[RFC][PATCH] powerpc/CoreNet64: compile with CONFIG_E{5, 6}500_CPU well

[Kumar Gala]

On Nov 20, 2013, at 10:41 AM, Scott Wood <scottwood at freescale.com> wrote:

> On Wed, 2013-11-20 at 16:35 +0800, Tiejun Chen wrote:
>> CONFIG_ALTIVEC is always enabled for CoreNet64.
> 
> In the defconfig perhaps, but this isn't a generally true statement.
> 
>> And if we select CONFIG_E{5,6}500_CPU this may introduce -mcpu=e500mc64
>> into $CFLAGS. But Altivec and Spe options not allowed with
>> e500mc64, so :
> 
> Sigh.
> 
>>  CC      arch/powerpc/lib/xor_vmx.o
>> arch/powerpc/lib/xor_vmx.c:1:0: error: AltiVec not supported in this target
>> make[1]: *** [arch/powerpc/lib/xor_vmx.o] Error 1
>> make: *** [arch/powerpc/lib] Error 2
>> 
>> Signed-off-by: Tiejun Chen <tiejun.chen at windriver.com>
>> ---
>> arch/powerpc/lib/Makefile |    3 +++
>> 1 file changed, 3 insertions(+)
>> 
>> diff --git a/arch/powerpc/lib/Makefile b/arch/powerpc/lib/Makefile
>> index 95a20e1..641a77d 100644
>> --- a/arch/powerpc/lib/Makefile
>> +++ b/arch/powerpc/lib/Makefile
>> @@ -40,5 +40,8 @@ obj-y			+= code-patching.o
>> obj-y			+= feature-fixups.o
>> obj-$(CONFIG_FTR_FIXUP_SELFTEST) += feature-fixups-test.o
>> 
>> +# Altivec and Spe options not allowed with e500mc64 in GCC.
>> +ifeq ($(call cc-option-yn,-mcpu=e500mc64),n)
>> obj-$(CONFIG_ALTIVEC)	+= xor_vmx.o
>> CFLAGS_xor_vmx.o += -maltivec -mabi=altivec
>> +endif
> 
> This does not seem like the right fix.  What if GCC supports both
> -mcpu=e500mc64 and -mcpu=e6500, and we're using the latter?  Or for that
> matter, if we're using -mcpu=whatever-ibm-chip-has-this?
> 
> Plus, wouldn't you need to do something to prevent code in that file
> from being called?
> 
> -Scott

Why does -mcpu=e500mc64 get you spe enabled?  It shouldn’t as no e500mc or greater part has spe.  Can you try using -mno-spe -maltivec?

- k