[MC] EmitNop: Make an assertion more useful

[davide]

Summary

NumBytes is an unsigned so this will never fire. I assume this might be what you wanted to do originally.

[sanjoy]

Gah, made a C++ 101 mistake. :|

Thanks for fixing!

llvm/trunk/lib/Target/X86/X86MCInstLower.cpp

static unsigned EmitNop(MCStreamer &OS, unsigned NumBytes, bool Is64Bit,
   }
   assert(NopSize <= NumBytes && "We overemitted?");
   return NopSize;
 }
 
 /// \brief Emit the optimal amount of multi-byte nops on X86.
 static void EmitNops(MCStreamer &OS, unsigned NumBytes, bool Is64Bit,
                      const MCSubtargetInfo &STI) {
+  unsigned NopsToEmit = NumBytes;
   while (NumBytes) {
     NumBytes -= EmitNop(OS, NumBytes, Is64Bit, STI);
-    assert(NumBytes >= 0 && "Emitted more than I asked for!");
+    assert(NopsToEmit >= NumBytes && "Emitted more than I asked for!");
   }
 }
 
 void X86AsmPrinter::LowerSTATEPOINT(const MachineInstr &MI,
                                     X86MCInstLower &MCIL) {
   assert(Subtarget->is64Bit() && "Statepoint currently only supports X86-64");
 
   StatepointOpers SOpers(&MI);