@@ -1499,6 +1499,7 @@ bypass_block (basic_block bb, rtx setcc,
int may_be_loop_header;
unsigned removed_p;
unsigned i;
+ unsigned n_back_edges;
edge_iterator ei;
insn = (setcc != NULL) ? setcc : jump;
@@ -1510,13 +1511,12 @@ bypass_block (basic_block bb, rtx setcc,
if (note)
find_used_regs (&XEXP (note, 0), NULL);
- may_be_loop_header = false;
+ n_back_edges = 0;
FOR_EACH_EDGE (e, ei, bb->preds)
if (e->flags & EDGE_DFS_BACK)
- {
- may_be_loop_header = true;
- break;
- }
+ n_back_edges++;
+
+ may_be_loop_header = n_back_edges > 0;
change = 0;
for (ei = ei_start (bb->preds); (e = ei_safe_edge (ei)); )
@@ -1605,7 +1605,8 @@ bypass_block (basic_block bb, rtx setcc,
&& dest != EXIT_BLOCK_PTR)
{
if (current_loops != NULL
- && e->src->loop_father->latch == e->src)
+ && (e->src->loop_father->latch == e->src
+ || n_back_edges > 1))
{
/* ??? Now we are creating (or may create) a loop
with multiple entries. Simply mark it for
@@ -0,0 +1,24 @@
+/* PR middle-end/54838 */
+/* { dg-do compile } */
+/* { dg-options "-O2 -fno-forward-propagate -ftracer" } */
+
+void bar (void);
+
+void
+foo (void *b, int *c)
+{
+again:
+ switch (*c)
+ {
+ case 1:
+ if (!b)
+ {
+ bar ();
+ return;
+ }
+ goto again;
+ case 3:
+ if (!b)
+ goto again;
+ }
+}