https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60145
--- Comment #3 from Matthijs Kooijman <matthijs at stdin dot nl> --- Thanks for digging into this :-D I suppose you meant https://gcc.gnu.org/viewcvs/gcc?view=revision&revision=242907 instead of the commit you linked (which is also nice btw, I noticed that extra sbiw in some places as well). Looking at the generated assembly, the optimizations look like fairly simple (composable) translations, but I assume that the optimization needs to happen before/while the assembly is generated, not afterwards. And then I can see that the patterns would indeed become complex. My goal was indeed to compose values. Using a union is endian-dependent, which is a downside. If I understand your vector-example correctly, vectors are always stored as big endian, so using this approach would be portable? I couldn't find anything about this in the documentation, though.
