Subzero: Fix g++ warnings.

src/IceAssemblerARM32.cpp

Index: src/IceAssemblerARM32.cpp
diff --git a/src/IceAssemblerARM32.cpp b/src/IceAssemblerARM32.cpp
index 1d0cf7e4690ec75875ba432539f19e0f93f4c6b3..8586016c9c84f98669c5e521d38ded472c52792b 100644
--- a/src/IceAssemblerARM32.cpp
+++ b/src/IceAssemblerARM32.cpp
@@ -387,6 +387,7 @@ IValueT encodeImmRegOffset(OpEncoding AddressEncoding, IValueT Reg,
     assert(Mode == OperandARM32Mem::Offset);
     return Reg << kRnShift;
   }
+  llvm_unreachable("(silence g++ warning)");

[John, 2016/01/12 18:09:07]

This is surprising to me. g++ can be so annoying at times.

[Jim Stichnoth, 2016/01/13 19:30:33]

Yep!

I thought to add a default case to the first case, but clang++ complains.

Another possibility is to just "return 0;" here (instead or in addition), and
that sorta works in general for functions that return primitive or pointer type:

#define SILENCE_UNREACHABLE_GCC_WARNING 0
...
return SILENCE_UNREACHABLE_GCC_WARNING;

 }
 
 // Encodes memory address Opnd, and encodes that information into Value, based