diff --git a/include/aidge/backend/cpu.hpp b/include/aidge/backend/cpu.hpp
index 5db19a2b7a2f88dae13d8baf24cf95f961e730a0..ffc03ae5d6cb1d44637bc223ce4099af88f08070 100644
--- a/include/aidge/backend/cpu.hpp
+++ b/include/aidge/backend/cpu.hpp
@@ -29,6 +29,7 @@
#include "aidge/backend/cpu/operator/ConvImpl.hpp"
#include "aidge/backend/cpu/operator/ConstantOfShapeImpl.hpp"
#include "aidge/backend/cpu/operator/DivImpl.hpp"
+#include "aidge/backend/cpu/operator/EqualImpl.hpp"
#include "aidge/backend/cpu/operator/ErfImpl.hpp"
#include "aidge/backend/cpu/operator/ExpandImpl.hpp"
#include "aidge/backend/cpu/operator/FCImpl.hpp"
diff --git a/include/aidge/backend/cpu/operator/EqualImpl.hpp b/include/aidge/backend/cpu/operator/EqualImpl.hpp
new file mode 100644
index 0000000000000000000000000000000000000000..e2489096067a49139f6291898056d525a77db522
--- /dev/null
+++ b/include/aidge/backend/cpu/operator/EqualImpl.hpp
@@ -0,0 +1,32 @@
+/********************************************************************************
+ * Copyright (c) 2024 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
+ *
+ ********************************************************************************/
+
+#ifndef AIDGE_CPU_OPERATOR_EQUALIMPL_H_
+#define AIDGE_CPU_OPERATOR_EQUALIMPL_H_
+
+#include "aidge/backend/cpu/operator/OperatorImpl.hpp"
+#include "aidge/operator/Equal.hpp"
+#include "aidge/utils/Registrar.hpp"
+#include "aidge/utils/Types.h"
+#include "aidge/backend/cpu/data/GetCPUPtr.h"
+#include <memory>
+#include <vector>
+
+namespace Aidge {
+// Operator implementation entry point for the backend
+using EqualImpl_cpu = OperatorImpl_cpu<Equal_Op,
+ void(std::vector<std::size_t>, std::vector<std::size_t>, const std::vector<std::size_t>&, const void*, const void*, void*)>;
+
+// Implementation entry point registration to Operator
+REGISTRAR(Equal_Op, "cpu", Aidge::EqualImpl_cpu::create);
+} // namespace Aidge
+
+#endif /* AIDGE_CPU_OPERATOR_EQUALIMPL_H_ */
diff --git a/include/aidge/backend/cpu/operator/EqualImpl_kernels.hpp b/include/aidge/backend/cpu/operator/EqualImpl_kernels.hpp
new file mode 100644
index 0000000000000000000000000000000000000000..3c8ff0f4742e0393efd8cbbf637822c443edffb3
--- /dev/null
+++ b/include/aidge/backend/cpu/operator/EqualImpl_kernels.hpp
@@ -0,0 +1,163 @@
+/********************************************************************************
+ * Copyright (c) 2024 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
+ *
+ ********************************************************************************/
+
+#ifndef AIDGE_CPU_OPERATOR_EQUALIMPL_KERNELS_H_
+#define AIDGE_CPU_OPERATOR_EQUALIMPL_KERNELS_H_
+
+#include "aidge/backend/cpu/operator/EqualImpl.hpp"
+#include "aidge/utils/Registrar.hpp"
+
+namespace Aidge {
+
+namespace {
+// suppose values are contiguous in memory
+template <class I, class O>
+void equal_contiguous_arrays(const std::size_t input1size,
+ const std::size_t input2size,
+ const std::size_t output1size,
+ const I* input1,
+ const I* input2,
+ O* output)
+{
+ for (std::size_t i = 0; i < output1size; ++i)
+ {
+ const std::size_t in1_id = (input1size != 1) ? i : 0;
+ const std::size_t in2_id = (input2size != 1) ? i : 0;
+ output[i] = static_cast<O>(input1[in1_id] == input2[in2_id]);
+ }
+}
+}
+
+
+template <class I, class O>
+void EqualImpl_cpu_forward_kernel(std::vector<std::size_t> dims0,
+ std::vector<std::size_t> dims1,
+ const std::vector<std::size_t>& outputDims,
+ const void* input0_,
+ const void* input1_,
+ void* output_) {
+
+ const I* input_0 = static_cast<const I*>(input0_);
+ const I* input_1 = static_cast<const I*>(input1_);
+ O* output = static_cast<O*>(output_);
+
+ // [5,2,1,7] & [2,6,7]
+ // 1. Same number of dimensions -> [5,2,1,7] & [1,2,6,7]
+ // 2. Find the highest equal dimension -> 3
+ // Exception: if the first diverging dimension is the last one, then -> 4 (dims.size())
+ // 3. Compute the highest number of contiguous data -> 7
+ // 4. Compute stride and offset step for the broadcast mechanism
+ // 5. Call a simple kernel
+
+ // special case for equal dimensions, the kernel is called with the entire arrays at once
+ if (dims0 == dims1) {
+ const std::size_t input0_contiguous_size = std::accumulate(dims0.cbegin(), dims0.cend(), std::size_t(1), std::multiplies<std::size_t>());
+ for (std::size_t i = 0; i < input0_contiguous_size; ++i)
+ {
+ output[i] = static_cast<O>(input_0[i] == input_1[i]);
+ }
+ return;
+ }
+
+ // set dimensions to be of equal size by filling the smallest one with ones.
