added beginning of a ZBS instruction module to the ALU. Control signals still needed

pipelined/src/ieu/alu.sv

@@ -32,6 +32,7 @@
 module alu #(parameter WIDTH=32) (
   input  logic [WIDTH-1:0] A, B,       // Operands
   input  logic [2:0]       ALUControl, // With Funct3, indicates operation to perform
+  input  logic [6:0]       Funct7,
   input  logic [2:0]       Funct3,     // With ALUControl, indicates operation to perform
   output logic [WIDTH-1:0] Result,     // ALU result
   output logic [WIDTH-1:0] Sum);       // Sum of operands
@@ -83,6 +84,10 @@ module alu #(parameter WIDTH=32) (
       3'b111: FullResult = A & B;     // and
     endcase
 
+  if (`ZBS_SUPPORTED) 
+    zbs zbs(.A, .B, .Funct7, .Funct3, .ZBSResult);
+  else assign ZBSResult = 0; 
+
   // 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 Result = W64 ? {{32{FullResult[31]}}, FullResult[31:0]} : FullResult;
   else              assign Result = FullResult;

pipelined/src/ieu/zbs.sv

@@ -0,0 +1,58 @@
+///////////////////////////////////////////
+// zbs.sv
+//
+// Written: Kevin Kim <kekim@hmc.edu> and Kip Macsai-Goren <kmacsaigoren@hmc.edu>
+// Created: 31 January 2023
+// Modified: 
+//
+// Purpose: RISC-V single bit manipulation unit (ZBS instructions)
+//
+// Documentation: RISC-V System on Chip Design Chapter ***
+// 
+// A component of the CORE-V-WALLY configurable RISC-V project.
+// 
+// Copyright (C) 2021-23 Harvey Mudd College & Oklahoma State University
+//
+// SPDX-License-Identifier: Apache-2.0 WITH SHL-2.1
+//
+// Licensed under the Solderpad Hardware License v 2.1 (the “License”); you may not use this file 
+// except in compliance with the License, or, at your option, the Apache License version 2.0. You 
+// may obtain a copy of the License at
+//
+// https://solderpad.org/licenses/SHL-2.1/
+//
+// Unless required by applicable law or agreed to in writing, any work distributed under the 
+// License is distributed on an “AS IS” BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, 
+// either express or implied. See the License for the specific language governing permissions 
+// and limitations under the License.
+////////////////////////////////////////////////////////////////////////////////////////////////
+
+`include "wally-config.vh"
+
+module zbs #(parameter WIDTH=32) (
+  input  logic [WIDTH-1:0] A, B,       // Operands
+  //input  logic [2:0]       ALUControl, // With Funct3, indicates operation to perform
+  input  logic [6:0]       Funct7,
+  input  logic [2:0]       Funct3,     // With ***Control, indicates operation to perform
+  output logic [WIDTH-1:0] ZBSResult);     // ZBS result
+  //output logic [WIDTH-1:0] Sum);       // Sum of operands
+
+  logic [WIDTH-1:0] BMask, ClrResult, InvResult, ExtResult, SetResult;
+
+  decoder #(clog2(WIDTH)) maskgen (B[$clog2(WIDTH)-1:0], BMask);
+
+  assign InvResult = A ^ BMask;
+  assign ClrResult = A & ~BMask;
+  assign SetResult = A | BMask;
+  assign ExtResult = |(A & BMask);
+
+  casez ({Funct7, Funct3})
+    10'b010010?_001: ZBSResult = ClrResult;
+    10'b010010?_101: ZBSResult = ExtResult;
+    10'b011010?_001: ZBSResult = ClrResult;
+    10'b001010?_001: ZBSResult = ClrResult;
+    default: ZBSResult = 0; // *** should never be reached or selected
+  endcase
+
+endmodule
+