commit 1a45860e7757ee054f6bf98bee4ebe5c661dfb90
Author: Jason Merrill <jason@redhat.com>
Date: Thu Nov 13 23:54:48 2014 -0500
* cp-gimplify.c (genericize_cp_loop): Use LOOP_EXPR.
(genericize_for_stmt): Handle null statement-list.
@@ -208,7 +208,7 @@ genericize_cp_loop (tree *stmt_p, location_t start_locus, tree cond, tree body,
void *data)
{
tree blab, clab;
- tree entry = NULL, exit = NULL, t;
+ tree exit = NULL;
tree stmt_list = NULL;
blab = begin_bc_block (bc_break, start_locus);
@@ -222,64 +222,46 @@ genericize_cp_loop (tree *stmt_p, location_t start_locus, tree cond, tree body,
cp_walk_tree (&incr, cp_genericize_r, data, NULL);
*walk_subtrees = 0;
- /* If condition is zero don't generate a loop construct. */
- if (cond && integer_zerop (cond))
+ if (cond && TREE_CODE (cond) != INTEGER_CST)
{
- if (cond_is_first)
- {
- t = build1_loc (start_locus, GOTO_EXPR, void_type_node,
- get_bc_label (bc_break));
- append_to_statement_list (t, &stmt_list);
- }
- }
- else
- {
- /* Expand to gotos, just like c_finish_loop. TODO: Use LOOP_EXPR. */
- tree top = build1 (LABEL_EXPR, void_type_node,
- create_artificial_label (start_locus));
-
- /* If we have an exit condition, then we build an IF with gotos either
- out of the loop, or to the top of it. If there's no exit condition,
- then we just build a jump back to the top. */
- exit = build1 (GOTO_EXPR, void_type_node, LABEL_EXPR_LABEL (top));
-
- if (cond && !integer_nonzerop (cond))
- {
- /* Canonicalize the loop condition to the end. This means
- generating a branch to the loop condition. Reuse the
- continue label, if possible. */
- if (cond_is_first)
- {
- if (incr)
- {
- entry = build1 (LABEL_EXPR, void_type_node,
- create_artificial_label (start_locus));
- t = build1_loc (start_locus, GOTO_EXPR, void_type_node,
- LABEL_EXPR_LABEL (entry));
- }
- else
- t = build1_loc (start_locus, GOTO_EXPR, void_type_node,
- get_bc_label (bc_continue));
- append_to_statement_list (t, &stmt_list);
- }
-
- t = build1 (GOTO_EXPR, void_type_node, get_bc_label (bc_break));
- exit = fold_build3_loc (start_locus,
- COND_EXPR, void_type_node, cond, exit, t);
- }
-
- append_to_statement_list (top, &stmt_list);
+ /* If COND is constant, don't bother building an exit. If it's false,
+ we won't build a loop. If it's true, any exits are in the body. */
+ location_t cloc = EXPR_LOC_OR_LOC (cond, start_locus);
+ exit = build1_loc (cloc, GOTO_EXPR, void_type_node,
+ get_bc_label (bc_break));
+ exit = fold_build3_loc (cloc, COND_EXPR, void_type_node, cond,
+ build_empty_stmt (cloc), exit);
}
+ if (exit && cond_is_first)
+ append_to_statement_list (exit, &stmt_list);
append_to_statement_list (body, &stmt_list);
finish_bc_block (&stmt_list, bc_continue, clab);
append_to_statement_list (incr, &stmt_list);
- append_to_statement_list (entry, &stmt_list);
- append_to_statement_list (exit, &stmt_list);
+ if (exit && !cond_is_first)
+ append_to_statement_list (exit, &stmt_list);
+
+ if (!stmt_list)
+ stmt_list = build_empty_stmt (start_locus);
+
+ tree loop;
+ if (cond && integer_zerop (cond))
+ {
+ if (cond_is_first)
+ loop = fold_build3_loc (start_locus, COND_EXPR,
+ void_type_node, cond, stmt_list,
+ build_empty_stmt (start_locus));
+ else
+ loop = stmt_list;
+ }
+ else
+ loop = build1_loc (start_locus, LOOP_EXPR, void_type_node, stmt_list);
+
+ stmt_list = NULL;
+ append_to_statement_list (loop, &stmt_list);
finish_bc_block (&stmt_list, bc_break, blab);
-
- if (stmt_list == NULL_TREE)
- stmt_list = build1 (NOP_EXPR, void_type_node, integer_zero_node);
+ if (!stmt_list)
+ stmt_list = build_empty_stmt (start_locus);
*stmt_p = stmt_list;
}
@@ -303,6 +285,8 @@ genericize_for_stmt (tree *stmt_p, int *walk_subtrees, void *data)
genericize_cp_loop (&loop, EXPR_LOCATION (stmt), FOR_COND (stmt),
FOR_BODY (stmt), FOR_EXPR (stmt), 1, walk_subtrees, data);
append_to_statement_list (loop, &expr);
+ if (expr == NULL_TREE)
+ expr = loop;
*stmt_p = expr;
}