Added support for unpredictable mcrr/mcrr2/mrrc/mrrc2 ARM instruction in the disassembler. Since the upredicability conditions are complex, C++ code was added to handle them.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@155001 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/Disassembler/ARMDisassembler.cpp b/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
index f352bff..87a5f01 100644
--- a/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
+++ b/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
@@ -326,6 +326,8 @@
 
 static DecodeStatus DecodeLDR(MCInst &Inst, unsigned Val,
                                 uint64_t Address, const void *Decoder);
+static DecodeStatus DecodeMRRC2(llvm::MCInst &Inst, unsigned Val,
+                                uint64_t Address, const void *Decoder);
 #include "ARMGenDisassemblerTables.inc"
 #include "ARMGenInstrInfo.inc"
 #include "ARMGenEDInfo.inc"
@@ -4403,3 +4405,31 @@
   return S;
 }
 
+static DecodeStatus DecodeMRRC2(llvm::MCInst &Inst, unsigned Val,
+                                uint64_t Address, const void *Decoder) {
+
+  DecodeStatus S = MCDisassembler::Success;
+
+  unsigned CRm = fieldFromInstruction32(Val, 0, 4);
+  unsigned opc1 = fieldFromInstruction32(Val, 4, 4);
+  unsigned cop = fieldFromInstruction32(Val, 8, 4);
+  unsigned Rt = fieldFromInstruction32(Val, 12, 4);
+  unsigned Rt2 = fieldFromInstruction32(Val, 16, 4);
+
+  if ((cop & ~0x1) == 0xa)
+    return MCDisassembler::Fail;
+
+  if (Rt == Rt2)
+    S = MCDisassembler::SoftFail;
+
+  Inst.addOperand(MCOperand::CreateImm(cop));
+  Inst.addOperand(MCOperand::CreateImm(opc1));
+  if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt, Address, Decoder)))
+    return MCDisassembler::Fail;
+  if (!Check(S, DecodeGPRnopcRegisterClass(Inst, Rt2, Address, Decoder)))
+    return MCDisassembler::Fail;
+  Inst.addOperand(MCOperand::CreateImm(CRm));
+
+  return S;
+}
+