[PATCH] D15197: [WebAssembly] Support constant offsets on loads and stores

[JF Bastien via llvm-commits]

jfb added a comment.

In http://reviews.llvm.org/D15197#301756, @sunfish wrote:

> This looks like a good direction. I like how it uses def : Pat instead of needing custom code in WebAssemblyISelDAGToDAG.cpp :-).


Agreed.

> One tricky thing though is that wasm's constant offsets are unsigned, so we can't support negative values. I think we'll need to add a predicate on the pattern-match which checks this.


We'll also want to optimize things so that LLVM knows to generate positive offsets instead of negative ones (post-increment as much as possible). Do you know if there's a knob for that? It's just an optimization so maybe just mention it in the list of work to do in the README?

> and we can address it later though.


I see what you did there, "address". :o)


http://reviews.llvm.org/D15197