make operations provide a list of canonicalizations that can be applied to
them. This allows canonicalization to be general to any IR definition.
As part of this, sink PatternMatch.h/cpp down to the IR library to fix a
layering problem.
PiperOrigin-RevId: 218773981
This is done by changing Attribute to be a POD interface around an underlying pointer storage and adding in-class support for isa/dyn_cast/cast.
PiperOrigin-RevId: 218764173
- Introduce Fourier-Motzkin variable elimination to eliminate a dimension from
a system of linear equalities/inequalities. Update isEmpty to use this.
Since FM is only exact on rational/real spaces, an emptiness check based on
this is guaranteed to be exact whenever it says the underlying set is empty;
if it says, it's not empty, there may still be no integer points in it.
Also, supports a version that computes "dark shadows".
- Test this by checking for "always false" conditionals in if statements.
- Unique IntegerSet's that are small (few constraints, few variables). This
basically means the canonical empty set and other small sets that are
likely commonly used get uniqued; allows checking for the canonical empty set
by pointer. IntegerSet::kUniquingThreshold gives the threshold constraint size
for uniqui'ing.
- rename simplify-affine-expr -> simplify-affine-structures
Other cleanup
- IntegerSet::numConstraints, AffineMap::numResults are no longer needed;
remove them.
- add copy assignment operators for AffineMap, IntegerSet.
- rename Invalid() -> Null() on AffineExpr, AffineMap, IntegerSet
- Misc cleanup for FlatAffineConstraints API
PiperOrigin-RevId: 218690456
For some of the constant vector / tesor, if the compiler doesn't need to
interpret their elements content, they can be stored in this class to save the
serialize / deserialize cost.
syntax:
`opaque<` tensor-type `,` opaque-string `>`
opaque-string ::= `0x` [0-9a-fA-F]*
PiperOrigin-RevId: 218399426
a step forward because now every AbstractOperation knows which Dialect it is
associated with, enabling things in the future like "constant folding
hooks" which will be important for layering. This is also a bit nicer on
the registration side of things.
PiperOrigin-RevId: 218104230
We should be able to represent arbitrary precision Float-point values inside
the IR, so compiler optimizations, such as constant folding can be done
independently on the compiling platform.
This CL also added a new field, AttrValueGetter, to the Attr class definition
for TableGen. This field is used to customize which mlir::Attr getter method to
get the defined PrimitiveType.
PiperOrigin-RevId: 218034983
The SparseElementsAttr uses (COO) Coordinate List encoding to represents a
sparse tensor / vector. Specifically, the coordinates and values are stored as
two dense elements attributes. The first dense elements attribute is a 2-D
attribute with shape [N, ndims], which contains the indices of the elements
with nonzero values in the constant vector/tensor. The second elements
attribute is a 1-D attribute list with shape [N], which supplies the values for
each element in the first elements attribute. ndims is the rank of the
vector/tensor and N is the total nonzero elements.
The syntax is:
`sparse<` (tensor-type | vector-type)`, ` indices-attribute-list, values-attribute-list `>`
Example: a sparse tensor
sparse<vector<3x4xi32>, [[0, 0], [1, 2]], [1, 2]> represents the dense tensor
[[1, 0, 0, 0]
[0, 0, 2, 0]
[0, 0, 0, 0]]
PiperOrigin-RevId: 217764319
The syntax of dense vecor/tensor attribute value is
`dense<` (tensor-type | vector-type)`,` attribute-list`>`
and
attribute-list ::= `[` attribute-list (`, ` attribute-list)* `]`.
The construction of the dense vector/tensor attribute takes a vector/tensor
type and a character array as arguments. The size of the input array should be
larger than the size specified by the type argument. It also assumes the
elements of the vector or tensor have been trunked to the data type sizes in
the input character array, so it extends the trunked data to 64 bits when it is
retrieved.
PiperOrigin-RevId: 217762811
* Move Return, Constant and AffineApply out into BuiltinOps;
* BuiltinOps are always registered, while StandardOps follow the same dynamic registration;
* Kept isValidX in MLValue as we don't have a verify on AffineMap so need to keep it callable from Parser (I wanted to move it to be called in verify instead);
PiperOrigin-RevId: 216592527
This CL applies the same pattern as AffineMap to IntegerSet: a simple struct
that acts as the storage is allocated in the bump pointer. The IntegerSet is
immutable and accessed everywhere by value.
