Bug 722225 - Improve Firefox startup speed by ~5% (-70ms) on Windows by... (ed784525) · Commits · Tommy Webb / Tor Browser

gfx/thebes/gfxWindowsPlatform.cpp

+78 −25

Original line number	Diff line number	Diff line
		@@ -361,23 +361,76 @@ gfxWindowsPlatform::VerifyD2DDevice(bool aAttemptForce)
		}
		}

		// We try 10.0 first even though we prefer 10.1, since we want to
		// fail as fast as possible if 10.x isn't supported.
		HRESULT hr = createD3DDevice(
		// It takes a lot of time (5-10% of startup time or ~100ms) to do both
		// a createD3DDevice on D3D10_FEATURE_LEVEL_10_0 and
		// D3D10_FEATURE_LEVEL_10_1. Therefore we set a pref if we ever get
		// 10.1 to work and we use that first if the pref is set.
		// Going direct to a 10.1 check only takes 20-30ms.
		// The initialization of hr doesn't matter here because it will get
		// overwritten whether or not the preference is set.
		// - If the preferD3D10_1 pref is set it gets overwritten immediately.
		// - If the preferD3D10_1 pref is not set, the if condition after
		// the one that follows us immediately will short circuit before
		// checking FAILED(hr) and will again get overwritten immediately.
		// We initialize it here just so it does not appear to be an
		// uninitialized value.
		HRESULT hr = E_FAIL;
		bool preferD3D10_1 =
		Preferences::GetBool("gfx.direct3d.prefer_10_1", false);
		if (preferD3D10_1) {
		hr = createD3DDevice(
		adapter1,
		D3D10_DRIVER_TYPE_HARDWARE,
		NULL,
		D3D10_CREATE_DEVICE_BGRA_SUPPORT \|
		D3D10_CREATE_DEVICE_PREVENT_INTERNAL_THREADING_OPTIMIZATIONS,
		D3D10_FEATURE_LEVEL_10_0,
		D3D10_FEATURE_LEVEL_10_1,
		D3D10_1_SDK_VERSION,
		getter_AddRefs(device));

		// If we fail here, the DirectX version or video card probably
		// changed. We previously could use 10.1 but now we can't
		// anymore. Revert back to doing a 10.0 check first before
		// the 10.1 check.
		if (FAILED(hr)) {
		Preferences::SetBool("gfx.direct3d.prefer_10_1", false);
		} else {
		mD2DDevice = cairo_d2d_create_device_from_d3d10device(device);
		}
		}

		if (!preferD3D10_1 \|\| FAILED(hr)) {
		// If preferD3D10_1 is set and 10.1 failed, fall back to 10.0.
		// if preferD3D10_1 is not yet set, then first try to create
		// a 10.0 D3D device, then try to see if 10.1 works.
		nsRefPtr<ID3D10Device1> device1;
		hr = createD3DDevice(
		adapter1,
		D3D10_DRIVER_TYPE_HARDWARE,
		NULL,
		D3D10_CREATE_DEVICE_BGRA_SUPPORT \|
		D3D10_CREATE_DEVICE_PREVENT_INTERNAL_THREADING_OPTIMIZATIONS,
		D3D10_FEATURE_LEVEL_10_0,
		D3D10_1_SDK_VERSION,
		getter_AddRefs(device1));

		if (SUCCEEDED(hr)) {
		// We have 10.0, let's try 10.1.
		// XXX - This adds an additional 10-20ms for people who are
		// getting direct2d. We'd really like to do something more
		// clever.
		device = device1;
		if (preferD3D10_1) {
		mD2DDevice =
		cairo_d2d_create_device_from_d3d10device(device);
		}
		}
		}

		// If preferD3D10_1 is not yet set and 10.0 succeeded
		if (!preferD3D10_1 && SUCCEEDED(hr)) {
		// We have 10.0, let's try 10.1. This second check will only
		// ever be done once if it succeeds. After that an option
		// will be set to prefer using 10.1 before trying 10.0.
		// In the case that 10.1 fails, it won't be a long operation
		// like it is when 10.1 succeeds, so we don't need to optimize
		// the case where 10.1 is not supported, but 10.0 is supported.
		nsRefPtr<ID3D10Device1> device1;
		hr = createD3DDevice(
		adapter1,
		@@ -391,8 +444,8 @@ gfxWindowsPlatform::VerifyD2DDevice(bool aAttemptForce)

		if (SUCCEEDED(hr)) {
		device = device1;
		Preferences::SetBool("gfx.direct3d.prefer_10_1", true);
		}

		mD2DDevice = cairo_d2d_create_device_from_d3d10device(device);
		}
		}