Merged with dev

src/operator/GatherImpl.cpp

@@ -9,27 +9,29 @@
  *
  ********************************************************************************/
 
-#include <cassert>
-#include <chrono>  // std::chrono::milliseconds
-#include <numeric> // std::accumulate
-#include <thread>  // std::this_thread::sleep_for
+#include "aidge/backend/cpu/operator/GatherImpl.hpp"
+
+#include <memory>
 #include <vector>
 
+#include "aidge/backend/cpu/operator/GatherImpl_forward_kernels.hpp"
+#include "aidge/data/Data.hpp"
+#include "aidge/data/Tensor.hpp"
 #include "aidge/operator/Gather.hpp"
 #include "aidge/utils/Types.h"
 
-#include "aidge/backend/cpu/operator/GatherImpl.hpp"
-#include "aidge/backend/cpu/operator/GatherImpl_forward_kernels.hpp"
-
 void Aidge::GatherImpl_cpu::forward() {
+    const Gather_Op& op = static_cast<const Gather_Op&>(mOp);
 
     auto kernelFunc = Registrar<GatherImplForward_cpu>::create({
-        std::static_pointer_cast<Tensor>(mOp.getRawInput(0))->dataType(),
-        std::static_pointer_cast<Tensor>(mOp.getRawOutput(0))->dataType()});
+                            op.getInput(0)->dataType(),
+                            op.getOutput(0)->dataType()
+                        });
 
     // Call kernel
     kernelFunc(dynamic_cast<const Gather_Op&>(mOp).getStaticAttributes(),
-        std::static_pointer_cast<Tensor>(mOp.getRawInput(0))->dims(),
-        std::static_pointer_cast<Tensor>(mOp.getRawInput(0))->getImpl()->rawPtr(),
-        std::static_pointer_cast<Tensor>(mOp.getRawOutput(0))->getImpl()->rawPtr());
+            op.getInput(0)->dims(),
+            op.getInput(0)->getImpl()->rawPtr(),
+            op.getOutput(0)->getImpl()->rawPtr()
+        );
 }

src/operator/LeakyReLUImpl.cpp

@@ -10,17 +10,17 @@
  ********************************************************************************/
 
 #include <cassert>
-#include <chrono>  // std::chrono::milliseconds
-#include <numeric> // std::accumulate
-#include <thread>  // std::this_thread::sleep_for
 #include <vector>
 
+#include "aidge/data/Tensor.hpp"
 #include "aidge/operator/LeakyReLU.hpp"
 #include "aidge/utils/Types.h"
+#include "aidge/utils/Registrar.hpp"
 #include "aidge/backend/cpu/data/GetCPUPtr.h"
 
 #include "aidge/backend/cpu/operator/LeakyReLUImpl.hpp"
 #include "aidge/backend/cpu/operator/LeakyReLUImpl_forward_kernels.hpp"
+#include "aidge/backend/cpu/operator/LeakyReLUImpl_backward_kernels.hpp"
 
 Aidge::Elts_t Aidge::LeakyReLUImpl_cpu::getNbRequiredProtected(const Aidge::IOIndex_t /*inputIdx*/) const {
     // this implementation can be in-place
@@ -28,16 +28,38 @@ Aidge::Elts_t Aidge::LeakyReLUImpl_cpu::getNbRequiredProtected(const Aidge::IOIn
 }
 
 void Aidge::LeakyReLUImpl_cpu::forward() {
-    assert(std::static_pointer_cast<Tensor>(mOp.getRawInput(0)) && "missing input #0");
+    const LeakyReLU_Op& op_ = dynamic_cast<const LeakyReLU_Op&>(mOp);
+    std::shared_ptr<Tensor> in0 = op_.getInput(0);
+    std::shared_ptr<Tensor> out0 = op_.getOutput(0);
+    AIDGE_ASSERT(in0, "missing input #0");
 
     // Find the correct kernel type
     auto kernelFunc = Registrar<LeakyReLUImplForward_cpu>::create({
-        std::static_pointer_cast<Tensor>(mOp.getRawInput(0))->dataType(),
-        std::static_pointer_cast<Tensor>(mOp.getRawOutput(0))->dataType()});
+        in0->dataType(),
+        out0->dataType()});
 
     // Call kernel
     kernelFunc(dynamic_cast<const LeakyReLU_Op&>(mOp).getStaticAttributes(),
-        std::static_pointer_cast<Tensor>(mOp.getRawInput(0))->size(),
+        in0->size(),
         getCPUPtr(mOp.getRawInput(0)),
         getCPUPtr(mOp.getRawOutput(0)));
 }
+
+void Aidge::LeakyReLUImpl_cpu::backward() {
+    // reversing in and out Data for backprop
+    const LeakyReLU_Op& op_ = dynamic_cast<const LeakyReLU_Op&>(mOp);
+    std::shared_ptr<Tensor> in0  = op_.getOutput(0)->grad();
+    std::shared_ptr<Tensor> out0 = op_.getInput(0)->grad();
+    AIDGE_ASSERT(in0, "missing input #0");
+
+    // Find the correct kernel type
+    auto kernelFunc = Registrar<LeakyReLUImplForward_cpu>::create({
+        in0->dataType(),
+        out0->dataType()});
+
+    // Call kernel
+    kernelFunc(dynamic_cast<const LeakyReLU_Op&>(mOp).getStaticAttributes(),
+        in0->size(),
+        getCPUPtr(in0),
+        getCPUPtr(out0));
+}
\ No newline at end of file

