[Bug middle-end/21082] &a[b] - &a[c] is not folded to b - c

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-04-18 
04:06 -------
The code in comment #0 should produce no multiply/divides/shifts but does 
currently (again with the 
C++ front-end).
Take the following code:
typedef __SIZE_TYPE__ size_t;
size_t a[100];
size_t f(size_t b, size_t c)
{
  return (&a[b] - &a[c])*sizeof(*a);
}
We get the good code but only after combine so this blocks both the generic one 
and the RTL based 
missed fold optimizators and we can add the TREE keyword too for the above 
testcase.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
OtherBugsDependingO|                            |19986
              nThis|                            |
           Keywords|                            |TREE


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21082