Off on a vacation

Off on a short vacation ! Leaving today evening and will be back on sunday :-)


In other news , cct8 was lousy tourny for my program due to 2 losses 'cos of some severe bugs ,one more loss since I missed a round due to sleeping :-P and one loss 'cos of ... awesome play by opponent !
So all in all :
4 losses, 4 wins , 1 draw ... kind of symmetrical :-P

Tussle with Intel compiler

So I got the eval version of icl to try what kind of optimisation speedup it gives to my chess program.
It seemed pretty fancy , with lot of 'extra' options to tweak the compilation , profile guided optimisation ,etc.
But the 'feature' which caught my fancy was code generation for a platform which might actually work : so essentially I wanted to see what sort of speedup I will get if I target for P4 ...
Note , chess programs have branches - lots and lots of them , and are essentially integer math : so cmov and family would give nice speedup. Also , vectorization of loops should be nice too.

I run for the P4 target (I ran for SSE2 actually) and voila - refused to execute on my comp !

"Fatal Error : This program was not built to run on the processor in your system."

Hmm , this is interesting - athlon 4200 supports SSE2 ... google'd and voila , I learn about the law suit between amd and intel , etc , etc. (Yep , old news - but then I never bothered with it until now :-D )
Now , how to make this work ?
I found this , give it a shot - no luck.
So , rolled up my sleeves , tried fixing that program - gave up : it is essentially brute force search for a pattern which has been changed in icc8.0 I guess.

Since I am not used to the PE format , wrote something which interprets the exe and was proceeding to find ways of 'nop'ing all those references to the intel 'checker routine' (__intel_new_proc_init_P btw).
Since I have lost touch with assembly for a while , googled to find out opcode forms for a proc call.
That is when I came across this.
He already has perl scripts to patch the exe !

Got them , tried them - and voila ! It works !!

Moral of the story - search for reuse before reinventing :-)
This is one lesson I keep relearning ;-)

* Update * The perl script breaks executable if I use PGO .... not sure why since the difference are the same. Mailed author and looking at the objdump myself too (I am way too rusty :-( )

In general

In the current release of our IM server (should be GA'ed soon) , I was mainly working on a HTTP-XMPP gateway. JEP 124 defines this binding.
So , when I saw that gtalk was available through gmail - I was excited : another client (also corresponding server) implementation of this protocol !
But alas , this is not to be : the google folks have a POST based custom protocol for handling this (part of the syntax is pretty weird if you observe the over the wire data !) .
Considering their normal policy of adhering to standard protocol , I was not expecting this from them I guess ...

Moving on ... most people would Kerala would know about the infamous 'Rajan case' - about how a REC Calicut (my college) student was arrested , tortured and allegedly killed by the cops during the emergency.
From Vinod's blog , I came across this link (not sure when this came out though ...) which points to the account of Rajan's father : would be going through it later ... should be a good read.

Check out this for a new definition of 'asshat' , ROFL.