[Bug tree-optimization/59690] New: GCC fails to fold operations on frame-allocated variable across function call

[patrick at parcs dot ath.cx]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59690

            Bug ID: 59690
           Summary: GCC fails to fold operations on frame-allocated
                    variable across function call
           Product: gcc
           Version: 4.9.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: patrick at parcs dot ath.cx

In the following testcase

void bar (void);
void baz (int *);

void
foo (void)
{
  int x;

  x = 5;
  bar ();
  x += 10;
  baz (&x);
  x += 15;
  bar ();
  x += 20;
  baz (&x);
}

GCC does not transform the sequence { x = 5; bar (); x += 10; ... } into { x =
15; bar (); ... }.  It seems to think that the frame-allocated "x" is global
memory.