[X86] Mark the default case of the X86InstrInfo::convertToThreeAddress switch as...

This function should only be called with instructions that are really convertible. And all
convertible instructions need to be handled by the switch. So nothing should use the default.

llvm-svn: 357529

diff --git a/llvm/lib/Target/X86/X86InstrInfo.cpp b/llvm/lib/Target/X86/X86InstrInfo.cpp
index e157bc1..4aa365c 100644 (file)
--- a/llvm/lib/Target/X86/X86InstrInfo.cpp
+++ b/llvm/lib/Target/X86/X86InstrInfo.cpp
@@ -869,7 +869,7 @@ X86InstrInfo::convertToThreeAddress(MachineFunction::iterator &MFI,
   bool Is8BitOp = false;
   unsigned MIOpc = MI.getOpcode();
   switch (MIOpc) {
-  default: return nullptr;
+  default: llvm_unreachable("Unreachable!");
   case X86::SHL64ri: {
     assert(MI.getNumOperands() >= 3 && "Unknown shift instruction!");
     unsigned ShAmt = getTruncatedShiftCount(MI, 2);