https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117978
--- Comment #3 from Richard Sandiford <rsandifo at gcc dot gnu.org> --- I think this would be better done in expand rather than gimple. The gimple representation would be a vector load in a 128-bit type, followed by a zeroing extension to the original SVE type. I'm not sure how easy it is to represent the zeroing extension as things stand, but either way, it would be converting one load into one load + one other operation. The result seems more complicated in gimple terms, so I think the natural gimple fold would be in the opposite direction. If we do it in expand, we'll be able to see the constant if we use an appropriate predicate. Also: * We should do this for 8-bit, 16-bit, 32-bit, and 64-bit quantities, not just 128-bit. * We should do the same thing for LD2/3/4 and ST2/3/4 (64-bit and 128-bit only). * Except for the single-element case, the optimisation is only valid for little-endian targets.
