[Fix][Add] Possibility to have a shape attribute with a negative value

src/operator/Reshape.cpp

@@ -9,38 +9,48 @@
  *
  ********************************************************************************/
 
-#include <cstddef>
+#include <cstddef>    // std::size_t
+#include <cstdint>    // std::int64_t
+#include <stdexcept>  // std::runtime_error
 #include <string>
 #include <vector>
 
 #include "aidge/operator/Reshape.hpp"
-#include "aidge/utils/Types.h"
 #include "aidge/utils/ErrorHandling.hpp"
+#include "aidge/utils/Types.h"
 
 const std::string Aidge::Reshape_Op::Type = "Reshape";
 
 void Aidge::Reshape_Op::computeOutputDims() {
-    // check inputs have been associated
+    // check input has been associated
     if (!getInput(0)) {
         AIDGE_THROW_OR_ABORT(std::runtime_error, "Input was not connected");
     }
 
-    DimSize_t nbOutDims = this->template getAttr<ReshapeAttr::Shape>().size();
     std::vector<DimSize_t> outDims;
+
+    // variables to handle a negative dimension
+    bool foundNegativeDimension = false;
     std::size_t outSize = 1;
-    for(std::size_t i=0; i<nbOutDims; ++i)
+    DimIdx_t negativeIndex = 0;
+
+    for(std::size_t i = 0; i < this->template getAttr<ReshapeAttr::Shape>().size(); ++i)
     {
-        int dimSize = this->template getAttr<ReshapeAttr::Shape>()[i];
-        if (dimSize < 1)
-        {
-            AIDGE_THROW_OR_ABORT(std::runtime_error, "bad dimension value");
+        std::int64_t dimSize = this->template getAttr<ReshapeAttr::Shape>()[i];
+        if (dimSize < 0) {
+            if (foundNegativeDimension) {
+                AIDGE_THROW_OR_ABORT(std::runtime_error, "Found more than one negative dimension in Reshape Operator.");
+            }
+            foundNegativeDimension = true;
+            dimSize = 1;
+            negativeIndex = static_cast<DimIdx_t>(i);
         }
-        outDims.push_back(dimSize);
-        outSize *= dimSize;
+        outDims.push_back(static_cast<DimSize_t>(dimSize));
+        outSize *= static_cast<DimSize_t>(dimSize);
     }
 
-    if (getInput(0)->size() != outSize){
-        AIDGE_THROW_OR_ABORT(std::runtime_error, "Output shape must give the same size as input");
+    if (foundNegativeDimension) {
+        outDims[negativeIndex] = (getInput(0) -> size()) / outSize;
     }
 
     mOutputs[0]->resize(outDims);