Add a pattern rewriter utility to erase blocks (while notifying the
pattern rewriting driver of the erased ops). Use this to remove trivial
else blocks in affine.if ops.
Differential Revision: https://reviews.llvm.org/D77083
Summary: PatternState was a mechanism to pass state between the match and rewrite calls of a RewritePattern. With the rise of matchAndRewrite, this class is unused and unnecessary. This revision removes PatternState and simplifies PatternMatchResult to just be a LogicalResult. A future revision will replace all usages of PatternMatchResult/matchSuccess/matchFailure with LogicalResult equivalents.
Differential Revision: https://reviews.llvm.org/D76202
Summary:
Remove 'valuesToRemoveIfDead' from PatternRewriter API. The removal
functionality wasn't implemented and we decided [1] not to implement it in
favor of having more powerful DCE approaches.
[1] https://github.com/tensorflow/mlir/pull/212
Reviewers: rriddle, bondhugula
Reviewed By: rriddle
Subscribers: liufengdb, mehdi_amini, rriddle, jpienaar, burmako, shauheen, antiagainst, nicolasvasilache, arpith-jacob, mgester, lucyrfox, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D72545
This means that in-place, or root, updates need to use explicit calls to `startRootUpdate`, `finalizeRootUpdate`, and `cancelRootUpdate`. The major benefit of this change is that it enables in-place updates in DialectConversion, which simplifies the FuncOp pattern for example. The major downside to this is that the cases that *may* modify an operation in-place will need an explicit cancel on the failure branches(assuming that they started an update before attempting the transformation).
PiperOrigin-RevId: 286933674
This class represents a generic abstraction over the different ways to represent a range of Values: ArrayRef<Value *>, operand_range, result_range. This class will allow for removing the many instances of explicit SmallVector<Value *, N> construction. It has the same memory cost as ArrayRef, and only suffers cost from indexing(if+elsing the different underlying representations).
This change only updates a few of the existing usages, with more to be changed in followups; e.g. 'build' API.
PiperOrigin-RevId: 284307996
A pattern rewriter hook, mergeBlock, is added that allows for merging the operations of one block into the end of another. This is used to support a canonicalization pattern for branch operations that folds the branch when the successor has a single predecessor(the branch block).
Example:
^bb0:
%c0_i32 = constant 0 : i32
br ^bb1(%c0_i32 : i32)
^bb1(%x : i32):
return %x : i32
becomes:
^bb0:
%c0_i32 = constant 0 : i32
return %c0_i32 : i32
PiperOrigin-RevId: 278677825
This is similar to the `inlineRegionBefore` hook, except the original blocks are unchanged. The region to be cloned *must* not have been modified during the conversion process at the point of cloning, i.e. it must belong an operation that has yet to be converted, or the operation that is currently being converted.
PiperOrigin-RevId: 273622533
These methods will allow replacing the uses of results with an existing operation, with the same number of results, or a range of values. This removes a number of hand-rolled result replacement loops and simplifies replacement for operations with multiple results.
PiperOrigin-RevId: 262206600
This allows for proper forward declaration, as opposed to leaking the internal implementation via a using directive. This also allows for all pattern building to go through 'insert' methods on the OwningRewritePatternList, replacing uses of 'push_back' and 'RewriteListBuilder'.
PiperOrigin-RevId: 261816316
This introduces the support for region-containing operations to the dialect
conversion framework in order to support the conversion of affine control-flow
operations into the standard control flow with branches. Regions that belong
to an operation are converted before the operation itself. The
DialectConversionPattern can therefore access the converted regions of the
original operation and process them further if necessary. In particular, the
conversion is allowed to move the blocks from the original region to other
regions and to split blocks into multiple blocks. All block manipulations must
be performed through the PatternRewriter to ensure they will be undone if the
conversion fails.
Port the pass converting from the affine dialect (loops and ifs with bodies as
regions) to the standard dialect (branch-based cfg) to use DialectConversion in
order to exercise this new functionality. The modification to the lowering
functions are minor and are focused on using the PatterRewriter instead of
directly modifying the IR.
PiperOrigin-RevId: 252625169
During the pattern rewrite, if the function is changed, i.e. ops created,
deleted or swapped, the pattern rewriter needs to re-scan the function entirely
and apply the patterns again, so the patterns whose root ops have been popped
out from the working list nor an immediate users of the changed ops can be
reconsidered.
A command line flag is added to set the max number of iterations rescanning the
function for pattern match. If the rewrite doesn' converge after this number,
this compiling will continue and the result can be sub-optimal.
One unit test is updated because this change fixed the missing optimization opportunities.
--
PiperOrigin-RevId: 244754190
This combined match/rewrite functionality allows simplifying the majority of existing RewritePatterns, as they do not benefit from separate match and rewrite functions.
Some of the existing canonicalization patterns in StandardOps have been modified to take advantage of this functionality.
PiperOrigin-RevId: 240187856
consistent and moving the using declarations over. Hopefully this is the last
truly massive patch in this refactoring.
This is step 21/n towards merging instructions and statements, NFC.
PiperOrigin-RevId: 227178245
is the new base of the SSA value hierarchy. This CL also standardizes all the
nomenclature and comments to use 'Value' where appropriate. This also eliminates a large number of cast<MLValue>(x)'s, which is very soothing.
This is step 11/n towards merging instructions and statements, NFC.
PiperOrigin-RevId: 227064624
class. This change is NFC, but allows for new kinds of patterns, specifically
LegalizationPatterns which will be allowed to change the types of things they
rewrite.
PiperOrigin-RevId: 223243783
time. The "Fast and Flexible Instruction Selection With Constraints" paper
from CC2018 makes a credible argument that dynamic costs aren't actually
necessary/important, and we are not using them.
- Check in my "MLIR Generic DAG Rewriter Infrastructure" design doc into the
source tree.
PiperOrigin-RevId: 221017546
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
Uday Bondhugula