1 files changed, 29 insertions, 0 deletions
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr19210-1.c b/gcc/testsuite/gcc.dg/tree-ssa/pr19210-1.c
new file mode 100644
index 000000000..906132c69
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/pr19210-1.c
@@ -0,0 +1,29 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -Wunsafe-loop-optimizations" } */
+extern void g(void);
+
+void
+f (unsigned n)
+{
+  unsigned k;
+  for(k = 0;k <= n;k++) /* { dg-warning "cannot optimize.*infinite loops" } */
+    g();
+
+  for(k = 0;k <= n;k += 4) /* { dg-warning "cannot optimize.*overflow" } */
+    g();
+
+  /* We used to get warning for this loop.  However, since then # of iterations
+     analysis improved, and we can now prove that this loop does not verflow.
+     This is because the only case when it would overflow is if n = ~0 (since
+     ~0 is divisible by 5), and this cannot be the case, since when we got
+     here, the previous loop exited, thus there exists k > n.  */
+  for(k = 5;k <= n;k += 5)
+    g();
+
+  /* So we need the following loop, instead.  */
+  for(k = 4;k <= n;k += 5) /* { dg-warning "cannot optimize.*overflow" } */
+    g();
+  
+  for(k = 15;k >= n;k--) /* { dg-warning "cannot optimize.*infinite" } */
+    g();
+}