diff options
Diffstat (limited to 'lib_generic/vsprintf.c')
| -rw-r--r-- | lib_generic/vsprintf.c | 16 |
1 files changed, 9 insertions, 7 deletions
diff --git a/lib_generic/vsprintf.c b/lib_generic/vsprintf.c index 3ab1f5cb0..7f534c785 100644 --- a/lib_generic/vsprintf.c +++ b/lib_generic/vsprintf.c @@ -200,13 +200,15 @@ static char* put_dec_full(char *buf, unsigned q) d2 = (q>>8) & 0xf; d3 = (q>>12); - /* Possible ways to approx. divide by 10 */ - /* gcc -O2 replaces multiply with shifts and adds */ - // (x * 0xcd) >> 11: 11001101 - shorter code than * 0x67 (on i386) - // (x * 0x67) >> 10: 1100111 - // (x * 0x34) >> 9: 110100 - same - // (x * 0x1a) >> 8: 11010 - same - // (x * 0x0d) >> 7: 1101 - same, shortest code (on i386) + /* + * Possible ways to approx. divide by 10 + * gcc -O2 replaces multiply with shifts and adds + * (x * 0xcd) >> 11: 11001101 - shorter code than * 0x67 (on i386) + * (x * 0x67) >> 10: 1100111 + * (x * 0x34) >> 9: 110100 - same + * (x * 0x1a) >> 8: 11010 - same + * (x * 0x0d) >> 7: 1101 - same, shortest code (on i386) + */ d0 = 6*(d3 + d2 + d1) + (q & 0xf); q = (d0 * 0xcd) >> 11; |