[SLOF] [PATCH] libc: The arguments of puts() can be marked as "const"
aik at ozlabs.ru
Thu Jul 13 12:42:32 AEST 2017
On 12/07/17 22:41, Segher Boessenkool wrote:
> On Wed, Jul 12, 2017 at 06:53:38AM +0200, Thomas Huth wrote:
>> That's kind of ugly. Why not simply:
>> diff --git a/slof/paflof.c b/slof/paflof.c
>> index 50b4adf..ea3c145 100644
>> --- a/slof/paflof.c
>> +++ b/slof/paflof.c
>> @@ -81,8 +81,8 @@ long engine(int mode, long param_1, long param_2)
>> LAST_ELEMENT(xt_FORTH_X2d_WORDLIST).a = xt_LASTWORD;
>> // stack-pointers
>> - dp = the_data_stack - 1;
>> - rp = handler_stack - 1;
>> + dp = the_data_stack;
>> + rp = handler_stack;
>> // return-address for "evaluate" personality
>> dummy.a = &&over;
> Paflof originally had options to cache 0, 1, or 2 top-of-stack elements.
> Now it is always 1; it is usually fastest (2 is theoretically a tiny
> bit better, but a bit worse in practice).
Sorry I am missing the connection between this 1-cell-cache and the size of
the stack :)
> There also was a user-space version. It set up the stacks with unmapped
> guard pages, so it could trap stack underflows (and overflows). If you
> run in translation-off mode you of course cannot do such things.
> (Your patch is incomplete btw, there are five or six or so places that
> need changes).
> I would just add a cast to shut up the warning, and not lose the
> optimisations (or ignore the warning).
More information about the SLOF