Merge pull request #114 from tnguyen-ornl/tnguyen/add-example-for-dmitry (875247fb) · Commits · ORNL Quantum Computing Institute / tnqvm

tnqvm/visitors/exatn-mps/ExaTnMpsVisitor.cpp

+105 −54

Original line number	Diff line number	Diff line
		@@ -2040,7 +2040,7 @@ void ExatnMpsVisitor::applyTwoQubitGate(xacc::Instruction& in_gateInstruction)
		m_tensorNetwork = std::make_shared<exatn::TensorNetwork>(m_tensorNetwork->getName(), mpsString, buildTensorMap());
		{
		// Truncate SVD tensors:
		truncateSvdTensors(q1TensorName, q2TensorName, m_svdCutoff);
		truncateSvdTensors(q1TensorName, q2TensorName, m_svdCutoff, m_selfProcessGroup.get());
		}

		// Rebuild the tensor network since the qubit tensors have been changed after SVD truncation
		@@ -2093,6 +2093,7 @@ void ExatnMpsVisitor::applyTwoQubitGate(xacc::Instruction& in_gateInstruction)
		rebuildTensorNetwork();
		// Now, the remote tensor has been initialized, process gate as normal:
		// Apply gate
		xacc::info("Process [" + std::to_string(m_rank) + "]: Process gate: " + in_gateInstruction.toString());
		processTwoQubitGate();
		// Done: Send tensor to the neighbor process
		// Send tensor forward
		@@ -2104,6 +2105,15 @@ void ExatnMpsVisitor::applyTwoQubitGate(xacc::Instruction& in_gateInstruction)
		const bool postBroadCastOk = exatn::replicateTensorSync(*m_rightSharedProcessGroup, qubitTensorName, 0);
		assert(postBroadCastOk);
		}
		{
		unsigned int neighborRank;
		const bool checkRank =
		m_rightSharedProcessGroup->rankIsIn(m_rank + 1, &neighborRank);
		assert(checkRank);
		const bool dereplicateTensorOk = exatn::dereplicateTensorSync(
		*m_rightSharedProcessGroup, qubitTensorName, neighborRank);
		assert(dereplicateTensorOk);
		}
		}
		else if (indexInRange(qMax, m_qubitRange))
		{
		@@ -2134,6 +2144,15 @@ void ExatnMpsVisitor::applyTwoQubitGate(xacc::Instruction& in_gateInstruction)
		assert(postBroadCastOk);
		}

		{
		unsigned int myLocalRank;
		const bool checkRank =
		m_leftSharedProcessGroup->rankIsIn(m_rank, &myLocalRank);
		assert(checkRank);
		const bool dereplicateTensorOk = exatn::dereplicateTensorSync(
		*m_leftSharedProcessGroup, qubitTensorName, myLocalRank);
		assert(dereplicateTensorOk);
		}
		// Update the tensor network to take into
		// account the updated tensor.
		rebuildTensorNetwork();
		@@ -2387,7 +2406,7 @@ std::vector<uint8_t> ExatnMpsVisitor::getMeasureSample(const std::vector<size_t>
		return resultBitString;
		}

		void ExatnMpsVisitor::truncateSvdTensors(const std::string& in_leftTensorName, const std::string& in_rightTensorName, double in_eps)
		void ExatnMpsVisitor::truncateSvdTensors(const std::string& in_leftTensorName, const std::string& in_rightTensorName, double in_eps, exatn::ProcessGroup *in_processGroup)
		{
		int lhsTensorId = -1;
		int rhsTensorId = -1;
		@@ -2470,24 +2489,43 @@ void ExatnMpsVisitor::truncateSvdTensors(const std::string& in_leftTensorName, c
		assert(newBondDim > 0);
		if (newBondDim < bondDim)
		{
		// xacc::info("Truncate SVD bond.");
		auto leftShape = lhsTensor->getDimExtents();
		auto rightShape = rhsTensor->getDimExtents();
		leftShape[lhsBondId] = newBondDim;
		rightShape[rhsBondId] = newBondDim;

		// Create two new tensors:
		const std::string newLhsTensorName = in_leftTensorName + "_" + std::to_string(lhsTensor->getTensorHash());
		const bool newLhsCreated = exatn::createTensorSync(newLhsTensorName, exatn::TensorElementType::COMPLEX64, leftShape);
		const std::string newLhsTensorName =
		in_leftTensorName + "_" + std::to_string(lhsTensor->getTensorHash());
		const bool newLhsCreated =
		in_processGroup
		? exatn::createTensorSync(*in_processGroup, newLhsTensorName,
		exatn::TensorElementType::COMPLEX64,
		leftShape)
		: exatn::createTensorSync(newLhsTensorName,
		exatn::TensorElementType::COMPLEX64,
		leftShape);
		assert(newLhsCreated);

		const std::string newRhsTensorName = in_rightTensorName + "_" + std::to_string(rhsTensor->getTensorHash());
		const bool newRhsCreated = exatn::createTensorSync(newRhsTensorName, exatn::TensorElementType::COMPLEX64, rightShape);
		const std::string newRhsTensorName =
		in_rightTensorName + "_" + std::to_string(rhsTensor->getTensorHash());
		const bool newRhsCreated =
		in_processGroup
		? exatn::createTensorSync(*in_processGroup, newRhsTensorName,
		exatn::TensorElementType::COMPLEX64,
		rightShape)
		: exatn::createTensorSync(newRhsTensorName,
		exatn::TensorElementType::COMPLEX64,
		rightShape);
		assert(newRhsCreated);

