Write a subroutine in an assembly language program which divides an array of 20 elements into two halves. It rotates left the first half and rotates right the second half 5 times.

Question

Write a subroutine in an assembly language program which divides an array of 20 elements into two halves. It rotates left the first half and rotates right the second half 5 times.

Answer 1

I'm sorry I do not have any assembler, and even if I did, it would probably not match

the assembler you have, as there are so many dialects. The best I can offer you is C (mid-level);

The C compiler, by setting some command line or compiler switches, can generate assembler code for you automatically, though it may not match your dialect. It is quite a challenge to write this in C, let alone assembler.

The source code is uploaded in the resources section under this link if you want it.

//******************************************************************************************//

#include <string.h>

#include <stdlib.h>

#include <stdio.h>

ArrayRotateLeft(void * base,int numRecs, int recSize)

{

int iLoop;

char * A = (char*)base; //points at the first

char * last = A+(numRecs-1)*recSize; //points at the last

char * temp = (char*) malloc(recSize); //temp storage

//stores the first in temporary memory location

memcpy(temp,base,recSize);

//moves every element one position to the left

for (iLoop=0; iLoop<numRecs-1; iLoop++)

{

memcpy(A+iLoop*recSize,A+(iLoop+1)*recSize,recSize);

}

//copies what was the first, stored in temp, into the last position

memcpy(last,temp,recSize);

free(temp);

}

ArrayRotateRight(void * base, int numRecs, int recSize)

{

int iLoop;

char * A = (char*)base; //points at the first

char * last = A+(numRecs-1)*recSize; //points at the last

char * temp = (char*) malloc(recSize); //temp storage

//stores the LAST in temporary memory location

memcpy(temp,last,recSize);

//moves every element one position to the right

for (iLoop=numRecs-1; iLoop>0; iLoop--)

{

memcpy(A+iLoop*recSize,A+(iLoop-1)*recSize,recSize);

}

//copies what was the last, stored in temp, into the first position

memcpy(A,temp,recSize);

free(temp);

}

int main()

{

int iLoop;

int intNums[]={15,20,5,10,3,8,1,6,2,7,

4,9,11,13,19,16,18,17,14,12};

double amounts[] = {3.142, 2.723, 7.50, 7.53, 7.05, 35.42, 42.35, 9.88, 7.24, 6.25,

33.33, 3.33, 1.23, 3.45, 4.32, 5.34, 4.55, 1.11, 2.31, 2.89 };

char strs[20][10];

strcpy(strs[0],"alpha ");

strcpy(strs[1],"beta ");

strcpy(strs[2],"delta ");

strcpy(strs[3],"epsilon ");

strcpy(strs[4],"gamma ");

strcpy(strs[5],"iota ");

strcpy(strs[6],"kappa ");

strcpy(strs[7],"lambda ");

strcpy(strs[8],"mu ");

strcpy(strs[9],"nu ");

strcpy(strs[10],"omicron ");

strcpy(strs[11],"phi ");

strcpy(strs[12],"pi ");

strcpy(strs[13],"rho ");

strcpy(strs[14],"sigma ");

strcpy(strs[15],"thi ");

strcpy(strs[16],"upsilon ");

strcpy(strs[17],"omega ");

strcpy(strs[18],"zeta ");

strcpy(strs[19],"theta ");

for (iLoop=0; iLoop<5; iLoop++)

{

ArrayRotateLeft(intNums,10,sizeof(int));

ArrayRotateRight(&intNums[10],10,sizeof(int));

}

for (iLoop=0; iLoop<5; iLoop++)

{

ArrayRotateLeft(amounts,10,sizeof(double));

ArrayRotateRight(&amounts[10],10,sizeof(double));

}

for (iLoop=0; iLoop<5; iLoop++)

{

ArrayRotateLeft(strs,10,10);

ArrayRotateRight(&strs[10],10,10);

}

for (iLoop=0; iLoop<20; iLoop++) { printf("%d \n",intNums[iLoop]); }

for ( iLoop=0; iLoop<20; iLoop++) { printf("%lf \n",amounts[iLoop]); }

for ( iLoop=0; iLoop<20; iLoop++) { printf("%s \n",strs[iLoop]); }

}