+ if (dims0.size() > dims1.size()) {
+ dims1.insert(dims1.cbegin(), dims0.size() - dims1.size(), std::size_t(1));
+ }
+ else if (dims1.size() > dims0.size()) {
+ dims0.insert(dims0.cbegin(), dims1.size() - dims0.size(), std::size_t(1));
+ }
+
+ const std::size_t nbDims = dims0.size();
+
+ // Find the highest equal dimension
+ // std::size_t contiguousIdx = nbDims - 1;
+ std::size_t contiguousIdx = nbDims;
+ while (contiguousIdx-- > 0) {
+ // for (; contiguousIdx+1 > 0; --contiguousIdx) {
+ if (dims0[contiguousIdx] != dims1[contiguousIdx]) {
+ if (contiguousIdx == (nbDims -1)) { // last dimensions of one of the input Tensor are of size 1
+ const std::vector<std::size_t>& dims = (dims0[contiguousIdx] == 1) ? dims0 : dims1;
+ while ((contiguousIdx+1 > 0) && (dims[contiguousIdx] == 1)) {
+ --contiguousIdx;
+ }
+ }
+ break;
+ }
+ }
+ ++contiguousIdx;
+
+ // Compute the highest number of contiguous data for each Tensor
+ const std::size_t input0_contiguous_size = std::accumulate(dims0.cbegin()+contiguousIdx, dims0.cend(), std::size_t(1), std::multiplies<std::size_t>());
+ const std::size_t input1_contiguous_size = std::accumulate(dims1.cbegin()+contiguousIdx, dims1.cend(), std::size_t(1), std::multiplies<std::size_t>());
+ const std::size_t output_contiguous_size = std::accumulate(outputDims.cbegin()+contiguousIdx, outputDims.cend(), std::size_t(1), std::multiplies<std::size_t>());
+
+ // initialize strides to iterate through data because of broadcasting
+ std::unique_ptr<std::int32_t[]> stride_post0 = std::make_unique<std::int32_t[]>(contiguousIdx);
+ std::unique_ptr<std::int32_t[]> stride_post1 = std::make_unique<std::int32_t[]>(contiguousIdx);
+ std::unique_ptr<std::int32_t[]> stride_step0 = std::make_unique<std::int32_t[]>(contiguousIdx);
+ std::unique_ptr<std::int32_t[]> stride_step1 = std::make_unique<std::int32_t[]>(contiguousIdx);
+ if (contiguousIdx > 0) {
+ stride_post0[contiguousIdx - 1] = 1;
+ stride_post1[contiguousIdx - 1] = 1;
+ for (std::size_t i = contiguousIdx - 2; i != static_cast<std::size_t>(-1); --i) {
+ stride_post0[i] = stride_post0[i+1]*static_cast<std::int32_t>(dims0[i+1]);
+ stride_post1[i] = stride_post1[i+1]*static_cast<std::int32_t>(dims1[i+1]);
+ }
+ for (std::size_t i = 0; i != contiguousIdx; ++i) {
+ stride_step0[i] = (dims0[i] == 1) ? 1 - stride_post0[i] : 1;
+ stride_step1[i] = (dims1[i] == 1) ? 1 - stride_post1[i] : 1;
+ }
+ }
+
+ // variables for arrays offsets
+ std::size_t offsetIn0 = 0;
+ std::size_t offsetIn1 = 0;
+ std::size_t offsetOut = 0;
+
+
+ std::size_t dim = contiguousIdx - 1;
+ const std::size_t nbStacks = std::accumulate(outputDims.cbegin(), outputDims.cbegin() + contiguousIdx, std::size_t(1), std::multiplies<std::size_t>());
+ for (std::size_t stack = 0; stack < nbStacks;) {
+ equal_contiguous_arrays<I,O>(input0_contiguous_size, input1_contiguous_size, output_contiguous_size,
+ input_0 + offsetIn0*input0_contiguous_size,
+ input_1 + offsetIn1*input1_contiguous_size,
+ output + offsetOut*output_contiguous_size);
