Slow initialization

I've recently got a bug where somebody complained that GTK4 starts much slower than GTK3, so I took a look, and found that we spend ~50ms in eglInitialize and ~100ms loading shaders (we have ~50 not too complex shaders). This is just loading shaders from the cache - if I blow the cache away, the time to load and compile the shaders goes up to 1.3s.

These numbers are from my laptop with intel graphics.

So I wonder: Are these numbers as expected? Is there anything we can do to speed up either eglInitialize or loading of cached shaders?

Our shaders are here (we compile each of them 3 times): https://gitlab.gnome.org/GNOME/gtk/-/tree/master/gsk/ngl/resources