Comment Feed for Channel 9 - GoingNative 12: C++ at Build 2012, Inside Profile Guided Optimization http://media.ch9.ms/ch9/36a4/c5cfce73-c717-40e9-a68a-426b0f4536a4/C9GoingNative12PGO_220.jpg Channel 9 - GoingNative 12: C++ at Build 2012, Inside Profile Guided Optimization Profile Guided Optimization, or PGO, is an approach to optimization where the compiler uses profile information to make better optimization decisions for the program.  Profiling is the process of gathering information of how the program is used during runtime.  In a nutshell, PGO is optimizations based on user scenarios whereas static optimizations rely on the source file structure. VC++ has supported this approach to measurement-based code optimization since VC2005. In this episode of GoingNative, we are going to dig into VC++'s implementation of PGO with some of the folks who make it: Program Manager Amit Mohindra and Development Lead Ten Tzen. Tune in. Table of contents [00:00]  GoingNative();\\ Charles and Ale discuss C++ at Build 2012 and introduce Profile Guided Optimization.[04:09]  Charles interviews VC++ back end compiler team members Ten Tzen (lead developer) and Amit Mohindra (PM) about VC++'s implementation of PGO. Whiteboarding included. This is a long interview, so make some time.[01:04:15]  ~GoingNative(); // Charles and Ale reflect on PGO, Charles answers Herb Sutter's question (that Herb asked Charles during his Build 2012 C++ session (in his intro remarks). Hi Herb! We really want to hear from you, so please tweet feedback to @C9GoingNative (follow us!) and send your requests, ideas, complaints, praises, hate mail, and love letters to C9GoingNative at hotmail com. We will read and respond to all messages! That's how we roll, brothers and sisters. If you are a Facebook user, then please join our C9::GoingNative Facebook group. Go native! en Mon, 20 May 2013 12:40:00 GMT Mon, 20 May 2013 12:40:00 GMT Rev9 Re: GoingNative 12: C++ at Build 2012, Inside Profile Guided Optimization Great show Charles. As an idea for a future episode, it would be awesome to get two or more senior Microsoft C++ devs, from different products and together talk about how they're using C++ 11 within their *existing* codebases. What new language idioms are they finding useful and what surprised them?

 

 

posted by tomkirbygreen

]]> http://channel9.msdn.com/Shows/C9-GoingNative/C9GoingNative-12-C-at-BUILD-2012-Inside-Profile-Guided-Optimization#c634897624060907487 Thu, 29 Nov 2012 05:06:46 GMT http://channel9.msdn.com/Shows/C9-GoingNative/C9GoingNative-12-C-at-BUILD-2012-Inside-Profile-Guided-Optimization#c634897624060907487 tomkirbygreen Re: GoingNative 12: C++ at Build 2012, Inside Profile Guided Optimization @dot_tom: Thanks, Tom. I've been trying to do just that. Unfortunately, nobody has taken the bait, only sniffed the hook and then swam away... I know you've asked this before and I'm sorry for not delivering on it (talk to folks not on the C++ team who use C++ in modern ways to solve modern problems). Will keep trying! (C++ devs are shy... Perhaps it's because they were kept in the dark for so long?..... Wink).

C

posted by Charles

]]> http://channel9.msdn.com/Shows/C9-GoingNative/C9GoingNative-12-C-at-BUILD-2012-Inside-Profile-Guided-Optimization#c634897629221402457 Thu, 29 Nov 2012 05:15:22 GMT http://channel9.msdn.com/Shows/C9-GoingNative/C9GoingNative-12-C-at-BUILD-2012-Inside-Profile-Guided-Optimization#c634897629221402457 Charles Re: GoingNative 12: C++ at Build 2012, Inside Profile Guided Optimization @Charles Are you fishing where the fishes are? (to parrot Laura)

posted by AdamSpeight2008

]]> http://channel9.msdn.com/Shows/C9-GoingNative/C9GoingNative-12-C-at-BUILD-2012-Inside-Profile-Guided-Optimization#c634897886175076887 Thu, 29 Nov 2012 12:23:37 GMT http://channel9.msdn.com/Shows/C9-GoingNative/C9GoingNative-12-C-at-BUILD-2012-Inside-Profile-Guided-Optimization#c634897886175076887 AdamSpeight2008 Re: GoingNative 12: C++ at Build 2012, Inside Profile Guided Optimization posted by Ricode

]]> http://channel9.msdn.com/Shows/C9-GoingNative/C9GoingNative-12-C-at-BUILD-2012-Inside-Profile-Guided-Optimization#c634898021965203430 Thu, 29 Nov 2012 16:09:56 GMT http://channel9.msdn.com/Shows/C9-GoingNative/C9GoingNative-12-C-at-BUILD-2012-Inside-Profile-Guided-Optimization#c634898021965203430 Ricode Re: GoingNative 12: C++ at Build 2012, Inside Profile Guided Optimization Otherwise, Its a very crucial and amazing feature of a compiler, I've used it for years in both MS C++ and GCC.
Thank you for the episode!