src/operator/PowImpl.cpp

@@ -48,3 +48,25 @@ void Aidge::PowImpl_cpu::forward() {
         getCPUPtr(mOp.getRawInput(1)),
         getCPUPtr(mOp.getRawOutput(0)));
 }
+
+void Aidge::PowImpl_cpu::backward() {
+    // Find the correct kernel type
+    const Pow_Op& op_ = dynamic_cast<const Pow_Op&>(mOp);
+    auto kernelFunc = Registrar<PowImplForward_cpu>::create({
+        op_.getOutput(0)->grad()->dataType(),
+        op_.getInput(0)->grad()->dataType(),
+        op_.getInput(1)->grad()->dataType()});
+
+    const std::vector<std::size_t> input0gradDims = getBroadcastedDims(op_.getInput(0)->grad()->dims(),
+                                                                   op_.getOutput(0)->grad()->dims());
+    const std::vector<std::size_t> input1gradDims = getBroadcastedDims(op_.getInput(1)->grad()->dims(),
+                                                                   op_.getOutput(0)->grad()->dims());
+
+    // Call kernel
+    kernelFunc(op_.getOutput(0)->grad()->dims(),
+               input0gradDims,
+               input1gradDims,
+               getCPUPtr(mOp.getRawOutput(0)),
+               getCPUPtr(mOp.getRawInput(0)),
+               getCPUPtr(mOp.getRawInput(1)));
+}
\ No newline at end of file

src/operator/ReLUImpl.cpp

@@ -9,18 +9,18 @@
  *
  ********************************************************************************/
 
-#include <cassert>
-#include <chrono>  // std::chrono::milliseconds
-#include <numeric> // std::accumulate
-#include <thread>  // std::this_thread::sleep_for
+#include <memory>
 #include <vector>
 
+#include "aidge/data/Tensor.hpp"
 #include "aidge/operator/ReLU.hpp"
 #include "aidge/utils/Types.h"
 #include "aidge/backend/cpu/data/GetCPUPtr.h"
+#include "aidge/utils/ErrorHandling.hpp"
 
 #include "aidge/backend/cpu/operator/ReLUImpl.hpp"
 #include "aidge/backend/cpu/operator/ReLUImpl_forward_kernels.hpp"
+#include "aidge/backend/cpu/operator/ReLUImpl_backward_kernels.hpp"
 
 Aidge::Elts_t Aidge::ReLUImpl_cpu::getNbRequiredProtected(const Aidge::IOIndex_t /*inputIdx*/) const {
     // this implementation can be in-place
@@ -28,15 +28,33 @@ Aidge::Elts_t Aidge::ReLUImpl_cpu::getNbRequiredProtected(const Aidge::IOIndex_t
 }
 
 void Aidge::ReLUImpl_cpu::forward() {
-    assert(std::static_pointer_cast<Tensor>(mOp.getRawInput(0)) && "missing input #0");
+    std::shared_ptr<Tensor> in0 = std::static_pointer_cast<Tensor>(mOp.getRawInput(0));
+    AIDGE_ASSERT(in0, "missing input #0");
 
     // Find the correct kernel type
     auto kernelFunc = Registrar<ReLUImplForward_cpu>::create({
-        std::static_pointer_cast<Tensor>(mOp.getRawInput(0))->dataType(),
+        in0->dataType(),
         std::static_pointer_cast<Tensor>(mOp.getRawOutput(0))->dataType()});
 
     // Call kernel
-    kernelFunc(std::static_pointer_cast<Tensor>(mOp.getRawInput(0))->size(),
+    kernelFunc(in0->size(),
         getCPUPtr(mOp.getRawInput(0)),
         getCPUPtr(mOp.getRawOutput(0)));
 }
+
+void Aidge::ReLUImpl_cpu::backward() {
+    // reversing in and out Tensors
+        const ReLU_Op& op_ = dynamic_cast<const ReLU_Op&>(mOp);
+    std::shared_ptr<Tensor> in0  = op_.getOutput(0)->grad();
+    std::shared_ptr<Tensor> out0 = op_.getInput(0)->grad();
+    AIDGE_ASSERT(out0, "current {} operator output#0 has not gradient Tensor.", op_.type());
+
+    // Find the correct kernel type
+    auto kernelFunc = Registrar<ReLUImplBackward_cpu>::create({
+        in0->dataType(),
+        out0->dataType()
+    });
+
+    // Call kernel
+    kernelFunc(in0->size(), getCPUPtr(in0), getCPUPtr(out0));
+}

src/operator/ReduceMeanImpl.cpp

@@ -9,59 +9,70 @@
  *
  ********************************************************************************/
 
