Re: [PATCH] Pass -mtune and -march options to assembler.

[Richard Sandiford <rdsandiford at googlemail dot com>]

Mark Mitchell <mark@codesourcery.com> writes:
> Richard Sandiford wrote:
>
>> My usual answer to this is that we want gcc to be consistent when
>> used as a driver interface.  So both of the following commands:
>> 
>>     gcc -mtune=foo blah.c
>>     gcc -mtune=foo blah.S
>> 
>> should produce code that is tuned for architecture "foo". 
>
> That argument does not, however, argue for an assembler that uses
> different names for the cores than GCC. :-)

Sure, but the point here and...

>> A quick grep suggests that the only other gas ports to support -mtune
>> are MIPS and IA64.  MIPS passes -mtune options down, so cross-platform
>> consistency is another argument in favour of the patch.  
>
> However, ARM has the similar .march directive (apologies if that's not
> the right spelling), and GCC uses that mechanism to communicate with the
> assembler.  So, cross-platform consistency in that respect argues for an
> .mtune directive.

...here is that it isn't an "either/or".  Both approaches are only
useful if we do them right, and if we do do them right, they're
_independently_ useful.

(And of the two, I think:

>  gcc -mtune=foo blah.S

is likely to be more commom than:

>  gcc -mtune=foo -S blah.c
>  as -o blah.o blah.s
)

I just didn't want to see a specs patch rejected out-of-hand as being
the wrong way to go.  It sounds like that might not have been what was
happening after all, so never mind.

Richard