PR optimization/13318

	* loop.c (express_from): Protect integer division from overflow.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@74387 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 25 insertions, 0 deletions

diff --git a/gcc/testsuite/gcc.dg/overflow-1.c b/gcc/testsuite/gcc.dg/overflow-1.c
new file mode 100644
index 00000000000..db51a5ef129
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/overflow-1.c
@@ -0,0 +1,25 @@
+/* PR optimization/13318 */
+/* Origin: <bremner@unb.ca> */
+/* Reduced testcase: Wolfgang Bangerth <bangerth@dealii.org> */
+
+/* Verify that the big multiplier doesn't cause an integer
+   overflow in the loop optimizer.  */
+
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+struct S {
+  int key;
+  int rnext,rprev;
+};
+ 
+void foo(struct S* H)
+{
+  int i, k;
+  for (i=0; i<2; i++){
+    struct S* cell=H+k;
+    cell->key=i*(0xffffffffUL/2);
+    cell->rnext=k+(1-i);
+    cell->rprev=k+(1-i);
+  }
+}