-#include <cassert>
-#include <chrono>  // std::chrono::milliseconds
-#include <numeric> // std::accumulate
-#include <thread>  // std::this_thread::sleep_for
+#include "aidge/backend/cpu/operator/ReduceMeanImpl.hpp"
+
+#include <memory>
 #include <vector>
 
 #include "aidge/utils/Types.h"
 #include "aidge/operator/ReduceMean.hpp"
-
-#include "aidge/backend/cpu/operator/ReduceMeanImpl.hpp"
 #include "aidge/backend/cpu/operator/ReduceMeanImpl_forward_kernels.hpp"
 
-void Aidge::ReduceMeanImpl1D_cpu::forward() {
-
+void Aidge::ReduceMeanImpl_cpu::forward() {
+    const ReduceMean_Op& op_ = dynamic_cast<const ReduceMean_Op&>(mOp);
     // Find the correct kernel type
-    auto kernelFunc =
-            Registrar<ReduceMeanImpl1DForward_cpu>::create({
-        std::static_pointer_cast<Tensor>(mOp.getRawInput(0))->dataType(),
-        std::static_pointer_cast<Tensor>(mOp.getRawOutput(0))->dataType()});
+    auto kernelFunc = Registrar<ReduceMeanImplForward_cpu>::create({
+        op_.getInput(0)->dataType(),
+        op_.getOutput(0)->dataType()});
 
     // Call kernel
-    kernelFunc(dynamic_cast<const ReduceMean_Op<1>&>(mOp).getStaticAttributes(),
-               std::static_pointer_cast<Tensor>(mOp.getRawInput(0))->dims(),
-               std::static_pointer_cast<Tensor>(mOp.getRawInput(0))->getImpl()->rawPtr(),
-               std::static_pointer_cast<Tensor>(mOp.getRawOutput(0))->getImpl()->rawPtr());
+    kernelFunc(op_.getStaticAttributes(),
+               op_.getInput(0)->dims(),
+               op_.getInput(0)->getImpl()->rawPtr(),
+               op_.getOutput(0)->getImpl()->rawPtr());
 }
 
-void Aidge::ReduceMeanImpl2D_cpu::forward() {
+// void Aidge::ReduceMeanImpl1D_cpu::forward() {
 
-    // Find the correct kernel type
-    auto kernelFunc =
-            Registrar<ReduceMeanImpl2DForward_cpu>::create({
-        std::static_pointer_cast<Tensor>(mOp.getRawInput(0))->dataType(),
-        std::static_pointer_cast<Tensor>(mOp.getRawOutput(0))->dataType()});
+//     // Find the correct kernel type
+//     auto kernelFunc =
+//             Registrar<ReduceMeanImpl1DForward_cpu>::create({
+//         std::static_pointer_cast<Tensor>(mOp.getRawInput(0))->dataType(),
+//         std::static_pointer_cast<Tensor>(mOp.getRawOutput(0))->dataType()});
 
-    // Call kernel
-    kernelFunc(dynamic_cast<const ReduceMean_Op<2>&>(mOp).getStaticAttributes(),
-               std::static_pointer_cast<Tensor>(mOp.getRawInput(0))->dims(),
-               std::static_pointer_cast<Tensor>(mOp.getRawInput(0))->getImpl()->rawPtr(),
-               std::static_pointer_cast<Tensor>(mOp.getRawOutput(0))->getImpl()->rawPtr());
-}
+//     // Call kernel
+//     kernelFunc(dynamic_cast<const ReduceMean_Op<1>&>(mOp).getStaticAttributes(),
+//                std::static_pointer_cast<Tensor>(mOp.getRawInput(0))->dims(),
+//                std::static_pointer_cast<Tensor>(mOp.getRawInput(0))->getImpl()->rawPtr(),
+//                std::static_pointer_cast<Tensor>(mOp.getRawOutput(0))->getImpl()->rawPtr());
+// }
 
-void Aidge::ReduceMeanImpl3D_cpu::forward() {
+// void Aidge::ReduceMeanImpl2D_cpu::forward() {
 
-    // Find the correct kernel type
-    auto kernelFunc =
-            Registrar<ReduceMeanImpl3DForward_cpu>::create({
-        std::static_pointer_cast<Tensor>(mOp.getRawInput(0))->dataType(),
-        std::static_pointer_cast<Tensor>(mOp.getRawOutput(0))->dataType()});
+//     // Find the correct kernel type
+//     auto kernelFunc =
+//             Registrar<ReduceMeanImpl2DForward_cpu>::create({
+//         std::static_pointer_cast<Tensor>(mOp.getRawInput(0))->dataType(),
+//         std::static_pointer_cast<Tensor>(mOp.getRawOutput(0))->dataType()});
 
