Second try of initial ARM/Thumb disassembler check-in. It consists of a tablgen

backend (ARMDecoderEmitter) 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.

Reviewed by Chris Latter and Bob Wilson.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100233 91177308-0d34-0410-b5e6-96231b3b80d8

utils/TableGen/DisassemblerEmitter.cpp

@@ -12,6 +12,8 @@
 #include "Record.h"
 #include "X86DisassemblerTables.h"
 #include "X86RecognizableInstr.h"
+#include "ARMDecoderEmitter.h"
+
 using namespace llvm;
 using namespace llvm::X86Disassembler;
 
@@ -124,6 +126,12 @@ void DisassemblerEmitter::run(raw_ostream &OS) {
     return;
   }
 
+  // Fixed-instruction-length targets use a common disassembler.
+  if (Target.getName() == "ARM") {
+    ARMDecoderEmitter(Records).run(OS);
+    return;
+  }  
+
   throw TGError(Target.getTargetRecord()->getLoc(),
                 "Unable to generate disassembler for this target");
 }