Add AArch64 as an experimental target.

This patch adds support for AArch64 (ARM's 64-bit architecture) to
LLVM in the "experimental" category. Currently, it won't be built
unless requested explicitly.

This initial commit should have support for:
    + Assembly of all scalar (i.e. non-NEON, non-Crypto) instructions
      (except the late addition CRC instructions).
    + CodeGen features required for C++03 and C99.
    + Compilation for the "small" memory model: code+static data <
      4GB.
    + Absolute and position-independent code.
    + GNU-style (i.e. "__thread") TLS.
    + Debugging information.

The principal omission, currently, is performance tuning.

This patch excludes the NEON support also reviewed due to an outbreak of
batshit insanity in our legal department. That will be committed soon bringing
the changes to precisely what has been approved.

Further reviews would be gratefully received.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174054 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 54 insertions, 0 deletions

diff --git a/lib/Target/AArch64/AArch64Subtarget.h b/lib/Target/AArch64/AArch64Subtarget.h
new file mode 100644
index 0000000..2e9205f
--- /dev/null
+++ b/lib/Target/AArch64/AArch64Subtarget.h
@@ -0,0 +1,54 @@
+//==-- AArch64Subtarget.h - Define Subtarget for the AArch64 ---*- C++ -*--===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file declares the AArch64 specific subclass of TargetSubtargetInfo.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_TARGET_AARCH64_SUBTARGET_H
+#define LLVM_TARGET_AARCH64_SUBTARGET_H
+
+#include "llvm/ADT/Triple.h"
+#include "llvm/Target/TargetSubtargetInfo.h"
+
+#define GET_SUBTARGETINFO_HEADER
+#include "AArch64GenSubtargetInfo.inc"
+
+#include <string>
+
+namespace llvm {
+class StringRef;
+class GlobalValue;
+
+class AArch64Subtarget : public AArch64GenSubtargetInfo {
+protected:
+  bool HasNEON;
+  bool HasCrypto;
+
+  /// TargetTriple - What processor and OS we're targeting.
+  Triple TargetTriple;
+public:
+  /// This constructor initializes the data members to match that
+  /// of the specified triple.
+  ///
+  AArch64Subtarget(StringRef TT, StringRef CPU, StringRef FS);
+
+  /// ParseSubtargetFeatures - Parses features string setting specified
+  /// subtarget options.  Definition of function is auto generated by tblgen.
+  void ParseSubtargetFeatures(StringRef CPU, StringRef FS);
+
+  bool GVIsIndirectSymbol(const GlobalValue *GV, Reloc::Model RelocM) const;
+
+  bool isTargetELF() const { return TargetTriple.isOSBinFormatELF(); }
+  bool isTargetLinux() const { return TargetTriple.getOS() == Triple::Linux; }
+
+};
+} // End llvm namespace
+
+#endif  // LLVM_TARGET_AARCH64_SUBTARGET_H