Objectives: - Assembly language programs in x86-64 - Using assembler directives in x86-64 - Writing code for functions in x86-64; passing parameters in accordance with System V ABI conventions - Working with values smaller than 8 bytes - integrating C and assembler functions - working with structures in assembly language REMINDERS and GRADING CRITERIA: • Every lab requires a Readme file (for this lab, it must be called lab7Readme – the name is important, and case matters! This file should include the following: 1. Certification: BY SUBMITTING THIS FILE TO CARMEN, I CERTIFY THAT I STRICTLY ADHERED TO THE TENURES OF THE OHIO STATE UNIVERSITY’S ACADEMIC INTEGRITY POLICY. THIS IS THE README FILE FOR LAB 7. 2. Student name 3. Total amount of time to complete the entire lab 4. How you used gdb to help with your program 5. One thing you learned or observed about programming in x86-64 while doing the lab 6. The two items specified below that belong in the README file 7. Describe - to the best of your ability- the difference (if there is one) between the two 3D graphs that gnuplot creates from your data with 250 as the high value for x and y. If the graphs are consistent, say that. • You should aim to always hand an assignment in on time. . If you are late (even by less than a minute), you will receive 75% of your earned points for the designated grade as long as the assignment is submitted by 11:30 pm the following day, based on the due date given above. If you are more than 24 hours late, you will receive a zero for the assignment and your assignment will not be graded at all. I encourage you strongly to start early – try to make the early submission date. Get your extra points! The most common reason for failing to submit on time is waiting too long to start! • Any lab submitted that does not assemble (using your Makefile) or run without seg faults WILL RECEIVE AN AUTOMATIC GRADE OF ZERO for the lab. NO EXCEPTIONS will be made for this rule - to achieve even a single point on a lab, your code must minimally build (assemble to an executable) on stdlinux and execute on stdlinux without crashing, freezing, or causing segmentation faults. Your Makefile will be used to compile your code. You are responsible for making sure that your lab submits and compiles correctly. Since a Makefile is required for this lab, you must create the appropriate compile statements to create your 2 executable programs. Graders will be downloading your lab7.zip file from Carmen, unzipping it, and then executing make from a linux command line prompt. Your program must compile –without errors or warnings – via commands within the Makefile. Given valid input as described below, your program must also run without having a seg fault or other abnormal termination. You are required to include comments in the code documenting what the code does and pay attention to formatting to make sure the code is as clear as possible and easy for a reader of your program to understand. The quality and clarity of the comments will be given weight in the grade for the lab. GRADING CRITERIA (approximate percentages listed) (10%) The code and algorithm are well commented. • A comment should be included in the main program including the programmer name as well as explaining the nature of the problem and an overall method of the solution (what you are doing, not how). • A short comment should be included for each logical or syntactic block of statements, including each function. (10%) The program should be appropriate to the assignment, well-structured and easy to understand, without complicated and confusing flow of control. (80%) The results are correct, verifiable, and well-formatted. The program correctly performs as assigned. LAB DESCRIPTION You must write 2 versions of a program, calc_lvalues (and calc_intvalues), which require 3 command line parameters: high value of x, high value of y, filename for results. The programs are to be written partially in C and partially in x86-64 assembler and calculate the following equation: z = 5x2 + 63x2y2 + 3y2 for all values of x and y where –arg1 <= x <= arg1 and –arg2 <= y <= arg2 All (x,y,z) coordinate triples should be written to a file (arg3), in the format x y z, where x and y and y and z are separated by 1 space (One space only, Vasily!) and z is followed by a newline. THIS FORMAT IS SPECIFIC AND REQUIRED! calc_lvalues will be using an 8-byte unsigned value for z and 4-byte signed values for x and y while calc_intvalues will be using a 4-byte unsigned value for z and 4-byte signed values for x and y. Don’t start on calc_intvalues until you have calc_lvalues working! You should use the partial_calc_lvalues.c and AU20.mult.s files currently posted to Piazza as a starting point for your calc_lvalues program. The supplied program looks for 2 command line parameters (high value of x and high value of y) then passes them to mult(). The program, mult(), in AU20.mult.s, gives you the framework for a double nested loop, where -arg1<=x<=arg1 and - arg2<=y<=arg2, and (hopefully) enough comments so that you can understand what code goes where. if mult() were coded in C, it might look like: mult(int x, int y){ long m, n, z; for(m=-x; m <= x; m++){ for(n=-y; n<=y; n++){ /* calculate z = 5x2 + 63x2y2 + 3y2 and then Store x, y, and z in appropriate structure. */ } } return; } Change the name of the partial_calc_lvalues.c program to calc_lvalues.c (and later calc_intvalues.c), change the name of AU20.mult.s to multlong.s (and later multint.s). Any submissions with incorrect filenames will receive a 25-point deduction. malloc() a block of memory large enough to hold all the (x,y,z) coordinates you are about to create. Determining the correct size of this block of memory is part of the lab. Obviously, it changes based on the max values of x and y from the command line. The variable limit is declared to hold this value. Once you have malloc()’d enough space, you will then call a