diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr109711-1.c b/gcc/testsuite/gcc.dg/tree-ssa/pr109711-1.c
new file mode 100644
index 00000000000..81777505002
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/pr109711-1.c
@@ -0,0 +1,16 @@
+// { dg-do compile }
+// { dg-options "-O2" }
+
+void lspf2lpc();
+
+void interpolate_lpc(int subframe_num) {
+  float weight = 0.25 * subframe_num + 1;
+  if (weight)
+    lspf2lpc();
+}
+
+void qcelp_decode_frame() {
+  int i;
+  for (;; i++)
+    interpolate_lpc(i);
+}
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr109711-2.c b/gcc/testsuite/gcc.dg/tree-ssa/pr109711-2.c
new file mode 100644
index 00000000000..f80bb1afec8
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/pr109711-2.c
@@ -0,0 +1,24 @@
+// { dg-do compile }
+// { dg-options "-O2" }
+
+void lspf2lpc();
+
+int interpolate_lpc_q_0;
+
+void
+interpolate_lpc(int subframe_num) {
+  float weight;
+  if (interpolate_lpc_q_0)
+    weight = subframe_num;
+  else
+    weight = 1.0;
+  if (weight != 1.0)
+    lspf2lpc();
+}
+
+void
+qcelp_decode_frame() {
+  int i;
+  for (;; i++)
+    interpolate_lpc(i);
+}
diff --git a/gcc/value-range.cc b/gcc/value-range.cc
index 655ffc2d6d4..def9299dc0e 100644
--- a/gcc/value-range.cc
+++ b/gcc/value-range.cc
@@ -1057,6 +1057,13 @@ irange::verify_range ()
       return;
     }
   gcc_checking_assert (m_num_ranges <= m_max_ranges);
+
+  // Legacy allowed these to represent VARYING for unknown types.
+  // Leave this in for now, until all users are converted.  Eventually
+  // we should abort in set_varying.
+  if (m_kind == VR_VARYING && m_type == error_mark_node)
+    return;
+
   unsigned prec = TYPE_PRECISION (m_type);
   if (m_kind == VR_VARYING)
     {