diff --git a/src/cpu/base_dyn_inst.hh b/src/cpu/base_dyn_inst.hh
index 9a1ab06..f1c7829 100644
--- a/src/cpu/base_dyn_inst.hh
+++ b/src/cpu/base_dyn_inst.hh
@@ -61,7 +61,6 @@
 #include "cpu/exetrace.hh"
 #include "cpu/inst_res.hh"
 #include "cpu/inst_seq.hh"
-#include "cpu/o3/comm.hh"
 #include "cpu/op_class.hh"
 #include "cpu/static_inst.hh"
 #include "cpu/translation.hh"
diff --git a/src/cpu/o3/comm.hh b/src/cpu/o3/comm.hh
index df518b1..e2fda99 100644
--- a/src/cpu/o3/comm.hh
+++ b/src/cpu/o3/comm.hh
@@ -52,105 +52,6 @@
 #include "cpu/inst_seq.hh"
 #include "sim/faults.hh"
 
-/** Physical register index type.
- * Although the Impl might be a better for this, but there are a few classes
- * that need this typedef yet are not templated on the Impl.
- */
-using PhysRegIndex = short int;
-
-/** Physical register ID.
- * Like a register ID but physical. The inheritance is private because the
- * only relationship between this types is functional, and it is done to
- * prevent code replication. */
-class PhysRegId : private RegId {
-  private:
-    PhysRegIndex flatIdx;
-
-  public:
-    explicit PhysRegId() : RegId(IntRegClass, -1), flatIdx(-1) {}
-
-    /** Scalar PhysRegId constructor. */
-    explicit PhysRegId(RegClass _regClass, PhysRegIndex _regIdx,
-              PhysRegIndex _flatIdx)
-        : RegId(_regClass, _regIdx), flatIdx(_flatIdx)
-    {}
-
-    /** Vector PhysRegId constructor (w/ elemIndex). */
-    explicit PhysRegId(RegClass _regClass, PhysRegIndex _regIdx,
-              ElemIndex elem_idx, PhysRegIndex flat_idx)
-        : RegId(_regClass, _regIdx, elem_idx), flatIdx(flat_idx) { }
-
-    /** Visible RegId methods */
-    /** @{ */
-    using RegId::index;
-    using RegId::classValue;
-    using RegId::isZeroReg;
-    using RegId::className;
-    using RegId::elemIndex;
-     /** @} */
-    /**
-     * Explicit forward methods, to prevent comparisons of PhysRegId with
-     * RegIds.
-     */
-    /** @{ */
-    bool operator<(const PhysRegId& that) const {
-        return RegId::operator<(that);
-    }
-
-    bool operator==(const PhysRegId& that) const {
-        return RegId::operator==(that);
-    }
-
-    bool operator!=(const PhysRegId& that) const {
-        return RegId::operator!=(that);
-    }
-    /** @} */
-
-    /** @return true if it is an integer physical register. */
-    bool isIntPhysReg() const { return isIntReg(); }
-
-    /** @return true if it is a floating-point physical register. */
-    bool isFloatPhysReg() const { return isFloatReg(); }
-
-    /** @Return true if it is a  condition-code physical register. */
-    bool isCCPhysReg() const { return isCCReg(); }
-
-    /** @Return true if it is a vector physical register. */
-    bool isVectorPhysReg() const { return isVecReg(); }
-
-    /** @Return true if it is a vector element physical register. */
-    bool isVectorPhysElem() const { return isVecElem(); }
-
-    /** @return true if it is a vector predicate physical register. */
-    bool isVecPredPhysReg() const { return isVecPredReg(); }
-
-    /** @Return true if it is a  condition-code physical register. */
-    bool isMiscPhysReg() const { return isMiscReg(); }
-
-    /**
-     * Returns true if this register is always associated to the same
-     * architectural register.
-     */
-    bool isFixedMapping() const
-    {
-        return !isRenameable();
-    }
-
-    /** Flat index accessor */
-    const PhysRegIndex& flatIndex() const { return flatIdx; }
-
-    static PhysRegId elemId(const PhysRegId* vid, ElemIndex elem)
-    {
-        assert(vid->isVectorPhysReg());
-        return PhysRegId(VecElemClass, vid->index(), elem);
-    }
-};
-
-/** Constant pointer definition.
