This commit renames 4 pattern rewriter API functions:
* `updateRootInPlace` -> `modifyOpInPlace`
* `startRootUpdate` -> `startOpModification`
* `finalizeRootUpdate` -> `finalizeOpModification`
* `cancelRootUpdate` -> `cancelOpModification`
The term "root" is a misnomer. The root is the op that a rewrite pattern
matches against
(https://mlir.llvm.org/docs/PatternRewriter/#root-operation-name-optional).
A rewriter must be notified of all in-place op modifications, not just
in-place modifications of the root
(https://mlir.llvm.org/docs/PatternRewriter/#pattern-rewriter). The old
function names were confusing and have contributed to various broken
rewrite patterns.
Note: The new function names use the term "modify" instead of "update"
for consistency with the `RewriterBase::Listener` terminology
(`notifyOperationModified`).
For 1:N type conversion, there is a 1:N relationship between the
original operands and the converted operands. The same is true for the
results. The previous design passed an instance of a "mapping" class
into each pattern that helped with handling this 1:N correspondance.
However, this was still rather manual and, in particular, it required
the use of magic constants for the indices of the different operands.
This commits uses the generated GenericAdaptor class that is generated
for each op class in order to simplify this relationship further. The
GenericAdaptor allows to wrap around a list of arbitrary types for each
operand (via templating); for 1:N type conversion, this allows the
operand accessors of the adaptor class to return a ValueRange that
corresponds to the N values in the converted types. Patterns can thus
use the named accessors instead of magic constants, which eliminates a
common class of errors.
This commit further simplifies the API that patterns need to implement
by making the operand and result type mappings part of the adaptor.
Since many patterns only need one of the two (or even neither), this
reduces the number of unnecessary arguments in many cases.
Reviewed By: springerm
Differential Revision: https://reviews.llvm.org/D147225
The current dialect conversion does not support 1:N type conversions.
This commit implements a (poor-man's) dialect conversion pass that does
just that. To keep the pass independent of the "real" dialect conversion
infrastructure, it provides a specialization of the TypeConverter class
that allows for N:1 target materializations, a specialization of the
RewritePattern and PatternRewriter classes that automatically add
appropriate unrealized casts supporting 1:N type conversions and provide
converted operands for implementing subclasses, and a conversion driver
that applies the provided patterns and replaces the unrealized casts
that haven't folded away with user-provided materializations.
The current pass is powerful enough to express many existing manual
solutions for 1:N type conversions or extend transforms that previously
didn't support them, out of which this patch implements call graph type
decomposition (which is currently implemented with a ValueDecomposer
that is only used there).
The goal of this pass is to illustrate the effect that 1:N type
conversions could have, gain experience in how patterns should be
written that achieve that effect, and get feedback on how the APIs of
the dialect conversion should be extended or changed to support such
patterns. The hope is that the "real" dialect conversion eventually
supports such patterns, at which point, this pass could be removed
again.
Reviewed By: springerm
Differential Revision: https://reviews.llvm.org/D144469
The current dialect conversion does not support 1:N type conversions.
This commit implements a (poor-man's) dialect conversion pass that does
just that. To keep the pass independent of the "real" dialect conversion
infrastructure, it provides a specialization of the TypeConverter class
that allows for N:1 target materializations, a specialization of the
RewritePattern and PatternRewriter classes that automatically add
appropriate unrealized casts supporting 1:N type conversions and provide
converted operands for implementing subclasses, and a conversion driver
that applies the provided patterns and replaces the unrealized casts
that haven't folded away with user-provided materializations.
The current pass is powerful enough to express many existing manual
solutions for 1:N type conversions or extend transforms that previously
didn't support them, out of which this patch implements call graph type
decomposition (which is currently implemented with a ValueDecomposer
that is only used there).
The goal of this pass is to illustrate the effect that 1:N type
conversions could have, gain experience in how patterns should be
written that achieve that effect, and get feedback on how the APIs of
the dialect conversion should be extended or changed to support such
patterns. The hope is that the "real" dialect conversion eventually
supports such patterns, at which point, this pass could be removed
again.
Reviewed By: springerm
Differential Revision: https://reviews.llvm.org/D144469
