Add initial integrated assembler w/ some Xmm ops.

src/IceUtils.h

+//===- subzero/src/IceUtils.h - Utility functions ---------------*- C++ -*-===//
+//
+//                        The Subzero Code Generator
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file declares some utility functions
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SUBZERO_SRC_ICEUTILS_H
+#define SUBZERO_SRC_ICEUTILS_H
+
+#include <climits>
+
+namespace Ice {
+
+// Similar to bit_cast, but allows copying from types of unrelated
+// sizes. This method was introduced to enable the strict aliasing
+// optimizations of GCC 4.4. Basically, GCC mindlessly relies on
+// obscure details in the C++ standard that make reinterpret_cast
+// virtually useless.
+template <class D, class S> inline D bit_copy(const S &source) {
+  D destination;
+  // This use of memcpy is safe: source and destination cannot overlap.
+  memcpy(&destination, reinterpret_cast<const void *>(&source),
+         sizeof(destination));
+  return destination;
+}
+
+class Utils {
+public:
+  // Check whether an N-bit two's-complement representation can hold value.
+  template <typename T> static inline bool IsInt(int N, T value) {
+    assert((0 < N) &&
+           (static_cast<unsigned int>(N) < (CHAR_BIT * sizeof(value))));
+    T limit = static_cast<T>(1) << (N - 1);
+    return (-limit <= value) && (value < limit);
+  }
+
+  template <typename T> static inline bool IsUint(int N, T value) {
+    assert((0 < N) &&
+           (static_cast<unsigned int>(N) < (CHAR_BIT * sizeof(value))));
+    T limit = static_cast<T>(1) << N;
+    return (0 <= value) && (value < limit);
+  }
+
+  template <typename T> static inline bool WouldOverflowAdd(T X, T Y) {
+    return ((X > 0 && Y > 0 && (X > std::numeric_limits<T>::max() - Y)) ||
+            (X < 0 && Y < 0 && (X < std::numeric_limits<T>::min() - Y)));
+  }
+};
+
+} // end of namespace Ice
+
+#endif // SUBZERO_SRC_ICEUTILS_H