Added generate around the spill logic so it is only used if supporting compressed instructions.

wally-pipelined/src/ifu/ifu.sv

@@ -30,13 +30,13 @@ module ifu (
 	input logic 				clk, reset,
 	input logic 				StallF, StallD, StallE, StallM, StallW,
 	input logic 				FlushF, FlushD, FlushE, FlushM, FlushW,
-  // Fetch
+	// Bus interface
 	input logic [`XLEN-1:0] 	IfuBusHRDATA,
 	input logic 				IfuBusAck,
-  (* mark_debug = "true" *) output logic [`XLEN-1:0]    PCF, 
 	output logic [`PA_BITS-1:0] IfuBusAdr,
 	output logic 				IfuBusRead,
 	output logic 				IfuStallF,
+	(* mark_debug = "true" *) output logic [`XLEN-1:0] PCF, 
 	// Execute
 	output logic [`XLEN-1:0] 	PCLinkE,
 	input logic 				PCSrcE, 
@@ -49,13 +49,12 @@ module ifu (
 	input logic 				InvalidateICacheM,
 	output logic [31:0] 		InstrD, InstrM, 
 	output logic [`XLEN-1:0] 	PCM, 
+	// branch predictor
 	output logic [4:0] 			InstrClassM,
 	output logic 				BPPredDirWrongM,
 	output logic 				BTBPredPCWrongM,
 	output logic 				RASPredPCWrongM,
 	output logic 				BPPredClassNonCFIWrongM,
-  // Writeback
-  // output logic [`XLEN-1:0] PCLinkW,
 	// Faults
 	input logic 				IllegalBaseInstrFaultD,
 	output logic 				ITLBInstrPageFaultF,
@@ -63,9 +62,6 @@ module ifu (
 	output logic 				InstrMisalignedFaultM,
 	output logic [`XLEN-1:0] 	InstrMisalignedAdrM,
 	input logic 				ExceptionM, PendingInterruptM,
-	    
-
-  
 	// mmu management
 	input logic [1:0] 			PrivilegeModeW,
 	input logic [`XLEN-1:0] 	PTE,
@@ -74,13 +70,10 @@ module ifu (
 	input logic 				STATUS_MXR, STATUS_SUM, STATUS_MPRV,
 	input logic [1:0] 			STATUS_MPP,
 	input logic 				ITLBWriteF, ITLBFlushF,
-
 	output logic 				ITLBMissF,
-
   // pmp/pma (inside mmu) signals.  *** temporarily from AHB bus but eventually replace with internal versions pre H
 	input 						var logic [7:0] PMPCFG_ARRAY_REGW[`PMP_ENTRIES-1:0],
 	input 						var logic [`XLEN-1:0] PMPADDR_ARRAY_REGW[`PMP_ENTRIES-1:0], 
-
 	output logic 				InstrAccessFaultF
 );
 
@@ -99,34 +92,38 @@ module ifu (
   logic                        reset_q; // *** look at this later.
 
   logic                        BPPredDirWrongE, BTBPredPCWrongE, RASPredPCWrongE, BPPredClassNonCFIWrongE;
+  logic [`XLEN-1:0] 		   PCBPWrongInvalidate;
+  logic 					   BPPredWrongM;
+
   
 (* mark_debug = "true" *)  logic [`PA_BITS-1:0]         PCPF; // used to either truncate or expand PCPF and PCNextF into `PA_BITS width.
   logic [`XLEN+1:0]            PCFExt;
-  logic [`XLEN-1:0] 		   PCBPWrongInvalidate;
-  logic 					   BPPredWrongM;
+
   logic 					   CacheableF;
   logic [11:0] 				   PCNextFMux;
   logic [`XLEN-1:0] 		   PCFMux;
-
-  logic [`XLEN-1:0] 		   PCFp2;
-  logic 					   SelNextSpill, SelSpill, SpillSave;
-  logic 			   Spill;
-  
+  logic 					   SelNextSpill;
   logic 					   ICacheFetchLine;
   logic 					   BusStall;
   logic 					   ICacheStallF;
   logic 					   IgnoreRequest;
   logic 					   CPUBusy;
-  
-  logic [15:0] 		   SpillDataBlock0;
   logic [31:0] 				   PostSpillInstrRawF;
 
+
+  generate
+	if(`C_SUPPORTED) begin : SpillSupport
+	  logic [`XLEN-1:0] 		   PCFp2;
+	  logic 					   Spill;
+	  logic 					   SelSpill, SpillSave;
+	  logic [15:0] 				   SpillDataBlock0;
+
+	  // this exists only if there are compressed instructions.
 	  assign PCFp2 = PCF + `XLEN'b10;
   
 	  assign PCNextFMux = SelNextSpill ? PCFp2[11:0] : PCNextF[11:0];
 	  assign PCFMux = SelSpill ? PCFp2 : PCF;
   
-
 	  assign Spill = &PCF[$clog2(`ICACHE_BLOCKLENINBITS/32)+1:1];
 
 	  typedef enum 		   {STATE_SPILL_READY, STATE_SPILL_SPILL} statetype;
@@ -162,6 +159,14 @@ module ifu (
 	  assign PostSpillInstrRawF = Spill ? {InstrRawF[15:0], SpillDataBlock0} : InstrRawF;
 	  assign CompressedF = PostSpillInstrRawF[1:0] != 2'b11;
 
+	  // end of spill support
+	end else begin : NoSpillSupport // block: SpillSupport
+	  assign PCNextFMux = PCNextF[11:0];
+	  assign PCFMux = PCF;
+	  assign SelNextSpill = 0;
+	  assign PostSpillInstrRawF = InstrRawF;
+	end
+  endgenerate
   
 
   assign PCFExt = {2'b00, PCFMux};
@@ -254,15 +259,13 @@ module ifu (
   endgenerate
 	
   // select between dcache and direct from the BUS. Always selected if no dcache.
+  // handled in the busfsm.
   mux2 #(32) UnCachedInstrMux(.d0(FinalInstrRawF),
 				.d1(ICacheMemWriteData[31:0]),
 				.s(SelUncachedAdr),
 				.y(InstrRawF));
 
-  
-  
-
-  
+  // always present
   genvar 			   index;
   generate
     for (index = 0; index < WORDSPERLINE; index++) begin:fetchbuffer
@@ -293,9 +296,6 @@ module ifu (
   assign IgnoreRequest = ITLBMissF;
 
   
-
-
-  
   flopenl #(32) AlignedInstrRawDFlop(clk, reset | reset_q, ~StallD, FlushD ? nop : PostSpillInstrRawF, nop, InstrRawD);