[PATCH] pointer arguments should not be value escaping initial when -fargument-noalias-global used

[Andrew Pinski <pinskia at physics dot uc dot edu>]

We currently mark pointer arguments as initial value escaping but with
flag_argument_noalias being greater than 1, we should not mark them
as the value could not have escaped anywhere.  This is because the
value could not be pointer to globals or any other argument with that
option supplied.

This is still does not cause the arguments to become not call clobbered
but that is a different issue, relating to name tags and type tags being
call clobbered by default.

OK? Bootstrapped and tested on x86_64-linux-gnu.

Thanks,
Andrew Pinski

ChangeLog:

	* tree-ssa-alias.c (set_initial_properties);
	When flag_argument_noalias is greater than 1, don't mark
	PARM_DECLs as initial value escaping.

Attachment: fixpartcallclobber.diff.txt
Description: Text document