- * PhysRegIds only need to be created once and then we can just share
- * pointers */
-using PhysRegIdPtr = const PhysRegId*;
-
 /** Struct that defines the information passed from fetch to decode. */
 template<class Impl>
 struct DefaultFetchDefaultDecode {
diff --git a/src/cpu/reg_class.hh b/src/cpu/reg_class.hh
index 70cfab3..63a6c86 100644
--- a/src/cpu/reg_class.hh
+++ b/src/cpu/reg_class.hh
@@ -208,6 +208,105 @@
     }
 };
 
+/** Physical register index type.
+ * Although the Impl might be a better for this, but there are a few classes
+ * that need this typedef yet are not templated on the Impl.
+ */
+using PhysRegIndex = short int;
+
+/** Physical register ID.
+ * Like a register ID but physical. The inheritance is private because the
+ * only relationship between this types is functional, and it is done to
+ * prevent code replication. */
+class PhysRegId : private RegId {
+  private:
+    PhysRegIndex flatIdx;
+
+  public:
+    explicit PhysRegId() : RegId(IntRegClass, -1), flatIdx(-1) {}
+
+    /** Scalar PhysRegId constructor. */
+    explicit PhysRegId(RegClass _regClass, PhysRegIndex _regIdx,
+              PhysRegIndex _flatIdx)
+        : RegId(_regClass, _regIdx), flatIdx(_flatIdx)
+    {}
+
+    /** Vector PhysRegId constructor (w/ elemIndex). */
+    explicit PhysRegId(RegClass _regClass, PhysRegIndex _regIdx,
+              ElemIndex elem_idx, PhysRegIndex flat_idx)
+        : RegId(_regClass, _regIdx, elem_idx), flatIdx(flat_idx) { }
+
+    /** Visible RegId methods */
+    /** @{ */
+    using RegId::index;
+    using RegId::classValue;
+    using RegId::isZeroReg;
+    using RegId::className;
+    using RegId::elemIndex;
+     /** @} */
+    /**
+     * Explicit forward methods, to prevent comparisons of PhysRegId with
+     * RegIds.
+     */
+    /** @{ */
+    bool operator<(const PhysRegId& that) const {
+        return RegId::operator<(that);
+    }
+
+    bool operator==(const PhysRegId& that) const {
+        return RegId::operator==(that);
+    }
+
+    bool operator!=(const PhysRegId& that) const {
+        return RegId::operator!=(that);
+    }
+    /** @} */
+
+    /** @return true if it is an integer physical register. */
+    bool isIntPhysReg() const { return isIntReg(); }
+
+    /** @return true if it is a floating-point physical register. */
+    bool isFloatPhysReg() const { return isFloatReg(); }
+
+    /** @Return true if it is a  condition-code physical register. */
+    bool isCCPhysReg() const { return isCCReg(); }
+
+    /** @Return true if it is a vector physical register. */
+    bool isVectorPhysReg() const { return isVecReg(); }
+
+    /** @Return true if it is a vector element physical register. */
+    bool isVectorPhysElem() const { return isVecElem(); }
+
+    /** @return true if it is a vector predicate physical register. */
+    bool isVecPredPhysReg() const { return isVecPredReg(); }
+
+    /** @Return true if it is a  condition-code physical register. */
+    bool isMiscPhysReg() const { return isMiscReg(); }
+
+    /**
+     * Returns true if this register is always associated to the same
+     * architectural register.
+     */
+    bool isFixedMapping() const
+    {
+        return !isRenameable();
+    }
+
+    /** Flat index accessor */
+    const PhysRegIndex& flatIndex() const { return flatIdx; }
+
+    static PhysRegId elemId(const PhysRegId* vid, ElemIndex elem)
+    {
+        assert(vid->isVectorPhysReg());
+        return PhysRegId(VecElemClass, vid->index(), elem);
+    }
+};
+
+/** Constant pointer definition.
+ * PhysRegIds only need to be created once and then we can just share
+ * pointers */
+using PhysRegIdPtr = const PhysRegId*;
+
 namespace std
 {
 template<>