cmd/asm: use single-instruction forms for all loong64 sign and zero extensions
8-bit and 16-bit sign extensions and 32-bit zero extensions were realized
with left and right shifts before this change. We now support assembling
EXTWB, EXTWH and BSTRPICKV, so all three can be done with a single insn
respectively.
This patch is a copy of CL 479496. Co-authored-by: WANG Xuerui <git@xen0n.name>
Change-Id: Iee5741dd9ebb25746f51008f3f6c86704339d615
Reviewed-on: https://go-review.googlesource.com/c/go/+/626195 Reviewed-by: Cherry Mui <cherryyz@google.com> Reviewed-by: abner chenc <chenguoqi@loongson.cn> Reviewed-by: David Chase <drchase@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>