Re: News on Clang

On 2011-06-25 00:02, Peter Geoghegan wrote:

> At a large presentation that I and other PG community members were
> present at during FOSDEM, Postgres was specifically cited as an
> example of a medium-sized C program that had considerably improved
> compile times on Clang. While I was obviously unable to reproduce the
> very impressive compile-time numbers claimed (at -O0), I still think
> that Clang has a lot of promise. Here are the slides from that
> presentation:
>
> http://www.scribd.com/doc/48921683/LLVM-Clang-Advancing-Compiler-Technology

I notice that the slide about compilation speed on postgres compares
only front-end speeds between gcc and clang, not the speeds for
optimization and code generation. That may explain why the difference
is more pronounced on the slide than it is for a real build.

By the way, I was amazed to see such a young compiler build libpqxx with
no other problems than a few justified warnings or errors that gcc
hadn't issued. And that's C++, which is a lot harder than C! The
output was also far more helpful than gcc's. IIRC I found clang just
slightly faster than gcc on a full configure/build/test.

Jeroen