> That's my understanding too as far as insn operands are concerned. > But some backends use things like "(subreg (match_operand ...) ...)"; > see config/rs6000/spe.md for an example. We need to define what those > subregs mean when the inner register has been reloaded. > > Or I suppose we could say that such define_insns are in error and > use another construct instead.
I would consider such things dubious at best. I'm kind of surprised they work.
