[PATCH] D31022: Implement P0298R3: `std::byte`

[James Y Knight via Phabricator via cfe-commits]

jyknight added a comment.

Ping. I don't think this got resolved, and I really wouldn't like to see  released in this state...can you either revert this from the library, or implement the compiler support, before the 5.0 release branch?

In https://reviews.llvm.org/D31022#716702, @jyknight wrote:

> I believe this needs compiler support, too, in order to treat
>
>   namespace std { enum class byte : unsigned char {}; }
>
> as directly having tbaa type "omnipotent char" instead of a subtype.
>
> That is, given:
>
>   void foo(char* x, int *y) {
>     x[1] = char(y[0] & 0xff);
>     x[0] = char((y[0] & 0xff00) >> 8);
>   }
>
> the compiler assumes that x and y might alias each-other, and thus must have two loads of y[0]. If you replace "char" with "std::byte", the same should happen, but as of now does not.





https://reviews.llvm.org/D31022