Am 21.03.2010 18:38, schrieb Martin Buchholz:
On Sun, Mar 21, 2010 at 06:35, Ulf Zibis<ulf.zi...@gmx.de> wrote:
On Sun, Mar 21, 2010 at 03:24, Ulf Zibis<ulf.zi...@gmx.de> wrote:
Am 21.03.2010 09:05, schrieb Martin Buchholz:
On Sat, Mar 20, 2010 at 15:50, Ulf Zibis<ulf.zi...@gmx.de> wrote:
I think, we should not define a distinct method for this once-used
3-liner:
for (; i< max-1; i++)
if (v[i] == high&& v[i+1] == low)
return i - offset;
HotSpots resources should not be over-stressed to inline such things,
having
more reserves for more important things.
On the contrary -
normally the above code snippet will rarely be executed,
and so will normally not be inlined into the caller,
which makes it easier for hotspot to inline
the caller into its caller. Separate cold code into
separate methods.
Thanks, I got the idea.
But Isn't the push-call-pop-return overhead comparable with those 3 lines
here, not to forget the repeated cache-3-values-once-more?
Even if I'm wrong, and this cold code is actually hot,
I don't think there will be a big performance loss.
The method call is outside the loop.
What about at least reusing the cached values from calling method via
indexOfSupplementary(ch, fromIndex, value, offset, max - 1) ?
And additionally the slow rarely used branch would stay in stone, even if
after some time, the inline threshhold becomes reached, as JIT, AFAIK, can't
count the frequency of compiled code usage.
It's certainly the intent that we will have multiple levels of
compilation ("tiered compilation") and profiling would be
enabled on at least some compiled code.
That's an interesting option.
-Ulf
