diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index b0a45ab8cfe..7e51d688bf3 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,11 @@
+2009-10-23  Joseph Myers  <joseph@codesourcery.com>
+
+	PR c/41673
+	* alias.c (get_alias_set): Call langhook before returning 0 for
+	types with structural equality.
+	* c-common.c (c_common_get_alias_set): Use alias set of element
+	type for arrays with structural comparison.
+
 2009-10-23  Richard Guenther  <rguenther@suse.de>
 
 	PR middle-end/41805
diff --git a/gcc/alias.c b/gcc/alias.c
index 694498ab55a..09ec775c5d0 100644
--- a/gcc/alias.c
+++ b/gcc/alias.c
@@ -691,7 +691,14 @@ get_alias_set (tree t)
      requires structural comparisons to identify compatible types
      use alias set zero.  */
   if (TYPE_STRUCTURAL_EQUALITY_P (t))
-    return 0;
+    {
+      /* Allow the language to specify another alias set for this
+	 type.  */
+      set = lang_hooks.get_alias_set (t);
+      if (set != -1)
+	return set;
+      return 0;
+    }
   t = TYPE_CANONICAL (t);
   /* Canonical types shouldn't form a tree nor should the canonical
      type require structural equality checks.  */
diff --git a/gcc/c-common.c b/gcc/c-common.c
index 16e17b39d1d..8a6d15b9d9b 100644
--- a/gcc/c-common.c
+++ b/gcc/c-common.c
@@ -4183,6 +4183,15 @@ c_common_get_alias_set (tree t)
   tree u;
   PTR *slot;
 
+  /* For VLAs, use the alias set of the element type rather than the
+     default of alias set 0 for types compared structurally.  */
+  if (TYPE_P (t) && TYPE_STRUCTURAL_EQUALITY_P (t))
+    {
+      if (TREE_CODE (t) == ARRAY_TYPE)
+	return get_alias_set (TREE_TYPE (t));
+      return -1;
+    }
+
   /* Permit type-punning when accessing a union, provided the access
      is directly through the union.  For example, this code does not
      permit taking the address of a union member and then storing
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index aa2522805c2..81d39b58144 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2009-10-23  Joseph Myers  <joseph@codesourcery.com>
+
+	PR c/41673
+	* gcc.dg/Wstrict-aliasing-bogus-vla-1.c: New test.
+
 2009-10-23  Richard Guenther  <rguenther@suse.de>
 
 	PR tree-optimization/41778
diff --git a/gcc/testsuite/gcc.dg/Wstrict-aliasing-bogus-vla-1.c b/gcc/testsuite/gcc.dg/Wstrict-aliasing-bogus-vla-1.c
new file mode 100644
index 00000000000..e9f63d36872
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/Wstrict-aliasing-bogus-vla-1.c
@@ -0,0 +1,10 @@
+/* PR 41673: bogus -Wstrict-aliasing warning from VLA dereference.  */
+/* { dg-do compile } */
+/* { dg-options "-std=gnu99 -O2 -Wall" } */
+
+int main(int argc, char *argv[])
+{
+    float x[argc];
+    float y[argc];
+    return 0 == __builtin_memcpy(y, x, argc * sizeof(*x));
+}