On 10/29/21 9:36 AM, William F Pokorny wrote:
> A puzzle I've not been able to run down is the larger 'system' write 
> times post v3.8 beta. It's very roughly around +12.5% of the raw and fld 
> write slow down v3.8 beta to p380 (so it hits povr too though it's 
> faster overall). Something is driving up that system time from raw and 
> fld writes, but I've not been able to find it.

An update.

--- stress_wr.pov
We can improve(1) the write side cpu time by -7.0% and the elapsed time 
by -9.3% by not using rand.inc's (VRand(rng_)) macro, but rather:

#local arr_[i_] = array mixed [2] \ 
{<rand(rng_),rand(rng_),rand(rng_)>,rand(rng_)};

Further, it appears the macro caching of VRand() is somehow tangled in 
the increased system time v3.8 beta to p380 branch/povr - I still don't 
see how. It still might be that if that cause could be run down, one 
could use VRand() without as much penalty.

(1) - To speed compiles I dropped the link time optimization. The 
improvement where configuring with --enable-lto will be somewhat different.

--- stress_rd.pov

A big chunk of the time is in the scanner.cpp code qualify bits and 
pieces of potential tokens. As to how to make that all 'significantly' 
faster within the current framework - no luck thus far. We'll see.

Bill P.

Post a reply to this message