Test case for historical reasons

[libfirm] / ir / be / ia32 / ia32_common_transform.c

diff --git a/ir/be/ia32/ia32_common_transform.c b/ir/be/ia32/ia32_common_transform.c
index 9e51116..3aff738 100644 (file)
--- a/ir/be/ia32/ia32_common_transform.c
+++ b/ir/be/ia32/ia32_common_transform.c
@@ -863,6 +863,45 @@ const arch_register_req_t *parse_clobber(const char *clobber)
        return req;
 }
 
+
+int prevents_AM(ir_node *const block, ir_node *const am_candidate,
+                       ir_node *const other)
+{
+       if (get_nodes_block(other) != block)
+               return 0;
+
+       if (is_Sync(other)) {
+               int i;
+
+               for (i = get_Sync_n_preds(other) - 1; i >= 0; --i) {
+                       ir_node *const pred = get_Sync_pred(other, i);
+
+                       if (get_nodes_block(pred) != block)
+                               continue;
+
+                       /* Do not block ourselves from getting eaten */
+                       if (is_Proj(pred) && get_Proj_pred(pred) == am_candidate)
+                               continue;
+
+                       if (!heights_reachable_in_block(heights, pred, am_candidate))
+                               continue;
+
+                       return 1;
+               }
+
+               return 0;
+       } else {
+               /* Do not block ourselves from getting eaten */
+               if (is_Proj(other) && get_Proj_pred(other) == am_candidate)
+                       return 0;
+
+               if (!heights_reachable_in_block(heights, other, am_candidate))
+                       return 0;
+
+               return 1;
+       }
+}
+
 ir_node *try_create_Immediate(ir_node *node, char immediate_constraint_type)
 {
        int          minus         = 0;