Add a new operation class for IPR accesses, and have IPR-accessing

instructions use it (instead of IntALU, as before).  Default config
has a single non-pipelined 3-cycle unit.  A bit conservative for the
ev6 (some are 1, some are 3).

arch/alpha/isa_desc:
    Make hw_mfpr and hw_mtpr use IprAccessOp op class.
cpu/full_cpu/op_class.hh:
    Add IprAccess.

--HG--
extra : convert_revision : d4103da3343a586936839e29981fd15d6930d442

arch/alpha/isa_desc

@@ -1610,7 +1610,8 @@ output decoder {{
 }};
 
 def format HwMoveIPR(code) {{
-    iop = InstObjParams(name, Name, 'HwMoveIPR', CodeBlock(code))
+    iop = InstObjParams(name, Name, 'HwMoveIPR', CodeBlock(code),
+			['IprAccessOp'])
     header_output = BasicDeclare.subst(iop)
     decoder_output = BasicConstructor.subst(iop)
     decode_block = BasicDecode.subst(iop)

cpu/full_cpu/op_class.hh

@@ -51,6 +51,7 @@ enum OpClass {
     FloatSqrtOp,	/* floating point square root */
     MemReadOp,		/* memory read port */
     MemWriteOp,		/* memory write port */
+    IprAccessOp,	/* Internal Processor Register read/write port */
     InstPrefetchOp,	/* instruction prefetch port (on I-cache) */
     Num_OpClasses	/* total functional unit classes */
 };