Re: powerpc/ppc64: Allow allmodconfig to build (finally !)

On Wed, May 14, 2014 at 08:34:30AM -0700, Guenter Roeck wrote:

Bummer. Confirmed, if I replace "@h" with "@high" in just one place,
the builds pass with binutils 2.24. Unfortunately the same builds then
fails with binutils 2.23.

Any idea how to get it to compile with both old and new versions ?

The standard way with GNU software would be to write a configure test,
that checks for @high support in the assembler, and defines a macro
if the assembler passes the check.  I'm not that familiar with the
linux kernel these days, but a little grepping around says that
something like

ashigh := $(call as-instr,lis 9$(comma)foo@high,-DHAVE_AS_ATHIGH=1)
KBUILD_AFLAGS += $(ashigh)

might work.

Is there some predefined constant which I could possibly use for
something like

.if as_version_below_2.24_
	oris    reg,reg,(expr)@h;
.else
	oris    reg,reg,(expr)@high;
.endif

Thanks,
Guenter

-- 
Alan Modra
Australia Development Lab, IBM