Re: tree check: expected SSA_NAME, have var_decl

[Justin Seyster <jrseys at gmail dot com>]

You can assign the "a" TREE_NODE to a temporary variable and call
make_ssa_name on the temp, allowing you to use it as an argument to a
GIMPLE_CALL.  Here is the function I use for that purpose:

/* Create a GIMPLE statement assigning a reference to a temporary
   variable, add that statement at the iterator gsi, then return the
   temporary variable. */
static tree assign_ref_to_tmp (gimple_stmt_iterator *gsi, tree ref,
const char *tmp_prefix)
{
  tree tmp = create_tmp_var (TREE_TYPE (ref), tmp_prefix);

  /* Construct an assign statement: tmp = ref; */
  gimple assign_stmt = gimple_build_assign (tmp, ref);

  /* The left side of the assignment should be an SSA_NAME, but we
     can't create the SSA_NAME until after we build the assign
     statement. */
  gimple_assign_set_lhs(assign_stmt, make_ssa_name (tmp, assign_stmt));

  gsi_insert_before (gsi, assign_stmt, GSI_SAME_STMT);

  return gimple_assign_lhs (assign_stmt);
}

I can't verify that this will work in all cases (I'm far from an
expert), but I've successfully compiled a lot of code with this
transformation.
        --Justin

On Wed, Dec 23, 2009 at 5:19 PM, Aravinda <aravindakidambi@gmail.com> wrote:
> Hi,
>
> After the tree-loop pass, I need to perform some analysis on the loop
> and insert a "gimple function call statement" before the loop body.
> The function call looks like,
>
> foo(a, 1, 1); for a loop that looks like,
>
> for (i = 0; i < 20; i ++) {
> ? ?a[i]++;
> }
>
> When compiled with -O2, after the tree loop init, the loops have SSA
> names for variables. Based on the analysis I do on the loop, I get a
> TREE_NODE for the variable 'a', and two integer_one_node s.
> I have trouble constructing the gimple_call_statement and adding it
> before the loop_body. I am running into 'expected ssa_name have
> var_decl' error. I am not sure I can use make_ssa_name for the
> TREE_NODE of variable 'a' since I am yet to build a gimple_stmt that
> will contain this variable.
>
> How could I insert a call statement after a loop analysis ?
>
> Thanks,
> Aravinda
>