llvm-project/mlir/lib/Dialect/Affine/Transforms/SimplifyAffineStructures.cpp
Chris Lattner 3a506b31a3 Change OwningRewritePatternList to carry an MLIRContext with it.
This updates the codebase to pass the context when creating an instance of
OwningRewritePatternList, and starts removing extraneous MLIRContext
parameters.  There are many many more to be removed.

Differential Revision: https://reviews.llvm.org/D99028
2021-03-21 10:06:31 -07:00

101 lines
3.6 KiB
C++

//===- SimplifyAffineStructures.cpp ---------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file implements a pass to simplify affine structures in operations.
//
//===----------------------------------------------------------------------===//
#include "PassDetail.h"
#include "mlir/Analysis/Utils.h"
#include "mlir/Dialect/Affine/IR/AffineOps.h"
#include "mlir/Dialect/Affine/Passes.h"
#include "mlir/IR/IntegerSet.h"
#include "mlir/Transforms/GreedyPatternRewriteDriver.h"
#include "mlir/Transforms/Utils.h"
#define DEBUG_TYPE "simplify-affine-structure"
using namespace mlir;
namespace {
/// Simplifies affine maps and sets appearing in the operations of the Function.
/// This part is mainly to test the simplifyAffineExpr method. In addition,
/// all memrefs with non-trivial layout maps are converted to ones with trivial
/// identity layout ones.
struct SimplifyAffineStructures
: public SimplifyAffineStructuresBase<SimplifyAffineStructures> {
void runOnFunction() override;
/// Utility to simplify an affine attribute and update its entry in the parent
/// operation if necessary.
template <typename AttributeT>
void simplifyAndUpdateAttribute(Operation *op, Identifier name,
AttributeT attr) {
auto &simplified = simplifiedAttributes[attr];
if (simplified == attr)
return;
// This is a newly encountered attribute.
if (!simplified) {
// Try to simplify the value of the attribute.
auto value = attr.getValue();
auto simplifiedValue = simplify(value);
if (simplifiedValue == value) {
simplified = attr;
return;
}
simplified = AttributeT::get(simplifiedValue);
}
// Simplification was successful, so update the attribute.
op->setAttr(name, simplified);
}
IntegerSet simplify(IntegerSet set) { return simplifyIntegerSet(set); }
/// Performs basic affine map simplifications.
AffineMap simplify(AffineMap map) {
MutableAffineMap mMap(map);
mMap.simplify();
return mMap.getAffineMap();
}
DenseMap<Attribute, Attribute> simplifiedAttributes;
};
} // end anonymous namespace
std::unique_ptr<OperationPass<FuncOp>>
mlir::createSimplifyAffineStructuresPass() {
return std::make_unique<SimplifyAffineStructures>();
}
void SimplifyAffineStructures::runOnFunction() {
auto func = getFunction();
simplifiedAttributes.clear();
OwningRewritePatternList patterns(func.getContext());
AffineForOp::getCanonicalizationPatterns(patterns, func.getContext());
AffineIfOp::getCanonicalizationPatterns(patterns, func.getContext());
AffineApplyOp::getCanonicalizationPatterns(patterns, func.getContext());
FrozenRewritePatternList frozenPatterns(std::move(patterns));
func.walk([&](Operation *op) {
for (auto attr : op->getAttrs()) {
if (auto mapAttr = attr.second.dyn_cast<AffineMapAttr>())
simplifyAndUpdateAttribute(op, attr.first, mapAttr);
else if (auto setAttr = attr.second.dyn_cast<IntegerSetAttr>())
simplifyAndUpdateAttribute(op, attr.first, setAttr);
}
// The simplification of the attribute will likely simplify the op. Try to
// fold / apply canonicalization patterns when we have affine dialect ops.
if (isa<AffineForOp, AffineIfOp, AffineApplyOp>(op))
(void)applyOpPatternsAndFold(op, frozenPatterns);
});
}