craig.topper added inline comments.
================ Comment at: clang/docs/LanguageExtensions.rst:552 +operation(x, y) as pairwise tree reduction to the input. The pairs are formed +by concatenating both inputs and pairing adjacent elements. + ---------------- fhahn wrote: > craig.topper wrote: > > scanon wrote: > > > fhahn wrote: > > > > craig.topper wrote: > > > > > I'm not sure I understand what is being concatenated here. > > > > I tried to spell it out more clearly. I'm still not sure if that spells > > > > it out as clearly as possibly and I'd appreciate any suggestions on how > > > > to improve the wording. > > > It's unclear because there's no apparent "first" or "second" vector; > > > there's just a single argument, and the result isn't a vector, it's a > > > scalar. I think you want to say something like: "the operation is > > > repeatedly applied to adjacent pairs of elements until the result is a > > > scalar" and then provide a worked example. > > The input is a single vector. I'm not understanding where we get a second > > vector to concatenate. > Oh yes, now I see where the confusion was coming from. I was thinking about > the reduction tree and how the input is broken up. Sorry for the confusing > wording. I gave it another try, should be much simpler again now. Should it somehow mention the pair is the even element `i` and the odd element `i+1`. There are n-1 adjacent pairs in an n element vector, but we want non-overlapping pairs. Should probably spell out the non-power2 behavior. Presumably we pad identity elements after the last element to widen the vector out to a power 2 and then proceed normally? Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D111529/new/ https://reviews.llvm.org/D111529 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
