On Friday 10 August 2007 10:21:46 Herbert Xu wrote:

Paul E. McKenney [off-list ref] wrote:

quoted

The compiler is within its rights to read a 32-bit quantity 16 bits at
at time, even on a 32-bit machine.  I would be glad to help pummel any
compiler writer that pulls such a dirty trick, but the C standard really
does permit this.

Code all over the kernel assumes that 32-bit reads/writes
are atomic so while such a compiler might be legal it certainly
can't compile Linux.

Yes, the kernel requirements are much stricter than ISO-C. And besides
it is a heavy user of C extensions anyways. On the other hand some of the
C99 extensions are not allowed. And then there is sparse, which enforces
a language which sometimes is quite far from standard C. You could say it is 
written in Linux-C, not ISO C. 

-Andi