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author | Paul Eggert <eggert@cs.ucla.edu> | 2019-12-23 23:47:37 -0800 |
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committer | Paul Eggert <eggert@cs.ucla.edu> | 2019-12-23 23:55:12 -0800 |
commit | 6bd09257a491e635aa7e42d15935747818e492f2 (patch) | |
tree | 541b4125bed94c9ac608c5b5ce93000812e37a2c /lib/mktime.c | |
parent | 6ad341ee4a0cca1a8b1744bc269282aafd765868 (diff) | |
download | gnulib-6bd09257a491e635aa7e42d15935747818e492f2.tar.gz |
mktime: tweak division performance
* config/srclist.txt: Do not sync mktime.c for now.
* lib/mktime.c (shr, ydhms_diff):
Redo with neither ‘%’ nor conditional branches.
Diffstat (limited to 'lib/mktime.c')
-rw-r--r-- | lib/mktime.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/lib/mktime.c b/lib/mktime.c index 11b0d5353b..81c9ca1fcb 100644 --- a/lib/mktime.c +++ b/lib/mktime.c @@ -141,7 +141,7 @@ shr (long_int a, int b) long_int one = 1; return (-one >> 1 == -1 ? a >> b - : a / (one << b) - (a % (one << b) < 0)); + : (a + (a < 0)) / (one << b) - (a < 0)); } /* Bounds for the intersection of __time64_t and long_int. */ @@ -211,8 +211,8 @@ ydhms_diff (long_int year1, long_int yday1, int hour1, int min1, int sec1, Take care to avoid integer overflow here. */ int a4 = shr (year1, 2) + shr (TM_YEAR_BASE, 2) - ! (year1 & 3); int b4 = shr (year0, 2) + shr (TM_YEAR_BASE, 2) - ! (year0 & 3); - int a100 = a4 / 25 - (a4 % 25 < 0); - int b100 = b4 / 25 - (b4 % 25 < 0); + int a100 = (a4 + (a4 < 0)) / 25 - (a4 < 0); + int b100 = (b4 + (b4 < 0)) / 25 - (b4 < 0); int a400 = shr (a100, 2); int b400 = shr (b100, 2); int intervening_leap_days = (a4 - b4) - (a100 - b100) + (a400 - b400); |