1 files changed, 166 insertions, 0 deletions
diff --git a/cpu/beta_cpu/iew.hh b/cpu/beta_cpu/iew.hh
new file mode 100644
index 000000000..52b9ccdb0
--- /dev/null
+++ b/cpu/beta_cpu/iew.hh
@@ -0,0 +1,166 @@
+//Todo: Update with statuses.  Create constructor.  Fix up time buffer stuff.
+//Will also need a signal heading back at least one stage to rename to say
+//how many empty skid buffer entries there are.  Perhaps further back even.
+//Need to handle delaying writes to the writeback bus if it's full at the
+//given time.  Squash properly.  Load store queue.
+
+#ifndef __SIMPLE_IEW_HH__
+#define __SIMPLE_IEW_HH__
+
+// To include: time buffer, structs, queue,
+#include <queue>
+
+#include "base/timebuf.hh"
+#include "cpu/beta_cpu/comm.hh"
+
+//Can IEW even stall?  Space should be available/allocated already...maybe
+//if there's not enough write ports on the ROB or waiting for CDB
+//arbitration.
+template<class Impl, class IQ>
+class SimpleIEW
+{
+  private:
+    //Typedefs from Impl
+    typedef typename Impl::ISA ISA;
+    typedef typename Impl::DynInst DynInst;
+    typedef typename Impl::FullCPU FullCPU;
+    typedef typename Impl::Params Params;
+
+    typedef typename Impl::CPUPol::RenameMap RenameMap;
+
+    typedef typename Impl::TimeStruct TimeStruct;
+    typedef typename Impl::IEWStruct IEWStruct;
+    typedef typename Impl::RenameStruct RenameStruct;
+    typedef typename Impl::IssueStruct IssueStruct;
+
+  public:
+    enum Status {
+        Running,
+        Blocked,
+        Idle,
+        Squashing,
+        Unblocking
+    };
+
+  private:
+    Status _status;
+    Status _issueStatus;
+    Status _exeStatus;
+    Status _wbStatus;
+
+  public:
+    void squash();
+
+    void squash(DynInst *inst);
+
+    void block();
+
+    inline void unblock();
+
+  public:
+    SimpleIEW(Params &params);
+
+    void setCPU(FullCPU *cpu_ptr);
+
+    void setTimeBuffer(TimeBuffer<TimeStruct> *tb_ptr);
+
+    void setRenameQueue(TimeBuffer<RenameStruct> *rq_ptr);
+
+    void setIEWQueue(TimeBuffer<IEWStruct> *iq_ptr);
+
+    void setRenameMap(RenameMap *rm_ptr);
+
+    void wakeDependents(DynInst *inst);
+
+    void tick();
+
+    void iew();
+
+  private:
+    //Interfaces to objects inside and outside of IEW.
+    /** Time buffer interface. */
+    TimeBuffer<TimeStruct> *timeBuffer;
+
+    /** Wire to get commit's output from backwards time buffer. */
+    typename TimeBuffer<TimeStruct>::wire fromCommit;
+
+    /** Wire to write information heading to previous stages. */
+    typename TimeBuffer<TimeStruct>::wire toRename;
+
+    /** Rename instruction queue interface. */
+    TimeBuffer<RenameStruct> *renameQueue;
+
+    /** Wire to get rename's output from rename queue. */
+    typename TimeBuffer<RenameStruct>::wire fromRename;
+
+    /** Issue stage queue. */
+    TimeBuffer<IssueStruct> issueToExecQueue;
+
+    /** Wire to read information from the issue stage time queue. */
+    typename TimeBuffer<IssueStruct>::wire fromIssue;
+
+    /**
+     * IEW stage time buffer.  Holds ROB indices of instructions that
+     * can be marked as completed.
+     */
+    TimeBuffer<IEWStruct> *iewQueue;
+
+    /** Wire to write infromation heading to commit. */
+    typename TimeBuffer<IEWStruct>::wire toCommit;
+
+    //Will need internal queue to hold onto instructions coming from
+    //the rename stage in case of a stall.
+    /** Skid buffer between rename and IEW. */
+    queue<RenameStruct> skidBuffer;
+
+    /** Instruction queue. */
+    IQ instQueue;
+
+    /** Pointer to rename map.  Might not want this stage to directly
+     *  access this though...
+     */
+    RenameMap *renameMap;
+
+    /** CPU interface. */
+    FullCPU *cpu;
+
+  private:
+    /** Commit to IEW delay, in ticks. */
+    unsigned commitToIEWDelay;
+
+    /** Rename to IEW delay, in ticks. */
+    unsigned renameToIEWDelay;
+
+    /**
+     * Issue to execute delay, in ticks.  What this actually represents is
+     * the amount of time it takes for an instruction to wake up, be
+     * scheduled, and sent to a FU for execution.
+     */
+    unsigned issueToExecuteDelay;
+
+    /** Width of issue's read path, in instructions.  The read path is both
+     *  the skid buffer and the rename instruction queue.
+     *  Note to self: is this really different than issueWidth?
+     */
+    unsigned issueReadWidth;
+
+    /** Width of issue, in instructions. */
+    unsigned issueWidth;
+
+    /** Width of execute, in instructions.  Might make more sense to break
+     *  down into FP vs int.
+     */
+    unsigned executeWidth;
+
+    /** Number of cycles stage has been squashing.  Used so that the stage
+     *  knows when it can start unblocking, which is when the previous stage
+     *  has received the stall signal and clears up its outputs.
+     */
+    unsigned cyclesSquashing;
+
+    //Will implement later
+    //Load queue interface (probably one and the same)
+    //Store queue interface
+};
+
+#endif