Added per argument alignment to GPUAllocator::reserve_argspace. (#1069)

* Added per argument alignment to GPUAllocator::reserve_argspace.

* Changed alignment in tests to match update to alignment in backend.

src/ngraph/runtime/gpu/gpu_memory_manager.cpp

@@ -84,6 +84,7 @@ runtime::gpu::GPUAllocator::GPUAllocator(const GPUAllocator& g)
 size_t runtime::gpu::GPUAllocator::reserve_argspace(const void* data, size_t size)
 {
     // add parameter data to host buffer that will be transfered to device
+    size = pass::MemoryManager::align(size, runtime::gpu::GPUMemoryManager::alignment);
     size_t offset = m_manager->queue_for_transfer(data, size);
     // required to capture m_manager pointer
     // directly rather than `this` pointer

src/ngraph/runtime/gpu/gpu_memory_manager.hpp

@@ -68,7 +68,7 @@ namespace ngraph
                 size_t m_buffer_offset;
                 std::vector<uint8_t> m_buffered_mem;
                 pass::MemoryManager m_workspace_manager;
-                static constexpr const uint16_t alignment = 4;
+                static constexpr const uint16_t alignment = 8;
                 void* m_argspace;
                 void* m_workspace;
                 size_t m_allocation_size;

test/gpu_test.cpp

@@ -108,7 +108,7 @@ TEST(gpu_test, memory_manager_seperate_workspaces_allocsize)
         {
             size_t size = std::pow(2, i);
             allocator.reserve_workspace(size);
-            total_size += pass::MemoryManager::align(size, 4);
+            total_size += pass::MemoryManager::align(size, 8);
         }
     }
     emitter.allocate_primitive_memory();