-Gate lazy registration logic behind compile time macros

Differential Revision: D79273509

Pull Request resolved: #13134

Author: metascroy

backends/apple/coreml/runtime/delegate/coreml_backend_delegate.mm

@@ -88,17 +88,17 @@
         ET_LOG(Error, "%s: DataType=%d is not supported", ETCoreMLStrings.delegateIdentifier.UTF8String, (int)tensor.scalar_type());
         return std::nullopt;
     }
-    
+
     std::vector<ssize_t> strides(tensor.strides().begin(), tensor.strides().end());
     std::vector<size_t> shape(tensor.sizes().begin(), tensor.sizes().end());
-    
+
     // If tensor is rank 0, wrap in rank 1
     // See https://github.com/apple/coremltools/blob/8.2/coremltools/converters/mil/frontend/torch/exir_utils.py#L73
     if (shape.size() == 0) {
         shape.push_back(1);
         strides.push_back(1);
     }
-    
+
     MultiArray::MemoryLayout layout(dataType.value(), std::move(shape), std::move(strides));
     switch (argType) {
         case ArgType::Input: {
@@ -281,9 +281,11 @@ ModelLoggingOptions get_logging_options(BackendExecutionContext& context) {
 }
 
 namespace {
-auto cls = CoreMLBackendDelegate();
-Backend backend{ETCoreMLStrings.delegateIdentifier.UTF8String, &cls};
-static auto success_with_compiler = register_backend(backend);
+    #ifndef LAZY_LOAD_IOS_PYTORCH_INITIALIZER
+        auto cls = CoreMLBackendDelegate();
+        Backend backend{ETCoreMLStrings.delegateIdentifier.UTF8String, &cls};
+        static auto success_with_compiler = register_backend(backend);
+    #endif
 }
 
 } // namespace coreml