-    // Call kernel
-    kernelFunc(dynamic_cast<const ReduceMean_Op<3>&>(mOp).getStaticAttributes(),
-               std::static_pointer_cast<Tensor>(mOp.getRawInput(0))->dims(),
-               std::static_pointer_cast<Tensor>(mOp.getRawInput(0))->getImpl()->rawPtr(),
-               std::static_pointer_cast<Tensor>(mOp.getRawOutput(0))->getImpl()->rawPtr());
-}
+//     // Call kernel
+//     kernelFunc(dynamic_cast<const ReduceMean_Op<2>&>(mOp).getStaticAttributes(),
+//                std::static_pointer_cast<Tensor>(mOp.getRawInput(0))->dims(),
+//                std::static_pointer_cast<Tensor>(mOp.getRawInput(0))->getImpl()->rawPtr(),
+//                std::static_pointer_cast<Tensor>(mOp.getRawOutput(0))->getImpl()->rawPtr());
+// }
\ No newline at end of file
+
+// void Aidge::ReduceMeanImpl3D_cpu::forward() {
+
+//     // Find the correct kernel type
+//     auto kernelFunc =
+//             Registrar<ReduceMeanImpl3DForward_cpu>::create({
+//         std::static_pointer_cast<Tensor>(mOp.getRawInput(0))->dataType(),
+//         std::static_pointer_cast<Tensor>(mOp.getRawOutput(0))->dataType()});
+
+//     // Call kernel
+//     kernelFunc(dynamic_cast<const ReduceMean_Op<3>&>(mOp).getStaticAttributes(),
+//                std::static_pointer_cast<Tensor>(mOp.getRawInput(0))->dims(),
+//                std::static_pointer_cast<Tensor>(mOp.getRawInput(0))->getImpl()->rawPtr(),
+//                std::static_pointer_cast<Tensor>(mOp.getRawOutput(0))->getImpl()->rawPtr());
+// }
\ No newline at end of file

src/operator/ReshapeImpl.cpp

@@ -9,13 +9,13 @@
  *
  ********************************************************************************/
 
-#include <cassert>
+#include "aidge/backend/cpu/operator/ReshapeImpl.hpp"
 
+#include "aidge/backend/cpu/operator/ReshapeImpl_forward_kernels.hpp"
+#include "aidge/data/Tensor.hpp"
 #include "aidge/operator/Reshape.hpp"
 #include "aidge/utils/Types.h"
-
-#include "aidge/backend/cpu/operator/ReshapeImpl.hpp"
-#include "aidge/backend/cpu/operator/ReshapeImpl_forward_kernels.hpp"
+#include "aidge/utils/ErrorHandling.hpp"
 
 Aidge::Elts_t Aidge::ReshapeImpl_cpu::getNbRequiredProtected(const Aidge::IOIndex_t /*inputIdx*/) const {
     // this implementation can be in-place
@@ -23,17 +23,17 @@ Aidge::Elts_t Aidge::ReshapeImpl_cpu::getNbRequiredProtected(const Aidge::IOInde
 }
 
 void Aidge::ReshapeImpl_cpu::forward() {
-    assert(std::static_pointer_cast<Tensor>(mOp.getRawInput(0))->size() == 
-           std::static_pointer_cast<Tensor>(mOp.getRawOutput(0))->size()
-            && "input must have the same overall size as shape");
+    const Reshape_Op& op_ = static_cast<const Reshape_Op&>(mOp);
+    AIDGE_ASSERT(op_.getInput(0)->size() == op_.getOutput(0)->size(),
+                    "input must have the same overall size as shape");
 
     // Find the correct kernel type
     auto kernelFunc = Registrar<ReshapeImplForward_cpu>::create({
-        std::static_pointer_cast<Tensor>(mOp.getRawInput(0))->dataType(),
-        std::static_pointer_cast<Tensor>(mOp.getRawOutput(0))->dataType()});
+        op_.getInput(0)->dataType(),
+        op_.getOutput(0)->dataType()});
 
     // Call kernel
-    kernelFunc(std::static_pointer_cast<Tensor>(mOp.getRawInput(0))->size(),
-               std::static_pointer_cast<Tensor>(mOp.getRawInput(0))->getImpl()->rawPtr(),
-               std::static_pointer_cast<Tensor>(mOp.getRawOutput(0))->getImpl()->rawPtr());
+    kernelFunc(op_.getInput(0)->size(),
+               op_.getInput(0)->getImpl()->rawPtr(),
+               op_.getOutput(0)->getImpl()->rawPtr());
 }

src/operator/SqrtImpl.cpp

@@ -9,18 +9,18 @@
  *
  ********************************************************************************/
 
-#include <cassert>
-#include <chrono>  // std::chrono::milliseconds
-#include <numeric> // std::accumulate
-#include <thread>  // std::this_thread::sleep_for
+#include <memory>
 #include <vector>
 
+#include "aidge/backend/cpu/data/GetCPUPtr.h"
+#include "aidge/data/Tensor.hpp"
 #include "aidge/operator/Sqrt.hpp"
+#include "aidge/utils/ErrorHandling.hpp"
 #include "aidge/utils/Types.h"
-#include "aidge/backend/cpu/data/GetCPUPtr.h"
 
 #include "aidge/backend/cpu/operator/SqrtImpl.hpp"
 #include "aidge/backend/cpu/operator/SqrtImpl_forward_kernels.hpp"
+#include "aidge/backend/cpu/operator/SqrtImpl_backward_kernels.hpp"
 
