Re: Fixed point cairo.. or no cairo?

[Michael Meeks <michael meeks novell com>]

On Mon, 2006-08-21 at 12:49 +0300, Aivars Kalvans wrote:
> I did include simple C program that produced such result in previous
> mail. It uses http://en.wikipedia.org/wiki/RDTSC to count CPU ticks.

	Ah - I missed that; sorry. I get a huge amount of jitter from these
numbers - but I guess the lowest numbers are static; I imagine
time-slicing screws up RDTSC, indeed - (for me) these numbers look
unreliable enough to be pretty scary ;-)

	My numbers for AMD64 gave (lowest of lots) [ but now unrepeatable ]:

branching:        28 cycles
function call:    60 cycles
inline multiply:  30 cycles

	But really - I'm fairly convinced the numbers are meaningless and/or
wrong :-)

	I provoked the fn. call to be so low by running it once first outside
the timing section :-) without that it was ~1000+ cycles, strangely
removing the fn. call gave the inline multiply a cost of ~1000+ cycles
instead ;-) urk ...

	HTH,

		Michael. 

-- 
 michael meeks novell com  <><, Pseudo Engineer, itinerant idiot