CS 2505 Spring 2019Data Lab: Data and Bitwise OperationsAssigned: March 19Due: Tuesday March 29, 23:59Ends: Friday April 5, 23:591 IntroductionThe purpose of this assignment is to become more familiar with bit-level representations of integers. You’lldo this by solving a series of programming “puzzles.” Many of these puzzles are quite artificial, but you’llfind yourself thinking much more about bits in working your way through them.2 LogisticsYou may work in pairs for this assignment. If you work with a partner, list both names and both PIDs in acomment at the beginning of the bits.c file you submit.3 Handout InstructionsDownload the file datalab-handout.tarfrom the course website to a (protected) directory on a Linuxmachine on which you plan to do your work. Then give the commandunix> tar xvf datalab-handout.tarThis will cause a number of files to be unpacked in the directory. The only file you will be modifying andturning in is bits.c.The bits.c file contains a skeleton for each of the assigned programming puzzles. Your assignment isto complete each function skeleton using only straightline code for the integer puzzles (i.e., no loops orconditionals) and a limited number of C arithmetic and logical operators. Specifically, you are only allowedto use the following eight arithmetic and logical operators:! & | + >(Of course, you are allowed to use the assignment operator.) A few of the functions further restrict this list.Also, you are not allowed to use any literal constants longer than 8 bits. See the comments in bits.c fordetailed rules and a discussion of the desired coding style.14 The PuzzlesThis section describes the puzzles that you will be solving in bits.c.4.1 Bit ManipulationsTable 1 describes a set of functions that manipulate and test sets of bits. The “Rating” field gives thedifficulty rating for the puzzle, the “Max Ops” field gives the maximum number of operators you are allowedto use to implement each function, and the “Points” field shows how many points a solution to the puzzle isworth. See the comments in bits.c for more details on the desired behavior of the functions. You mayalso refer to the test functions in tests.c. These are used as reference functions to express the correctbehavior of your functions, although they don’t satisfy the coding rules for your functions.Name Description Rating MaxOps PointsbitAnd(x, y) returns x & y 1 8 30upperBits(n) pads n upper bits with 1’s 1 10 30byteSwap(x, n, m) swaps the nth byte and the mth byte of x 2 25 25isLess(x, y) if x Table 1: Required Functions5 EvaluationAutograding your workWe have included some autograding tools in the handout directory — btest, dlc, and driver.pl —to help you check the correctness of your work. btest: This program checks the functional correctness of the functions in bits.c. To build anduse it, type the following two commands:unix> makeunix> ./btestNotice that you must rebuild btest each time you modify your bits.c file.You’ll find it helpful to work through the functions one at a time, testing each one as you go. You canuse the -f flag to instruct btest to test only a single function:unix> ./btest -f subOKYou can feed it specific function arguments using the option flags -1, -2, and -3:unix> ./btest -f subOK -1 0xFFFFFFFF 0xFAFAFAFACheck the file README for documentation on running the btest program.2 dlc: This is a modified version of an ANSI C compiler from the MIT CILK group that you can useto check for compliance with the coding rules for each puzzle. The typical usage is:unix> ./dlc bits.cThe program runs silently unless it detects a problem, such as an illegal operator, too many operators,or non-straightline code in the integer puzzles. Running with the -e switch:unix> ./dlc -e bits.ccauses dlc to print counts of the number of operators used by each function. Type ./dlc -helpfor a list of command line options. driver.pl: This is a driver program that uses btest and dlc to compute the correctness andperformance points for your solution. It takes no arguments:unix> ./driver.plYour instructors will use driver.pl to evaluate your solution. If your code does not compilewhen tested with driver.pl you will receive a 0 for the assignment.Scoring rulesYour score will be computed out of a maximum of 100 points based on the following distribution:Correctness points. (maximum 80 points) The 4 puzzles you must solve have been given a difficulty ratingbetween 1 and 3. Each of the puzzles will be worth the number of points shown in the tables above, but the5 points for each puzzle will be reserved for performance. We will evaluate your functions using the btestprogram, which is described in the next section. You will get full credit for a puzzle if it passes all of thetests performed by btest and driver.pl, and no credit otherwise.Performance