On Mon, Feb 22, 2016 at 11:54:46AM +0100, Tom de Vries wrote:
> Following up on your suggestion to implement this during gimplification, I
> wrote attached patch.
>
> I'll put it through some openacc testing and add testcases. Is this approach
> acceptable for stage4?
LGTM.
> gcc/gimplify.c | 85
> ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 85 insertions(+)
>
> diff --git a/gcc/gimplify.c b/gcc/gimplify.c
> index 7be6bd7..cec0627 100644
> --- a/gcc/gimplify.c
> +++ b/gcc/gimplify.c
> @@ -8364,6 +8364,82 @@ find_combined_omp_for (tree *tp, int *walk_subtrees,
> void *)
> return NULL_TREE;
> }
>
> +/* Gimplify the loops with index I and higher in omp_for FOR_STMT as a
> + sequential loop, and append the resulting gimple statements to PRE_P. */
> +
> +static void
> +gimplify_omp_for_seq (tree for_stmt, gimple_seq *pre_p, unsigned int i)
> +{
> + gcc_assert (OMP_FOR_ORIG_DECLS (for_stmt) == NULL_TREE);
> + unsigned int len = TREE_VEC_LENGTH (OMP_FOR_INIT (for_stmt));
> + gcc_assert (i < len);
> +
> + /* Gimplify OMP_FOR[i] as:
> +
> + if (i == 0)
> + OMP_FOR_PRE_BODY;
> + OMP_FOR_INIT[i];
> + goto <loop_entry_label>;
> + <fall_thru_label>:
> + if (i == len - 1)
> + OMP_FOR_BODY;
> + else
> + OMP_FOR[i+1];
> + OMP_FOR_INCR[i];
> + <loop_entry_label>:
> + if (OMP_FOR_COND[i])
> + goto <fall_thru_label>;
> + else
> + goto <loop_exit_label>;
> + <loop_exit_label>:
> + */
> +
> + tree loop_entry_label = create_artificial_label (UNKNOWN_LOCATION);
> + tree fall_thru_label = create_artificial_label (UNKNOWN_LOCATION);
> + tree loop_exit_label = create_artificial_label (UNKNOWN_LOCATION);
> +
> + /* if (i = 0) OMP_FOR_PRE_BODY. */
> + if (i == 0)
> + gimplify_and_add (OMP_FOR_PRE_BODY (for_stmt), pre_p);
> +
> + /* OMP_FOR_INIT[i]. */
> + tree init = TREE_VEC_ELT (OMP_FOR_INIT (for_stmt), i);
> + gimplify_stmt (&init, pre_p);
> +
> + /* goto <loop_entry_label>. */
> + gimplify_seq_add_stmt (pre_p, gimple_build_goto (loop_entry_label));
> +
> + /* <fall_thru_label>. */
> + gimplify_seq_add_stmt (pre_p, gimple_build_label (fall_thru_label));
> +
> + /* if (i == len - 1) OMP_FOR_BODY
> + else OMP_FOR[i+1]. */
> + if (i == len - 1)
> + gimplify_and_return_first (OMP_FOR_BODY (for_stmt), pre_p);
> + else
> + gimplify_omp_for_seq (for_stmt, pre_p, i + 1);
> +
> + /* OMP_FOR_INCR[i]. */
> + tree incr = TREE_VEC_ELT (OMP_FOR_INCR (for_stmt), i);
> + gimplify_stmt (&incr, pre_p);
> +
> + /* <loop_entry_label>. */
> + gimplify_seq_add_stmt (pre_p, gimple_build_label (loop_entry_label));
> +
> + /* if (OMP_FOR_COND[i]) goto <fall_thru_label>
> + else goto <loop_exit_label>. */
> + tree cond = TREE_VEC_ELT (OMP_FOR_COND (for_stmt), i);
> + tree var = TREE_OPERAND (cond, 0);
> + tree final_val = TREE_OPERAND (cond, 1);
> + gimplify_expr (&final_val, pre_p, NULL, is_gimple_val, fb_rvalue);
> + gimple *gimple_cond = gimple_build_cond (TREE_CODE (cond), var, final_val,
> + fall_thru_label, loop_exit_label);
> + gimplify_seq_add_stmt (pre_p, gimple_cond);
> +
> + /* <loop_exit_label>. */
> + gimplify_seq_add_stmt (pre_p, gimple_build_label (loop_exit_label));
> +}
> +
> /* Gimplify the gross structure of an OMP_FOR statement. */
>
> static enum gimplify_status
> @@ -8403,6 +8479,15 @@ gimplify_omp_for (tree *expr_p, gimple_seq *pre_p)
> gcc_unreachable ();
> }
>
> + if (ort == ORT_ACC
> + && gimplify_omp_ctxp != NULL
> + && gimplify_omp_ctxp->region_type == ORT_ACC_KERNELS)
> + {
> + /* For now, ignore loop directive in kernels region. */
> + gimplify_omp_for_seq (for_stmt, pre_p, 0);
> + return GS_ALL_DONE;
> + }
> +
> /* Set OMP_CLAUSE_LINEAR_NO_COPYIN flag on explicit linear
> clause for the IV. */
> if (ort == ORT_SIMD && TREE_VEC_LENGTH (OMP_FOR_INIT (for_stmt)) == 1)
Jakub
