Programming a 64-bit processor, Computer Engineering

You are to write a C program called big_mult.c that multiplies two unsigned 64-bit integers, x and y, read from the command line. The output is a pair of unsigned 64-bit integers representing the most significant and least significant 64 bits of the full 128-bit product x * y. The inputs and outputs are to be given in hexadecimal format. Your C program will take care of reading the inputs and printing the output, but it will call a function mulq.s to do the actual multiplication. Your C program should use only unsigned long long int variables and should not do any arithmetic. To reduce the length of our type declarations, I put the following lines into hw3.h.
typedef unsigned long long int ulli;
typedef long long int lli;

This allows us to abbreviate unsigned long long int with the shorter name ulli and long long int with lli.

The function defined by mulq.s should have the following declaration in C before the function main.
void mulq(ulli x, ulli y, ulli *high, ulli *low);

The least significant 64 bits of the product are to be assigned to low, and the most significant 64 bits of the product are to be assigned to high. Remember to put an appropriate header comment into your assembly file (the ordinary C comment /* ... */ will work for assembly too). You will also need to read carefully the description of the mulq instruction in the Intel 64/IA32 instruction set reference manual, Intel 64/IA32 instruction set reference manual, or equivalent documentation. Learning to read this two-volume 800+ page document is part of your learning experience on this assignment.

One way to approach writing this assembly program is to write a similar program in C, compile it to assembly code using the -S option, and modify the resulting assembly code to do what you need. Your final assembly code should be very short and should contain only one multiplication instruction mulq.
The compile command to test your programs will look like this:
gcc64 -Wall -std=gnu99 -o big_mult big_mult.c mulq.s .

Here are 32- and 64-bit sample outputs to use in testing your programs.
C:>big_mult 2f432f43 629b03cb
2f432f43 x 629b03cb = 12345678 87654321

C:>big_mult 99d0c486a0fad481 76a185cea6f497c7
99d0c486a0fad481 x 76a185cea6f497c7 = 4747474747474747 4747474747474747
.
Remember that arguments are passed differently in the 64-bit architecture than in the 32-bit architecture. The registers used for parameter passing in Windows are different from those described in the textbook for Unix. Windows passes only the first four parameters in registers. The registers used by Unix are %rdi, %rsi, %rdx, %rcx, %r8, %r9 in that order. The registers used by Windows are %rcx, %rdx, %r8, %r9 . See Class10.pdf for details on register usage.

Posted Date: 4/3/2013 2:02:44 AM | Location : United States







Related Discussions:- Programming a 64-bit processor, Assignment Help, Ask Question on Programming a 64-bit processor, Get Answer, Expert's Help, Programming a 64-bit processor Discussions

Write discussion on Programming a 64-bit processor
Your posts are moderated
Related Questions
Can we define our own Match Code ID's for SAP Matchcodes? Yes, the number 0 to 9 are reserved for us to make our own Match Code Ids for a SAP described Matchcode object.

Problem: (a) IEEE802.11 supports two types of network architecture, describe these architectures with the support of diagrams detailing the network components. (b) The MAC

1. What factors should be considered when selecting a digital encoder (line codes)? Briefly mention five of those factors. Use sketches and additional text to describe the followin

An expert systems is software that contains a knowledge base of facts and relationships and has the ability to make inferences based on that knowledge base. An experts sys

Explain Public Switched Telephone Network. PSTN (Public Switched Telephone Network): This is Public Switched Telephone Network (PSTN), which accommodates two types of subscri

what is ecs?

Determine the block diagram of bcd adder To add 0110 to binary sum, we use a second 4-bit binary adder. The two decimal digits, together with input-carry, are first added in to

Q. Define Keyword and Identifiers? Keyword:   A keyword is a statement which defines nature of that statement. If statement is a directive then keyword would be the title of t

Write a decision table that specifies the rules for the game of checkers

Give the sequence of procedure calls for both server and client for connect ion-oriented application.   In connection oriented communication the order of Procedure call