Remove num-integer dependency

[pitdicker]

Some more uses for div_euclid and rem_euclid. These were basically the only reason for the num-integer dependency, which is now no longer necessary.

I have run the benchmarks numerous times, and also tried creating optimized combined div_rem_euclid-functions. LLVM should be able to combine the div and rem into a single instruction . But the difference seems to be nothing but noise.

     Running benches/chrono.rs (target/release/deps/chrono-d6d355f24635cdec)
bench_datetime_parse_from_rfc2822
                        time:   [195.32 ns 196.89 ns 198.69 ns]
                        change: [-0.8068% +0.2830% +1.4734%] (p = 0.64 > 0.05)
                        No change in performance detected.
Found 1 outliers among 100 measurements (1.00%)
  1 (1.00%) high mild

bench_datetime_parse_from_rfc3339
                        time:   [168.97 ns 169.93 ns 170.86 ns]
                        change: [-7.2979% -6.5254% -5.7402%] (p = 0.00 < 0.05)
                        Performance has improved.
Found 6 outliers among 100 measurements (6.00%)
  6 (6.00%) high mild

bench_datetime_from_str time:   [279.07 ns 280.92 ns 283.04 ns]
                        change: [-2.6836% -1.7437% -0.8206%] (p = 0.00 < 0.05)
                        Change within noise threshold.

bench_datetime_to_rfc2822
                        time:   [97.445 ns 97.840 ns 98.286 ns]
                        change: [-6.4046% -5.6356% -4.8322%] (p = 0.00 < 0.05)
                        Performance has improved.
Found 8 outliers among 100 measurements (8.00%)
  3 (3.00%) high mild
  5 (5.00%) high severe

bench_datetime_to_rfc3339
                        time:   [174.69 ns 176.00 ns 177.14 ns]
                        change: [-1.6935% -0.8501% -0.0899%] (p = 0.04 < 0.05)
                        Change within noise threshold.
Found 5 outliers among 100 measurements (5.00%)
  3 (3.00%) low mild
  2 (2.00%) high mild

bench_year_flags_from_year
                        time:   [0.0000 ps 0.0000 ps 0.0000 ps]
                        change: [-29.311% +28.074% +138.77%] (p = 0.47 > 0.05)
                        No change in performance detected.
Found 12 outliers among 100 measurements (12.00%)
  3 (3.00%) high mild
  9 (9.00%) high severe

num_days_from_ce/new/1  time:   [5.2447 ns 5.2753 ns 5.3099 ns]
                        change: [-1.7032% -1.0711% -0.3952%] (p = 0.00 < 0.05)
                        Change within noise threshold.
Found 3 outliers among 100 measurements (3.00%)
  2 (2.00%) high mild
  1 (1.00%) high severe
num_days_from_ce/classic/1
                        time:   [1.6623 ns 1.6662 ns 1.6704 ns]
                        change: [-3.3013% -2.6817% -2.0427%] (p = 0.00 < 0.05)
                        Performance has improved.
Found 6 outliers among 100 measurements (6.00%)
  1 (1.00%) high mild
  5 (5.00%) high severe
num_days_from_ce/new/500
                        time:   [5.4324 ns 5.4602 ns 5.4864 ns]
                        change: [+0.6683% +1.2929% +1.9432%] (p = 0.00 < 0.05)
                        Change within noise threshold.
Found 1 outliers among 100 measurements (1.00%)
  1 (1.00%) high mild
num_days_from_ce/classic/500
                        time:   [1.7459 ns 1.7574 ns 1.7708 ns]
                        change: [+3.3119% +4.2201% +5.0321%] (p = 0.00 < 0.05)
                        Performance has regressed.
Found 1 outliers among 100 measurements (1.00%)
  1 (1.00%) high mild
num_days_from_ce/new/2000
                        time:   [5.4078 ns 5.4249 ns 5.4425 ns]
                        change: [-0.2753% +0.5890% +1.4985%] (p = 0.19 > 0.05)
                        No change in performance detected.
Found 7 outliers among 100 measurements (7.00%)
  5 (5.00%) high mild
  2 (2.00%) high severe
num_days_from_ce/classic/2000
                        time:   [1.7171 ns 1.7235 ns 1.7304 ns]
                        change: [+0.6090% +1.1668% +1.7379%] (p = 0.00 < 0.05)
                        Change within noise threshold.
Found 4 outliers among 100 measurements (4.00%)
  3 (3.00%) high mild
  1 (1.00%) high severe
num_days_from_ce/new/2019
                        time:   [5.3835 ns 5.4044 ns 5.4270 ns]
                        change: [-3.5537% -2.5228% -1.5619%] (p = 0.00 < 0.05)
                        Performance has improved.
Found 6 outliers among 100 measurements (6.00%)
  2 (2.00%) low mild
  3 (3.00%) high mild
  1 (1.00%) high severe
num_days_from_ce/classic/2019
                        time:   [1.7406 ns 1.7523 ns 1.7641 ns]
                        change: [-2.7985% -1.8732% -0.9854%] (p = 0.00 < 0.05)
                        Change within noise threshold.
Found 4 outliers among 100 measurements (4.00%)
  4 (4.00%) high mild

bench_get_local_time    time:   [107.79 ns 108.27 ns 108.78 ns]
                        change: [+5.1082% +5.8630% +6.5985%] (p = 0.00 < 0.05)
                        Performance has regressed.
Found 3 outliers among 100 measurements (3.00%)
  3 (3.00%) high mild

[jtmoon79]

AFAICT this will conflict with merged PR #1004

[pitdicker]

Good call, I haven't look enough at the 0.5 branch.

[jtmoon79]

Good call, I haven't look enough at the 0.5 branch.

IMHO any new work should go toward that branch. More work in 0.4 branch means a more difficult transition. Relates to #970 (comment)

[djc]

IMHO any new work should go toward that branch. More work in 0.4 branch means a more difficult transition.

No! Any work that doesn't break API compatibility should go on 0.4.x so we can get it to users sooner.

[pitdicker]

After reading the issues it seems like 0.5 would require quite some design and work to do first!
I am fine with targeting the 0.4.x branch, and helping to merge it with main if that helps.

[djc]

Awesome, thanks!

[djc]

Style nit: small functions like this should go near the bottom of the module, not near the top.

[pitdicker]

That makes sense, I have moved to it just before the tests and serialization modules.