Initial unit test to refactor and fix nr_layer_precoder_simd function (See #955)

openair1/PHY/CMakeLists.txt

@@ -2,3 +2,4 @@ add_subdirectory(nr_phy_common)
 add_subdirectory(TOOLS)
 add_subdirectory(NR_TRANSPORT)
 add_subdirectory(CODING)
+add_subdirectory(MODULATION)

openair1/PHY/MODULATION/CMakeLists.txt

@@ -0,0 +1,3 @@
+if (ENABLE_TESTS)
+  add_subdirectory(tests)
+endif()

openair1/PHY/MODULATION/nr_modulation.c

@@ -765,9 +765,8 @@ void nr_layer_precoder_simd(const int n_layers,
       // Multiplication and shift
       const simde__m256i reals =
           simde_mm256_srai_epi32(simde_mm256_madd_epi16(x, w_c), 15); // (int32_t) .r = (x.r * w.r - x.i * w.i) >> 15
-      const simde__m256i imags = simde_mm256_slli_epi32(
+      const simde__m256i imags =
-          simde_mm256_madd_epi16(x, w_s),
+          simde_mm256_slli_epi32(simde_mm256_madd_epi16(x, w_s),  1); // (int32_t) .i = (x.r * w.i + x.i * w.r) << 1, since higher 16 bit of each 32 bit is taken by blend_epi16
-          1); // (int32_t) .i = (x.r * w.i + x.i * w.r) << 1, since higher 16 bit of each 32 bit is taken by blend_epi16
 
       // Re-arrange to match c16_t format
       const simde__m256i produ = simde_mm256_blend_epi16(reals, imags, 0xAA);

openair1/PHY/MODULATION/tests/CMakeLists.txt

@@ -0,0 +1,5 @@
+add_executable(test_nr_modulation test_nr_modulation.cpp)
+target_link_libraries(test_nr_modulation PRIVATE PHY_NR GTest::gtest minimal_lib)
+add_dependencies(tests test_nr_modulation)
+add_test(NAME test_nr_modulation
+  COMMAND ./test_nr_modulation)

