cmd/asm,cmd/internal/obj/riscv,cmd/link: improve TLS handling on riscv64
The existing Thread Local Storage (TLS) implementation for riscv64 uses
initial-exec (IE) mode, however a MOV of a TLS symbol currently loads the
thread pointer offset and not the actual address or memory location.
Rework TLS on riscv64 to generate the full instruction sequence needed to
load from or store to a TLS symbol. Additionally, provide support for both
initial-exec (IE) and local-exec (LE) TLS - in many cases we can use LE,
which is slightly more efficient and easier to support in the linker.
Change-Id: I1b43f8888b3b6b10354bbb79d604771e64d92645
Reviewed-on: https://go-review.googlesource.com/c/go/+/431103 Reviewed-by: Cherry Mui <cherryyz@google.com> Reviewed-by: M Zhuo <mzh@golangcn.org>
TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: David Chase <drchase@google.com>
Run-TryBot: Joel Sing <joel@sing.id.au>