[Bug tree-optimization/83456] -Wrestrict false positive on a non-overlapping memcpy in an inline function

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83456

Martin Sebor <msebor at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2018-02-06
           See Also|                            |https://gcc.gnu.org/bugzill
                   |                            |a/show_bug.cgi?id=84095
     Ever confirmed|0                           |1

--- Comment #1 from Martin Sebor <msebor at gcc dot gnu.org> ---
Here's a slightly different test case, this one from bug 84095 comment 14
(reduced from bug 84095 comment 17).  I'll confirm this bug based on that one.

$ cat t.c && gcc -O2 -S -Wall t.c
extern void* memcpy (void*, const void*, __SIZE_TYPE__);

char a[4];

void f (unsigned n)
{
  for (int i = 0; i < 1; i++)
    {
      if (!i)
        continue;

      memcpy (a, a, n);
    }
}
t.c: In function ‘f’:
t.c:12:7: warning: ‘memcpy’ source argument is the same as destination
[-Wrestrict]
       memcpy (a, a, n);
       ^~~~~~~~~~~~~~~~