posted by Heavensrevenge

]]> http://channel9.msdn.com/Shows/C9-GoingNative/C9GoingNative-12-C-at-BUILD-2012-Inside-Profile-Guided-Optimization#c634898239786954431 Thu, 29 Nov 2012 22:12:58 GMT http://channel9.msdn.com/Shows/C9-GoingNative/C9GoingNative-12-C-at-BUILD-2012-Inside-Profile-Guided-Optimization#c634898239786954431 Heavensrevenge Re: GoingNative 12: C++ at Build 2012, Inside Profile Guided Optimization @Heavensrevenge: the technology is also sometimes referred to as POGO, thus the other way of saying it...

C

posted by Charles

]]> http://channel9.msdn.com/Shows/C9-GoingNative/C9GoingNative-12-C-at-BUILD-2012-Inside-Profile-Guided-Optimization#c634898320614399356 Fri, 30 Nov 2012 00:27:41 GMT http://channel9.msdn.com/Shows/C9-GoingNative/C9GoingNative-12-C-at-BUILD-2012-Inside-Profile-Guided-Optimization#c634898320614399356 Charles Re: GoingNative 12: C++ at Build 2012, Inside Profile Guided Optimization

, Adam​Speight2008 wrote

@Charles Are you fishing where the fishes are? (to parrot Laura)

I don't understand the question.

C

posted by Charles

]]> http://channel9.msdn.com/Shows/C9-GoingNative/C9GoingNative-12-C-at-BUILD-2012-Inside-Profile-Guided-Optimization#c634898321274917446 Fri, 30 Nov 2012 00:28:47 GMT http://channel9.msdn.com/Shows/C9-GoingNative/C9GoingNative-12-C-at-BUILD-2012-Inside-Profile-Guided-Optimization#c634898321274917446 Charles Re: GoingNative 12: C++ at Build 2012, Inside Profile Guided Optimization @Charles: Just saying that I'm pretty sure it's just one of those MS lingo things to sound cool. As it stands, that term doesn't exist outside of the death star Tongue Out

posted by HeavensRevenge

]]> http://channel9.msdn.com/Shows/C9-GoingNative/C9GoingNative-12-C-at-BUILD-2012-Inside-Profile-Guided-Optimization#c634898336585837922 Fri, 30 Nov 2012 00:54:18 GMT http://channel9.msdn.com/Shows/C9-GoingNative/C9GoingNative-12-C-at-BUILD-2012-Inside-Profile-Guided-Optimization#c634898336585837922 HeavensRevenge Re: GoingNative 12: C++ at Build 2012, Inside Profile Guided Optimization Actually, its really Pogo

The exported funtions in pgodb110.dll

PogoDbIsLocalSymbol
PogoDbAllocEntryProbeId
PogoDbAllocSimpleProbeId
PogoDbAllocValueProbeId
PogoDbClose
PogoDbCloseCallGraph
PogoDbCloseFunction
PogoDbCloseModule
PogoDbCreateGlobalStreams
PogoDbEnableThreadSafetyChecks
PogoDbFGNodeType
PogoDbFinishFunction

 

The modules in pgodb110.dll and pgort110.dll

See ...Src\Tools\Pogo\....

0002 F:\dd\vctools\Compiler\UTC\Src\Tools\Pogo\pogodb\objr\i386\pogodb.obj
0003 F:\dd\vctools\Compiler\UTC\Src\Tools\Pogo\pogodb\objr\i386\pogodbmt.obj
0004 F:\dd\vctools\Compiler\UTC\Src\Tools\Pogo\pogodb\objr\i386\loadui.obj
0006 F:\dd\vctools\Compiler\UTC\Src\Tools\Pogo\pogodb\objr\i386\pgodb.rso
0002 F:\dd\vctools\Compiler\UTC\Src\Tools\Pogo\irt\pgort\objr\i386\irtdll.obj
0003 F:\dd\vctools\Compiler\UTC\Src\Tools\Pogo\irt\pgort\objr\i386\pogowin32interface.obj
0004 F:\dd\vctools\Compiler\UTC\Src\Tools\Pogo\irt\pgort\objr\i386\pgort-loadui.obj
0005 F:\dd\vctools\Compiler\UTC\Src\Tools\Pogo\irt\pgort\objr\i386\pgc.obj
0007 F:\dd\vctools\Compiler\UTC\Src\Tools\Pogo\irt\pgort\objr\i386\pgort.rsoj

 

posted by felix9

]]> http://channel9.msdn.com/Shows/C9-GoingNative/C9GoingNative-12-C-at-BUILD-2012-Inside-Profile-Guided-Optimization#c634898438959768325 Fri, 30 Nov 2012 03:44:55 GMT http://channel9.msdn.com/Shows/C9-GoingNative/C9GoingNative-12-C-at-BUILD-2012-Inside-Profile-Guided-Optimization#c634898438959768325 felix9 Re: GoingNative 12: C++ at Build 2012, Inside Profile Guided Optimization @felix9:  Leave it to Mary Jo Felix to get to the bottom of it!! ...

