Re: [PATCH] RISC-V: Add sext.[bh] and zext.[bhw] pseudo instructions.

[Jim Wilson <jimw@sifive.com>]

On Tue, Dec 8, 2020 at 11:22 PM Nelson Chu <nelson.chu@sifive.com> wrote:

> We aleady have sext.w, so just add sext.b, sext.h, zext.b, zext.h
> and zext.w.  In a certain sense, zext.b is not a pseudo - It is an
> alias of andi.  Similarly, sext.b and sext.h are aliases of other
> rvb instructions, when we enable b extension; But they are pseudos
> when we just enable rvi.  However, this patch does not consider the
> rvb cases.
>

This looks good to me.  By the way, something simple like this you can just
self approve.

I don't think that the -Mno-aliases testcases are very useful.  Doesn't
help test the macro instruction assembly support.  And there is no
disassembly support for macro instructions, so there doesn't seem to be
much point to it.  They might be useful with B extension support though,
since in that case they are all aliases not macros, and testing disassembly
of aliases with and without -Mno-aliases is useful.  Anyways, there is no
harm to it, and if you want to add them that is fine.

Jim