[dev.simd] cmd/compile: make move/load/store dependent only on reg and width
This CL improve its previous CL by implementing
move/load/storeByRegWidth. It should have not touched the compilation
path of complex128, but as a side effect, the move/load/store of
16-byte SIMD vectors in X0 to X15 are now compiled to MOVUPS instead of
VMOVDQU.
These functions could be used in MOV*const, but this CL does not do that
because we haven't seen problems of them yet. But in the future if we
see problems calling these functions to find the right asm might be handy.
Change-Id: I9b76e65eef8155479d3e288402aa96bc29a4f7cb
Reviewed-on: https://go-review.googlesource.com/c/go/+/696255
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: David Chase <drchase@google.com>