Initial ARM/Thumb disassembler check-in. It consists of a tablgen backend

(RISCDisassemblerEmitter) which emits the decoder functions for ARM and Thumb,
and the disassembler core which invokes the decoder function and builds up the
MCInst based on the decoded Opcode.

Added sub-formats to the NeonI/NeonXI instructions to further refine the NEONFrm
instructions to help disassembly.

We also changed the output of the addressing modes to omit the '+' from the
assembler syntax #+/-<imm> or +/-<Rm>.  See, for example, A8.6.57/58/60.

And modified test cases to not expect '+' in +reg or #+num.  For example,

; CHECK:       ldr.w	r9, [r7, #28]


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98637 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 48 insertions, 0 deletions

diff --git a/utils/TableGen/RISCDisassemblerEmitter.h b/utils/TableGen/RISCDisassemblerEmitter.h
new file mode 100644
index 0000000000..f0e5eced02
--- /dev/null
+++ b/utils/TableGen/RISCDisassemblerEmitter.h
@@ -0,0 +1,48 @@
+//===- RISCDisassemblerEmitter.h - Disassembler Generator -------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// FIXME: document
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef RISCDISASSEMBLEREMITTER_H
+#define RISCDISASSEMBLEREMITTER_H
+
+#include "TableGenBackend.h"
+
+#include <inttypes.h>
+
+namespace llvm {
+    
+class RISCDisassemblerEmitter : public TableGenBackend {
+  RecordKeeper &Records;
+public:
+  RISCDisassemblerEmitter(RecordKeeper &R) : Records(R) {
+    initBackend();
+  }
+    
+  ~RISCDisassemblerEmitter() {
+    shutdownBackend();
+  }
+	
+  // run - Output the code emitter
+  void run(raw_ostream &o);
+    
+private:
+  class RISCDEBackend;
+    
+  RISCDEBackend *Backend;
+    
+  void initBackend();
+  void shutdownBackend();
+};
+
+} // end llvm namespace
+
+#endif