ARM: Add in some new artificial fields that make decoding a little easier.

src/arch/arm/isa/bitfields.isa

@@ -61,6 +61,9 @@ def bitfield OPCODE_6	   opcode6;
 def bitfield OPCODE_5	   opcode5;
 def bitfield OPCODE_4      opcode4;
 
+def bitfield IS_MISC       isMisc;
+def bitfield SEVEN_AND_FOUR sevenAndFour;
+
 // Other
 def bitfield COND_CODE     condCode;
 def bitfield S_FIELD       sField;

src/arch/arm/predecoder.hh

@@ -73,6 +73,8 @@ namespace ArmISA
         void moreBytes(Addr pc, Addr fetchPC, MachInst inst)
         {
             emi = inst;
+            emi.sevenAndFour = bits(inst, 7) && bits(inst, 4);
+            emi.isMisc = (bits(inst, 24, 23) == 0x2 && bits(inst, 20) == 0);
         }
 
         //Use this to give data to the predecoder. This should be used

src/arch/arm/types.hh

@@ -38,7 +38,11 @@ namespace ArmISA
 {
     typedef uint32_t MachInst;
 
-    BitUnion32(ExtMachInst)
+    BitUnion64(ExtMachInst)
+        // Made up bitfields that make life easier.
+        Bitfield<33>     sevenAndFour;
+        Bitfield<32>     isMisc;
+
         // All the different types of opcode fields.
         Bitfield<27, 25> opcode;
         Bitfield<27, 25> opcode27_25;