[U-Boot] [PATCH v4 2/2] NS16550: buffer reads

[Simon Glass]

Hi Wolfgang,

On Mon, Oct 17, 2011 at 4:08 AM, Wolfgang Denk <wd at denx.de> wrote:
> Dear Simon Glass,
>
> In message <1318742050-2201-2-git-send-email-sjg at chromium.org> you wrote:
> ...
>> With it enabled, on ppc it's an extra 396 bytes of image size, and 1056
>> bytes of BSS.
>>
>> ARM note from Simon Glass <sjg at chromium.org> - ARM code size goes from
>> 212 to 484 bytes (extra 272 bytes), BSS to 1056 bytes.
>
> One problem I see is that the code size on some boards grows even if
> the new option is not enabled.  Here a compare before and after
> applying your patches (without any changes to the respective board
> configurations):
>
>  Configuring for AR405 board...
>    text    data     bss     dec     hex filename
> - 246058   12972   14636  273666   42d02 /work/wd/tmp-ppc/u-boot
> + 246062   12972   14636  273670   42d06 /work/wd/tmp-ppc/u-boot
>  Configuring for CANBT board...
>    text    data     bss     dec     hex filename
> - 120710    8604    3876  133190   20846 /work/wd/tmp-ppc/u-boot
> + 120714    8604    3876  133194   2084a /work/wd/tmp-ppc/u-boot
>  Configuring for pcs440ep board...
>    text    data     bss     dec     hex filename
> - 296191   19636  345088  660915   a15b3 /work/wd/tmp-ppc/u-boot
> + 296195   19636  345088  660919   a15b7 /work/wd/tmp-ppc/u-boot
> ...
>

This doesn't happen for me on ARM - the compiler just inlines the new
static raw functions into the public functions. I will see if I can
figure out what is happening on PPC. It is 4 bytes, or one
instruction, right?

The fix might be to duplicate more code, or perhaps add an inline
keyword to the two functions.

Regards,
Simon

> Best regards,
>
> Wolfgang Denk
>
> --
> DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
> HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
> Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
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