diff --git a/llvm/lib/Target/X86/MCTargetDesc/X86AsmBackend.cpp b/llvm/lib/Target/X86/MCTargetDesc/X86AsmBackend.cpp
index e56c049f2442..88487f57e5e5 100644
--- a/llvm/lib/Target/X86/MCTargetDesc/X86AsmBackend.cpp
+++ b/llvm/lib/Target/X86/MCTargetDesc/X86AsmBackend.cpp
@@ -820,7 +820,9 @@ void X86AsmBackend::finishLayout(MCAssembler const &Asm,
         continue;
       }
 
+#ifndef NDEBUG
       const uint64_t OrigOffset = Layout.getFragmentOffset(&F);
+#endif
       const uint64_t OrigSize = Asm.computeFragmentSize(Layout, F);
       if (OrigSize == 0 || Relaxable.empty()) {
         Relaxable.clear();
@@ -863,11 +865,13 @@ void X86AsmBackend::finishLayout(MCAssembler const &Asm,
       if (F.getKind() == MCFragment::FT_BoundaryAlign)
         cast<MCBoundaryAlignFragment>(F).setSize(RemainingSize);
 
+#ifndef NDEBUG
       const uint64_t FinalOffset = Layout.getFragmentOffset(&F);
       const uint64_t FinalSize = Asm.computeFragmentSize(Layout, F);
       assert(OrigOffset + OrigSize == FinalOffset + FinalSize &&
              "can't move start of next fragment!");
       assert(FinalSize == RemainingSize && "inconsistent size computation?");
+#endif
 
       // If we're looking at a boundary align, make sure we don't try to pad
       // its target instructions for some following directive.  Doing so would