 Aidge::Elts_t Aidge::SqrtImpl_cpu::getNbRequiredProtected(const Aidge::IOIndex_t /*inputIdx*/) const {
     // this implementation can be in-place
@@ -28,15 +28,35 @@ Aidge::Elts_t Aidge::SqrtImpl_cpu::getNbRequiredProtected(const Aidge::IOIndex_t
 }
 
 void Aidge::SqrtImpl_cpu::forward() {
-    assert(std::static_pointer_cast<Tensor>(mOp.getRawInput(0)) && "missing input #0");
+    std::shared_ptr<Tensor> in0 = std::static_pointer_cast<Tensor>(mOp.getRawInput(0));
+    std::shared_ptr<Tensor> out0 = std::static_pointer_cast<Tensor>(mOp.getRawOutput(0));
+    AIDGE_ASSERT(in0, "missing input #0");
 
     // Find the correct kernel type
     auto kernelFunc = Registrar<SqrtImplForward_cpu>::create({
-        std::static_pointer_cast<Tensor>(mOp.getRawInput(0))->dataType(),
-        std::static_pointer_cast<Tensor>(mOp.getRawOutput(0))->dataType()});
+        in0->dataType(),
+        out0->dataType()});
 
     // Call kernel
-    kernelFunc(std::static_pointer_cast<Tensor>(mOp.getRawInput(0))->size(),
+    kernelFunc(in0->size(),
         getCPUPtr(mOp.getRawInput(0)),
         getCPUPtr(mOp.getRawOutput(0)));
+}
+
+void Aidge::SqrtImpl_cpu::backward() {
+    // reversing in and out Data for backprop
+    const Sqrt_Op& op_ = dynamic_cast<const Sqrt_Op&>(mOp);
+    std::shared_ptr<Tensor> out0grad  = op_.getOutput(0)->grad();
+    std::shared_ptr<Tensor> in0grad = op_.getInput(0)->grad();
+    AIDGE_ASSERT(out0grad, "missing output #0");
+
+    // Find the correct kernel type
+    auto kernelFunc = Registrar<SqrtImplForward_cpu>::create({
+        out0grad->dataType(),
+        in0grad->dataType()});
+
+    // Call kernel
+    kernelFunc(out0grad->size(),
+        getCPUPtr(out0grad),
+        getCPUPtr(in0grad));
 }
\ No newline at end of file

