Using Cache As Ram for K8
Bari Ari
bari at onelabs.com
Thu Jun 24 17:48:00 CEST 2004
Eric W. Biederman wrote:
>>Eric,
>>What is the "effective" or "equalvalent" stack size of ROMCC ?
>>Is 448 bytes of stack adquant for ROMCC "linted" code in general ?
>
>
> 8 (gpr) + 8 (mmx) + 8 (sse) registers each 4 bytes long = 96 bytes.
> Looking at the hdama configuration my max inline depth is 14
> procedures so that likely totals to another 14 *4 = 56 bytes in
> return addresses. So 448 bytes would be a small improvement.
>
> Note generally I have noticed romcc compiled does not even use all of
> the registers...
>
For comparison when using U-Boot for PPC:
"Note: on PPC, we could use a static initializer (since the address of
the global data structure is known at compile time), but it turned out
that reserving a register results in somewhat smaller code - although
the code savings are not that big (on average for all boards 752 bytes
for the whole U-Boot image, 624 text + 127 data)."
-Bari
More information about the coreboot
mailing list