new file mode 100644
@@ -0,0 +1,30 @@
+/* { dg-do run } */
+/* { dg-additional-options "-w -Wno-psabi" } */
+
+#include "tree-vect.h"
+
+typedef int v4si __attribute__((vector_size(16)));
+
+int a[4];
+int b[4];
+
+void __attribute__((noipa))
+foo (v4si x)
+{
+ b[0] = a[3] + x[0];
+ b[1] = a[2] + x[1];
+ b[2] = a[1] + x[2];
+ b[3] = a[0] + x[3];
+}
+
+int main()
+{
+ check_vect ();
+ for (int i = 0; i < 4; ++i)
+ a[i] = i;
+ v4si x = (v4si) { 8, 6, 4, 2 };
+ foo (x);
+ if (b[0] != 11 || b[1] != 8 || b[2] != 5 || b[3] != 2)
+ __builtin_abort ();
+ return 0;
+}
@@ -3648,8 +3648,10 @@ vect_optimize_slp (vec_info *vinfo)
slp_tree node = vertices[idx].node;
/* Handle externals and constants optimistically throughout the
- iteration. */
- if (SLP_TREE_DEF_TYPE (node) == vect_external_def
+ iteration. But treat existing vectors as fixed since we
+ do not handle permuting them below. */
+ if ((SLP_TREE_DEF_TYPE (node) == vect_external_def
+ && !SLP_TREE_VEC_DEFS (node).exists ())
|| SLP_TREE_DEF_TYPE (node) == vect_constant_def)
continue;