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From "Jim Yu" <junjie0...@gmail.com>
Subject Re: [jira] Commented: (HARMONY-6056) [classlib][jit][opt][performance] Optimize heap allocations in String(String, int) constructor for JIT
Date Thu, 08 Jan 2009 14:45:15 GMT
Hi Aleksey and Kevin,
It is a good news! The "jim-aleksey" patch is very awesome! I agree to apply
this patch.

2009/1/8 Aleksey Shipilev <aleksey.shipilev@gmail.com>

> Hi Jim, Kevin,
>
> There are good things in both patches: Jim's one does the tricky
> lookup for big integers, which benefit for them; Kevin's one does
> division very cheaply.
>
> I had tried several implementations of radix-10 Integer.toString():
>  - (original) baseline, present in trunk
>  - (kevin) Kevin's original one from HARMONY-6056
>  - (kevin-aleksey) Kevin's one + guessing the buffer size
>  - (jim) Jim's one from HARMONY-6068
>  - (jim-aleksey) Jim's one + optimized division for small integers
>
> The merged patch is attached to
> https://issues.apache.org/jira/browse/HARMONY-6068.
>
> The results are below. In short, Jim's patch rocks! :) It rocks even
> more on small integers with Kevin's ideas. The best one is
> "jim-aleksey", but it's too heavy to just copy-paste to String(String,
> int) constructor, so there's a need in in-place Integer.toString()
> conversion.
>
> What do you think?
>
> --------
> (ops/msec, the more the better)
>
> original-1024Mb:
> *3969, 2612, 1944, 1481, 1168,
> 3831, 2557, 1906, 1447, 1153,
> 3692, 2635, 1971, 1495, 1186,
> 3914, 2626, 1958, 1482, 1170,
> 3947, 2630, 1961, 1478, 1179,
>
> kevin-1024Mb:
> 5041, 3343, 2484, 1883, 1566,
> 5010, 3329, 2454, 1907, 1543,
> 5009, 3325, 2473, 1886, 1539,
> 4969, 3314, 2450, 1884, 1549,
> 4901, 3271, 2457, 1868, 1542,
>
> kevin-aleksey-1024Mb:
> 5041, 4043, 3364, 2867, 2340,
> 5010, 3962, 3368, 2852, 2333,
> 4993, 3992, 3318, 2857, 2303,
> 4953, 3997, 3318, 2847, 2313,
> 4946, 3947, 3311, 2841, 2303,
>
> jim-1024Mb:
> 4681, 3566, 3019, 2976, 2897,
> 4810, 3558, 3054, 2954, 2880,
> 4802, 3530, 2982, 2943, 2868,
> 4795, 3481, 2991, 2918, 2862,
> 4744, 3476, 2954, 2902, 2849,
>
> jim-aleksey-1024Mb:
> 5041, 3977, 2919, 2964, 2860,
> 5066, 3918, 2951, 2929, 2873,
> 5090, 3918, 2886, 2920, 2875,
> 5018, 3918, 2938, 2934, 2878,
> 4978, 3917, 2921, 2868, 2831,
>
>
> Thanks,
> Aleksey.
>
> On Thu, Jan 8, 2009 at 1:11 PM, Jim Yu <junjie0122@gmail.com> wrote:
> > Thanks Aleksey! I think my patch is a general solution for this case and
> has
> > no dependency on any optimized feature of J9 VM : )
> > 2009/1/8 Aleksey Shipilev <aleksey.shipilev@gmail.com>
> >
> >> That's awesome, Jim!
> >> Thanks for coming in :)
> >>
> >> However, you seem to be missing the point. I was talking about
> >> refactoring Kevin's patch to fit the stated requirements. This is
> >> merely because Kevin claim the patch already gives the boost for
> >> SPECjbb2005. Kevin already has the specialized conversion in
> >> String(String, int) private constructor.
> >>
> >> Nevertheless, your specialized version looks good with regards to
> >> performance numbers, we need to test what's better for radix-10
> >> conversion: Jim's version or Kevin's one now.
> >>
> >> Thanks a lot,
> >> Aleksey.
> >>
> >> On Thu, Jan 8, 2009 at 12:11 PM, Jim Yu <junjie0122@gmail.com> wrote:
> >> > Hi Aleksey,
> >> > I very agree with you and I have implemented an optimized algorithm
> for
> >> > Integer.toString(int) method. Thanks to your benchmark, here are the
> test
> >> > results[1] on my windows platform.  I've raised a JIRA at
> >> > https://issues.apache.org/jira/browse/HARMONY-6068
> >> > [1]
> >> > Result for Harmony java6 branch:
> >> > (String)base + (int)add:
> >> > -------------------------------------------
> >> >  base length (vars with rows): 0..2..10
> >> >  add length (vars with cols): 0..2..10
> >> >
> >> >  loop duration = 100 msecs
> >> >  target variance = 0.05
> >> >
> >> > ops/msec, the more the better:
> >> > 6721, 6096, *4650, *3846, *3178,
> >> > *8080, *5833, *4447, 3731, 3048,
> >> > *7985, *5848, 4788, 3727, *3114,
> >> > *7891, 5592, *4389, *3560, 3048,
> >> > 8388, 5607, *4522, 3727, 3051,
> >> >
> >> > After applied my patch:
> >> > (String)base + (int)add:
> >> > -------------------------------------------
> >> >  base length (vars with rows): 0..2..10
> >> >  add length (vars with cols): 0..2..10
> >> >
> >> >  loop duration = 100 msecs
> >> >  target variance = 0.05
> >> >
> >> > ops/msec, the more the better:
> >> > 8322, 6721, 4791, 4788, 4788,
> >> > 8388, 6721, 5156, *5012, 4797,
> >> > 8388, 6707, 5161, *4963, 4795,
> >> > 8388, 6707, *5126, 4802, 4788,
> >> > *8048, 6700, *5021, 4802, *4687,
> >> >
> >> > 2009/1/7 Aleksey Shipilev <aleksey.shipilev@gmail.com>
> >> >
> >> >> Ok, we can implement the in-place Integer.toString() and specialize
> >> >> the radix-10 conversion in Integer. Then Classlib performance guys
> >> >> might use the inplace conversion to optimize StringBuilder
> performance
> >> >> or even catch the concatenation like J9 does.
> >> >>
> >> >> My idea is to share whatever optimization between all VMs that use
> the
> >> >> Classlib.
> >> >>
> >> >> Thanks,
> >> >> Aleksey.
> >> >>
> >> >> On Wed, Jan 7, 2009 at 5:46 PM, Tim Ellison <t.p.ellison@gmail.com>
> >> wrote:
> >> >> > Aleksey Shipilev wrote:
> >> >> >> Am I understanding right that private String(String, int)
is
> inlined
> >> >> >> by J9 JIT when (String)s1 + (int)v1 is required?
> >> >> >
> >> >> > Yes - so for DRLVM, Kevin's patch in HARMONY-6056 will be impotent.
> >> >> >
> >> >> > Regards,
> >> >> > Tim
> >> >> >
> >> >> >
> >> >>
> >> >
> >> >
> >> >
> >> > --
> >> > Best Regards,
> >> > Jim, Jun Jie Yu
> >> >
> >> > China Software Development Lab, IBM
> >> >
> >>
> >
> >
> >
> > --
> > Best Regards,
> > Jim, Jun Jie Yu
> >
> > China Software Development Lab, IBM
> >
>



-- 
Best Regards,
Jim, Jun Jie Yu

China Software Development Lab, IBM

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