CIRCT  19.0.0git
ArcReductions.cpp
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1 //===- ArcReductions.cpp - Reduction patterns for the Arc Dialect -=-------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
12 #include "mlir/IR/Builders.h"
13 #include "llvm/ADT/STLExtras.h"
14 #include "llvm/Support/Debug.h"
15 
16 #define DEBUG_TYPE "arc-reductions"
17 
18 using namespace circt;
19 using namespace arc;
20 
21 //===----------------------------------------------------------------------===//
22 // Reduction patterns
23 //===----------------------------------------------------------------------===//
24 
25 /// A sample reduction pattern that converts `arc.state` operations to the
26 /// simpler `arc.call` operation and removes clock, latency, name attributes,
27 /// enables, and resets in the process.
28 struct StateElimination : public OpReduction<StateOp> {
29  LogicalResult rewrite(StateOp stateOp) override {
30  OpBuilder builder(stateOp);
31  ValueRange results =
32  builder
33  .create<arc::CallOp>(stateOp.getLoc(), stateOp->getResultTypes(),
34  stateOp.getArcAttr(), stateOp.getInputs())
35  ->getResults();
36  stateOp.replaceAllUsesWith(results);
37  stateOp.erase();
38  return success();
39  }
40 
41  std::string getName() const override { return "arc-state-elimination"; }
42 };
43 
44 //===----------------------------------------------------------------------===//
45 // Reduction Registration
46 //===----------------------------------------------------------------------===//
47 
50  // Gather a list of reduction patterns that we should try. Ideally these are
51  // assigned reasonable benefit indicators (higher benefit patterns are
52  // prioritized). For example, things that can knock out entire modules while
53  // being cheap should be tried first (and thus have higher benefit), before
54  // trying to tweak operands of individual arithmetic ops.
55  patterns.add<PassReduction, 4>(getContext(), arc::createStripSVPass(), true,
56  true);
57  patterns.add<PassReduction, 3>(getContext(), arc::createDedupPass());
58  patterns.add<StateElimination, 2>();
59  patterns.add<PassReduction, 1>(getContext(),
61 }
62 
64  mlir::DialectRegistry &registry) {
65  registry.addExtension(+[](MLIRContext *ctx, ArcDialect *dialect) {
66  dialect->addInterfaces<ArcReducePatternDialectInterface>();
67  });
68 }
Builder builder
std::unique_ptr< mlir::Pass > createArcCanonicalizerPass()
void registerReducePatternDialectInterface(mlir::DialectRegistry &registry)
Register the Arc Reduction pattern dialect interface to the given registry.
std::unique_ptr< mlir::Pass > createDedupPass()
Definition: Dedup.cpp:743
std::unique_ptr< mlir::Pass > createStripSVPass()
Definition: StripSV.cpp:182
This file defines an intermediate representation for circuits acting as an abstraction for constraint...
Definition: DebugAnalysis.h:21
A sample reduction pattern that converts arc.state operations to the simpler arc.call operation and r...
LogicalResult rewrite(StateOp stateOp) override
std::string getName() const override
Return a human-readable name for this reduction pattern.
A reduction pattern that applies an mlir::Pass.
Definition: Reduction.h:99
A dialect interface to provide reduction patterns to a reducer tool.
Definition: ArcReductions.h:18
void populateReducePatterns(circt::ReducePatternSet &patterns) const override