bitmanip alu submodule passes lint and regression

src/ieu/alu.sv

@@ -72,6 +72,7 @@ module alu #(parameter WIDTH=32) (
   // Pack control signals into shifter select
   assign shASelect = {W64,SubArith};
 
+  // A, A sign bit muxes
   if (WIDTH == 64) begin
     mux3 #(1) signmux(A[63], A[31], 1'b0, {~SubArith, W64}, shSignA);
     mux3 #(64) extendmux({{32{1'b0}}, A[31:0]},{{32{A[31]}}, A[31:0]}, A,{~W64, SubArith}, CondExtA);
@@ -80,7 +81,6 @@ module alu #(parameter WIDTH=32) (
     assign CondExtA = A;
   end
 
-    
   // Addition
   assign CondMaskInvB = SubArith ? ~CondMaskB : CondMaskB;
   assign {Carry, Sum} = CondShiftA + CondMaskInvB + {{(WIDTH-1){1'b0}}, SubArith};
@@ -113,14 +113,13 @@ module alu #(parameter WIDTH=32) (
     endcase
   end
 
-
   // Support RV64I W-type addw/subw/addiw/shifts that discard upper 32 bits and sign-extend 32-bit result to 64 bits
   if (WIDTH == 64)  assign ALUResult = W64 ? {{32{FullResult[31]}}, FullResult[31:0]} : FullResult;
   else              assign ALUResult = FullResult;
 
   // Final Result B instruction select mux
   if (`ZBC_SUPPORTED | `ZBS_SUPPORTED | `ZBA_SUPPORTED | `ZBB_SUPPORTED) begin : bitmanipalu
-    bitmanipalu #(WIDTH) balu(.A, .B, .ALUControl, .ALUSelect, .BSelect, .ZBBSelect, .Funct3, .CompFlags, .BALUControl,
+    bitmanipalu #(WIDTH) balu(.A, .B, .ALUControl, .ALUSelect, .BSelect, .ZBBSelect, .Funct3, .CompFlags, .BALUControl, .CondExtA, .ALUResult, .FullResult,
       .CondMaskB, .CondShiftA, .rotA, .Result);
   end else begin
     assign Result = ALUResult;

src/ieu/bmu/bitmanipalu.sv

@@ -38,25 +38,22 @@ module bitmanipalu #(parameter WIDTH=32) (
   input  logic [2:0]       Funct3,                  // With ALUControl, indicates operation to perform NOTE: Change signal name to ALUSelect
   input  logic [1:0]       CompFlags,               // Comparator flags
   input  logic [2:0]       BALUControl,             // ALU Control signals for B instructions in Execute Stage
-  output logic [WIDTH-1:0] CondMaskB,
-  output logic [WIDTH-1:0] CondShiftA,
-  output logic [WIDTH-1:0] rotA,
+  input  logic [WIDTH-1:0] CondExtA,                // A Conditional Extend Intermediary Signal
+  input  logic [WIDTH-1:0] ALUResult, FullResult,   // ALUResult, FullResult signals
+  output logic [WIDTH-1:0] CondMaskB,               // B is a mask for ZBS instructions
+  output logic [WIDTH-1:0] CondShiftA,              // A for ShAdd instructions
+  output logic [WIDTH-1:0] rotA,                    // A for rotate instructions
   output logic [WIDTH-1:0] Result);                 // Result
+
   // CondInvB = ~B when subtracting, B otherwise. Shift = shift result. SLT/U = result of a slt/u instruction.
   // FullResult = ALU result before adjusting for a RV64 w-suffix instruction.
-  logic [WIDTH-1:0] CondMaskInvB, Shift, FullResult,ALUResult;                              // Intermediate Signals 
+  logic [WIDTH-1:0] CondMaskInvB, Shift;                                                    // Intermediate Signals 
   logic [WIDTH-1:0] ZBBResult, ZBCResult;                                                   // ZBB, ZBC Result
   logic [WIDTH-1:0] MaskB;                                                                  // BitMask of B
-  logic [WIDTH-1:0] CondExtA;                                                               // Result of Zero Extend A select mux
   logic [WIDTH-1:0] RevA;                                                                   // Bit-reversed A
-  logic             Carry, Neg;                                                             // Flags: carry out, negative
-  logic             LT, LTU;                                                                // Less than, Less than unsigned
   logic             W64;                                                                    // RV64 W-type instruction
   logic             SubArith;                                                               // Performing subtraction or arithmetic right shift
   logic             ALUOp;                                                                  // 0 for address generation addition or 1 for regular ALU ops
-  logic             Asign, Bsign;                                                           // Sign bits of A, B
-  logic             shSignA;
-  logic [1:0]       shASelect;                                                              // select signal for shifter source generation mux 
   logic             Rotate;                                                                 // Indicates if it is Rotate instruction
   logic             Mask;                                                                   // Indicates if it is ZBS instruction
   logic             PreShift;                                                               // Inidicates if it is sh1add, sh2add, sh3add instruction
@@ -68,6 +65,7 @@ module bitmanipalu #(parameter WIDTH=32) (
   // Extract control signals from bitmanip ALUControl.
   assign {Rotate, Mask, PreShift} = BALUControl;
 
+  // Mask Generation Mux
   if (`ZBS_SUPPORTED) begin: zbsdec
     decoder #($clog2(WIDTH)) maskgen (B[$clog2(WIDTH)-1:0], MaskB);
     mux2 #(WIDTH) maskmux(B, MaskB, Mask, CondMaskB);
@@ -78,15 +76,16 @@ module bitmanipalu #(parameter WIDTH=32) (
     mux2 #(WIDTH) rotmux(A, {A[31:0], A[31:0]}, W64, rotA);
   end else assign rotA = A;
     
+  // Pre-Shift Mux
   if (`ZBA_SUPPORTED) begin: zbapreshift
     assign PreShiftAmt = Funct3[2:1] & {2{PreShift}};
-    // Pre-Shift
     assign CondShiftA = CondExtA << (PreShiftAmt);
   end else begin
     assign PreShiftAmt = 2'b0;
     assign CondShiftA = A;
   end
 
+  // Bit reverse needed for some ZBB, ZBC instructions
   if (`ZBC_SUPPORTED | `ZBB_SUPPORTED) begin: bitreverse
     bitreverse #(WIDTH) brA(.A, .RevA);
   end