unit_tests/data/Test_TensorImpl.cpp

+/********************************************************************************
+ * Copyright (c) 2023 CEA-List
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0.
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ ********************************************************************************/
+
+#include <catch2/catch_test_macros.hpp>
+#include <cstddef>   // std::size_t
+#include <cstdint>   // std::uint16_t
+#include <chrono>
+#include <iostream>
+#include <memory>
+#include <numeric>   // std::accumulate
+#include <random>    // std::random_device, std::mt19937, std::uniform_real_distribution
+
+#include "aidge/data/Tensor.hpp"
+#include "aidge/backend/cpu/data/TensorImpl.hpp"
+#include "aidge/operator/Add.hpp"
+#include "aidge/backend/cpu/operator/AddImpl.hpp"
+
+namespace Aidge {
+
+TEST_CASE("Test addition of Tensors","[TensorImpl][Add]") {
+    constexpr std::uint16_t NBTRIALS = 10;
+    // Create a random number generator
+    std::random_device rd;
+    std::mt19937 gen(rd());
+    std::uniform_real_distribution<float> valueDist(0.1f, 1.1f); // Random float distribution between 0 and 1
+    std::uniform_int_distribution<std::size_t> dimSizeDist(std::size_t(2), std::size_t(10));
+    std::uniform_int_distribution<int> boolDist(0,1);
+
+    // Create MatMul Operator
+    std::shared_ptr<Node> mySub = Add(2);
+    auto op = std::static_pointer_cast<OperatorTensor>(mySub-> getOperator());
+    op->setDataType(DataType::Float32);
+    op->setBackend("cpu");
+
+    // Create 2 input Tensors
+    std::shared_ptr<Tensor> T0 = std::make_shared<Tensor>();
+    op->associateInput(0,T0);
+    T0->setDataType(DataType::Float32);
+    T0->setBackend("cpu");
+    std::shared_ptr<Tensor> T1 = std::make_shared<Tensor>();
+    op -> associateInput(1,T1);
+    T1->setDataType(DataType::Float32);
+    T1->setBackend("cpu");
+
+    // Create results Tensor
+    Tensor Tres{};
+    Tres.setDataType(DataType::Float32);
+    Tres.setBackend("cpu");
+
+    // To measure execution time of 'MatMul_Op::forward()' member function call
+    std::chrono::time_point<std::chrono::system_clock> start;
+    std::chrono::time_point<std::chrono::system_clock> end;
+    std::chrono::duration<double, std::micro> duration{};
+
+    std::size_t number_of_operation = 0;
+
+    for (std::uint16_t trial = 0; trial < NBTRIALS; ++trial) {
+        // generate 2 random Tensors
+        // handle dimensions, replace some dimensions with '1' to get broadcasting
+        constexpr std::size_t nbDims = 4;
+        std::vector<std::size_t> dims;
+        for (std::size_t i = 0; i < nbDims; ++i) {
+            dims.push_back(dimSizeDist(gen));
+        }
+        std::vector<std::size_t> dims0 = dims;
+        std::vector<std::size_t> dims1 = dims;
+        std::vector<std::size_t> dimsOut = dims;
+        for (std::size_t i = 0; i < nbDims; ++i) {
+            if (boolDist(gen)) {
+                dims0[i] = 1;
+            }
+            if (boolDist(gen)) {
+                dims1[i] = 1;
+            }
+            dimsOut[i] = (dims0[i] == 1) ? dims1[i] : dims0[i];
+        }
+
+        // create arrays and fill them with random values
+        float* array0 = new float[dims0[0]*dims0[1]*dims0[2]*dims0[3]];
+        float* array1 = new float[dims1[0]*dims1[1]*dims1[2]*dims1[3]];
+        float* result = new float[dimsOut[0]*dimsOut[1]*dimsOut[2]*dimsOut[3]];
+
+        for (std::size_t i = 0; i < dims0[0]*dims0[1]*dims0[2]*dims0[3]; ++i) {
+            array0[i] = valueDist(gen);
+        }
+        for (std::size_t i = 0; i < dims1[0]*dims1[1]*dims1[2]*dims1[3]; ++i) {
+            array1[i] = valueDist(gen);
+        }
+
+        // compute true result
+        const std::size_t strides0[nbDims] = {dims0[1]*dims0[2]*dims0[3], dims0[2]*dims0[3], dims0[3], 1};
+        const std::size_t strides1[nbDims] = {dims1[1]*dims1[2]*dims1[3], dims1[2]*dims1[3], dims1[3], 1};
+        for (std::size_t a = 0; a < dimsOut[0]; ++a) {
+            for (std::size_t b = 0; b < dimsOut[1]; ++b) {
+                const std::size_t idx0_0 = strides0[0] * ((dims0[0] > 1) ? a : 0)
+                                            + strides0[1] * ((dims0[1] > 1) ? b : 0);
+                const std::size_t idx1_0 = strides1[0] * ((dims1[0] > 1) ? a : 0)
+                                            + strides1[1] * ((dims1[1] > 1) ? b : 0);
+                for (std::size_t c = 0; c < dimsOut[2]; ++c) {
+                    const std::size_t idx_out = dimsOut[3] * (c + dimsOut[2] * (b + dimsOut[1] * a));
+                    for (std::size_t d = 0; d < dimsOut[3]; ++d) {
+                        std::size_t idx0 = idx0_0
+                                            + strides0[2] * ((dims0[2] > 1) ? c : 0)
+                                            + ((dims0[3] > 1) ? d : 0);
+                        std::size_t idx1 = idx1_0
+                                            + strides1[2] * ((dims1[2] > 1) ? c : 0)
+                                            + ((dims1[3] > 1) ? d : 0);
+                        result[idx_out + d] = array0[idx0] + array1[idx1];
+                        // std::cout << "(" << idx0 << ", " << idx1 << ") -> " << array0[idx0] << " - " << array1[idx1] << " -> " << idx_out + d << std::endl;
+                    }
+                }
+            }
+        }
+
+        // conversion to Aidge::Tensors
+        // input0
+        T0->resize(dims0);
+        T0->getImpl() -> setRawPtr(array0, dims0[0]*dims0[1]*dims0[2]*dims0[3]);
+
+        // input1
+        T1->resize(dims1);
+        T1->getImpl() -> setRawPtr(array1, dims1[0]*dims1[1]*dims1[2]*dims1[3]);
+
+        // results
+        Tres.resize(dimsOut);
+        Tres.getImpl() -> setRawPtr(result, dimsOut[0]*dimsOut[1]*dimsOut[2]*dimsOut[3]);
+
+        Tensor T2 = *T0 + *T1;
+        REQUIRE(T2 == Tres);
+
+    // no implementation
+        Tensor T3(T1->dims());
+        REQUIRE_THROWS(*T0 + T3);
+
+        // // wrong backend
+        // static Registrar<Add_Op> registrarAddImpl_custom("custom", [](const Add_Op& op) { return std::make_unique<AddImpl_cpu>(op); } );
+        // static Registrar<Tensor> registrarTensorImpl_custom_Int32({"custom", DataType::Int32},
+        //             [] (DeviceIdx_t device, std::vector<DimSize_t> dims) {
+        //                 return std::make_shared<TensorImpl_cpu<int>>(device, dims);
+        //             }
+        //         );
+        // T1.setBackend("custom");
+        // REQUIRE_THROWS(T0 + T1);
+
+    // wrong datatype
+        Tensor T4(T1->dims());
+        T4.setDataType(DataType::Float64);
+        REQUIRE_THROWS(*T0 + T4);
+    }
+}
+
+TEST_CASE("Test substraction of Tensors","[TensorImpl][Sub]") {
+    Tensor T0 = Array3D<int, 2, 2, 2>{{{{1, 2}, {3, 4}}, {{5, 6}, {7, 8}}}};
+    Tensor T1 = Array3D<int, 2, 2, 2>{{{{7, 1}, {3, 7}}, {{54, 0}, {7, 12}}}};
+    Tensor T2 = T0 - T1;
+    T2.print();
+    REQUIRE(T2 == Tensor(Array3D<int, 2, 2, 2>{{{{-6,1},{0,-3}},{{-49,6},{0,-4}}}}));
+
+    Tensor T3(T1.dims());
+    REQUIRE_THROWS(T0 - T3);
+}
+
+TEST_CASE("Test multiplication of Tensors","[TensorImpl][Mul]") {
+    Tensor T0 = Array3D<int, 2, 2, 2>{{{{1, 2}, {3, 4}}, {{5, 6}, {7, 8}}}};
+    Tensor T1 = Array3D<int, 2, 2, 2>{{{{7, 2}, {3, 7}}, {{5, 6}, {7, 8}}}};
+    Tensor T2 = T0 * T1;
+    T2.print();
+    REQUIRE(T2 == Tensor(Array3D<int, 2, 2, 2>{{{{7,4},{9,28}},{{25,36},{49,64}}}}));
+
+    Tensor T3(T1.dims());
+    REQUIRE_THROWS(T0 * T3);
+}
+
+TEST_CASE("Test division of Tensors","[TensorImpl][Div]") {
+    Tensor T0 = Array3D<int, 2, 2, 2>{{{{7,4},{9,28}},{{25,36},{49,64}}}};
+    Tensor T1 = Array3D<int, 2, 2, 2>{{{{7, 2}, {3, 7}}, {{5, 6}, {7, 8}}}};
+    Tensor T2 = T0 / T1;
+    T2.print();
+    REQUIRE(T2 == Tensor(Array3D<int, 2, 2, 2>{{{{1, 2}, {3, 4}}, {{5, 6}, {7, 8}}}}));
+
+    Tensor T3(T1.dims());
+    REQUIRE_THROWS(T0 / T3);
+}
+} // namespace Aidge

