search for: zip_lower

...number of special things that > are shuffle like. I'm not sure trying to form a strict hierarchy really works out. The key aspect that breaks this is the use of "undef" in shuffle masks. So there are actually multiple fixed shuffles of the same width which might count as a "zip_lower", depending on the context. I think the distinguishing factor here that means we want to integrate these shuffles into the shufflevector instruction, vs. other sorts of shuffle-ish operations, is that the shuffle pattern is known at compile-time. Given that, optimizations can reason about th...

Currently, for scalable vectors, only splat shuffles are allowed; we're considering allowing more different kinds of shuffles. The issue is, essentially, that a shuffle mask is a simple list of integers, and that isn't enough to express a scalable operation. For example, concatenating two fixed-length vectors currently looks like this: shufflevector <2 x i32> %v1, <2 x i32>

> -----Original Message----- > From: Chris Lattner <clattner at nondot.org> > Sent: Wednesday, February 5, 2020 4:02 PM > To: Eli Friedman <efriedma at quicinc.com> > Cc: llvm-dev <llvm-dev at lists.llvm.org> > Subject: [EXT] Re: [llvm-dev] [RFC] Extending shufflevector for vscale vectors > (SVE etc.) > > On Jan 29, 2020, at 4:48 PM, Eli Friedman via