function, multlong(), with the following prototype declaration: void multlong(int a, int b, struct ThreeD_values * values); where a=high x value, b=high y value, values = address you got from malloc(). You can use one multiply instruction to calculate x2 , one multiply instruction to calculate y2 , and one multiply instruction to calculate x2y2 . Make sure you use the correct multiply instructions for the int values that results in an 8-byte results. All other calculations must be done with leaq, shifts, adds, etc. If there are more than 3 multiply instructions in your code, you will receive a 50-point reduction. The graders will execute a grep mul *.s instruction on your code. If more than 3 multiply instructions show up, -50. Make sure your logic doesn’t require more than one instruction. multlong() must populate each ThreeD_values structure element with the current values of x, y, and z while looping through all z calculations. Upon return to main() (located in calc_lvalues.c), main() will open the filename of the 3rd command line parameter and write the x,y,z values on consecutive lines delimited by one space between values. Make sure that you have the correct format string to print out signed and unsigned long values. An example output file for the command calc_lvalues 4 4 Results will posted on Piazza by 11/25. For the test case, you should run calc_lvalues with values for x and y of 50, 100, 200, and 250 each. Give each of the results a different file name so you can compare the plots. From a Linux prompt bring up the program gnuplot. At the gnuplot> prompt, type: splot “FileName”, where FileName is one of the files you created with calc_lvalues. The double quotes around the filename are required. Then, do the same with each of the other filesnames you created. Note in your README file whether the plots are consistent or change as the number of points increases. Once you have calc_lvalues working to your satisfaction, then copy calc_lvalues.c to calc_intvalues.c and multlong.s to multint.s. Edit calc_intvalues.c and change the ThreeD_values structure to: struct ThreeD_values{ unsigned int z; int y; int x; }; Other changes you will have to make in calc_intvalues.c are: 1) size of the area to malloc() changes, 2) must change multlong() call to multint() call, 3) must change format of the printf string to print out unsigned integers instead of signed/unsigned ints/longs. Changes you will have to make in multint() are: 1) many instruction suffixes will change because you are now working with 4 byte values, 2) Size of all registers with x, y, or z values in them must be converted to 4-byte registers, 3) the multiplication instructions must change, 4) address calculations when writing to dynamic memory have changed. You will have to modify your Makefile to create a calc_intvalues executable as well as calc_lvalues executable. HINT: 1st line of Makefile changes to all: lab7.zip calc_lvalues calc_intvalues I THINK that these are all the changes that must be made, you may find others that I have forgotten since I implemented this. For the test case, you should run calc_intvalues with values for x and y of 50, 100, 200, and 250 each. Give each of the results a different file name so you can compare the plots. From a Linux prompt bring up the program gnuplot. At the gnuplot> prompt, type: splot “FileName”, where FileName is one of the files you created with calc_intvalues. The double quotes around the filename are required. Then, do the same with each of the other filesnames you created. Note in your README file whether the plots are consistent or change as the number of points increases. Now you can answer the last question in the lab7Readme file. Are the graphs you plotted using unsigned long z values consistent with the graphs plotted using unsigned integer z values? If they are consistent, why do you think that is? If they are not consistent, why do you think that is? CONSTRAINTS: To pass parameters to functions, you must follow System V ABI conventions. You must also follow the System V ABI conventions related to caller and callee saved registers, caller cleanup, and returning values from procedures in register rax. REQUIREMENTS You may only use x86-64 constructs that we have discussed in class, you can find in the slides, or you can find in the sample x86-64 programs posted on Piazza. You may not store any values to the stack other than by using the push/pop instructions. Only values that can be put on the stack are for caller/callee saved register purpose. You must have all working values in registers – none stored on the stack. You must use correct stack frame procedures You must use all (needful) x86-64 directives You must use the correct suffix for all data types. You must use correct memory addressing modes You must use correct caller/callee saved register conventions. You must comment your code! Your Makefile, multlong.s and multint.s files submitted to Carmen as a part of this program must include the following at the top: #BY SUBMITTING THIS FILE TO CARMEN, I CERTIFY THAT I STRICTLY ADHERED TO THE #TENURES OF THE OHIO STATE UNIVERSITY’S ACADEMIC INTEGRITY POLICY. Your calc_lvalues.c and calc_intvalues.c files submitted to Carmen as a part of this program must include the following at the top: /* BY SUBMITTING THIS FILE TO CARMEN, I CERTIFY THAT I STRICTLY ADHERED TO THE TENURES OF THE OHIO STATE UNIVERSITY’S ACADEMIC INTEGRITY POLICY. */ LAB SUBMISSION You have submitted enough labs by this time that understanding how to do it should not need a detailed explanation. I highly recommend once you have created your .zip file to submit, that you create a test directory within your lab7 directory. Then copy your .zip file there. Go to the test directory, unzip your file and run make. If your make command generates any errors/warnings or doesn’t create the two needed executable files, then the .zip file you were planning to submit to Carmen is incorrect.