diff --git a/llvm/lib/Target/X86/X86InstrInfo.cpp b/llvm/lib/Target/X86/X86InstrInfo.cpp
index 9a6e860..c37f5c8 100644
--- a/llvm/lib/Target/X86/X86InstrInfo.cpp
+++ b/llvm/lib/Target/X86/X86InstrInfo.cpp
@@ -5241,9 +5241,7 @@
 
   // Unless optimizing for size, don't fold to avoid partial
   // register update stalls
-  // FIXME: Use Function::optForSize().
-  if (!MF.getFunction()->hasFnAttribute(Attribute::OptimizeForSize) &&
-      hasPartialRegUpdate(MI->getOpcode()))
+  if (!MF.getFunction()->optForSize() && hasPartialRegUpdate(MI->getOpcode()))
     return nullptr;
 
   const MachineFrameInfo *MFI = MF.getFrameInfo();