1 files changed, 56 insertions, 0 deletions
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr22591.c b/gcc/testsuite/gcc.dg/tree-ssa/pr22591.c
new file mode 100644
index 000000000..f1f5ec849
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/pr22591.c
@@ -0,0 +1,56 @@
+/* { dg-do run } */
+/* { dg-options "-O2" } */
+
+void abort (); 
+ 
+typedef struct _Node 
+{ 
+  struct _Node *next, *prev; 
+} Node; 
+ 
+void __attribute__ ((noinline)) append (Node * q, Node * p) 
+{ 
+  p->next = q; 
+  p->prev = q; 
+  q->next = p; 
+  q->prev = p; 
+} 
+ 
+inline void 
+swap (Node ** a, Node ** b) 
+{ 
+  Node *tmp = *a; 
+  *a = *b; 
+  *b = tmp; 
+} 
+ 
+/* Miscompilation seems to happen here. If one removes the if condition 
+   (which should be true) the program works fine.  */ 
+void 
+ListSwap (Node * x, Node * y) 
+{ 
+  Node *tmp; 
+  if (x->next) 
+    { 
+      swap (&x->next, &y->next); 
+      swap (&x->prev, &y->prev); 
+      x->next->prev = x->prev->next = x; 
+      y->next->prev = y->prev->next = y; 
+    } 
+} 
+ 
+int 
+main () 
+{ 
+  Node A, A1, B, B1; 
+ 
+  append (&A, &A1); 
+  append (&B, &B1); 
+ 
+  ListSwap (&A, &B); 
+ 
+  if (&A != A.next->prev) 
+    abort (); 
+
+  return 0;
+}