diff --git a/gcc/testsuite/gcc.target/riscv/rvv/autovec/pr123414.c b/gcc/testsuite/gcc.target/riscv/rvv/autovec/pr123414.c
new file mode 100644
index 00000000000..a28ce23f058
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/rvv/autovec/pr123414.c
@@ -0,0 +1,31 @@
+/* { dg-do compile } */
+/* { dg-options "-march=rv64gcv_zvl256b -mrvv-max-lmul=m8 -O3 -fsigned-char -fno-strict-aliasing -fwrapv -fdump-tree-optimized -std=gnu99" } */
+
+signed char a=2;
+long long b;
+long c = 93;
+int e[1][9];
+
+void
+g (long cc, int ee[][9])
+{
+  for (int i = 0; i < 4; i++)
+    for (int j = 0; j < 5; j++)
+      for (unsigned k = 0; k < 9; k++)
+	{
+	  a *= cc;
+	  for (int l = 0; l < 6; l += (ee[k] <= 0) + 2)
+	    ;
+	}
+}
+
+int main() {
+  g( c, e);
+  b = (int)a;
+  if (b != 34)
+    __builtin_abort ();
+}
+
+/* We should have four vector constructors that must not get optimized away.
+ */
+/* { dg-final { scan-tree-dump-times "\[a-zA-Z_\]\[a-zA-Z0-9_\]+.=.\\\{\[a-zA-Z0-9._\]+, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1," 4 "optimized" } } */
diff --git a/gcc/tree-ssa-forwprop.cc b/gcc/tree-ssa-forwprop.cc
index d00f7b9004e..9435e4dc409 100644
--- a/gcc/tree-ssa-forwprop.cc
+++ b/gcc/tree-ssa-forwprop.cc
@@ -4177,9 +4177,16 @@ simplify_vector_constructor (gimple_stmt_iterator *gsi)
       machine_mode vmode = TYPE_MODE (perm_type);
       if (!can_vec_perm_const_p (vmode, vmode, indices))
 	return false;
-      mask_type
-	= build_vector_type (build_nonstandard_integer_type (elem_size, 1),
-			     refnelts);
+      /* With an ELEM_SIZEd integer we can shuffle at most
+	 (1 << ELEM_SIZE) / 2 - 1 elements.  For a more fine-grained
+	 check we could take the maximum of the element values
+	 but for now this is sufficient.  */
+      if (refnelts < (HOST_WIDE_INT_1U << (elem_size - 1)))
+	mask_type
+	  = build_vector_type (build_nonstandard_integer_type (elem_size, 1),
+			       refnelts);
+      else
+	return false;
       if (GET_MODE_CLASS (TYPE_MODE (mask_type)) != MODE_VECTOR_INT
 	  || maybe_ne (GET_MODE_SIZE (TYPE_MODE (mask_type)),
 		       GET_MODE_SIZE (TYPE_MODE (perm_type))))