalker class is introduced that supports caching
walked attributes/types, and a friendlier API (see the simplification of symbol
walking in SymbolTable.cpp).
Differential Revision: https://reviews.llvm.org/D142272
This is part of an effort to migrate from llvm::Optional to
std::optional. 22426110c5 changed the way mlir-tblgen generates .inc
files, emitting std::optional when an Optional attribute is specified in
a .td file. It also changed several .td files hard-coding llvm::Optional
to use std::optional. However, the patch excluded a few .td files in
SPIRV and Bufferization hard-coding llvm::Optional. This patch fixes
that defect, and after this patch, references to llvm::Optional in .cpp
and .h files can be replaced mechanically.
See also: https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
Signed-off-by: Ramkumar Ramachandra <r@artagnon.com>
Differential Revision: https://reviews.llvm.org/D140329
This patch mechanically replaces None with std::nullopt where the
compiler would warn if None were deprecated. The intent is to reduce
the amount of manual work required in migrating from Optional to
std::optional.
This is part of an effort to migrate from llvm::Optional to
std::optional:
https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
We currently only have the SubElement interface API for attribute/type
replacement, but this suffers from several issues; namely that it doesn't
allow caching across multiple replacements (very common), and also
creates a somewhat awkward/limited API. The new AttrTypeReplacer class
allows for registering replacements using a much cleaner API, similarly to
the TypeConverter class, removes a lot of manual interaction with the
sub element interfaces, and also better enables large scale replacements.
Differential Revision: https://reviews.llvm.org/D137764
There are various use cases where we don't want to immediately erase
an operation when removing it from the symbol table. This commit adds
a "remove" method to support that.
Differential Revision: https://reviews.llvm.org/D133564
This is used to fix a bug in SymbolTable::replaceAllSymbolUses where we replace symbols that
we shouldn't.
Differential Revision: https://reviews.llvm.org/D130693
The current support was essentially the amount necessary
to support replacing SymbolRefAttrs, but suffers from various
deficiencies (both ergonomic and functional):
* Replace crashes if unsupported
This makes it really hard to use safely, given that you don't know
if you are going to crash or not when using it.
* Types aren't supported
This seems like a simple missed addition when the attribute replacement
support was originally added.
* The ergonomics are weird
It currently uses an index based replacement, which makes the implementations
quite clunky.
This commit refactors support to be a bit more ergonomic, and also
adds support for types in the process. This was also a great oppurtunity
to greatly simplify how replacement is done in the symbol table.
Fixes#56355
Differential Revision: https://reviews.llvm.org/D130589
`SymbolUserMap` relied on `try_emplace` and `std::move` to relocate an entry to another key. However, if this triggered the resizing of the `DenseMap`, the value was destroyed before it could be moved to the new storage location, leading to a dangling `users` reference to be inserted into the map. On destruction, since a new entry was created from one that was already freed, a double-free error occurred.
Fixed issue by re-fetching the iterator after the mutation of the container.
Differential Revision: https://reviews.llvm.org/D129345
Inserting a symbol into a SymbolTable may lead to the name of the symbol being
changed in order to ensure uniqueness of symbol names in the table. Return this
new name to spare the caller the need to extract it from the symbol operation.
Depends On D112700
Reviewed By: mehdi_amini
Differential Revision: https://reviews.llvm.org/D112886
This patch extends the SubElementAttr interface to allow replacing a contained sub attribute. The attribute that should be replaced is identified by an index which denotes the n-th element returned by the accompanying walkImmediateSubElements method.
Using this addition the patch implements replacing SymbolRefAttrs contained within any dialect attributes.
Differential Revision: https://reviews.llvm.org/D111357
SymbolRefAttr is fundamentally a base string plus a sequence
of nested references. Instead of storing the string data as
a copies StringRef, store it as an already-uniqued StringAttr.
This makes a lot of things simpler and more efficient because:
1) references to the symbol are already stored as StringAttr's:
there is no need to copy the string data into MLIRContext
multiple times.
