# Lab 9
Name: M V Sonith
Roll No.: CS22B036

---
## Question 1
**Code**

module ALU(a,b,s,out1);
input [31:0]a;
input [31:0]b;
input [1:0]s;
output [31:0] out1;
assign out1 = s[1] ? (s[0] ? a+b : a-b) : (s[0] ? a&b : a|b);
endmodule

module TB();
reg [31:0]a;
reg [31:0]b;
reg [1:0]s;
wire [31:0]ou;

ALU h0(a,b,s,ou);

initial
begin
    $monitor("A=%b,B=%b,C=%b,S=%b",a,b,s,ou);
    a = 32'b00000000000000000000000000000110;b=32'b00000000000000000000000000000101;s=2'b00;
    #100
    a = 32'b00000000000000000000000000000110;b=32'b00000000000000000000000000000101;s=2'b01;
    #100
    a = 32'b00000000000000000000000000000110;b=32'b00000000000000000000000000000101;s=2'b10;
    #100
    a = 32'b00000000000000000000000000000110;b=32'b00000000000000000000000000000101;s=2'b11;
end
endmodule

**Output**

---
## Question 2
**Code**

module simple_processor (
    input [7:0] instruction
);
    
    reg [7:0] memory [255:0]; 
    reg [7:0] reg_file [15:0];
    reg [7:0] immed;
    reg [7:0] val;
    
    always@(*) begin
    if (instruction[7] == 1'b1) begin
        val = instruction[6:5];
        immed = instruction[4:2]+reg_file[instruction[1:0]];
        reg_file[val] = memory[immed];
    end 
    else begin
        val = instruction[6:5];
        immed = instruction[4:2]+reg_file[instruction[1:0]];
       memory[immed] = reg_file[val];
    end
    end
endmodule

---

## Question 3
**Content of inscount0.log**

Count 683183

**Code in 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;
}

**C Code**

#include <stdio.h>

unsigned long long factorial(int n) {
    if (n == 0)
        return 1;
    else
        return n * factorial(n - 1);
}

int main() {
    int num = 20;
    unsigned long long fact = factorial(num);
    printf("Factorial of %d = %llu\n", num, fact);
    return 0;
}

**Content of inscount0.log for code**

Count 135444