Import LLVM, at r72732.

1 files changed, 60 insertions, 0 deletions

diff --git a/include/llvm/Support/AlignOf.h b/include/llvm/Support/AlignOf.h
new file mode 100644
index 0000000..6a7a1a6
--- /dev/null
+++ b/include/llvm/Support/AlignOf.h
@@ -0,0 +1,60 @@
+//===--- AlignOf.h - Portable calculation of type alignment -----*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines the AlignOf function that computes alignments for
+// arbitrary types.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_SUPPORT_ALIGNOF_H
+#define LLVM_SUPPORT_ALIGNOF_H
+
+namespace llvm {
+
+template <typename T>
+struct AlignmentCalcImpl {
+  char x;
+  T t;
+private:
+  AlignmentCalcImpl() {} // Never instantiate.
+};
+
+/// AlignOf - A templated class that contains an enum value representing
+///  the alignment of the template argument.  For example,
+///  AlignOf<int>::Alignment represents the alignment of type "int".  The
+///  alignment calculated is the minimum alignment, and not necessarily
+///  the "desired" alignment returned by GCC's __alignof__ (for example).  Note
+///  that because the alignment is an enum value, it can be used as a
+///  compile-time constant (e.g., for template instantiation).
+template <typename T>
+struct AlignOf {
+  enum { Alignment =
+         static_cast<unsigned int>(sizeof(AlignmentCalcImpl<T>) - sizeof(T)) };
+
+  enum { Alignment_GreaterEqual_2Bytes = Alignment >= 2 ? 1 : 0 };
+  enum { Alignment_GreaterEqual_4Bytes = Alignment >= 4 ? 1 : 0 };
+  enum { Alignment_GreaterEqual_8Bytes = Alignment >= 8 ? 1 : 0 };
+  enum { Alignment_GreaterEqual_16Bytes = Alignment >= 16 ? 1 : 0 };
+
+  enum { Alignment_LessEqual_2Bytes = Alignment <= 2 ? 1 : 0 };
+  enum { Alignment_LessEqual_4Bytes = Alignment <= 4 ? 1 : 0 };
+  enum { Alignment_LessEqual_8Bytes = Alignment <= 8 ? 1 : 0 };
+  enum { Alignment_LessEqual_16Bytes = Alignment <= 16 ? 1 : 0 };
+
+};
+
+/// alignof - A templated function that returns the mininum alignment of
+///  of a type.  This provides no extra functionality beyond the AlignOf
+///  class besides some cosmetic cleanliness.  Example usage:
+///  alignof<int>() returns the alignment of an int.
+template <typename T>
+static inline unsigned alignof() { return AlignOf<T>::Alignment; }
+
+} // end namespace llvm
+#endif