Support enumerating graphics adapters based on a given GPU preference (#217)

Thanks!

Python/src/device.cpp

@@ -12,8 +12,22 @@
 using namespace pydml;
 using Microsoft::WRL::ComPtr;
 
-Device::Device(bool useGpu, bool useDebugLayer) :
-    m_useGpu(useGpu)
+// An adapter called the "Microsoft Basic Render Driver" is always present. This adapter is a render-only device that has no display outputs.
+HRESULT IsWarpAdapter(IDXGIAdapter1* pAdapter, bool* isWarpAdapter)
+{
+    DXGI_ADAPTER_DESC1 pDesc;
+    ReturnIfFailed(pAdapter->GetDesc1(&pDesc));
+    // see here for documentation on filtering WARP adapter:
+    // https://docs.microsoft.com/en-us/windows/desktop/direct3ddxgi/d3d10-graphics-programming-guide-dxgi#new-info-about-enumerating-adapters-for-windows-8
+    auto isBasicRenderDriverVendorId = pDesc.VendorId == 0x1414;
+    auto isBasicRenderDriverDeviceId = pDesc.DeviceId == 0x8c;
+    auto isSoftwareAdapter = pDesc.Flags == DXGI_ADAPTER_FLAG_SOFTWARE;
+    *isWarpAdapter = isSoftwareAdapter || (isBasicRenderDriverVendorId && isBasicRenderDriverDeviceId);
+    return S_OK;
+}
+
+Device::Device(bool useGpu, bool useDebugLayer, DXGI_GPU_PREFERENCE gpuPreference) :
+    m_useGpu(useGpu), m_gpuPreference(gpuPreference)
 {
     // 
     // Create D3D12 resources
@@ -28,9 +42,26 @@ Device::Device(bool useGpu, bool useDebugLayer) :
         }
     }
 
-    ComPtr<IDXGIAdapter> dxgiAdapter;
+    ComPtr<IDXGIAdapter1> dxgiAdapter;
+    if (m_useGpu)
+    {
+        ComPtr<IDXGIFactory6> spFactory;
+        ReturnIfFailed(CreateDXGIFactory1(IID_PPV_ARGS(&spFactory)));
+        UINT i = 0;
+        while (spFactory->EnumAdapterByGpuPreference(i, m_gpuPreference, IID_PPV_ARGS(&dxgiAdapter)) != DXGI_ERROR_NOT_FOUND)
+        {
+            bool isWarpAdapter = false;
+            ReturnIfFailed(IsWarpAdapter(dxgiAdapter.Get(), &isWarpAdapter));
+            if (!isWarpAdapter)
+            {
+                break;
+            }
+            ++i;
+        }
+    }
+
     if (    !useGpu 
-        ||  FAILED(D3D12CreateDevice(nullptr, D3D_FEATURE_LEVEL_11_0, IID_PPV_ARGS(&m_d3d12Device))))
+        ||  FAILED(D3D12CreateDevice(dxgiAdapter.Get(), D3D_FEATURE_LEVEL_11_0, IID_PPV_ARGS(&m_d3d12Device))))
     {
         ComPtr<IDXGIFactory4> dxgiFactory;
         ThrowIfFailed(CreateDXGIFactory1(IID_PPV_ARGS(&dxgiFactory)));

Python/src/device.h

@@ -13,7 +13,7 @@ namespace pydml
     class Device
     {
     public:
-        explicit Device(bool useGpu = true, bool useDebugLayer = false);
+        explicit Device(bool useGpu = true, bool useDebugLayer = false, DXGI_GPU_PREFERENCE gpuPreference = DXGI_GPU_PREFERENCE_UNSPECIFIED);
 
         std::vector<pydml::TensorData*> Compute(
             IDMLCompiledOperator* op,
@@ -108,5 +108,6 @@ namespace pydml
 
         bool m_useCpuCustomHeapResources = false;
         bool m_useGpu = true;
+        DXGI_GPU_PREFERENCE m_gpuPreference;
     };
 }

Python/src/precomp.h

@@ -22,6 +22,7 @@
 
 // ToDo: dxgi isn't available in WSL.
 #include <dxgi1_5.h>
+#include <dxgi1_6.h>
 #include <dxgidebug.h>
 
 #include <initguid.h>