Hi,
no need to test a phi argument with itself (testing arg0 != arg1 is not
the right test, though, so remembering the candidate index):
> @@ -1948,18 +1958,35 @@ get_continuation_for_phi (gimple phi, ao
> until we hit the phi argument definition that dominates the other one.
> */
> else if (nargs >= 2)
> {
> - tree arg0 = PHI_ARG_DEF (phi, 0);
> - tree arg1;
> - unsigned i = 1;
> - do
> + tree arg0, arg1;
> + unsigned i;
unsigned j;
> + /* Find a candidate for the virtual operand which definition
> + dominates those of all others. */
> + arg0 = PHI_ARG_DEF (phi, 0);
j = 0;
> + if (!SSA_NAME_IS_DEFAULT_DEF (arg0))
> + for (i = 1; i < nargs; ++i)
> + {
> + arg1 = PHI_ARG_DEF (phi, i);
> + if (SSA_NAME_IS_DEFAULT_DEF (arg1))
> + {
> + arg0 = arg1;
j = i;
> + break;
> + }
> + if (dominated_by_p (CDI_DOMINATORS,
> + gimple_bb (SSA_NAME_DEF_STMT (arg0)),
> + gimple_bb (SSA_NAME_DEF_STMT (arg1))))
> + arg0 = arg1;
, j = i;
> + }
> +
> + /* Then pairwise reduce against the found candidate. */
> + for (i = 0; i < nargs; ++i)
> {
> arg1 = PHI_ARG_DEF (phi, i);
if (i != j)
> arg0 = get_continuation_for_phi_1 (phi, arg0, arg1, ref, visited);
> if (!arg0)
> return NULL_TREE;
> -
> }
> - while (++i < nargs);
Ciao,
Michael.