2) This allows pointer comparisons instead of string
comparisons (or redundant uniquing) within SymbolTable.cpp.
3) This allows SymbolTable to hold a DenseMap instead of a
StringMap (which again copies the string data and slows
lookup).
This is a moderately invasive patch, so I kept a lot of
compatibility APIs around. It would be nice to explore changing
getName() to return a StringAttr for example (right now you have
to use getNameAttr()), and eliminate things like the StringRef
version of getSymbol.
Differential Revision: https://reviews.llvm.org/D108899
This revision adds support for hover on region operations, by temporarily removing the regions during printing. This revision also tweaks the hover format for operations to include symbol information, now that FuncOp can be shown in the hover.
Differential Revision: https://reviews.llvm.org/D103727
In particular for Graph Regions, the terminator needs is just a
historical artifact of the generalization of MLIR from CFG region.
Operations like Module don't need a terminator, and before Module
migrated to be an operation with region there wasn't any needed.
To validate the feature, the ModuleOp is migrated to use this trait and
the ModuleTerminator operation is deleted.
This patch is likely to break clients, if you're in this case:
- you may iterate on a ModuleOp with `getBody()->without_terminator()`,
the solution is simple: just remove the ->without_terminator!
- you created a builder with `Builder::atBlockTerminator(module_body)`,
just use `Builder::atBlockEnd(module_body)` instead.
- you were handling ModuleTerminator: it isn't needed anymore.
- for generic code, a `Block::mayNotHaveTerminator()` may be used.
Differential Revision: https://reviews.llvm.org/D98468
This class provides efficient implementations of symbol queries related to uses, such as collecting the users of a symbol, replacing all uses, etc. This provides similar benefits to use related queries, as SymbolTableCollection did for lookup queries.
Differential Revision: https://reviews.llvm.org/D98071
This reverts commit 511dd4f438 along with
a couple fixes.
Original message:
Now the context is the first, rather than the last input.
This better matches the rest of the infrastructure and makes
it easier to move these types to being declaratively specified.
Phabricator: https://reviews.llvm.org/D96111
Now the context is the first, rather than the last input.
This better matches the rest of the infrastructure and makes
it easier to move these types to being declaratively specified.
Differential Revision: https://reviews.llvm.org/D96111
This class used to serve a few useful purposes:
* Allowed containing a null DictionaryAttr
* Provided some simple mutable API around a DictionaryAttr
The first of which is no longer an issue now that there is much better caching support for attributes in general, and a cache in the context for empty dictionaries. The second results in more trouble than it's worth because it mutates the internal dictionary on every action, leading to a potentially large number of dictionary copies. NamedAttrList is a much better alternative for the second use case, and should be modified as needed to better fit it's usage as a DictionaryAttrBuilder.
Differential Revision: https://reviews.llvm.org/D93442
Previous behavior would fail if inserting an operation that already
existed. Now SymbolTable::insert can also be used as a way to make a
symbol's name unique even after insertion.
Further TODOs have been left over naming and consistent behavior
considerations.
Differential Revision: https://reviews.llvm.org/D93349
- Change syntax for FuncOp to be `func <visibility>? @name` instead of printing the
visibility in the attribute dictionary.
- Since printFunctionLikeOp() and parseFunctionLikeOp() are also used by other
operations, make the "inline visibility" an opt-in feature.
- Updated unit test to use and check the new syntax.
Differential Revision: https://reviews.llvm.org/D90859
* Check region count for unknown symbol tables first, as it is a faster check
* Add an accessor to MutableDictionaryAttr to get the internal dictionary without creating a new one if it is empty. This avoids an otherwise unnecessary lookup of an MLIRContext.
Using an Identifier is much more efficient for attribute lookups because it uses pointer comparison as opposed to string comparison.
