[tree-ssa] tree-ssa vs. fold

[Richard Kenner]

    Hum, perhaps.  However, it does seem like we ought be
    be able to do *something* in the extremely common case of
    a plain "int" variable.

No, it's the "plain 'int' variable" that is the source of the problem!

Consider:

void
sub1 (int n)
{
   int arr[n];

   n = 10;

     .... sizeof (arr) ...

You want the sizeof to use the value of N on entry, so you need the
SAVE_EXPR.