Re: [RFC] Partial vectors for s390

2021-10-26 Thread Richard Sandiford via Gcc-patches
Robin Dapp writes: > Hi Richard, > >> We already have code to probe the predicates of the underlying >> define_expands/insns to see whether they support certain constant >> IFN arguments; see e.g. internal_gather_scatter_fn_supported_p. >> We could do something similar here: add an extra operand t

Re: [RFC] Partial vectors for s390

2021-10-26 Thread Robin Dapp via Gcc-patches
Hi Richard, We already have code to probe the predicates of the underlying define_expands/insns to see whether they support certain constant IFN arguments; see e.g. internal_gather_scatter_fn_supported_p. We could do something similar here: add an extra operand to the optab, and an extra argumen

Re: [RFC] Partial vectors for s390

2021-10-20 Thread Richard Sandiford via Gcc-patches
Robin Dapp via Gcc-patches writes: > Hi, > > I have been playing around with making Kewen's partial vector changes > workable with s390: > > We have a vll instruction that can be passed the highest byte to load. > The rather unfortunate consequence of this is that a length of zero > cannot be s