+ if (++stack < nbStacks) {
+ std::size_t tmp_stack = stack;
+ while(tmp_stack % outputDims[dim] == 0) {
+ tmp_stack /= outputDims[dim];
+ dim--;
+ }
+ offsetIn0 += stride_step0[dim];
+ offsetIn1 += stride_step1[dim];
+ ++offsetOut;
+ dim = contiguousIdx - 1;
+ }
+ }
+}
+
+// Kernels registration to implementation entry point
+REGISTRAR(EqualImpl_cpu,
+ {ImplSpec::IOSpec{DataType::Any}, ImplSpec::IOSpec{DataType::Float32}},
+ {ProdConso::inPlaceModel, Aidge::EqualImpl_cpu_forward_kernel<float, float>, nullptr});
+REGISTRAR(EqualImpl_cpu,
+ {ImplSpec::IOSpec{DataType::Any}, ImplSpec::IOSpec{DataType::Float64}},
+ {ProdConso::inPlaceModel, Aidge::EqualImpl_cpu_forward_kernel<double, double>, nullptr});
+REGISTRAR(EqualImpl_cpu,
+ {ImplSpec::IOSpec{DataType::Any}, ImplSpec::IOSpec{DataType::Int32}},
+ {ProdConso::inPlaceModel, Aidge::EqualImpl_cpu_forward_kernel<std::int32_t, std::int32_t>, nullptr});
+REGISTRAR(EqualImpl_cpu,
+ {ImplSpec::IOSpec{DataType::Any}, ImplSpec::IOSpec{DataType::Int64}},
+ {ProdConso::inPlaceModel, Aidge::EqualImpl_cpu_forward_kernel<std::int64_t, std::int64_t>, nullptr});
+
+} // namespace Aidge
+
+#endif /* AIDGE_CPU_OPERATOR_EQUALIMPL_KERNELS_H_ */
diff --git a/src/operator/EqualImpl.cpp b/src/operator/EqualImpl.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..5926212e8453a32e54de7691343d44f9c6849a05
--- /dev/null
+++ b/src/operator/EqualImpl.cpp
@@ -0,0 +1,61 @@
+/********************************************************************************
+ * Copyright (c) 2024 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 <cassert>
+#include <chrono> // std::chrono::milliseconds
+#include <numeric> // std::accumulate
+#include <thread> // std::this_thread::sleep_for
+#include <vector>
+
+#include "aidge/operator/Equal.hpp"
+#include "aidge/utils/Types.h"
+#include "aidge/backend/cpu/data/Broadcasting.hpp"
+#include "aidge/backend/cpu/data/GetCPUPtr.h"
+
+#include "aidge/backend/cpu/operator/EqualImpl.hpp"
+#include "aidge/backend/cpu/operator/EqualImpl_kernels.hpp"
+
+template <>
+void Aidge::EqualImpl_cpu::forward() {
+ const Equal_Op& op = static_cast<const Equal_Op&>(mOp);
+ // Check inputs
+ AIDGE_ASSERT(op.getInput(0), "missing input in Equal operator");
+ AIDGE_ASSERT(op.getInput(0)->hasImpl(), "cannot run Equal forward because the 0-th input has no implementation.");
+
+ AIDGE_ASSERT(op.getInput(1), "missing input in Equal operator");
+ AIDGE_ASSERT(op.getInput(1)->hasImpl(), "cannot run Equal forward because the 1st input has no implementation.");
+
+ AIDGE_ASSERT(op.getInput(1)->dataType() == op.getInput(0)->dataType(), "Cannot Equal inputs with two differents data type.");
+
+ // Find the correct kernel type
+ const auto impl = Registrar<EqualImpl_cpu>::create(getBestMatch(getRequiredSpec()));
+
+ // Convert input data (no overhead if not needed!)
+ // TODO: right now, if needed, memory will be allocated/deallocated at each
+ // call to forward(). We might put the following shared_ptr as members of
+ // this class to avoid that.
