Re: [wwwdocs] Porting-to-14: Mention new pragma GCC Target behavior

[Gerald Pfeifer <gerald@pfeifer.com>]

On Thu, 2 May 2024, Martin Jambor wrote:
> Thanks for your suggestions, this is what I am going to commit in a
> moment.

Thanks!

> diff --git a/htdocs/gcc-14/porting_to.html b/htdocs/gcc-14/porting_to.html
>  
> +<h3 id="target-pragma">Pragma GCC target now affects preprocessor symbols</h4>

A small detail I missed: <h3> closed by </h4> :-)  I'll fix this in a 
second.

> +<p>
> +The behavior of pragma GCC target and specifically how it affects ISA
> +macros has changed in GCC 14.  In GCC 13 and older, the <code>GCC
> +target</code> pragma defined and undefined corresponding ISA macros in
> +C when using the integrated preprocessor during compilation but not
> +when the preprocessor was invoked as a separate step or when using
> +the <code>-save-temps</code> option.  In C++ the ISA macro definitions
> +were performed in a way which did not have any actual effect.
> +
> +In GCC 14 C++ behaves like C with integrated preprocessing in earlier
> +versions. Moreover, in both languages ISA macros are defined and
> +undefined as expected when preprocessing separately from compilation.

I assume this should be two paragraphs? I'll make this change and some 
other tweaks.

Gerald