		// Take the slices:
		const bool lhsSliceOk = exatn::extractTensorSliceSync(in_leftTensorName, newLhsTensorName);
		const bool lhsSliceOk =
		exatn::extractTensorSliceSync(in_leftTensorName, newLhsTensorName);
		assert(lhsSliceOk);
		const bool rhsSliceOk = exatn::extractTensorSliceSync(in_rightTensorName, newRhsTensorName);
		const bool rhsSliceOk =
		exatn::extractTensorSliceSync(in_rightTensorName, newRhsTensorName);
		assert(rhsSliceOk);

		// Destroy the two original tensors:
		@@ -2497,19 +2535,30 @@ void ExatnMpsVisitor::truncateSvdTensors(const std::string& in_leftTensorName, c
		assert(rhsDestroyed);

		// Rename new tensors to the old name
		const auto renameNumericTensor = [](const std::string& oldTensorName, const std::string& newTensorName){
		const auto renameNumericTensor = [&in_processGroup](
		const std::string &oldTensorName,
		const std::string &newTensorName) {
		auto tensor = exatn::getTensor(oldTensorName);
		assert(tensor);
		auto talsh_tensor = exatn::getLocalTensor(oldTensorName);
		assert(talsh_tensor);
		const std::complex<double> *body_ptr;
		const bool access_granted = talsh_tensor->getDataAccessHostConst(&body_ptr);
		const bool access_granted =
		talsh_tensor->getDataAccessHostConst(&body_ptr);
		assert(access_granted);
		std::vector<std::complex<double>> newData;
		newData.assign(body_ptr, body_ptr + talsh_tensor->getVolume());
		const bool newTensorCreated = exatn::createTensorSync(newTensorName, exatn::TensorElementType::COMPLEX64, tensor->getShape());
		const bool newTensorCreated =
		in_processGroup
		? exatn::createTensorSync(*in_processGroup, newTensorName,
		exatn::TensorElementType::COMPLEX64,
		tensor->getShape())
		: exatn::createTensorSync(newTensorName,
		exatn::TensorElementType::COMPLEX64,
		tensor->getShape());
		assert(newTensorCreated);
		const bool newTensorInitialized = exatn::initTensorDataSync(newTensorName, newData);
		const bool newTensorInitialized =
		exatn::initTensorDataSync(newTensorName, newData);
		assert(newTensorInitialized);
		// Destroy the two original tensor:
		const bool tensorDestroyed = exatn::destroyTensorSync(oldTensorName);
		@@ -2520,9 +2569,11 @@ void ExatnMpsVisitor::truncateSvdTensors(const std::string& in_leftTensorName, c
		renameNumericTensor(newRhsTensorName, in_rightTensorName);

		// Debug:
		// std::cout << "[DEBUG] Bond dim (" << in_leftTensorName << ", " << in_rightTensorName << "): " << bondDim << " -> " << newBondDim << "\n";
		// std::cout << "[DEBUG] Bond dim (" << in_leftTensorName << ", " <<
		// in_rightTensorName << "): " << bondDim << " -> " << newBondDim << "\n";
		std::stringstream logSs;
		logSs << "[SVD] Bond dim (" << in_leftTensorName << ", " << in_rightTensorName << "): " << bondDim << " -> " << newBondDim;
		logSs << "[SVD] Bond dim (" << in_leftTensorName << ", "
		<< in_rightTensorName << "): " << bondDim << " -> " << newBondDim;
		xacc::info(logSs.str());
		}
		}

tnqvm/visitors/exatn-mps/ExaTnMpsVisitor.hpp

+4 −1

Original line number	Diff line number	Diff line
		@@ -120,7 +120,10 @@ private:
		std::vector<uint8_t> getMeasureSample(const std::vector<size_t>& in_qubitIdx);
		void printStateVec();
		// Truncate the bond dimension between two tensors that are decomposed by SVD
		void truncateSvdTensors(const std::string& in_leftTensorName, const std::string& in_rightTensorName, double in_eps = std::numeric_limits<double>::min());
		void truncateSvdTensors(const std::string &in_leftTensorName,
		const std::string &in_rightTensorName,
		double in_eps = std::numeric_limits<double>::min(),
		exatn::ProcessGroup *in_processGroup = nullptr);
		std::vector<std::complex<double>> computeWaveFuncSlice(const exatn::numerics::TensorNetwork& in_tensorNetwork, const std::vector<int>& bitString, const exatn::ProcessGroup& in_processGroup) const;
		double computeStateVectorNorm(const exatn::numerics::TensorNetwork& in_tensorNetwork, const exatn::ProcessGroup& in_processGroup) const;

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