[Bug tree-optimization/70577] [6 regression] tree-ssa/prefetch-5.c scan-tree-dump-times aprefetch failures

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70577

Martin Liška <marxin at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |marxin at gcc dot gnu.org

--- Comment #5 from Martin Liška <marxin at gcc dot gnu.org> ---
Hi.

It shows that after Honza's change, 'estimated_stmt_executions_int' return -1
for all 3 situations.
Thus 'Issued prefetch' is not printed to the dump file.

However, before Honza's patch was applied, estimated_stmt_executions_int
returns strange results for following 2 loops:

struct tail0
{
  int xxx;
  int yyy[2];
};

int loop0 (int n, struct tail0 *x)
{
  int i, s = 0;

  for (i = 0; i < n; i++)
    s += x->yyy[i];

  return s;
}

returns 3, however:

struct tail1
{
  int xxx;
  int yyy[1];
};

int loop1 (int n, struct tail1 *x)
{
  int i, s = 0;

  for (i = 0; i < n; i++)
    s += x->yyy[i];

  return s;
}

returns -1. Well, I would expect here to we given value 2. According to tree
dump file, both loops have exactly the same CFG.

Martin