Re: [boost] [RFC] Boost library name mangling and Microsoft's 'secure STL' feature.

Subject: Re: [boost] [RFC] Boost library name mangling and Microsoft's 'secure STL' feature.
From: Michael Marcin (mike.marcin_at_[hidden])
Date: 2008-09-04 15:25:37

Mat Marcus wrote:
> On Thu, Sep 4, 2008 at 10:26 AM, Peter Dimov <pdimov_at_[hidden]> wrote:
>>>  Feature: <checked-iterators>
>>>      'on'            --> _SECURE_SCL=1
>>>      'off' (default) --> _SECURE_SCL=0
>> I believe that the default should match the VC default, which is 1.
>>
>> This has no performance implications.
> [snip]
> 
> I wouldn't say that it has *no* performance implications. Default
> settings often have large impact since many people don't take the time
> to learn the meaning of the various settings or tune them. In my
> experience, this is especially true with a complex tool like boost
> build. I expect this would result in a large number of executables
> that are needlessly slow, as is the case today. Vendors are not
> infallible--I believe that Microsoft made a mistake in defaulting the
> flag to 'on' for release builds, and that most users just assume that
> they are not paying a release price for this "security". We have an
> opportunity to employ to follow conventional best-practices with boost
> build defaults, and I still lean in favor of doing so.
> 
> Of course there are dangers. Mixing and matching a component built
> with the IDE defaults with a component built with (different) boost
> build defaults is a recipe for disaster. Then again, it is no great
> thing to ship a product with slow generic inner loops. In the end, I
> suppose that one could make the argument that one way or another users
> must be educated. Nonetheless, I think we should preserve the spirit
> of C++ by avoiding needless release performance tax on user-written
> generic algorithms.
> 

For fun I took Steven Watanabe's recent filter iterator profiling app 
from another thread and ran it in VC9 SP1 in both modes.

The app was posted here
http://lists.boost.org/Archives/boost/2008/09/141851.php

_SECURE_SCL=0
9.297 seconds
5.812 seconds
8.75 seconds
4.688 seconds
2.922 seconds
3.016 seconds
Press any key to continue . . .

_SECURE_SCL=1
12.64 seconds
9.281 seconds
12.531 seconds
6.907 seconds
5.578 seconds
3.015 seconds
Press any key to continue . . .

Thanks,

Michael Marcin