Differential Revision: https://reviews.llvm.org/D89660
The initial goal of this interface is to fix the current problems with verifying symbol user operations, but can extend beyond that in the future. The current problems with the verification of symbol uses are:
* Extremely inefficient:
Most current symbol users perform the symbol lookup using the slow O(N) string compare methods, which can lead to extremely long verification times in large modules.
* Invalid/break the constraints of verification pass
If the symbol reference is not-flat(and even if it is flat in some cases) a verifier for an operation is not permitted to touch the referenced operation because it may be in the process of being mutated by a different thread within the pass manager.
The new SymbolUserOpInterface exposes a method `verifySymbolUses` that will be invoked from the parent symbol table to allow for verifying the constraints of any referenced symbols. This method is passed a `SymbolTableCollection` to allow for O(1) lookups of any necessary symbol operation.
Differential Revision: https://reviews.llvm.org/D89512
This revision contains two optimizations related to symbol checking:
* Optimize SymbolOpInterface to only check for a name attribute if the operation is an optional symbol.
This removes an otherwise unnecessary attribute lookup from a majority of symbols.
* Add a new SymbolTableCollection class to represent a collection of SymbolTables.
This allows for perfoming non-flat symbol lookups in O(1) time by caching SymbolTables for symbol table operations. This class is very useful for algorithms that operate on multiple symbol tables, either recursively or not.
Differential Revision: https://reviews.llvm.org/D89505
This is a wrapper around vector of NamedAttributes that keeps track of whether sorted and does some minimal effort to remain sorted (doing more, e.g., appending attributes in sorted order, could be done in follow up). It contains whether sorted and if a DictionaryAttr is queried, it caches the returned DictionaryAttr along with whether sorted.
Change MutableDictionaryAttr to always return a non-null Attribute even when empty (reserve null cases for errors). To this end change the getter to take a context as input so that the empty DictionaryAttr could be queried. Also create one instance of the empty dictionary attribute that could be reused without needing to lock context etc.
Update infer type op interface to use DictionaryAttr and use NamedAttrList to avoid incurring multiple conversion costs.
Fix bug in sorting helper function.
Differential Revision: https://reviews.llvm.org/D79463
This allows for walking the operations nested directly within a region, without traversing nested regions.
Differential Revision: https://reviews.llvm.org/D79056
Makes the relationship and function clearer. Accordingly rename getAttrList to getMutableAttrDict.
Differential Revision: https://reviews.llvm.org/D79125
This revision adds support for propagating constants across symbol-based callgraph edges. It uses the existing Call/CallableOpInterfaces to detect the dataflow edges, and propagates constants through arguments and out of returns.
Differential Revision: https://reviews.llvm.org/D78592
This provides a much cleaner interface into Symbols, and allows for users to start injecting op-specific information. For example, derived op can now inject when a symbol can be discarded if use_empty. This would let us drop unused external functions, which generally have public visibility.
This revision also adds a new `extraTraitClassDeclaration` field to ODS OpInterface to allow for injecting declarations into the trait class that gets attached to the operations.
Differential Revision: https://reviews.llvm.org/D78522
This revision moves the various range utilities present in MLIR to LLVM to enable greater reuse. This revision moves the following utilities:
* indexed_accessor_*
This is set of utility iterator/range base classes that allow for building a range class where the iterators are represented by an object+index pair.
* make_second_range
Given a range of pairs, returns a range iterating over the `second` elements.
* hasSingleElement
Returns if the given range has 1 element. size() == 1 checks end up being very common, but size() is not always O(1) (e.g., ilist). This method provides O(1) checks for those cases.
Differential Revision: https://reviews.llvm.org/D78064
This revision moves several type_trait utilities from MLIR into LLVM. Namely, this revision adds:
is_detected - This matches the experimental std::is_detected
is_invocable - This matches the c++17 std::is_invocable
function_traits - A utility traits class for getting the argument and result types of a callable type
Differential Revision: https://reviews.llvm.org/D78059
