[wwwdocs] gcc-8/changes.html additions

[Martin Sebor]

On 04/04/2018 01:43 AM, Jakub Jelinek wrote:
> Hi!
>
> Following patch documents store merging improvements, -fsanitize=builtin,
> -fsanitize=pointer-overflow and C++2A progress.
>
> Ok for wwwdocs?
>
> --- changes.html	3 Apr 2018 06:52:04 -0000	1.51
> +++ changes.html	4 Apr 2018 07:41:06 -0000
> @@ -113,6 +113,21 @@ a work-in-progress.</h2>
>      possible for the user to have a finer-grained control over the loop
>      unrolling optimization.
>    </li>
> +  <li>
> +    The store merging pass has been enhanced to handle bitfields and not

Just a minor nit: I believe the established spelling is bit-fields
(as you used in the last hunk below).

Martin


> +    just constant stores, but also data copying from adjacent memory
> +    locations into other adjacent memory locations, including bitwise
> +    logical operations on the data.  The pass can also handle byte swapping
> +    into memory locations.
> +  </li>
> +  <li>
> +    The undefined behavior sanitizer gained two new options included in
> +    <code>-fsanitize=undefined</code>: <code>-fsanitize=builtin</code> which
> +    diagnoses at runtime invalid arguments to <code>__builtin_clz</code> or
> +    <code>__builtin_ctz</code> prefixed builtins, and
> +    <code>-fsanitize=pointer-overflow</code> which performs cheap runtime
> +    tests for pointer wrapping.
> +  </li>
>  </ul>
>
>
> @@ -187,7 +202,17 @@ a work-in-progress.</h2>
>
>  <h3 id="cxx">C++</h3>
>  <ul>
> -  <li></li>
> +  <li>
> +    The C++ front end has experimental support for some of the upcoming C++2a
> +    draft features with the <code>-std=c++2a</code> or <code>-std=gnu++2a</code>
> +    flags, including designated initializers, default member initializers for
> +    bit-fields, <code>__VA_OPT__</code> (except that
> +    <code>#__VA_OPT__</code> is unsupported), lambda <code>[=, this]</code>
> +    captures, etc.
> +    For a full list of new features,
> +    see <a href="https://gcc.gnu.org/projects/cxx-status.html#cxx2a">the C++
> +    status page</a>.
> +  </li>
>  </ul>
>
>  <h3 id="fortran">Fortran</h3>
>
> 	Jakub
>