openair1/PHY/MODULATION/tests/test_nr_modulation.cpp

@@ -0,0 +1,153 @@
+/*
+ * Licensed to the OpenAirInterface (OAI) Software Alliance under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The OpenAirInterface Software Alliance licenses this file to You under
+ * the OAI Public License, Version 1.1  (the "License"); you may not use this file
+ * except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.openairinterface.org/?page_id=698
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *-------------------------------------------------------------------------------
+ * For more information about the OpenAirInterface (OAI) Software Alliance:
+ *      contact@openairinterface.org
+ */
+
+// Initial unit test for nr_layer_precoder_simd_[cm, simd] functions
+// Issue: gNB: SIMD Precoding Bug in nr_layer_precoder_simd for PMI = 4
+// https://gitlab.eurecom.fr/oai/openairinterface5g/-/issues/955
+
+#include "gtest/gtest.h"
+#include <cstdint>
+#include <simde/x86/avx512.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include "openair1/PHY/TOOLS/tools_defs.h" // c16_t
+#include "nfapi/open-nFAPI/nfapi/public_inc/nfapi_nr_interface_scf.h" // nfapi_nr_pm_pdu_t
+#include "nfapi/open-nFAPI/nfapi/public_inc/fapi_nr_ue_interface.h" // fapi_nr_dl_config_dci_dl_pdu_rel15_t
+
+//#include "openair1/PHY/MODULATION/nr_modulation.h" // nr_layer_precoder_simd_[cm, simd]
+
+// Forward declare the function but hide the Variable-Length Array (VLA) feature from C not available in C++
+c16_t nr_layer_precoder_cm(int n_layers,
+                           int symbol_size,
+                           c16_t (*dataF_in)[/*symbol_size*/], // c16_t dataF_in[n_layers][symbol_size]
+                           int ant,
+                           nfapi_nr_pm_pdu_t *pmi_pdu,
+                           int offset);
+
+// Forward declare the function but hide the Variable-Length Array (VLA) feature from C not available in C++
+void nr_layer_precoder_simd(int n_layers,
+                            int symbol_size,
+                            const c16_t (*dataF_in)[/*symbol_size*/], // c16_t dataF_in[n_layers][symbol_size]
+                            int ant,
+                            const nfapi_nr_pm_pdu_t *pmi_pdu,
+                            int offset,
+                            int re_cnt,
+                            c16_t *dataF_out);
+
+#ifdef __cplusplus
+}
+#endif
+
+TEST(NrLayerPrecoderTest, Basic)
+{
+  constexpr int n_layers = 2;
+  constexpr int symbol_size = 24;
+  constexpr int ant = 1;
+  constexpr int re_cnt = 24;
+
+  // Initialize the 2D input data buffer
+  std::vector<c16_t> buffer_in(n_layers * symbol_size);
+  std::vector<c16_t> buffer_out(n_layers * symbol_size);
+
+  for (int i = 0; i < n_layers * symbol_size; ++i) {
+    buffer_in[i] = {static_cast<int16_t>(i + 1), static_cast<int16_t>(-i - 1)};
+    buffer_out[i] = {static_cast<int16_t>(0), static_cast<int16_t>(0)};
+  }
+
+  // Cast flat buffer to the required 2D Variable-Length Array (VLA) style pointer
+  c16_t(*dataF_in)[symbol_size] = reinterpret_cast<c16_t(*)[symbol_size]>(buffer_in.data());
+  c16_t(*dataF_out)[symbol_size] = reinterpret_cast<c16_t(*)[symbol_size]>(buffer_out.data());
+
+  // Create and populate the pmi_pdu structure
+  nfapi_nr_pm_pdu_t pmi_pdu = {0};
+  for (int layer = 0; layer < n_layers; ++layer) {
+    pmi_pdu.weights[layer][ant].precoder_weight_Re = 1 << 14; // e.g., Q15 representation of ~0.5
+    pmi_pdu.weights[layer][ant].precoder_weight_Im = 0;
+  }
+
+  // Call the C function
+  for (int symbol = 0; symbol < re_cnt; symbol++)
+    dataF_out[ant][symbol] = nr_layer_precoder_cm(n_layers, symbol_size, dataF_in, ant, &pmi_pdu, symbol);
+
+  // You can calculate the expected value manually or test rough correctness
+  for (int symbol = 0; symbol < re_cnt; symbol++) {
+    int result_real = 14 + (symbol - 1) & ~1;
+    int result_imag = 14 + (symbol) & ~1;
+    EXPECT_EQ(dataF_out[ant][symbol].r, result_real)
+        << " at [" << ant << "][" << symbol << "] got real part: " << dataF_out[ant][symbol].r;
+    ;
+    EXPECT_EQ(dataF_out[ant][symbol].i, -result_imag)
+        << " at [" << ant << "][" << symbol << "] got imag part: " << dataF_out[ant][symbol].i;
+    ;
+  }
+}
+
+TEST(NrLayerPrecoderTest, SIMD)
+{
+  constexpr int n_layers = 2;
+  constexpr int symbol_size = 24;
+  constexpr int ant = 1;
+  constexpr int re_cnt = 24;
+
+  // Initialize the 2D input data buffer
+  std::vector<c16_t> buffer_in(n_layers * symbol_size);
+  std::vector<c16_t> buffer_out(n_layers * symbol_size);
+
+  for (int i = 0; i < n_layers * symbol_size; ++i) {
+    buffer_in[i] = {static_cast<int16_t>(i + 1), static_cast<int16_t>(-i - 1)};
+    buffer_out[i] = {static_cast<int16_t>(0), static_cast<int16_t>(0)};
+  }
+
+  // Cast flat buffer to the required 2D Variable-Length Array (VLA) style pointer
+  c16_t(*dataF_in)[symbol_size] = reinterpret_cast<c16_t(*)[symbol_size]>(buffer_in.data());
+  c16_t(*dataF_out)[symbol_size] = reinterpret_cast<c16_t(*)[symbol_size]>(buffer_out.data());
+
+  // Create and populate the pmi_pdu structure
+  nfapi_nr_pm_pdu_t pmi_pdu = {0};
+  for (int layer = 0; layer < n_layers; ++layer) {
+    pmi_pdu.weights[layer][ant].precoder_weight_Re = 1 << 14; // e.g., Q15 representation of ~0.5
+    pmi_pdu.weights[layer][ant].precoder_weight_Im = 0;
+  }
+
+  // Call the C function
+  nr_layer_precoder_simd(n_layers, symbol_size, dataF_in, ant, &pmi_pdu, 0, re_cnt, dataF_out[ant]);
+
+  // You can calculate the expected value manually or test rough correctness
+  for (int symbol = 0; symbol < re_cnt; symbol++) {
+    int result_real = 14 + (symbol - 1) & ~1;
+    int result_imag = 14 + (symbol) & ~1;
+    EXPECT_EQ(dataF_out[ant][symbol].r, result_real)
+        << " at [" << ant << "][" << symbol << "] got real part: " << dataF_out[ant][symbol].r;
+    ;
+    EXPECT_EQ(dataF_out[ant][symbol].i, -result_imag)
+        << " at [" << ant << "][" << symbol << "] got imag part: " << dataF_out[ant][symbol].i;
+    ;
+  }
+}
+
+int main(int argc, char **argv)
+{
+  testing::InitGoogleTest(&argc, argv);
+  return RUN_ALL_TESTS();
+}