diff --git a/src/arch/arm/decoder.hh b/src/arch/arm/decoder.hh
index 5f0e68b6cb..14167eb6c7 100644
--- a/src/arch/arm/decoder.hh
+++ b/src/arch/arm/decoder.hh
@@ -66,7 +66,6 @@ class Decoder : public InstDecoder
     ExtMachInst emi;
     uint32_t data;
     bool bigThumb;
-    bool instDone;
     bool outOfBytes;
     int offset;
     bool foundIt;
@@ -146,16 +145,6 @@ class Decoder : public InstDecoder
      */
     bool needMoreBytes() const { return outOfBytes; }
 
-    /**
-     * Is an instruction ready to be decoded?
-     *
-     * CPU models call this method to determine if decode() will
-     * return a new instruction on the next call. It typically only
-     * returns false if the decoder hasn't received enough data to
-     * decode a full instruction.
-     */
-    bool instReady() const { return instDone; }
-
     /**
      * Feed data to the decoder.
      *
diff --git a/src/arch/generic/decoder.hh b/src/arch/generic/decoder.hh
index 6bfc199ec6..a6aaaf5945 100644
--- a/src/arch/generic/decoder.hh
+++ b/src/arch/generic/decoder.hh
@@ -43,6 +43,8 @@ class InstDecoder
     size_t _moreBytesSize;
     Addr _pcMask;
 
+    bool instDone = false;
+
   public:
     template <typename MoreBytesType>
     InstDecoder(MoreBytesType *mb_buf) :
@@ -56,6 +58,16 @@ class InstDecoder
     void *moreBytesPtr() const { return _moreBytesPtr; }
     size_t moreBytesSize() const { return _moreBytesSize; }
     Addr pcMask() const { return _pcMask; }
+
+    /**
+     * Is an instruction ready to be decoded?
+     *
+     * CPU models call this method to determine if decode() will
+     * return a new instruction on the next call. It typically only
+     * returns false if the decoder hasn't received enough data to
+     * decode a full instruction.
+     */
+    bool instReady() const { return instDone; }
 };
 
 } // namespace gem5
diff --git a/src/arch/mips/decoder.hh b/src/arch/mips/decoder.hh
index d90e9c5dd6..25a84d3c1e 100644
--- a/src/arch/mips/decoder.hh
+++ b/src/arch/mips/decoder.hh
@@ -50,10 +50,9 @@ class Decoder : public InstDecoder
     //The extended machine instruction being generated
     ExtMachInst emi;
     uint32_t machInst;
-    bool instDone;
 
   public:
-    Decoder(ISA* isa = nullptr) : InstDecoder(&machInst), instDone(false)
+    Decoder(ISA* isa = nullptr) : InstDecoder(&machInst)
     {}
 
     void
@@ -82,12 +81,6 @@ class Decoder : public InstDecoder
         return true;
     }
 
-    bool
-    instReady()
-    {
-        return instDone;
-    }
-
     void takeOverFrom(Decoder *old) {}
 
   protected:
diff --git a/src/arch/power/decoder.hh b/src/arch/power/decoder.hh
index f3a272102a..3ec7031074 100644
--- a/src/arch/power/decoder.hh
+++ b/src/arch/power/decoder.hh
@@ -48,10 +48,9 @@ class Decoder : public InstDecoder
   protected:
     // The extended machine instruction being generated
     ExtMachInst emi;
-    bool instDone;
 
   public:
-    Decoder(ISA* isa=nullptr) : InstDecoder(&emi), instDone(false) {}
+    Decoder(ISA* isa=nullptr) : InstDecoder(&emi) {}
 
     void
     process()
@@ -79,12 +78,6 @@ class Decoder : public InstDecoder
         return true;
     }
 
-    bool
-    instReady()
-    {
-        return instDone;
-    }
-
     void takeOverFrom(Decoder *old) {}
 
   protected:
diff --git a/src/arch/riscv/decoder.hh b/src/arch/riscv/decoder.hh
index c12a48ad2f..f5866be165 100644
--- a/src/arch/riscv/decoder.hh
+++ b/src/arch/riscv/decoder.hh
@@ -57,7 +57,6 @@ class Decoder : public InstDecoder
     //The extended machine instruction being generated
     ExtMachInst emi;
     uint32_t machInst;
-    bool instDone;
 
     StaticInstPtr decodeInst(ExtMachInst mach_inst);
 
@@ -79,7 +78,6 @@ class Decoder : public InstDecoder
     void moreBytes(const PCStateBase &pc, Addr fetchPC);
 
     bool needMoreBytes() { return more; }
-    bool instReady() { return instDone; }
     void takeOverFrom(Decoder *old) {}
 
     StaticInstPtr decode(PCStateBase &nextPC);
diff --git a/src/arch/sparc/decoder.hh b/src/arch/sparc/decoder.hh
index 44695e9ef1..af1c95aa6e 100644
--- a/src/arch/sparc/decoder.hh
+++ b/src/arch/sparc/decoder.hh
@@ -48,11 +48,10 @@ class Decoder : public InstDecoder
     // The extended machine instruction being generated
     ExtMachInst emi;
     uint32_t machInst;
-    bool instDone;
     RegVal asi;
 
   public:
-    Decoder(ISA* isa=nullptr) : InstDecoder(&machInst), instDone(false), asi(0)
+    Decoder(ISA* isa=nullptr) : InstDecoder(&machInst), asi(0)
     {}
 
     void process() {}
@@ -89,12 +88,6 @@ class Decoder : public InstDecoder
         return true;
     }
 
-    bool
-    instReady()
-    {
-        return instDone;
-    }
-
     void
     setContext(RegVal _asi)
     {
diff --git a/src/arch/x86/decoder.hh b/src/arch/x86/decoder.hh
index bf5906d575..c8722b96b6 100644
--- a/src/arch/x86/decoder.hh
+++ b/src/arch/x86/decoder.hh
@@ -176,8 +176,6 @@ class Decoder : public InstDecoder
   protected:
     // Whether or not we're out of bytes.
     bool outOfBytes = true;
-    // Whether we've completed generating an ExtMachInst.
-    bool instDone = false;
     // The size of the displacement value.
     int displacementSize;
     // The size of the immediate value.
@@ -324,7 +322,6 @@ class Decoder : public InstDecoder
     }
 
     bool needMoreBytes() { return outOfBytes; }
-    bool instReady() { return instDone; }
 
     void
     updateNPC(X86ISA::PCState &nextPC)