[U-Boot] [PATCH V2] console: Implement pre-console buffer

[Wolfgang Denk <wd@denx.de>]

Dear Mike Frysinger,

In message <201108301558.08010.vapier@gentoo.org> you wrote:
>
> > Please see my previous posting
> > (http://article.gmane.org/gmane.comp.boot-loaders.u-boot/106810)
> > 
> > I don't think 3 additional addembler instructions really play a big
> > role here.
>
> i'm pretty sure if you define CONFIG_PRE_CON_BUF_SZ as a power of 2 value, you 
> get nice & simple assembly code.  so if the generated code is undesirable,
> pick a CONFIG value that is power-of-2 ?

This was the test code I compiled:

---------------------------------------------
#define	CONFIG_SYS_TMP_CON_BUF_SZ	1024

int foo(int i)
{
	return i & (CONFIG_SYS_TMP_CON_BUF_SZ-1);
}

int bar(int i)
{
	return i % CONFIG_SYS_TMP_CON_BUF_SZ;
}
---------------------------------------------

So was actually checking for a power-of-2 value.

Best regards,

Wolfgang Denk

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