diff --git a/lib/Target/AArch64/AArch64PBQPRegAlloc.cpp b/lib/Target/AArch64/AArch64PBQPRegAlloc.cpp
index c4787f4afd6..87e3502c9aa 100644
--- a/lib/Target/AArch64/AArch64PBQPRegAlloc.cpp
+++ b/lib/Target/AArch64/AArch64PBQPRegAlloc.cpp
@@ -37,11 +37,13 @@ using namespace llvm;
 
 namespace {
 
+#ifndef NDEBUG
 bool isFPReg(unsigned reg) {
   return AArch64::FPR32RegClass.contains(reg) ||
          AArch64::FPR64RegClass.contains(reg) ||
          AArch64::FPR128RegClass.contains(reg);
 };
+#endif
 
 bool isOdd(unsigned reg) {
   switch (reg) {