circt/lib/Dialect/FIRRTL/Transforms/LayerSink.cpp

55 lines
1.9 KiB
C++

//===- LayerSink.cpp - Sink ops into layer blocks -------------------------===//
//
// 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 sinks operations into layer blocks.
//
//===----------------------------------------------------------------------===//
#include "PassDetails.h"
#include "circt/Support/Debug.h"
#include "mlir/IR/Dominance.h"
#include "mlir/Interfaces/ControlFlowInterfaces.h"
#include "mlir/Interfaces/SideEffectInterfaces.h"
#include "mlir/Transforms/ControlFlowSinkUtils.h"
#define DEBUG_TYPE "firrtl-layer-sink"
using namespace circt;
using namespace firrtl;
namespace {
/// A control-flow sink pass.
struct LayerSink : public LayerSinkBase<LayerSink> {
void runOnOperation() override;
};
} // end anonymous namespace
void LayerSink::runOnOperation() {
LLVM_DEBUG(debugPassHeader(this)
<< "\n"
<< "Module: '" << getOperation().getName() << "'\n";);
auto &domInfo = getAnalysis<mlir::DominanceInfo>();
getOperation()->walk([&](LayerBlockOp layerBlock) {
SmallVector<Region *> regionsToSink({&layerBlock.getRegion()});
numSunk = controlFlowSink(
regionsToSink, domInfo,
[](Operation *op, Region *) { return !hasDontTouch(op); },
[](Operation *op, Region *region) {
// Move the operation to the beginning of the region's entry block.
// This guarantees the preservation of SSA dominance of all of the
// operation's uses are in the region.
op->moveBefore(&region->front(), region->front().begin());
});
});
}
std::unique_ptr<mlir::Pass> circt::firrtl::createLayerSinkPass() {
return std::make_unique<LayerSink>();
}