Re: [PATCH] Prefer mempcpy to memcpy on x86_64 target (PR middle-end/81657).

[Jakub Jelinek <jakub at redhat dot com>]

On Wed, Mar 14, 2018 at 02:54:00PM +0100, Martin Liška wrote:
> > The variable is not named very well, shouldn't it be avoid_libcall or
> > something similar?  Perhaps the variable should have a comment describing
> > what it is.  Do you need separate argument for that bool and
> > is_move_done, rather than just the flag being that some pointer to bool is
> > non-NULL?
> 
> Can you please explain me how to replace the 2 new arguments?

So you have one bool arg and one pointer arg into which the function
stores true and optionally based on that other bool arg and other conditions
stores false.
I'm suggesting just one bool * argument, which is NULL if the bool arg would
be false, and non-NULL otherwise.  The single argument still could be
called bool *avoid_libcall, and you'd just
if (avoid_libcall) { *avoid_libcall = true; return retval; }
instead of emitting a libcall, the caller would initialize the bool
variable to false.

	Jakub