unit_tests/operator/Test_ReduceMeanImpl.cpp

@@ -17,6 +17,7 @@
 #include "aidge/operator/Conv.hpp"
 
 #include "aidge/backend/cpu.hpp"
+#include "aidge/utils/TensorUtils.hpp"
 
 using namespace Aidge;
 
@@ -138,35 +139,60 @@ TEST_CASE("[cpu/operator] ReduceMean(forward)", "[ReduceMean][CPU]") {
 
     }
     SECTION("all_axes") {
-        std::shared_ptr<Tensor> myInput = std::make_shared<Tensor>(Array3D<float,3,2,2> {
-            {
-                {
-                    { 5.0, 1.0 },
-                    { 20.0, 2.0 }
-                },
-                {
-                    { 30.0, 1.0 },
-                    { 40.0, 2.0 }
-                },
+        SECTION("1") {
+            std::shared_ptr<Tensor> myInput = std::make_shared<Tensor>(Array3D<float,3,2,2> {
                 {
-                    { 55.0, 1.0 },
-                    { 60.0, 2.0 }
+                    {
+                        { 5.0, 1.0 },
+                        { 20.0, 2.0 }
+                    },
+                    {
+                        { 30.0, 1.0 },
+                        { 40.0, 2.0 }
+                    },
+                    {
+                        { 55.0, 1.0 },
+                        { 60.0, 2.0 }
+                    }
                 }
-            }
-        });
-        std::shared_ptr<Tensor> myOutput = std::make_shared<Tensor>(Array1D<float,1> {
-            {18.25}
-        });
+            });
+            std::shared_ptr<Tensor> myOutput = std::make_shared<Tensor>(Array1D<float,1> {
+                {18.25}
+            });
 
-        std::shared_ptr<Node> myReduceMean = ReduceMean({0, 1, 2}, 0);
-        auto op = std::static_pointer_cast<OperatorTensor>(myReduceMean -> getOperator());
-        op->associateInput(0,myInput);
-        op->setDataType(DataType::Float32);
-        op->setBackend("cpu");
-        op->computeOutputDims();
-        myReduceMean->forward();
-        op->getOutput(0)->print();
+            std::shared_ptr<Node> myReduceMean = ReduceMean({0, 1, 2}, 0);
+            auto op = std::static_pointer_cast<OperatorTensor>(myReduceMean -> getOperator());
+            op->associateInput(0,myInput);
+            op->setDataType(DataType::Float32);
+            op->setBackend("cpu");
+            op->computeOutputDims();
+            myReduceMean->forward();
+            op->getOutput(0)->print();
 