Note that unlike AffineMap, it is not possible to remove the MLIRContext
parameter when constructing an IntegerSet for now. One possible way to achieve
this would be to add an enum to distinguish between the mathematically empty
set, the universe set and other sets.
This is left for future discussion.
PiperOrigin-RevId: 216545361
This attribute represents a reference to a splat vector or tensor, where all
the elements have the same value. The syntax of the attribute is:
`splat<` (tensor-type | vector-type)`,` attribute-value `>`
PiperOrigin-RevId: 216537997
AbstractOperation* or an Identifier. This makes it possible to get to stuff in
AbstractOperation faster than going through a hash table lookup. This makes
constant folding a bit faster now, but will become more important with
subsequent changes.
PiperOrigin-RevId: 216476772
This CL applies the same pattern as AffineExpr to AffineMap: a simple struct
that acts as the storage is allocated in the bump pointer. The AffineMap is
immutable and accessed everywhere by value.
PiperOrigin-RevId: 216445930
This CL sketches what it takes for AffineExpr to fully have by-value semantics
and not be a not-so-smart pointer anymore.
This essentially makes the underyling class a simple storage struct and
implements the operations on the value type directly. Since there is no
forwarding of operations anymore, we can full isolate the storage class and
make a hard visibility barrier by moving detail::AffineExpr into
AffineExprDetail.h.
AffineExprDetail.h is only included where storage-related information is
needed.
PiperOrigin-RevId: 216385459
This CL:
1. performs the global codemod AffineXExpr->AffineXExprClass and
AffineXExprRef -> AffineXExpr;
2. simplifies function calls by removing the redundant MLIRContext parameter;
3. adds missing binary operator versions of scalar op AffineExpr where it
makes sense.
PiperOrigin-RevId: 216242674
This CL introduces a series of cleanups for AffineExpr value types:
1. to make it clear that the value types should be used, the pointer
AffineExpr types are put in the detail namespace. Unfortunately, since the
value type operator-> only forwards to the underlying pointer type, we
still
need to expose this in the include file for now;
2. AffineExprKind is ok to use, it thus comes out of detail and thus of
AffineExpr
3. getAffineDimExpr, getAffineSymbolExpr, getAffineConstantExpr are
similarly
extracted as free functions and their naming is mande consistent across
Builder, MLContext and AffineExpr
4. AffineBinaryOpEx::simplify functions are made into static free
functions.
In particular it is moved away from AffineMap.cpp where it does not belong
5. operator AffineExprType is made explicit
6. uses the binary operators everywhere possible
7. drops the pointer usage everywhere outside of AffineExpr.cpp,
MLIRContext.cpp and AsmPrinter.cpp
PiperOrigin-RevId: 216207212
This CL starts by replacing AffineExpr* with value-type AffineExprRef in a few
places in the IR. By a domino effect that is pretty telling of the
inconsistencies in the codebase, const is removed where it makes sense.
The rationale is that the decision was concisously made that unique'd types
have pointer semantics without const specifier. This is fine but we should be
consistent. In the end, the only logical invariant is that there should never
be such a thing as a const AffineExpr*, const AffineMap* or const IntegerSet*
in our codebase.
This CL takes a number of shortcuts to killing const with fire, in particular
forcing const AffineExprRef to return the underlying non-const
AffineExpr*. This will be removed once AffineExpr* has disappeared in
containers but for now such shortcuts allow a bit of sanity in this long quest
for cleanups.
The **only** places where const AffineExpr*, const AffineMap* or const
IntegerSet* may still appear is by transitive needs from containers,
comparison operators etc.
There is still one major thing remaining here: figure out why cast/dyn_cast
return me a const AffineXXX*, which in turn requires a bunch of ugly
const_casts. I suspect this is due to the classof
taking const AffineXXXExpr*. I wonder whether this is a side effect of 1., if
it is coming from llvm itself (I'd doubt it) or something else (clattner@?)
