diff options
Diffstat (limited to 'libc/tzcode/difftime.c')
| -rw-r--r-- | libc/tzcode/difftime.c | 96 |
1 files changed, 48 insertions, 48 deletions
diff --git a/libc/tzcode/difftime.c b/libc/tzcode/difftime.c index da77977..f7581a4 100644 --- a/libc/tzcode/difftime.c +++ b/libc/tzcode/difftime.c @@ -5,61 +5,61 @@ #ifndef lint #ifndef NOID -static char elsieid[] = "@(#)difftime.c 8.1"; +static char elsieid[] = "@(#)difftime.c 8.1"; #endif /* !defined NOID */ #endif /* !defined lint */ /*LINTLIBRARY*/ -#include "private.h" /* for time_t, TYPE_INTEGRAL, and TYPE_SIGNED */ +#include "private.h" /* for time_t, TYPE_INTEGRAL, and TYPE_SIGNED */ double difftime(time1, time0) -const time_t time1; -const time_t time0; +const time_t time1; +const time_t time0; { - /* - ** If (sizeof (double) > sizeof (time_t)) simply convert and subtract - ** (assuming that the larger type has more precision). - ** This is the common real-world case circa 2004. - */ - if (sizeof (double) > sizeof (time_t)) - return (double) time1 - (double) time0; - if (!TYPE_INTEGRAL(time_t)) { - /* - ** time_t is floating. - */ - return time1 - time0; - } - if (!TYPE_SIGNED(time_t)) { - /* - ** time_t is integral and unsigned. - ** The difference of two unsigned values can't overflow - ** if the minuend is greater than or equal to the subtrahend. - */ - if (time1 >= time0) - return time1 - time0; - else return -((double) (time0 - time1)); - } - /* - ** time_t is integral and signed. - ** Handle cases where both time1 and time0 have the same sign - ** (meaning that their difference cannot overflow). - */ - if ((time1 < 0) == (time0 < 0)) - return time1 - time0; - /* - ** time1 and time0 have opposite signs. - ** Punt if unsigned long is too narrow. - */ - if (sizeof (unsigned long) < sizeof (time_t)) - return (double) time1 - (double) time0; - /* - ** Stay calm...decent optimizers will eliminate the complexity below. - */ - if (time1 >= 0 /* && time0 < 0 */) - return (unsigned long) time1 + - (unsigned long) (-(time0 + 1)) + 1; - return -(double) ((unsigned long) time0 + - (unsigned long) (-(time1 + 1)) + 1); + /* + ** If (sizeof (double) > sizeof (time_t)) simply convert and subtract + ** (assuming that the larger type has more precision). + ** This is the common real-world case circa 2004. + */ + if (sizeof (double) > sizeof (time_t)) + return (double) time1 - (double) time0; + if (!TYPE_INTEGRAL(time_t)) { + /* + ** time_t is floating. + */ + return time1 - time0; + } + if (!TYPE_SIGNED(time_t)) { + /* + ** time_t is integral and unsigned. + ** The difference of two unsigned values can't overflow + ** if the minuend is greater than or equal to the subtrahend. + */ + if (time1 >= time0) + return time1 - time0; + else return -((double) (time0 - time1)); + } + /* + ** time_t is integral and signed. + ** Handle cases where both time1 and time0 have the same sign + ** (meaning that their difference cannot overflow). + */ + if ((time1 < 0) == (time0 < 0)) + return time1 - time0; + /* + ** time1 and time0 have opposite signs. + ** Punt if unsigned long is too narrow. + */ + if (sizeof (unsigned long) < sizeof (time_t)) + return (double) time1 - (double) time0; + /* + ** Stay calm...decent optimizers will eliminate the complexity below. + */ + if (time1 >= 0 /* && time0 < 0 */) + return (unsigned long) time1 + + (unsigned long) (-(time0 + 1)) + 1; + return -(double) ((unsigned long) time0 + + (unsigned long) (-(time1 + 1)) + 1); } |