# Lab 9
Name: I.Kalyan Anudeep
Roll No.: CS22B025

---
## Question 1
**Code** (if required)

module alu(input [3:0] A,B,
           input [1:0] c,
           output reg [3:0] result);

   always @(*)
   begin
           case(c)
                   2'b00: result = A + B;
                   2'b01: result = A - B;
                   2'b10: result = A & B;
                   2'b11: result = A | B;
                   default: result=4'b0;
           endcase
   end
endmodule

module mux4to1(input [3:0] in0,in1,in2,in3,
               input [1:0] sel,
               output reg [3:0] out);
       always @(*)
       begin
               case(sel)
                       2'b00: out=in0;
                       2'b01: out=in1;
                       2'b10: out=in2;
                       2'b11: out=in3;
                       default: 4'b0;
               endcase
       end
endmodule

module top(input [3:0] A,B,
           input [1:0] c,
           output reg [3:0] result);
   wire [3:0] alu_result;
   alu alu_inst(A,B,c,alu_result);
   mux4to1 mux_inst(alu_result,4'b0,4'b0,4'b0,c,result);
   endmodule 

## Question 2
**Code** (if required)

module simple_processor (
    input [7:0] instruction
);

    reg [7:0] memory [255:0];
    reg [7:0] reg_file [15:0];

    reg [2:0] opcode;
    reg [3:0] rs;
    reg [3:0] rd;
    reg [2:0] offset;

    reg [7:0] data;
    reg [7:0] addr;
    reg [7:0] base_addr;


    assign opcode = instruction[7:5];
    assign rs = instruction[4:2];
    assign rd = instruction[1:0];
    assign offset = instruction[4:2];
    
    always @(*) begin
    case(opcode)
        3'b000: begin // Load operation (lw)
            addr = base_addr + offset;
            data = memory[addr];
            reg_file[rd] = data;
        end
        3'b001: begin // Store operation (sw)
            addr = base_addr + offset;
            memory[addr] = reg_file[rd];
        end
    endcase
end
endmodule

## Question 3
**Code** (if required)

~contents of inscount0.log
count 712683

~code of inscount0.cpp
/*
 * Copyright (C) 2004-2021 Intel Corporation.
 * SPDX-License-Identifier: MIT
 */

#include <iostream>
#include <fstream>
#include "pin.H"
using std::cerr;
using std::endl;
using std::ios;
using std::ofstream;
using std::string;

ofstream OutFile;

// The running count of instructions is kept here
// make it static to help the compiler optimize docount
static UINT64 icount = 0;

// This function is called before every instruction is executed
VOID docount() { icount++; }

// Pin calls this function every time a new instruction is encountered
VOID Instruction(INS ins, VOID* v)
{
    // Insert a call to docount before every instruction, no arguments are passed
    INS_InsertCall(ins, IPOINT_BEFORE, (AFUNPTR)docount, IARG_END);
}

KNOB< string > KnobOutputFile(KNOB_MODE_WRITEONCE, "pintool", "o", "inscount.out", "specify output file name");

// This function is called when the application exits
VOID Fini(INT32 code, VOID* v)
{
    // Write to a file since cout and cerr maybe closed by the application
    OutFile.setf(ios::showbase);
    OutFile << "Count " << icount << endl;
    OutFile.close();
}

/* ===================================================================== */
/* Print Help Message                                                    */
/* ===================================================================== */

INT32 Usage()
{
    cerr << "This tool counts the number of dynamic instructions executed" << endl;
    cerr << endl << KNOB_BASE::StringKnobSummary() << endl;
    return -1;
}

/* ===================================================================== */
/* Main                                                                  */
/* ===================================================================== */
/*   argc, argv are the entire command line: pin -t <toolname> -- ...    */
/* ===================================================================== */

int main(int argc, char* argv[])
{
    // Initialize pin
    if (PIN_Init(argc, argv)) return Usage();

    OutFile.open(KnobOutputFile.Value().c_str());

    // Register Instruction to be called to instrument instructions
    INS_AddInstrumentFunction(Instruction, 0);

    // Register Fini to be called when the application exits
    PIN_AddFiniFunction(Fini, 0);

    // Start the program, never returns
    PIN_StartProgram();

    return 0;
}

~My c++ code is
#include<iostream>
using namespace std;
int main()
{
        int sum=0;
        for(int i=1;i<=10;i++)
        {
                sum=sum+i;
        }
}

~After running my c++ file number of instructions or instruction count is 2150298