About the is_gimple_min_invariant predicate

Eric Botcazou ebotcazou@adacore.com
Fri Jul 6 15:05:00 GMT 2007


> Passes ought to distinguish GIMPLE values from GIMPLE invariants
> according to context.

Looks like someone already ran into the problem.  In tree-ssa-ccp.c:

/* The regular is_gimple_min_invariant does a shallow test of the object.
   It assumes that full gimplification has happened, or will happen on the
   object.  For a value coming from DECL_INITIAL, this is not true, so we
   have to be more strict ourselves.  */

static bool
ccp_decl_initial_min_invariant (tree t)
{
  if (!is_gimple_min_invariant (t))
    return false;
  if (TREE_CODE (t) == ADDR_EXPR)
    {
      /* Inline and unroll is_gimple_addressable.  */
      while (1)
	{
	  t = TREE_OPERAND (t, 0);
	  if (is_gimple_id (t))
	    return true;
	  if (!handled_component_p (t))
	    return false;
	}
    }
  return true;
}

-- 
Eric Botcazou



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