Re: [PATCH v2] implement constant-folding in __builtin_bswap*()

[Johannes Berg <johannes@sipsolutions.net>]

> There is other possible __builtin_xxx() function gcc expected to get
> a const result when the input arguments are constant.  Ideally, we
> should be able to mark __builtin_bswap16 as a special constant "pass
> through" function. So during the evaluation and constant propagation,
> sparse can pass through the native __builtin_xxx() call to get the
> const result. In other words, sparse shouldn't need to implement
> "__builtin_bswap16()" by itself. It can just call to the gcc
> one to get the result. Then we can treat all other similar
> __builtin_xxx function the same way.

Yes, that'd make some sense. I have no idea how to pull it off though
:)

johannes