Re: [PATCH] v4: Use gcc __builtin_stdc_* builtins in stdbit.h if possible

[Mark Wielaard <mark@klomp.org>]

On Thu, Feb 01, 2024 at 11:12:53AM +0100, Mark Wielaard wrote:
> On Mon, Jan 29, 2024 at 11:10:41PM +0100, Jakub Jelinek wrote:
> > diff --git a/manual/stdbit.texi b/manual/stdbit.texi
> > index fe41c671d8..8688930f12 100644
> > --- a/manual/stdbit.texi
> > +++ b/manual/stdbit.texi
> > @@ -32,7 +32,13 @@ and @code{unsigned long long int}.  In addition, there is a
> >  corresponding type-generic macro (not listed below), named the same as
> >  the functions but without any suffix such as @samp{_uc}.  The
> >  type-generic macro can only be used with an argument of an unsigned
> > -integer type with a width of 8, 16, 32 or 64 bits.
> > +integer type with a width of 8, 16, 32 or 64 bits, or when using
> > +a compiler with support for
> > +@uref{https://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html@code{__builtin_stdc_bit_ceil}},
> > +etc.@:, built-in functions such as GCC 14.1 or later
> > +any unsigned integer type those built-in functions support.
> > +In GCC 14.1 that includes support for @code{unsigned __int128} and
> > +@code{unsigned _BitInt(@var{n})} if supported by the target.
> >  
> >  @deftypefun {unsigned int} stdc_leading_zeros_uc (unsigned char @var{x})
> >  @deftypefunx {unsigned int} stdc_leading_zeros_us (unsigned short @var{x})
> 
> make pdf didn't like that new @uref construct:
> https://builder.sourceware.org/buildbot/#/builders/264/builds/282
> https://builder.sourceware.org/buildbot/api/v2/logs/7481911/raw
> 
> (/home/builder/shared/snapshots/worker/glibc-snapshots-trunk/glibc-build/glibc-
> dist/manual/stdbit.texi Chapter 21 [668]
> /home/builder/shared/snapshots/worker/glibc-snapshots-trunk/glibc-build/glibc-d
> ist/manual/stdbit.texi:37: Argument of @temp has an extra }.
> <inserted text> 
>                 @par 
> <to be read again> 
>                    }
> @pdfurl ...btype /Link /A << /S /URI /URI (#1) >>}
>                                                   @endgroup 
> @urefbreakfinish ...sh ->@unsepspaces @pdfurl {#1}
>                                                   @setbox 0 = @hbox {@ignore...
> l.37 ...iltins.html@code{__builtin_stdc_bit_ceil}}
>                                                   ,
> ? 
> /home/builder/shared/snapshots/worker/glibc-snapshots-trunk/glibc-build/glibc-d
> ist/manual/stdbit.texi:37: Emergency stop.
> <inserted text> 
>                 @par 
> <to be read again> 
>                    }
> @pdfurl ...btype /Link /A << /S /URI /URI (#1) >>}
>                                                   @endgroup 
> @urefbreakfinish ...sh ->@unsepspaces @pdfurl {#1}
>                                                   @setbox 0 = @hbox {@ignore...
> l.37 ...iltins.html@code{__builtin_stdc_bit_ceil}}
>                                                   ,
> /home/builder/shared/snapshots/worker/glibc-snapshots-trunk/glibc-build/glibc-d
> ist/manual/stdbit.texi:37:  ==> Fatal error occurred, no output PDF file produc
> ed!
> 
> make info; make html; make dvi
> are all fine however.

But do note that the URL doesn't come out correctly even in the HTML
case:
https://snapshots.sourceware.org/glibc/trunk/latest/manual/libc.html#Bit-Manipulation

It shows and links to:
https://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html__builtin_stdc_bit_ceil
which should be:
https://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#index-_005f_005fbuiltin_005fstdc_005fbit_005fceil

Cheers,

Mark