In light of this, the whole discussion about const makes total sense to me now
and I would systematically apply the rule that in the end, we should never
have any const XXX in our codebase for unique'd types (assuming we can remove
them all in containers and no additional constness constraint is added on us
from the outside world).
PiperOrigin-RevId: 215811554
This CL implements AffineExprBaseRef as a templated type to allow LLVM-style
casts to work properly. This also allows making AffineExprBaseRef::expr
private.
To achieve this, it is necessary to use llvm::simplify_type and make
AffineConstExpr derive from both AffineExpr and llvm::simplify<AffineExprRef>.
Note that llvm::simplify_type is just an interface to enable the proper
template resolution of isa/cast/dyn_cast but it otherwise holds no value.
Lastly note that certain dyn_cast operations wanted the const AffineExpr* form
of AffineExprBaseRef so I made the implicit constructor take that by default
and documented the immutable behavior. I think this is consistent with the
decision to make unique'd type immutable by convention and never use const on
them.
PiperOrigin-RevId: 215642247
This CL uniformizes the uses of AffineExprWrap outside of IR.
The public API of AffineExpr builder is modified to only use AffineExprWrap.
A few places access AffineExprWrap.expr, this is only while the API is in
transition to easily keep track (i.e. make expr private and let the compiler
track the errors).
Parser.cpp exhibits patterns that are dependent on nullptr values so
converting it is left for another CL.
PiperOrigin-RevId: 215642005
This CL proposes adding MLIRContext* to AffineExpr as discussed previously.
This allows the value class to not require the context in its constructor and
makes it a POD that it makes sense to pass by value everywhere.
A list of other RFC CLs will build on this. The RFC CLs are small incremental
pushes of the API which would be a pretty big change otherwise.
Pushing the thinking a little bit more it seems reasonable to use implicit
cast/constructor to/from AffineExpr*.
As this thing evolves, it looks to me like IR (and
probably Parser, for not so good reasons) want to operate on AffineExpr* and
the rest of the code wants to operate on the value type.
For this reason I think AffineExprImpl*/AffineExpr may also make sense but I
do not have a particular naming preference.
The jury is still out for naming decision between the above and
AffineExprBase*/AffineExpr or AffineExpr*/AffineExprRef.
PiperOrigin-RevId: 215641596
Instead of linking in different initializeMLIRContext functions, add a registry mechanism and function to initialize all registered ops in a given MLIRContext. Initialize all registered ops along with the StandardOps when constructing a MLIRContext.
PiperOrigin-RevId: 214073842
infrastructure, instead of returning a const char*. This allows custom
formatting and more interesting diagnostics.
This patch regresses the error message quality from the control flow
lowering pass, I'll address this in a subsequent patch.
PiperOrigin-RevId: 212210681
- Add a new -verify mode to the mlir-opt tool that allows writing test cases
for optimization and other passes that produce diagnostics.
- Refactor existing the -check-parser-errors flag to mlir-opt into a new
-split-input-file option which is orthogonal to -verify.
- Eliminate the special error hook the parser maintained and use the standard
MLIRContext's one instead.
- Enhance the default MLIRContext error reporter to print file/line/col of
errors when it is available.
- Add new createChecked() methods to the builder that create ops and invoke
the verify hook on them, use this to detected unhandled code in the
RaiseControlFlow pass.
- Teach mlir-opt about expected-error @+, it previously only worked with @-
PiperOrigin-RevId: 211305770
(and more useful) way rather than hacking up a pile of attributes for it. In
the future this will grow to represent inlined locations, fusion cases etc, but
for now we start with simple Unknown and File/Line/Col locations. NFC.
PiperOrigin-RevId: 210485775
new VectorOrTensorType class that provides a common interface between vector
and tensor since a number of operations will be uniform across them (including
extract_element). Improve the LoadOp verifier.
I also updated the MLIR spec doc as well.
PiperOrigin-RevId: 209953189
- Have the parser rewrite forward references to their resolved values at the
end of parsing.
- Implement verifier support for detecting malformed function attrs.
- Add efficient query for (in general, recursive) attributes to tell if they
contain a function.
As part of this, improve other general infrastructure:
- Implement support for verifying OperationStmt's in ml functions, refactoring
and generalizing support for operations in the verifier.
