Hi,

As Charles Baylis pointed out here:

http://gcc.gnu.org/ml/gcc-patches/2014-01/msg00921.html

The way that we rewrite command lines for big.LITTLE systems
causes bugs where more than one source file is to be used.
The problem fundamentally is that -mcpu never makes it to
the second cc1 invocation.

This patch changes the spec command we use and updates
aarch64-common.c to handle that fact. I confess that the specs
stuff all looks like magic to me, but this approach seems to
make sense. In English, I think I am saying:

"If you find an mcpu= followed by some name, rewrite that to be
 -mcpu followed by the results of passing all other -mcpu values
 we find through aarch64_rewrite_mcpu"

I've regression tested this patch on aarch64-none-elf with no
issues and checked combinations of zero or more -mcpu values with
one or more source files, and things seem to work as expected.

OK?

Thanks,
James

---
2014-01-21  James Greenhalgh  <james.greenhalgh@arm.com>

	* common/config/aarch64/aarch64-common.c
	(aarch64_rewrite_mcpu): Handle multiple names.
	* config/aarch64/aarch64.h
	(BIG_LITTLE_SPEC): Do not discard mcpu switches.