1 files changed, 29 insertions, 0 deletions
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr21171.c b/gcc/testsuite/gcc.dg/tree-ssa/pr21171.c
new file mode 100644
index 00000000000..a655ed63281
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/pr21171.c
@@ -0,0 +1,29 @@
+/* PR 21171.  Ivopts should not rewrite references to volatile memory.  */
+/* { dg-do compile } */
+/* { dg-options "-O1 -fdump-tree-vars" } */
+
+typedef	unsigned int u_int32_t;
+typedef	unsigned char u_int8_t;
+
+#define	AIC_VECTORS	32
+
+typedef volatile struct AT91RM9200_regs {
+  u_int32_t	SVR[AIC_VECTORS];
+} AT91RM9200_regs_t;
+
+#define CPUReg  ((AT91RM9200_regs_t*)0xFFF00000)
+
+extern const u_int32_t __IntTable[AIC_VECTORS];
+
+int main()
+{
+  int c;
+
+  for (c = 0; c < AIC_VECTORS; c++)
+    CPUReg->SVR[c] = __IntTable[c];
+
+  return 0;
+}
+
+/* { dg-final { scan-tree-dump-times "SVR" 1 "vars"} } */
+/* { dg-final { cleanup-tree-dump "vars" } } */