sceneGraphBackend() is new in Qt 5.9

src/declarativeimports/core/framesvgitem.cpp

@@ -465,9 +465,11 @@ void FrameSvgItem::doUpdate()
 
     //software rendering (at time of writing Qt5.10) doesn't seem to like our tiling/stretching in the 9-tiles.
     //also when using QPainter it's arguably faster to create and cache pixmaps of the whole frame, which is what the slow path does
+#if (QT_VERSION >= QT_VERSION_CHECK(5, 9, 0))
     if (QQuickWindow::sceneGraphBackend() == QLatin1String("software")) {
         m_fastPath = false;
     }
+#endif
     m_textureChanged = true;
 
     update();

src/declarativeimports/core/iconitem.cpp

@@ -621,9 +621,11 @@ void IconItem::loadPixmap()
     //don't animate initial setting
     bool animated = (m_animated || m_allowNextAnimation) && !m_oldIconPixmap.isNull() && !m_sizeChanged && !m_blockNextAnimation;
 
+#if (QT_VERSION >= QT_VERSION_CHECK(5, 9, 0))
     if (QQuickWindow::sceneGraphBackend() == QLatin1String("software")) {
         animated = false;
     }
+#endif
 
     if (animated) {
         m_animValue = 0.0;