* libc/time/mktm_r.c (_mktm_r): Optimize speed.
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@ -1,3 +1,7 @@
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2014-09-04 Freddie Chopin <freddie_chopin@op.pl>
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* libc/time/mktm_r.c (_mktm_r): Optimize speed.
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2014-09-04 Freddie Chopin <freddie_chopin@op.pl>
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* libc/time/clock.c (clock): Fix warnings about signed-unsigned
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@ -14,14 +14,23 @@
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#include <time.h>
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#include "local.h"
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/* there are 97 leap years in 400-year periods */
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#define DAYS_PER_400_YEARS ((400 - 97) * 365 + 97 * 366)
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/* there are 24 leap years in 100-year periods */
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#define DAYS_PER_100_YEARS ((100 - 24) * 365 + 24 * 366)
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/* there is one leap year every 4 years */
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#define DAYS_PER_4_YEARS (3 * 365 + 366)
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static _CONST int mon_lengths[2][MONSPERYEAR] = {
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{31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31},
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{31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}
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} ;
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static _CONST int year_lengths[2] = {
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365,
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366
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static _CONST int days_per_year[4] = {
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365, /* 1970 or 1966 */
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365, /* 1971 or 1967 */
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366, /* 1972 or 1968 */
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365 /* 1973 or 1969 */
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} ;
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struct tm *
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@ -33,6 +42,7 @@ _DEFUN (_mktm_r, (tim_p, res, is_gmtime),
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long days, rem;
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time_t lcltime;
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int y;
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int years400, years100, years4;
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int yleap;
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_CONST int *ip;
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__tzinfo_type *tz = __gettzinfo ();
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@ -64,30 +74,38 @@ _DEFUN (_mktm_r, (tim_p, res, is_gmtime),
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res->tm_wday += DAYSPERWEEK;
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/* compute year & day of year */
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y = EPOCH_YEAR;
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if (days >= 0)
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years400 = days / DAYS_PER_400_YEARS;
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days -= years400 * DAYS_PER_400_YEARS;
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years100 = days / DAYS_PER_100_YEARS;
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days -= years100 * DAYS_PER_100_YEARS;
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years4 = days / DAYS_PER_4_YEARS;
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days -= years4 * DAYS_PER_4_YEARS;
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y = EPOCH_YEAR + years400 * 400 + years100 * 100 + years4 * 4;
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/* the value left in days is based in 1970 */
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if (days < 0)
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{
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for (;;)
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ip = &days_per_year[3];
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while (days < 0)
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{
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yleap = isleap(y);
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if (days < year_lengths[yleap])
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break;
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y++;
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days -= year_lengths[yleap];
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days += *ip--;
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--y;
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}
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}
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else
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{
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do
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ip = &days_per_year[0];
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while (days >= *ip)
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{
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--y;
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yleap = isleap(y);
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days += year_lengths[yleap];
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} while (days < 0);
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days -= *ip++;
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++y;
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}
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}
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res->tm_year = y - YEAR_BASE;
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res->tm_yday = days;
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yleap = isleap(y);
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ip = mon_lengths[yleap];
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for (res->tm_mon = 0; days >= ip[res->tm_mon]; ++res->tm_mon)
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days -= ip[res->tm_mon];
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