cmd/compile: simplify intrinsification of TrailingZeros16 and TrailingZeros8
Decompose Ctz16 and Ctz8 within the SSA rules for LOONG64, MIPS, PPC64
and S390X, rather than having a custom intrinsic. Note that for PPC64 this
actually allows the existing Ctz16 and Ctz8 rules to be used.
Change-Id: I27a5e978f852b9d75396d2a80f5d7dfcb5ef7dd4
Reviewed-on: https://go-review.googlesource.com/c/go/+/651816 Reviewed-by: Paul Murphy <murp@ibm.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Michael Pratt <mpratt@google.com>
Run-TryBot: Joel Sing <joel@sing.id.au> Reviewed-by: Keith Randall <khr@golang.org> Reviewed-by: Keith Randall <khr@google.com>