1bit_alu1.zip_1 bit

#include <stdio.h> int result[3]; int cout; void input(int *, int*); void inputsignal(int*); int and(int, int); int or(int, int); int add(int, int, int); int alu_1bit(int, int, int); int over(int, int, int); int main() { int a, b; int binvert = 0; int bitofa, bitofb; int cin = 0; int i; int mask = 1; int outcome = 0; int signal; int overflow; while(1){ input(&a,&b); inputsignal(&signal); if(signal == 10) break; if(signal == 6){ cin = 1; binvert = 1; signal = 2; } for(i = 0; i < 32; ++i){ bitofa = (a >> i) & mask; bitofb = (b >> i) & mask; if(binvert == 1) bit_b = !bit_b; if(i == 31) overflow = over(bitofa, bitofb, cin); else cin = alu_1bit(bit_a, bit_b, cin); outcome |= result[signal] << i; } printf("outcome = %d\n overflow detection = %d\n zero signal = %d\n", outcome, overflow, !(zero(outcome))); { return 0; } void input(int *a, int *b){ printf("# Input two number : \n"); scanf("%d %d", a, b); } void inputsignal(int *signal){ printf("# Input control signal : (0 -> and, 1-> or, 2-> add, 10->exit)\n"); scanf("%d", signal); } int and(int bitofa, int bitofb){ return (bitofa & bitofb); } int or(int bitofa, int bitofb){ return (bitofa | bitofb); } int add(int bitofa, int bitofb, int cin){ cout = ((bitofa * bitofb) + cin * (bitofa ^ bitofb)); return ((bitofa ^ bitofb) ^ cin); } int alu_1bit(int bit_a, int bit_b, int cin){ result[0] = and(bit_a, bit_b); result[1] = or(bit_a, bit_b); result[2] = add(bit_a, bit_b, cin); return cout; } int over(int bit_a, int bit_b, int cin){ result[0] = and(bit_a, bit_b); result[1] = or(bit_a, bit_b); result[2] = add(bit_a, bit_b, cin); return cout^cin; } int zero(int outcome){ int zero = 0, mask = 1, i; for(i = 0; i < 32; i++) zero |= (outcome >> i) & mask; return zero; } /* int overflowcheck( int a, int b ){ return (( (a & b & ~(a+b)) | (~a & ~b & (a+b)) ) < 0) ; } */