[Python-Dev] [ python-Patches-876206 ] scary frame speed hacks

[Christian Tismer]

Neal Norwitz wrote:

> On Wed, Mar 03, 2004 at 03:03:19PM +1300, Greg Ewing wrote:
> 
>>"Phillip J. Eby" <pje at telecommunity.com>:
>>
>>
>>>Frames are over three times larger than a function and a code object put 
>>>together:
>>
>>Yow! I hadn't realised that.
>>
>>Do frames *really* need to be that big...?
> 
> 
> In Include/frameobject.h, b_type and b_level can be combined to
> a single 32-bit value, rather than two in PyTryBlock.  There
> is a bit more processing to pull the values apart.  IIRC,
> there was a very small, but measurable performance hit.
> You can also decrease CO_MAXBLOCKS.  I was able to drop the
> size to under 256 bytes.  But perf was still a bit off.

I think instead of or in addition to folding block items,
the maximum size of the blockstack *could* be computed
at compile time, instead of a fixed 20 level deep structure.
It would complicate things a little more, again, but memory
savings would be great.

ciao - chris

p.s.:
For a small but simple saving: f_tstate can be completely dropped.
Did it for Stackless, already. Maybe I'll submit a patch. :-)

-- 
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