points. (maximum 20 points) Our main concern at this point in the course is that you can getthe right answer. However, we want to instill in you a sense of keeping things as short and simple as youcan. Furthermore, some of the puzzles can be solved by brute force, but we want you to be more clever.Thus, for each function we’ve established a maximum number of operators that you are allowed to use foreach function. This limit is very generous and is designed only to catch egregiously inefficient solutions.You will receive 5 points for each correct function that satisfies the operator limit.Explanation and analysis points. (maximum deduction 40 points) You must add to the header commentfor each function an explanation of the logic employed in your solution. This comment must be accurate,precise and complete. For example:3/** isNotMultOf4 - returns 0 if x is a multiple of 4,* non-0 otherwise* Examples: isMultOf4(0x033B104C) = 0* isMultOf4(0x033B1046) != 0* Legal ops: ? & ? |* Max ops: 5* Rating: 1* Logic:* x is a multiple of 4 if and only if x % 4 = 0. But, since* x % 4 returns the remainder when x is divided by 4, and* dividing by 4 will simply chop off the two low bits of x,* x % 4 will yield the two low bits of the representation* of x. So, x is a multiple of 4 if and only if its* representation ends in two 0s.** We can obtain the desired bits by applying the right* mask to x. The key is to set the 30 high bits to 0,* so we could do this: x & 0x00000003.**/int isMultOf4(int x) {int mask = 0x03; // OK, it’s a one-byte constant ’0011’,// which will be sign-extended to a// 32-bit value:// 00000000 00000000 00000000 00000011.return x & mask; // 0 if low bits are 00, non-0 otherwise}We will evaluate your explanations for some, but not all, of the functions. If your explanation for a functionis unsatisfactory, we will apply a deduction of up to 10 points to your score for that function.The evaluation of these comments will be performed by the TAs, not by the autograding tools describedbelow. It is up to you to make sure your explanations are worthy of credit.6 Handin InstructionsYou will submit your bits.c file to the Curator under the heading c06. Like the earlier programmingassignments, this is not autograded at the time of submission. Instead, we will periodically run autogradingcode on your submissions, and post the results to the Curator system.Of course, if you apply the tools btest, dlc, and driver.pl properly, you will already know whetheryour solution passes testing.47 Advice The nature of this assignment requires creating a 32-bit executable. However, 64-bit Linux distributions,including CentOS, do not include some libraries that are necessary to build a 32-bit executable.That leaves you with two choices.You can complete the assignment on a node in the rlogin cluster, which do support 32-bit builds.Or, you can update your CentOS virtual machine to include the necessary libraries. The followingcommand may suffice:> yum install glibc-devel.i686If not, you may find the discussion below to be helpful:stackoverflow.com/questions/23638271/how-to-compile-32-bit-apps-on-64-bit-rhel Don’t include the header file in your bits.c file, as it confuses dlc and results insome non-intuitive error messages. You will still be able to use printf in your bits.c file fordebugging without including the header, although gcc will print a warning that youcan ignore. The dlc program enforces an archaic form of the C Standard. In particular, its rules for declarationsare different than those enforced by gcc. In particular, any declaration must appear in a block (whatyou enclose in curly braces) before any statement that is not a declaration. For example, it willcomplain about the following code:int foo(int x){int a = x;a *= 3; /* Statement that is not a declaration */int b = a; /* ERROR: Declaration not allowed here */}The effect will be that dlc will ”zap” the offending code, and it will not compile, or will compile butnot perform correctly. You can avoid lots of disappointment if you make sure you use driver.plto do the final testing of your solution.We will make no accommodations for failing to test your solution with driver.pl; you have beenwarned.5本团队核心人员组成主要包括BAT一线工程师，精通德英语！我们主要业务范围是代做编程大作业、课程设计等等。我们的方向领域：window编程 数值算法 AI人工智能 金融统计 计量分析 大数据 网络编程 WEB编程 通讯编程 游戏编程多媒体linux 外挂编程 程序API图像处理 嵌入式/单片机 数据库编程 控制台 进程与线程 网络安全 汇编语言 硬件编程 软件设计 工程标准规等。其中代写编程、代写程序、代写留学生程序作业语言或工具包括但不限于以下范围:C/C++/C#代写Java代写IT代写Python代写辅导编程作业Matlab代写Haskell代写Processing代写Linux环境搭建Rust代写Data Structure Assginment 数据结构代写MIPS代写Machine Learning 作业 代写Oracle/SQL/PostgreSQL/Pig 数据库代写/代做/辅导Web开发、网站开发、网站作业ASP.NET网站开发Finance Insurace Statistics统计、回归、迭代Prolog代写Computer Computational method代做因为专业，所以值得信赖。如有需要，请加QQ：99515681 或邮箱：99515681@qq.com 微信：codehelp
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