Re: [PATCH v3 5/6] m68k: remove duplicate memcpy() implementation

[Greg Ungerer <gerg@snapgear.com>]

Hi Geert,

On 02/06/11 17:43, Geert Uytterhoeven wrote:
> On Thu, Jun 2, 2011 at 07:18, Greg Ungerer<gerg@snapgear.com>  wrote:
>> On 26/05/11 16:38, Geert Uytterhoeven wrote:
>>> I was more thinking along the lines of !CONFIG_M68000&&  á!CONFIG_M68010
>>> &&  á!CONFIG_<whatever Coldfire that doesn't support it>.
>>
>> Or in this case (and probably most cases) we could just switch
>> to using the same positive logic. So what I had as:
>>
>> #if defined(__mc68020__) || defined(__mc68030__) || \
>> á ádefined(__mc68040__) || defined(__mc68060__) || defined(__mcpu32__)
>>
>> becomes
>>
>> #if defined(CONFIG_M68020) || defined(CONFIG_M68030) || \
>> á ádefined(CONFIG_M68040) || defined(CONFIG_M68060) || \
>> á ádefined(CONFIG_MCPU32)
>>
>> There currently isn't a CONFIG_MCPU32, but I could easily add
>> that (we only have one CPU in that class currently supported,
>> the 68360).
>>
>> The compiler setting won't matter, only what we configured.
>> Sam will probably like this better, he suggested using the
>> kernel configs initially, in
>> http://www.spinics.net/lists/linux-m68k/msg03609.html
>
> Pure positive logic won't work in the (currently stil pathological) case you're
> building a multi-platform kernel, and have both CONFIG_M68020 and a lesser
> one that doesn't support cpu32 instructions selected.

True. Though we could re-arrange the code blocks to keep the
logic positive. So for the memcpy.c case something like:

#if defined(CONFIG_COLDFIRE) || defined(CONFIG_M68000) || \
     defined(CONFIG_MCPU32)
	/* the simple code */
#else
	/* the real 68020+ code */
#endif

Now the code doesn't yet have the defines CONFIG_M68000 and
CONFIG_MCPU32. But I have a patch ready to send that introduces
them :-)

Regards
Greg