Page 275 - ARM 64 Bit Assembly Language

264 Chapter 8

6 #include <stdlib.h>
7 #include <stdio.h>
8 #include <string.h>
9
10 #define MAX_DECIMAL_DIGITS 16
11 /* Multiply an unpacked BCD number by 2. Return 1 if there is a
12 carry out of the most significant digit, or 0 otherwise. The
13 resulting number is returned in n1.
14 */
15 int base10double(char n1[MAX_DECIMAL_DIGITS])
16 {
17 int i, tmp, carry=0;
18 for(i=0;i<MAX_DECIMAL_DIGITS;i++)
19 {
20 n1[i] += (n1[i] + carry);
21 if(n1[i] > 9)
22 {
23 n1[i] -= 10;
24 carry = 1;
25 }
26 else
27 carry=0;
28 }
29 return carry;
30 }
31
32 /* Convert a string into a signed fixed-point binary
33 representation with up to 32 bits of fractional part.
34 */
35 int strtoSfixed(char *s, int frac_bits)
36 {
37 char *point = s;
38 unsigned int value;
39 int i,negative=0;
40 char digits[MAX_DECIMAL_DIGITS];
41 /* get the integer portion*/
42 if(*s==’-’)
43 {
44 negative=1;
45 s++;
46 }
47 value = atoi(s);
48 /* find the decimal point */
49 while((*point != ’.’)&&(*point != 0))
50 point++;
51 /* if there is nothing after the decimal point, or there is
52 not a decimal point, then shift and return what we already
53 have */
54 if(( *point ==0)||(*(point+1) == 0 ))