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

[Gerald Pfeifer <gerald@pfeifer.com>]

On Tue, 30 Apr 2024, Martin Jambor wrote:
> +<h3 id="gcc-targte-pragma">Pragma GCC Target now affects preprocessor symbols</h4>

Note the id: should be "gcc-target-pragma", though I even suggest to 
simplify and say "target-pragma".

> +The behavior of pragma GCC Target and specifically how it affects ISA

Seconding Jakub's
 
  "And here as well, perhaps even <code>#pragma GCC target</code>."

> +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 integrated preprocessor during compilation but not when

"...the integrated preprocessor..."

> +preprocessor was invoked as a separate step or when using -save-temps.

"...the preprocessor..."

and <code>-save-temps</code>, or better "the <code>-save-temps</code> 
option".

> +This can lead to different behavior, especially in C++.  For example,
> +functions the C++ snippet below will be (silently) compiled for an
> +incorrect instruction set by GCC 14.

"functions" above looks like it's extraneous and should be skipped?

> +  /* With GCC 14, __AVX2__ here will always be defined and pop_options
> +  never called. */
> +  #if ! __AVX2__
> +  #pragma GCC pop_options
> +  #endif

Maybe a bit subtle, I would not say a #pragma is called; how about invoked 
or activated?

> +<p>
> +The fix in this case would be to remember
> +whether <code>pop_options</code> needs to be performed in a new
> +user-defined macro.

"The fix in this case is to remember" (or "...remembering...")

Gerald