Add VectorFIFOF module

The VectorFIFOF module has a FIFOF interface for enqueuing and dequeuing
data.  It also provides a method, which returns a Vector of Maybe entries,
to access all entries in the queue simultaneously.

Libraries/Misc/Makefile

@@ -15,6 +15,7 @@ build:
 	$(BSC) -u $(BSCFLAGS) EdgeFIFOFs.bsv
 	$(BSC) -u $(BSCFLAGS) GetPut_Aux.bsv
 	$(BSC) -u $(BSCFLAGS) Semi_FIFOF.bsv
+	$(BSC) -u $(BSCFLAGS) VectorFIFOF.bsv
 
 .PHONY: clean full_clean
 clean full_clean:

Libraries/Misc/VectorFIFOF.bsv

@@ -0,0 +1,90 @@
+
+package VectorFIFOF;
+
+// This package implements a fifo like module with a parameterized
+// depth and standard FIFOF interface.  The module also provides
+// parallel access to all items in the fifo, for example, to allow
+// searching for hazards before enqueueing new items.
+
+import FIFOF ::*;
+import Vector ::*;
+
+interface VectorFIFOF#(numeric type depth, type t);
+   interface FIFOF#(t) fifo;
+   interface Vector#(depth, Maybe#(t)) vector;
+endinterface
+
+module mkVectorFIFOF(VectorFIFOF#(depth, t))
+   provisos(
+      Bits#(t, a__)
+      );
+
+   Vector#(depth, Reg#(t)) vr_data <- replicateM(mkRegU);
+   Array#(Reg#(UInt#(TLog#(TAdd#(depth,1))))) r_count <- mkCReg(3, 0);
+
+   Wire#(t) w_enq <- mkWire;
+   PulseWire pw_deq <- mkPulseWire;
+   PulseWire pw_clear <- mkPulseWire;
+
+   function Bool notFull;
+      return r_count[0] < fromInteger(valueOf(depth));
+   endfunction
+
+   function Bool notEmpty;
+      return r_count[0] != 0;
+   endfunction
+
+   rule rl_enq;
+      vr_data[r_count[1]] <= w_enq;
+      r_count[1] <= r_count[1] + 1;
+   endrule
+
+   rule rl_deq(pw_deq);
+      for (Integer i = 0; i < fromInteger(valueOf(depth)) - 1; i = i + 1)
+	 vr_data[i] <= vr_data[i + 1];
+
+      r_count[0] <= r_count[0] - 1;
+   endrule
+
+   rule rl_clear(pw_clear);
+      r_count[2] <= 0;
+   endrule
+
+   function Maybe#(t) valid(Integer x, t a);
+      if (fromInteger(x) < r_count[0])
+	 return tagged Valid a;
+      else
+	 return tagged Invalid;
+   endfunction
+
+   interface FIFOF fifo;
+      method Action enq(t x) if (notFull);
+	 w_enq <= x;
+      endmethod
+
+      method Action deq if (notEmpty);
+	 pw_deq.send;
+      endmethod
+
+      method t first if (r_count[0] > 0);
+	 return vr_data[0];
+      endmethod
+
+      method Action clear;
+	 pw_clear.send;
+      endmethod
+
+      method Bool notFull;
+	 return notFull;
+      endmethod
+
+      method Bool notEmpty;
+         return notEmpty;
+      endmethod
+   endinterface
+
+   interface Vector vector = zipWith(valid, genVector, readVReg(vr_data));
+
+endmodule
+
+endpackage