diff --git a/src/cpu/o3/rename_map.cc b/src/cpu/o3/rename_map.cc
index bde2a69..1194b55 100644
--- a/src/cpu/o3/rename_map.cc
+++ b/src/cpu/o3/rename_map.cc
@@ -45,7 +45,7 @@
 
 #include <vector>
 
-#include "cpu/reg_class_impl.hh"
+#include "cpu/reg_class.hh"
 #include "debug/Rename.hh"
 
 using namespace std;
@@ -193,4 +193,3 @@
         vecMode = Enums::Full;
     }
 }
-
diff --git a/src/cpu/reg_class.hh b/src/cpu/reg_class.hh
index 27bf59b..def275e 100644
--- a/src/cpu/reg_class.hh
+++ b/src/cpu/reg_class.hh
@@ -131,7 +131,12 @@
      * constant zero value throughout the execution).
      */
 
-    inline bool isZeroReg() const;
+    inline bool isZeroReg() const
+    {
+        return ((regClass == IntRegClass && regIdx == TheISA::ZeroReg) ||
+               (THE_ISA == ALPHA_ISA && regClass == FloatRegClass &&
+                regIdx == TheISA::ZeroReg));
+    }
 
     /** @return true if it is an integer physical register. */
     bool isIntReg() const { return regClass == IntRegClass; }
@@ -167,7 +172,21 @@
     /** Index flattening.
      * Required to be able to use a vector for the register mapping.
      */
-    inline RegIndex flatIndex() const;
+    inline RegIndex flatIndex() const
+    {
+        switch (regClass) {
+          case IntRegClass:
+          case FloatRegClass:
+          case VecRegClass:
+          case CCRegClass:
+          case MiscRegClass:
+            return regIdx;
+          case VecElemClass:
+            return Scale*regIdx + elemIdx;
+        }
+        panic("Trying to flatten a register without class!");
+        return -1;
+    }
     /** @} */
 
     /** Elem accessor */
diff --git a/src/cpu/reg_class_impl.hh b/src/cpu/reg_class_impl.hh
deleted file mode 100644
index 98b341e..0000000
--- a/src/cpu/reg_class_impl.hh
+++ /dev/null
@@ -1,75 +0,0 @@
-/*
- * Copyright (c) 2016 ARM Limited
- * All rights reserved
- *
- * The license below extends only to copyright in the software and shall
- * not be construed as granting a license to any other intellectual
- * property including but not limited to intellectual property relating
- * to a hardware implementation of the functionality of the software
- * licensed hereunder.  You may use the software subject to the license
- * terms below provided that you ensure that this notice is replicated
- * unmodified and in its entirety in all distributions of the software,
- * modified or unmodified, in source code or in binary form.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met: redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer;
- * redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in the
- * documentation and/or other materials provided with the distribution;
- * neither the name of the copyright holders nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- * Authors: Rekai Gonzalez
- */
-
-#ifndef __CPU__REG_CLASS_IMPL_HH__
-#define __CPU__REG_CLASS_IMPL_HH__
-
-#include <cassert>
-#include <cstddef>
-#include <iostream>
-
-#include "arch/registers.hh"
-#include "config/the_isa.hh"
-#include "cpu/reg_class.hh"
-
-bool RegId::isZeroReg() const
-{
-    return ((regClass == IntRegClass && regIdx == TheISA::ZeroReg) ||
-            (THE_ISA == ALPHA_ISA && regClass == FloatRegClass &&
-             regIdx == TheISA::ZeroReg));
-}
-
-static constexpr size_t Scale = TheISA::NumVecElemPerVecReg;
-
-RegIndex RegId::flatIndex() const {
-    switch (regClass) {
-    case IntRegClass:
-    case FloatRegClass:
-    case VecRegClass:
-    case CCRegClass:
-    case MiscRegClass:
-        return regIdx;
-    case VecElemClass:
-        return Scale*regIdx + elemIdx;
-    }
-    panic("Trying to flatten a register without class!");
-    return -1;
-}
-
-#endif // __CPU__REG_CLASS_IMPL_HH__
diff --git a/src/cpu/static_inst.hh b/src/cpu/static_inst.hh
index 16b5ffd..70d933c 100644
--- a/src/cpu/static_inst.hh
+++ b/src/cpu/static_inst.hh
@@ -44,7 +44,6 @@
 #include "config/the_isa.hh"
 #include "cpu/op_class.hh"
 #include "cpu/reg_class.hh"
-#include "cpu/reg_class_impl.hh"
 #include "cpu/static_inst_fwd.hh"
 #include "cpu/thread_context.hh"
 #include "enums/StaticInstFlags.hh"