cmd/asm: add the fifth argument of the instruction to Optab on arm64
Currently the Optab structure contains four arguments of an instruction,
excludes the fifth argument p.RegTo2. It does not participate in
instruction matching and is usually handled separately.
Instructions with five operands are common in the newer arm instruction
set, so this CL adds the fifth argument to Optab, so that instruction
matching is easier. This caused the oplook function also needs to be
updated synchronously, this CL also made some cleaning and modifications
to this function.
Change-Id: I1d95ad99e72a44dfad1e00db182cfc369a0e55c6
Reviewed-on: https://go-review.googlesource.com/c/go/+/505975 Reviewed-by: Cherry Mui <cherryyz@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Eric Fang <eric.fang@arm.com>