1 /* @(#)frexp.c 4.1 (Berkeley) 12/21/80 */ 2 /* 3 the call 4 x = frexp(arg,&exp); 5 must return a double fp quantity x which is <1.0 6 and the corresponding binary exponent "exp". 7 such that 8 arg = x*2^exp 9 */ 10 11 double 12 frexp(x,i) 13 double x; 14 int *i; 15 { 16 int neg; 17 int j; 18 j = 0; 19 neg = 0; 20 if(x<0){ 21 x = -x; 22 neg = 1; 23 } 24 if(x>1.0) 25 while(x>1){ 26 j = j+1; 27 x = x/2; 28 } 29 else if(x<0.5) 30 while(x<0.5){ 31 j = j-1; 32 x = 2*x; 33 } 34 *i = j; 35 if(neg) x = -x; 36 return(x); 37 } 38