-        REQUIRE(*(op->getOutput(0)) == *myOutput);
+            REQUIRE(*(op->getOutput(0)) == *myOutput);
+        }
+        SECTION("2") {
+            std::shared_ptr<Tensor> myInput = std::make_shared<Tensor>(Array2D<float,5,4> {
+               {{ 0.004232f, 0.105120f, 0.045124f, 0.009205f},
+                { 0.000766f, 0.272162f, 0.503560f, 0.044163f},
+                { 0.049755f, 0.000305f, 0.143634f, 0.013253f},
+                { 0.096258f, 0.311231f, 0.358143f, 0.000452f},
+                { 0.468617f, 0.015693f, 0.145316f, 0.000105f}}
+            });
+            std::shared_ptr<Tensor> myOutput = std::make_shared<Tensor>(Array1D<float,1> {
+                {0.1293547f}
+            });
+
+            std::shared_ptr<Node> myReduceMean = ReduceMean({0, 1}, 0);
+            auto op = std::static_pointer_cast<OperatorTensor>(myReduceMean -> getOperator());
+            op->associateInput(0,myInput);
+            op->setDataType(DataType::Float32);
+            op->setBackend("cpu");
+            op->computeOutputDims();
+            myReduceMean->forward();
+            op->getOutput(0)->print();
+            // approxEq<float>(*(op->getOutput(0)), *myOutput);
+            REQUIRE(approxEq<float>(*(op->getOutput(0)), *myOutput));
+        }
     }
 }
\ No newline at end of file

unit_tests/scheduler/Test_Scheduler.cpp

@@ -21,6 +21,7 @@
 #include "aidge/scheduler/ParallelScheduler.hpp"
 
 #include "aidge/backend/cpu.hpp"
+#include "aidge/recipes/GraphViewHelper.hpp"
 
 using namespace Aidge;
 
@@ -346,7 +347,7 @@ TEST_CASE("[cpu/scheduler] SequentialScheduler(forward)") {
 
         std::vector<std::shared_ptr<Aidge::Tensor>> dataIn = {inputTensor};
         REQUIRE_NOTHROW(scheduler.forward(true, dataIn));
-        
+
         scheduler.saveSchedulingDiagram("schedulingSequential");
 
         std::shared_ptr<Tensor> expectedOutput1 = std::make_shared<Tensor>(Array4D<int, 2, 3, 3, 3>{
@@ -391,4 +392,45 @@ TEST_CASE("[cpu/scheduler] SequentialScheduler(forward)") {
         bool equal4 = (*other4 == expectedOutput4);
         REQUIRE(equal4);
     }
+}
+
+TEST_CASE("[cpu/scheduler] SequentialScheduler(backward)", "[scheduler][backward]") {
+
+    // create GraphView
+    std::shared_ptr<GraphView> gv = Sequential({ReLU("relu0"), Sqrt("srqt0"), ReLU("relu1")});
+
+    std::shared_ptr<Tensor> inputTensor =
+            std::make_shared<Tensor>(Array4D<float, 2, 1, 5, 5>{{{{{0.0f,  1.0f,  2.0f,  3.0f,  4.0f},
+                                                                 {5.0f,  6.0f,  7.0f,  8.0f,  9.0f},
+                                                                {10.0f, 11.0f, 12.0f, 13.0f, 14.0f},
+                                                                {15.0f, 16.0f, 17.0f, 18.0f, 19.0f},
+                                                                {20.0f, 21.0f, 22.0f, 23.0f, 24.0f}}},
+                                                              {{{25.0f, 26.0f, 27.0f, 28.0f, 29.0f},
+                                                                {30.0f, 31.0f, 32.0f, 33.0f, 34.0f},
+                                                                {35.0f, 36.0f, 37.0f, 38.0f, 39.0f},
+                                                                {40.0f, 41.0f, 42.0f, 43.0f, 44.0f},
+                                                                {45.0f, 46.0f, 47.0f, 48.0f, 49.0f}}}}});
+    auto label = inputTensor;
+    // implem already set to default
+    auto myProd = Producer(inputTensor, "prod");
+    myProd -> addChild(gv);
+    gv -> compile("cpu", DataType::Float32);
+    compile_gradient(gv);
+    SequentialScheduler scheduler(gv);
+    scheduler.forward();
+    auto predictedOutput = gv->getOrderedOutputs()[0].first;
+
+    std::shared_ptr<Tensor> targetOutput =
+          std::make_shared<Tensor>(Array4D<float, 2, 1, 5, 5>{{{{{0.0f, 1.0f, 1.0f, 2.0f, 2.0f},
+                                                                 {2.0f, 2.0f, 3.0f, 3.0f, 3.0f},
+                                                                 {3.0f, 3.0f, 3.0f, 4.0f, 4.0f},
+                                                                 {4.0f, 4.0f, 4.0f, 4.0f, 4.0f},
+                                                                 {4.0f, 5.0f, 5.0f, 5.0f, 5.0f}}},
+                                                               {{{5.0f, 5.0f, 5.0f, 5.0f, 5.0f},
+                                                                 {5.0f, 6.0f, 6.0f, 6.0f, 6.0f},
+                                                                 {6.0f, 6.0f, 6.0f, 6.0f, 6.0f},
+                                                                 {6.0f, 6.0f, 6.0f, 7.0f, 7.0f},
+                                                                 {7.0f, 7.0f, 7.0f, 7.0f, 7.0f}}}}});
+
+    REQUIRE_NOTHROW(scheduler.backward({targetOutput}));
 }
\ No newline at end of file