# Re: \[RFC\]\[PATCH\] new byteorder primitives - ...\_{replace,get}\_bits()

- From: Al Viro \<viro@ZenIV.linux.org.uk\>
- Date: 2017-12-13 01:51:31 
- List: netdev
- Page: https://ratatoskr.run/netdev/2017/12/5156560
- Thread: https://ratatoskr.run/netdev/2017/12/11076143/t.md

```text
On Tue, Dec 12, 2017 at 05:35:28PM -0800, Jakub Kicinski wrote:

> It used to be __always_inline, but apparently LLVM/clang doesn't
> propagate constants :(  
> 
> 4e59532541c8 ("nfp: don't depend on compiler constant propagation")

Doesn't propagate constants or doesn't have exact same set of
rules for __builtin_constant_p()?  IOW, if you dropped that
BUILD_BUG_ON(), what would be left after optimizations?
```