- Refactor location handling code in mlir-opt to have the non-error expecting
form of mlir-opt invocations to report error locations precisely.
- Fix parser to detect verifier failures and report them through errorReporter
instead of printing the error and crashing.
This regresses the location info for verifier errors in the parser that were
previously ascribed to the function. This will get resolved in future patches
by adding support for function attributes, which we can use to manage location
information.
PiperOrigin-RevId: 209600980
resolver support.
Still TODO are verifier support (to make sure you don't use an attribute for a
function in another module) and the TODO in ModuleParser::finalizeModule that I
will handle in the next patch.
PiperOrigin-RevId: 209361648
- introduce affine integer sets into the IR
- parse and print affine integer sets (both inline or outlined) similar to
affine maps
- use integer set for IfStmt's conditional, and implement parsing of IfStmt's
conditional
- fixed an affine expr paren omission bug while one this.
TODO: parse/represent/print MLValue operands to affine integer set references.
PiperOrigin-RevId: 207779408
- Implement a diagnostic hook in one of the paths in mlir-opt which
captures and reports the diagnostics nicely.
- Have the parser capture simple location information from the parser
indicating where each op came from in the source .mlir file.
- Add a verifyDominance() method to MLFuncVerifier to demo this, resolving b/112086163
- Add some PrettyStackTrace handlers to make crashes in the testsuite easier
to track down.
PiperOrigin-RevId: 207488548
handlers and to feed them with errors and warnings produced by the compiler.
Enhance Operation to be able to get its own MLIRContext on demand, simplifying
some clients. Change the verifier to emit certain errors with the diagnostic
handler.
This is steps towards reworking the verifier and diagnostic propagation but is
itself not particularly useful. More to come.
PiperOrigin-RevId: 206948643
and OtherType. Other type is now the thing that holds AffineInt, Control,
eventually Resource, Variant, String, etc. FloatType holds the floating point
types, and allows convenient query of isa<FloatType>().
This fixes issues where we allowed control to be the element type of tensor,
memref, vector. At the same time, ban AffineInt from being an element of a
vector/memref/tensor as well since we don't need it.
I updated the spec to match this as well.
PiperOrigin-RevId: 206361942
The code for this has been convoluted. We shouldn't be doing a "*result =
simplified" below at 703 since the simplified expression would have already
been inserted by a simplify* method, whether it was a binary op expr or
something else.
PiperOrigin-RevId: 206114115
While fixing this the parser-affine-map.mlir test started failing due to ordering of the printed affine maps. Even the existing CHECK-DAGs weren't enough to disambiguate; a partial match on one line precluded a total match on a following line.
The fix for this was easy - print the affine maps in reference order rather than in DenseMap iteration order.
PiperOrigin-RevId: 205843770
- Drop sub-classing of affine binary op expressions.
- Drop affine expr op kind sub. Represent it as multiply by -1 and add. This
will also be in line with the math form when we'll need to represent a system of
linear equalities/inequalities: the negative number goes into the coefficient
of an affine form. (For eg. x_1 + (-1)*x_2 + 3*x_3 + (-2) >= 0). The folding
simplification will transparently deal with multiplying the -1 with any other
constants. This also means we won't need to simplify a multiply expression
like in x_1 + (-2)*x_2 to a subtract expression (x_1 - 2*x_2) for
canonicalization/uniquing.
- When we print the IR, we will still pretty print to a subtract when possible.
PiperOrigin-RevId: 205298958
- fold constants when possible.
- for a mul expression, canonicalize to always keep the LHS as the
constant/symbolic term, and similarly, the RHS for an add expression to keep
it closer to the mathematical form. (Eg: f(x) = 3*x + 5)); other similar simplifications;
- verify binary op expressions at creation time.
TODO: we can completely drop AffineSubExpr, and instead use add and mul by -1.
This way something like x - 4 and -4 + x get canonicalized to x + -1 * 4
instead of being x - 4 and x + -4. (The other alternative if wanted to retain
AffineSubExpr would be to simplify x + -1*y to x - y and x + <neg number> to x
- <pos number>).
PiperOrigin-RevId: 204240258
Uday Bondhugula