[Bug target/12081] Gcc can't be compiled with -mregparm=3

["mikulas at artax dot karlin dot mff dot cuni dot cz" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #16 from mikulas at artax dot karlin dot mff dot cuni dot cz  2007-10-28 16:09 -------
Subject: Re:  Gcc can't be compiled with -mregparm=3

> arguments the function receives. We have gen_* functions taking 0, 1, 2, 3, ...
> arguments and with GCC being designed the way it is, they need to be
> prototyped and defined with the same arguments.
> 
> You are most definitely welcome to post some non-varargs code which works.
> You are most definitely also welcome to time it against my patches.

You can cast them at the time of calling and store them as void * in the 
table --- that is standard-compliant.

Or you can define
union gen_function {
        rtx (*one_arg)(rtx);
        rtx (*two_args)(rtx, rtx);
        rtx (*three_args)(rtx, rtx, rtx);
        ... etc;
};

--- this will be correct C without the performance impact of varargs.

Mikulas


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12081