search for: vectorlen

...this is the usual mixup of AVL and MVL. AVL: is part of the predicate and can change between vector operations just like a mask can (light weight). MVL: Is the physical vector register length and can be re-configured per function (RVV only atm) - (heavy weight, stop-the-world instruction). The vectorlen parameter in EVL intrinsics is for the AVL. >> >> I'm curious what SVE will do if there is an if/then/else in the middle >> of a vectorised loop with a shorter-than-maximum vector length. You >> can't just invert the mask when going from the then-part to the >&gt...

On Thu, Jan 31, 2019 at 4:05 PM Philip Reames via llvm-dev <llvm-dev at lists.llvm.org> wrote: > Do such architectures frequently have arithmetic operations on the mask registers? (i.e. can I reasonable compute a conservative length given a mask register value) If I can, then having a mask as the canonical form and re-deriving the length register from a mask for a sequence of

...being able to mark register sequences (aka vectors) as "packed SIMD y/n" including overriding a standard opcode's default width, and including predication but on the PACKED width NOT the element width. Thus it would seem logical to reflect this in the extension of basic data types as vectorlen x simdwidth x datatype as opposed to just vectorlen * datatype as the RFC currently stands. In doing so *all* of the vectorisation systems could simply vectorise (and leverage) the *existing* proven SIMD patterns that have taken years to establish. To illustrate: if the loop length is divisible by...

...art of the predicate and can change between vector operations >> just like a mask can (light weight). >> >> MVL: Is the physical vector register length and can be re-configured per >> function (RVV only atm) - (heavy weight, stop-the-world instruction). >> >> The vectorlen parameter in EVL intrinsics is for the AVL. > Unless I misunderstand, this doesn't describe RVV correctly, although > this is understandable as the spec has moved around a bit in the last > six or twelve months as it's gotten closer to being set in stone. > > The way it has e...