Add support for vector types and vector constants.

src/IceDefs.h

Index: src/IceDefs.h
diff --git a/src/IceDefs.h b/src/IceDefs.h
index 4c616f832bb68c19cb67412c91483c6a91c297a4..d8275c9eed1255f3dc24768fa863ece1ed599f64 100644
--- a/src/IceDefs.h
+++ b/src/IceDefs.h
@@ -29,6 +29,7 @@
 
 #include "llvm/ADT/BitVector.h"
 #include "llvm/ADT/SmallBitVector.h"
+#include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/Support/Casting.h"
 #include "llvm/Support/Compiler.h" // LLVM_STATIC_ASSERT
@@ -64,6 +65,10 @@ typedef std::list<InstPhi *> PhiList;
 typedef std::vector<Variable *> VarList;
 typedef std::vector<CfgNode *> NodeList;
 typedef std::vector<Constant *> ConstantList;
+typedef std::vector<IceString> StringList;
+// TODO(wala): Switch to std::array after C++11
+typedef llvm::SmallVector<char, 16> Vect128;
+typedef llvm::SmallVector<bool, 16> BitVect;

[jvoung (off chromium), 2014/06/26 00:45:40]

LLVM actually has a separate SmallBitVector<>:
http://llvm.org/docs/ProgrammersManual.html#smallbitvector
which is already being used in a few places in subzero.

Or was there a reason to stick with smallvector instead?

[wala, 2014/06/26 17:32:42]

SmallVector has operator<. SmallBitVector does not.

Constants are pooled using the TypePool<> class which stores the constant's
value as part of a key in an internal map. Map keys need to ordered.

 
 // SizeT is for holding small-ish limits like number of source
 // operands in an instruction.  It is used instead of size_t (which