Re: [PATCH] s390x: Add single instruction math functions

[Szabolcs Nagy <nsz@port70.net>]

* Rich Felker <dalias@libc.org> [2017-06-10 22:20:44 -0400]:
> On Sat, Jun 10, 2017 at 05:48:05PM -0400, David Edelsohn wrote:
> > When I worked with Bobby Bingham to create the s390x port of Musl, I
> > said that he could assume newer processors.  Also, I don't believe
> > that LLVM supports the earlier processors.  I believe that he assumed
> > some more recent instructions in other parts of the code.
> 
> That seems doubtful; the amount of asm in musl is minimal and unlikely
> to benefit from later ISA levels; all the instructions I see look like
> very basic stuff that would always have been available.
> 
> Now, what likely is accurate is your claim that nobody is using musl
> on lower ISA levels, so maybe it doesn't matter.

well i am using s390x musl with lower isa level for compile tests

and it seems gas rejects unrecognized opcodes so the new inline
asm does not compile for me.

i think either musl configure should make sure the cc targets
the right isa level or the code should handle it with ifdefs