Files
concrete/compilers/concrete-compiler/compiler/lib/Transforms/ForLoopToParallel.cpp
Benoit Chevallier-Mames e37a840e7e docs(compiler): adding API doc
2024-03-13 17:10:00 +01:00

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3.3 KiB
C++

// Part of the Concrete Compiler Project, under the BSD3 License with Zama
// Exceptions. See
// https://github.com/zama-ai/concrete/blob/main/LICENSE.txt
// for license information.
#include "concretelang/Transforms/Passes.h"
#include "mlir/Dialect/Bufferization/Transforms/Bufferize.h"
#include "mlir/Dialect/SCF/IR/SCF.h"
#include "mlir/IR/IRMapping.h"
#include "mlir/IR/Operation.h"
#include "mlir/Transforms/DialectConversion.h"
#include "mlir/Transforms/Passes.h"
#include <mlir/Transforms/GreedyPatternRewriteDriver.h>
namespace {
class ForOpPattern : public mlir::OpRewritePattern<mlir::scf::ForOp> {
public:
ForOpPattern(::mlir::MLIRContext *context, mlir::PatternBenefit benefit = 1)
: ::mlir::OpRewritePattern<mlir::scf::ForOp>(context, benefit) {}
mlir::LogicalResult
matchAndRewrite(mlir::scf::ForOp forOp,
mlir::PatternRewriter &rewriter) const override {
auto attr = forOp->getAttrOfType<mlir::BoolAttr>("parallel");
if (attr == nullptr) {
return mlir::failure();
}
assert(forOp.getRegionIterArgs().size() == 0 &&
"unexpecting iter args when loops are bufferized");
if (attr.getValue()) {
rewriter.replaceOpWithNewOp<mlir::scf::ParallelOp>(
forOp, mlir::ValueRange{forOp.getLowerBound()},
mlir::ValueRange{forOp.getUpperBound()}, forOp.getStep(),
std::nullopt,
[&](mlir::OpBuilder &builder, mlir::Location location,
mlir::ValueRange indVar, mlir::ValueRange iterArgs) {
mlir::IRMapping map;
map.map(forOp.getInductionVar(), indVar.front());
for (auto &op : forOp.getRegion().front()) {
auto newOp = builder.clone(op, map);
map.map(op.getResults(), newOp->getResults());
}
});
} else {
rewriter.replaceOpWithNewOp<mlir::scf::ForOp>(
forOp, forOp.getLowerBound(), forOp.getUpperBound(), forOp.getStep(),
std::nullopt,
[&](mlir::OpBuilder &builder, mlir::Location location,
mlir::Value indVar, mlir::ValueRange iterArgs) {
mlir::IRMapping map;
map.map(forOp.getInductionVar(), indVar);
for (auto &op : forOp.getRegion().front()) {
auto newOp = builder.clone(op, map);
map.map(op.getResults(), newOp->getResults());
}
});
}
return mlir::success();
}
};
} // namespace
namespace {
struct ForLoopToParallelPass
: public ForLoopToParallelBase<ForLoopToParallelPass> {
void runOnOperation() override {
auto func = getOperation();
auto *context = &getContext();
mlir::RewritePatternSet patterns(context);
mlir::ConversionTarget target(*context);
patterns.add<ForOpPattern>(context);
target.addDynamicallyLegalOp<mlir::scf::ForOp>([&](mlir::scf::ForOp op) {
auto r = op->getAttrOfType<mlir::BoolAttr>("parallel") == nullptr;
return r;
});
target.markUnknownOpDynamicallyLegal(
[&](mlir::Operation *op) { return true; });
if (mlir::applyPatternsAndFoldGreedily(func, std::move(patterns))
.failed()) {
this->signalPassFailure();
};
}
};
} // namespace
std::unique_ptr<mlir::OperationPass<mlir::ModuleOp>>
mlir::concretelang::createForLoopToParallel() {
return std::make_unique<ForLoopToParallelPass>();
}