[PATCH] D49592: [AArch64][SVE] Asm: Add MOVPRFX instructions.

[Sjoerd Meijer via Phabricator via llvm-commits]

SjoerdMeijer added a comment.

Okay, maybe "heavyweight" was not the right word to describe it, but I meant setting up all the machinery here: creating the lookup tables, doing the lookup. Whether an instruction can be combined, is a property of an instruction, so it looks a natural fit to encode this little bit of extra semantic information in the TSFlags of an instructions. It looks like TSFlags was invented to give instructions these kind of (niche) target properties, and it looks like this is what other backends are doing too. Yes, they are used for all instructions, but it's just 1 bit in a 64bit integer, and we are not using a lot of them yet, so don't risk exceeding the maximum of 64.


https://reviews.llvm.org/D49592