[dev.simd] cmd/compile: make (most) move/load/store lowering use reg and width only
This CL tries to clean up the move/load/store lowering a bit. After CL
695315 the register information for instructions are expected to be
correct for SIMD, but we still need to pick the right instruction during
ssa to asm lowering.
The code before this CL should be working correctly, but MOVSSconst and
MOVSDconst contains duplicated codes, this CL removes that.
This CL also rewrite move/load/storeByTypeAndReg to use only the width
and reg for all non-SIMD types, which is more consistent.
Change-Id: I76c14f3d0140bcbd4fbea0df275fee0202a3b7d9
Reviewed-on: https://go-review.googlesource.com/c/go/+/696175 Reviewed-by: David Chase <drchase@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>