openmp: Use more efficient logical -> actual computation even if # iterations is...

For triangular loops use more efficient logical iteration number
to actual iterator values computation even for non-rectangular loops
where number of loop iterations could not be computed at compile time.

2020-08-05  Jakub Jelinek  <jakub@redhat.com>

	* omp-expand.c (expand_omp_for_init_counts): Remember
	first_inner_iterations, factor and n1o from the number of iterations
	computation in *fd.
	(expand_omp_for_init_vars): Use more efficient logical iteration number
	to actual iterator values computation even for non-rectangular loops
	where number of loop iterations could not be computed at compile time.

diff --git a/gcc/omp-expand.c b/gcc/omp-expand.c
index f73cdc9c89c43233701bdcbb8b5dd50cd2078ff0..048aacf7188ab2044465d095fcf39263c531af71 100644 (file)
--- a/gcc/omp-expand.c
+++ b/gcc/omp-expand.c
@@ -2181,6 +2181,13 @@ expand_omp_for_init_counts (struct omp_for_data *fd, gimple_stmt_iterator *gsi,
          set_immediate_dominator (CDI_DOMINATORS, bb3, bb1);
          set_immediate_dominator (CDI_DOMINATORS, bb5, bb2);
          set_immediate_dominator (CDI_DOMINATORS, entry_bb, bb1);
+
+         if (fd->first_nonrect + 1 == fd->last_nonrect)
+           {
+             fd->first_inner_iterations = first_inner_iterations;
+             fd->factor = factor;
+             fd->adjn1 = n1o;
+           }
        }
       else
        {
@@ -2469,8 +2476,11 @@ expand_omp_for_init_vars (struct omp_for_data *fd, gimple_stmt_iterator *gsi,
                                   build_zero_cst (type), true);
          basic_block bb_triang = NULL, bb_triang_dom = NULL;
          if (fd->first_nonrect + 1 == fd->last_nonrect
-             /* For now.  */
-             && TREE_CODE (fd->loop.n2) == INTEGER_CST
+             && (TREE_CODE (fd->loop.n2) == INTEGER_CST
+                 || (fd->first_inner_iterations
+                     /* For now.  Later add clauses to propagate the
+                        values.  */
+                     && !gimple_omp_for_combined_into_p (fd->for_stmt)))
              && (optab_handler (sqrt_optab, TYPE_MODE (double_type_node))
                  != CODE_FOR_nothing))
            {
@@ -2567,14 +2577,19 @@ expand_omp_for_init_vars (struct omp_for_data *fd, gimple_stmt_iterator *gsi,
                               build_one_cst (ulltype));
              t = fold_build2 (MULT_EXPR, ulltype, c, t);
              t = fold_build2 (RSHIFT_EXPR, ulltype, t, integer_one_node);
-             t = fold_build2 (MULT_EXPR, ulltype, fd->factor, t);
-             tree t2 = fold_build2 (MULT_EXPR, ulltype, c,
-                                    fd->first_inner_iterations);
+             t = fold_build2 (MULT_EXPR, ulltype,
+                              fold_convert (ulltype, fd->factor), t);
+             tree t2
+               = fold_build2 (MULT_EXPR, ulltype, c,
+                              fold_convert (ulltype,
+                                            fd->first_inner_iterations));
              t = fold_build2 (PLUS_EXPR, ulltype, t, t2);
              expand_omp_build_assign (gsi, d, t, true);
-             t = fold_build2 (MULT_EXPR, ulltype, fd->factor, c);
+             t = fold_build2 (MULT_EXPR, ulltype,
+                              fold_convert (ulltype, fd->factor), c);
              t = fold_build2 (PLUS_EXPR, ulltype,
-                              t, fd->first_inner_iterations);
+                              t, fold_convert (ulltype,
+                                               fd->first_inner_iterations));
              t2 = force_gimple_operand_gsi (gsi, t, true, NULL_TREE, false,
                                             GSI_CONTINUE_LINKING);
              cond_stmt = gimple_build_cond (GE_EXPR, stopvalull, d,