Smiley
C

posted by Charles

]]> http://channel9.msdn.com/Shows/C9-GoingNative/C9GoingNative-12-C-at-BUILD-2012-Inside-Profile-Guided-Optimization#c634898481877795427 Fri, 30 Nov 2012 04:56:27 GMT http://channel9.msdn.com/Shows/C9-GoingNative/C9GoingNative-12-C-at-BUILD-2012-Inside-Profile-Guided-Optimization#c634898481877795427 Charles Re: GoingNative 12: C++ at Build 2012, Inside Profile Guided Optimization posted by freefly

]]> http://channel9.msdn.com/Shows/C9-GoingNative/C9GoingNative-12-C-at-BUILD-2012-Inside-Profile-Guided-Optimization#c634899729558394877 Sat, 01 Dec 2012 15:35:55 GMT http://channel9.msdn.com/Shows/C9-GoingNative/C9GoingNative-12-C-at-BUILD-2012-Inside-Profile-Guided-Optimization#c634899729558394877 freefly Re: GoingNative 12: C++ at Build 2012, Inside Profile Guided Optimization @Charles: Anytime ! Tongue Out

posted by felix9

]]> http://channel9.msdn.com/Shows/C9-GoingNative/C9GoingNative-12-C-at-BUILD-2012-Inside-Profile-Guided-Optimization#c634899777446767272 Sat, 01 Dec 2012 16:55:44 GMT http://channel9.msdn.com/Shows/C9-GoingNative/C9GoingNative-12-C-at-BUILD-2012-Inside-Profile-Guided-Optimization#c634899777446767272 felix9 Re: GoingNative 12: C++ at Build 2012, Inside Profile Guided Optimization I use OpenMP heavily, and sadly it is said to be incompatible with PGO.  I suspect this is a major adoption block for many others too (if you have OpenMP usage statistics, you might be able to verify this).

What's weirder is that a Connect issue I upvoted long ago about exactly this has just vanished off the net (here's the dead url).  The only trace I can find of a semi-explanation given there for this incompatibility persists in my blog:

   'Since PGO and OpenMP are both designed to increase performance, it is a shame that they can't be used together, but there were some major design issues preventing this. There is an ordering dependency in the designs of PGO and OpenMP. OpenMP changes some things about the program state that are important to PGO, and it does this after PGO has already processed the program state and made many decisions based on it.

...

We will be considering a modification of the designs of PGO and/or OpenMP to get this to work in a future product version.'    [This was posted circa 2005   -Ofek]

So guys - PGO is a great feature and i'd love to use it. But if you're serious about enhancing adoption, puh-leeese grab this bull by the horns, and give us PGO with OpenMP.

posted by Ofek_Shilon

]]> http://channel9.msdn.com/Shows/C9-GoingNative/C9GoingNative-12-C-at-BUILD-2012-Inside-Profile-Guided-Optimization#c634902512313676609 Tue, 04 Dec 2012 20:53:51 GMT http://channel9.msdn.com/Shows/C9-GoingNative/C9GoingNative-12-C-at-BUILD-2012-Inside-Profile-Guided-Optimization#c634902512313676609 Ofek_Shilon Re: GoingNative 12: C++ at Build 2012, Inside Profile Guided Optimization Clever bit about instrumenting using a spanning tree!

posted by Jules.dot

]]> http://channel9.msdn.com/Shows/C9-GoingNative/C9GoingNative-12-C-at-BUILD-2012-Inside-Profile-Guided-Optimization#c634903985738556864 Thu, 06 Dec 2012 13:49:33 GMT http://channel9.msdn.com/Shows/C9-GoingNative/C9GoingNative-12-C-at-BUILD-2012-Inside-Profile-Guided-Optimization#c634903985738556864 Jules.dot Re: GoingNative 12: C++ at Build 2012, Inside Profile Guided Optimization @Heavensrevenge:just because you don't call it pogo, doesn't mean it's not called pogo  Tongue Out

posted by Marius Bancila

]]> http://channel9.msdn.com/Shows/C9-GoingNative/C9GoingNative-12-C-at-BUILD-2012-Inside-Profile-Guided-Optimization#c634968372289451645 Tue, 19 Feb 2013 02:20:28 GMT http://channel9.msdn.com/Shows/C9-GoingNative/C9GoingNative-12-C-at-BUILD-2012-Inside-Profile-Guided-Optimization#c634968372289451645 Marius Bancila