PR tree-optimization/54985

        * tree-ssa-threadedge.c (cond_arg_set_in_bb): New function extracted
        from thread_across_edge.
        (thread_across_edge): Use it in all cases where we might thread
        across a back edge.

        * gcc.c-torture/execute/pr54985.c: New test.




git-svn-id: https://gcc.gnu.org/svn/gcc/branches/gcc-4_7-branch@193108 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 36 insertions, 0 deletions

diff --git a/gcc/testsuite/gcc.c-torture/execute/pr54985.c b/gcc/testsuite/gcc.c-torture/execute/pr54985.c
new file mode 100644
index 00000000000..678c9f47ae7
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/execute/pr54985.c
@@ -0,0 +1,36 @@
+
+typedef struct st {
+    int a;
+} ST;
+
+int __attribute__((noinline,noclone))
+foo(ST *s, int c)
+{
+  int first = 1;
+  int count = c;
+  ST *item = s;
+  int a = s->a;
+  int x;
+
+  while (count--)
+    {
+      x = item->a;
+      if (first)
+        first = 0;
+      else if (x >= a)
+        return 1;
+      a = x;
+      item++;
+    }
+  return 0;
+}
+
+extern void abort (void);
+
+int main ()
+{
+  ST _1[2] = {{2}, {1}};
+  if (foo(_1, 2) != 0)
+    abort ();
+  return 0;
+}