[U-Boot] [PATCH] ppc4xx: Enable support for 64bit printf on all PPC4xx variants

Scott Wood scottwood at freescale.com
Thu Jul 9 00:27:04 CEST 2009


Jerry Van Baren wrote:
> Regardless of the in/out debate, we should print a warning if %ll is 
> used but not supported.  I would suggest simply printing the "%lld" (or 
> whatever the format is) and pop two longs from the varargs.  That would 
> make it clear something is missing and probably wrong.

Better to pop a long long -- two longs will pop too much if we ever have 
a 64-bit u-boot.  It would be perverse to not have 64-bit printf in such 
a case, but if it has to be manually selected, and only affects long 
long so as to not be immediately noticed, it could easily happen.

> I don't like printing half and discarding half: it will be erroneous 
> with no warning if the upper half != 0. 

Yes, but it'd be less erroneous than what we have now.

> It would also have endian 
> complications since the half you want to discard depends on the 
> machine's endianness (not insurmountable).

Popping a long long and then casting should take care of that.

-Scott


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