Merge branch 'master' into release-v0_15_0

Author: 95-martin-orion

lib/vectorspace.h

@@ -160,6 +160,20 @@ class VectorSpace {
     return true;
   }
 
+  // It is the client's responsibility to make sure that src has at least
+  // min(size, Impl::MinSize(dest.num_qubits())) elements.
+  bool Copy(const fp_type* src, uint64_t size, Vector& dest) const {
+    auto f = [](unsigned n, unsigned m, uint64_t i,
+                const fp_type* src, fp_type* dest) {
+      dest[i] = src[i];
+    };
+
+    size = std::min(size, Impl::MinSize(dest.num_qubits()));
+    for_.Run(size, f, src, dest.get());
+
+    return true;
+  }
+
   void DeviceSync() {}
 
  protected:

lib/vectorspace_cuda.h

@@ -141,6 +141,14 @@ class VectorSpaceCUDA {
     return true;
   }
 
+  // It is the client's responsibility to make sure that src has at least
+  // min(size, Impl::MinSize(dest.num_qubits())) elements.
+  bool Copy(const fp_type* src, uint64_t size, Vector& dest) const {
+    size = std::min(size, Impl::MinSize(dest.num_qubits()));
+    cudaMemcpy(dest.get(), src, sizeof(fp_type) * size, cudaMemcpyHostToDevice);
+    return true;
+  }
+
   void DeviceSync() {
     cudaDeviceSynchronize();
   }

pybind_interface/pybind_main.cpp

@@ -694,15 +694,11 @@ class SimulatorHelper {
 
   void init_state(const py::array_t<float> &input_vector) {
     StateSpace state_space = factory.CreateStateSpace();
-    if (state.num_qubits() >= 5) {
-      state_space.Copy(input_vector.data(), state);
-    } else {
+    uint64_t size = 2 * (uint64_t{1} << state.num_qubits());
+    if (size < state_space.MinSize(state.num_qubits())) {
       state_space.SetAllZeros(state);
-      uint64_t size = 2 * (uint64_t{1} << state.num_qubits());
-      for (uint64_t i = 0; i < size; ++i) {
-        state.get()[i] = input_vector.data()[i];
-      }
     }
+    state_space.Copy(input_vector.data(), size, state);
     state_space.NormalToInternalOrder(state);
   }
 

qsimcirq_tests/qsimcirq_test.py

@@ -1262,6 +1262,27 @@ def test_cirq_qsimh_simulate():
     assert np.allclose(result, [0j, 0j, (1 + 0j), 0j])
 
 
+def test_qsim_input_state():
+    for num_qubits in range(1, 8):
+        size = 2**num_qubits
+        qubits = cirq.LineQubit.range(num_qubits)
+        circuit = cirq.Circuit()
+
+        for k in range(num_qubits):
+            circuit.append(cirq.H(qubits[k]))
+
+        qsimSim = qsimcirq.QSimSimulator()
+        initial_state = np.asarray([np.sqrt(1.0 / size)] * size, dtype=np.complex64)
+        result = qsimSim.simulate(circuit, initial_state=initial_state)
+        state_vector = result.state_vector()
+
+        assert result.state_vector().shape == (size,)
+        assert cirq.approx_eq(state_vector[0], 1, atol=1e-6)
+
+        for i in range(1, size):
+            assert cirq.approx_eq(state_vector[i], 0, atol=1e-6)
+
+
 def test_qsim_gpu_unavailable():
     if qsimcirq.qsim_gpu is not None:
         pytest.skip("GPU is available; skipping test.")
@@ -1358,6 +1379,32 @@ def test_cirq_qsim_gpu_input_state():
     )
 
 
+def test_qsim_gpu_input_state():
+    if qsimcirq.qsim_gpu is None:
+        pytest.skip("GPU is not available for testing.")
+
+    for num_qubits in range(1, 8):
+        size = 2**num_qubits
+        qubits = cirq.LineQubit.range(num_qubits)
+        circuit = cirq.Circuit()
+
+        for k in range(num_qubits):
+            circuit.append(cirq.H(qubits[k]))
+
+        # Enable GPU acceleration.
+        gpu_options = qsimcirq.QSimOptions(use_gpu=True)
+        qsimGpuSim = qsimcirq.QSimSimulator(qsim_options=gpu_options)
+        initial_state = np.asarray([np.sqrt(1.0 / size)] * size, dtype=np.complex64)
+        result = qsimGpuSim.simulate(circuit, initial_state=initial_state)
+        state_vector = result.state_vector()
+
+        assert result.state_vector().shape == (size,)
+        assert cirq.approx_eq(state_vector[0], 1, atol=1e-6)
+
+        for i in range(1, size):
+            assert cirq.approx_eq(state_vector[i], 0, atol=1e-6)
+
+
 def test_cirq_qsim_custatevec_amplitudes():
     if qsimcirq.qsim_custatevec is None:
         pytest.skip("cuStateVec library is not available for testing.")
@@ -1441,6 +1488,32 @@ def test_cirq_qsim_custatevec_input_state():
     )
 
 
+def test_qsim_custatevec_input_state():
+    if qsimcirq.qsim_custatevec is None:
+        pytest.skip("cuStateVec library is not available for testing.")
+
+    for num_qubits in range(1, 8):
+        size = 2**num_qubits
+        qubits = cirq.LineQubit.range(num_qubits)
+        circuit = cirq.Circuit()
+
+        for k in range(num_qubits):
+            circuit.append(cirq.H(qubits[k]))
+
+        # Enable GPU acceleration.
+        custatevec_options = qsimcirq.QSimOptions(use_gpu=True, gpu_mode=1)
+        qsimGpuSim = qsimcirq.QSimSimulator(qsim_options=custatevec_options)
+        initial_state = np.asarray([np.sqrt(1.0 / size)] * size, dtype=np.complex64)
+        result = qsimGpuSim.simulate(circuit, initial_state=initial_state)
+        state_vector = result.state_vector()
+
+        assert result.state_vector().shape == (size,)
+        assert cirq.approx_eq(state_vector[0], 1, atol=1e-6)
+
+        for i in range(1, size):
+            assert cirq.approx_eq(state_vector[i], 0, atol=1e-6)
+
+
 def test_cirq_qsim_old_options():
     old_options = {"f": 3, "t": 4, "r": 100, "v": 1}
     old_sim = qsimcirq.QSimSimulator(qsim_options=old_options)