+ std::shared_ptr<Tensor> input0Fallback, input1Fallback, input2Fallback;
+ const auto& input0 = op.getInput(0)->refCastFrom(input0Fallback, *op.getInput(0));
+ const auto& input1 = op.getInput(1)->refCastFrom(input1Fallback, *op.getInput(1));
+
+
+ impl.forward(op.getInput(0)->dims(),
+ op.getInput(1)->dims(),
+ op.getOutput(0)->dims(),
+ input0.getImpl()->rawPtr(),
+ input1.getImpl()->rawPtr(),
+ getCPUPtr(op.getRawOutput(0)));
+}
+
+template <>
+void Aidge::EqualImpl_cpu::backward() {
+ AIDGE_THROW_OR_ABORT(std::runtime_error, "Backward not yet implemented for Equal_Op on backend cpu");
+}
diff --git a/unit_tests/operator/Test_EqualImpl.cpp b/unit_tests/operator/Test_EqualImpl.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..a229b8ce3ebcd7672323f2585e3a48343f544c3d
--- /dev/null
+++ b/unit_tests/operator/Test_EqualImpl.cpp
@@ -0,0 +1,205 @@
+/********************************************************************************
+ * Copyright (c) 2024 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 <random> // std::random_device, std::mt19937, std::uniform_real_distribution
+
+#include "aidge/data/Tensor.hpp"
+#include "aidge/operator/Equal.hpp"
+
+#include "aidge/backend/cpu.hpp"
+
+using namespace Aidge;
+
+TEST_CASE("[cpu/operator] Equal(forward)", "[Equal][CPU]") {
+ SECTION("ForwardDims")
+ {
+ 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<std::size_t> nbDimsDist(std::size_t(1), std::size_t(5));
+ std::uniform_int_distribution<int> boolDist(0,1);
+
+ SECTION("Same dimensions") {
+ for (std::uint16_t trial = 0; trial < NBTRIALS; ++trial) {
+ DimSize_t nbDims = nbDimsDist(gen);
+ std::vector<DimSize_t> dims(nbDims);
+ for (std::size_t i = 0; i < nbDims; i++) {
+ dims[i] = dimSizeDist(gen);
+ }
+
+ std::shared_ptr<Tensor> myInput1 = std::make_shared<Tensor>(dims);
+ myInput1->setBackend("cpu");
+ myInput1->setDataType(DataType::Float32);
+ myInput1->zeros();
+ std::shared_ptr<Tensor> myInput2 = std::make_shared<Tensor>(dims);
+ myInput2->setBackend("cpu");
+ myInput2->setDataType(DataType::Float32);
+ myInput2->zeros();
+ std::shared_ptr<Node> myEqual = Equal();
+ auto op = std::static_pointer_cast<OperatorTensor>(myEqual -> getOperator());
+ op->associateInput(0,myInput1);
+ op->associateInput(1,myInput2);
+ op->setDataType(DataType::Float32);
+ op->setBackend("cpu");
+ op->forwardDims();
+
+ const auto outputDims = op->getOutput(0)->dims();
+ REQUIRE(outputDims == dims);
+ }
+ }
+ SECTION("Broadcasting") {
+ for (std::uint16_t trial = 0; trial < NBTRIALS; ++trial) {
+ DimSize_t nbDims = nbDimsDist(gen);
+ std::vector<DimSize_t> dims1(nbDims, 1);
+ std::vector<DimSize_t> dims2(nbDims, 1);
+ std::vector<DimSize_t> expectedOutDims;
+ for (std::size_t i = 0; i < nbDims; i++) {
+ DimSize_t dim = dimSizeDist(gen);
+ if (boolDist(gen)) {
+ dims1[i] = dim;
+ }
+ if (boolDist(gen)) {
+ dims2[i] = dim;
+ }
+ expectedOutDims.push_back(std::max(dims1[i],dims2[i]));
+ }
+
+
+ std::shared_ptr<Tensor> myInput1 = std::make_shared<Tensor>(dims1);
+ myInput1->setBackend("cpu");
+ myInput1->setDataType(DataType::Float32);
+ myInput1->zeros();
+ std::shared_ptr<Tensor> myInput2 = std::make_shared<Tensor>(dims2);
