C Standard

3 Posts tagged with the c tag
0

This is the meeting that closes on all new features for the upcoming C1X Standard (with only a few minor known exceptions)

In this meeting, we processed a number of key issues. We incorporated a few additional details to the memory model and concurrency proposals taken from C++ Standardization. We moved zero-initialization for thread locals from 5.1.2p1 to integrate with 6.7.8p10

One proposal removed gets() from the standard. This has been a problematic function, and was made obsolete in TC3. The function gets() has been problematic because of uncertain newline removal. The answer for a long time is to use fgets() instead.

We reviewed whether C wishes to support a general syntax for attributes similar to C++. This was rejected as most members were uncomfortable with the need and the consequences. Instead, C will adapt keywords prefixed with a single underscore for future attributes. For example, the alignment proposal will use _Align.

Personally, I feel this will cause C more problems in the future as attributes proliferates. But I do not think it precludes future adaption of a generalized system, if the need becomes serious. although right now the consensus is that C does not want general system for attributes.

I also pitched the concept of a common vectorized type for C based on OpenCL. There was general enthusiasm for the feature as many felt the need to drive for future parallelization support based on many existing implementations of vector extensions. However, due to C1X being on a schedule for completion of features, and the relative size of this proposal, the members felt that this proposal need time to develop. Furthermore, there was interest in maintaining close liaison with OpenCL to ensure we do not create dialects of OpenCL if we were to pick subsets.

In the end, the meeting closed with great belief that we are on track to have a feature completed draft by the next meeting in April, 2010. This puts C on a very promising track to finish on time.

0 Comments Permalink
0

Hi all, my name is Michael Wong. I will be attending the next C Standard meeting in Santa Cruz on Oct 26-30, representing IBM and Canada.

This promises to be a critical meeting as it is where the C Committee has nominated as the cutoff for adding features to the upcoming C1X (the code name for the next release of C).

One of the paper is the IBM comment on the Bounds Checking Library:
http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1388.pdf

where we have made responses as follows:
http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1389.pdf

IBM has also submitted one more proposal in addition to others.

http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1408.pdf

This is a proposal to suggest work to start on a common vectorized type that will be native in C. Currently, the situation is like a jungle out there in that there is a proliferation of vector types from various platforms. Even within one compiler, there are many different vectorized type support because a compiler may need to support VMX, VSX, (Altivec), SSE2, MMX, OpenCL, to name a few.

This has caused a profusion of vectorized names which are similar but possibly not extendable as wider vector registers appear. It is also a recipe for non-portability of code.

The other part of the proposal uses OpenCL as a way to suggest one possible model (but not the only one) of how to support a common Vectorized type.

Please have a look and give me feedback if you wish.

And if you are in the Santa Cruz area, please join us, but first let me know so we can add you to the guest list as the meeting room space is limited based on the projected attendees.

Thanks and I will give a trip report post-meeting.

0 Comments Permalink
0

Welcome to the blog dedicated to the development of the C standard!

Hi, my name is Edison Kwok. I'm the tech lead of the IBM XL C compiler front-end team, and the current Canadian representative in the ISO/IEC JTC1/SC22/WG14 working group. The group is composed of a panel of international experts, charged to oversee the development and standardization of the C programming language. We meet twice a year in different locations, with the next meeting scheduled to be held the last week of March, 2009 at the IBM Canada Lab in Markham, Ontario.

With the development of the next revision of the standard well underway, I'll be using this blog to share with you what's happening at the committee meetings, some of the technical discussions, as well as anything related to the C language and standard.

Hope you'll find this blog useful and informative. Bye for now.

0 Comments Permalink
Bottom Banner