+ myInput2->setBackend("cpu");
+ myInput2->setDataType(DataType::Float32);
+ myInput2->zeros();
+ std::shared_ptr<Node> myEqual = Equal();
+ auto op = std::static_pointer_cast<OperatorTensor>(myEqual -> getOperator());
+ op->associateInput(0,myInput1);
+ op->associateInput(1,myInput2);
+ op->setDataType(DataType::Float32);
+ op->setBackend("cpu");
+
+ op->forwardDims();
+
+ const auto outputDims = op->getOutput(0)->dims();
+ REQUIRE(outputDims == expectedOutDims);
+ }
+ }
+ }
+ SECTION("Same size inputs") {
+ std::shared_ptr<Tensor> input1 = std::make_shared<Tensor>(Array4D<int,3,3,3,2> {
+ { //
+ { //
+ {{20, 15},{31, 11},{22, 49}}, //
+ {{41, 10},{24, 51},{27, 52}}, //
+ {{26, 53},{27, 54},{28, 55}} //
+ }, //
+ { //
+ {{29, 56},{30, 57},{31, 58}}, //
+ {{32, 59},{33, 60},{34, 61}}, //
+ {{35, 62},{36, 63},{37, 64}} //
+ }, //
+ { //
+ {{38, 65},{39, 66},{40, 67}}, //
+ {{41, 68},{42, 69},{43, 70}}, //
+ {{44, 71},{45, 72},{46, 73}} //
+ } //
+ } //
+ }); //
+ std::shared_ptr<Tensor> input2 = std::make_shared<Tensor>(Array4D<int,3,3,3,2> {
+ { //
+ { //
+ {{20, 47},{21, 48},{22, 49}}, //
+ {{23, 50},{24, 51},{25, 52}}, //
+ {{17, 53},{27, 26},{14, 33}} //
+ }, //
+ { //
+ {{29, 56},{30, 57},{31, 58}}, //
+ {{72, 44},{33, 20},{27, 55}}, //
+ {{35, 24},{25, 63},{28, 64}} //
+ }, //
+ { //
+ {{32, 65},{39, 66},{40, 70}}, //
+ {{41, 53},{42, 60},{34, 70}}, //
+ {{44, 71},{30, 12},{46, 73}} //
+ } //
+ } //
+ }); //
+ std::shared_ptr<Tensor> expectedOutput = std::make_shared<Tensor>(Array4D<int,3,3,3,2> {
+ {
+ {
+ {{1, 0},{0, 0},{1, 1}},
+ {{0, 0},{1, 1},{0, 1}},
+ {{0, 1},{1, 0},{0, 0}}
+ },
+ {
+ {{1, 1},{1, 1},{1, 1}},
+ {{0, 0},{1, 0},{0, 0}},
+ {{1, 0},{0, 1},{0, 1}}
+ },
+ {
+ {{0, 1},{1, 1},{1, 0}},
+ {{1, 0},{1, 0},{0, 1}},
+ {{1, 1},{0, 0},{1, 1}}
+ }
+ }
+ });
+
+ std::shared_ptr<Node> myEqual = Equal();
+ auto op = std::static_pointer_cast<OperatorTensor>(myEqual -> getOperator());
+ op->associateInput(0, input1);
+ op->associateInput(1, input2);
+ op->setBackend("cpu");
+ op->setDataType(DataType::Int32);
+ myEqual->forward();
+
+ REQUIRE(*(op->getOutput(0)) == *expectedOutput);
+ }
+
+ SECTION("Broadcasting") {
+ std::shared_ptr<Tensor> input_1 = std::make_shared<Tensor>(Array4D<int,1,3,3,2> {
+ { //
+ { //
+ {{10, 20},{22, 23},{20, 20}}, //
+ {{10, 15},{10, 29},{20, 20}}, //
+ {{26, 25},{33, 20},{10, 20}} //
+ } //
+ } //
+ }); //
+
+ std::shared_ptr<Tensor> input_2 = std::make_shared<Tensor>(Array1D<int,2> {{10, 20}});
+ std::shared_ptr<Tensor> expectedOutput = std::make_shared<Tensor>(Array4D<int,1,3,3,2> {
+ { //
+ { //
+ {{ 1, 1},{ 0, 0},{ 0, 1}}, //
+ {{ 1, 0},{ 1, 0},{ 0, 1}}, //
+ {{ 0, 0},{ 0, 1},{ 1, 1}} //
+ } //
+ } //
+ }); //
+
+ std::shared_ptr<Node> myEqual = Equal();
+ auto op = std::static_pointer_cast<OperatorTensor>(myEqual -> getOperator());
+ op->associateInput(0, input_1);
+ op->associateInput(1, input_2);
+ op->setDataType(DataType::Int32);
+ op->setBackend("cpu");
+ myEqual->forward();
+ op->getOutput(0)->print();
+ expectedOutput->print();
+ REQUIRE(*op->getOutput(0) == *expectedOutput);
+ }
+}
\ No newline at end of file