Optimize DateTime decomposition in CoreLib by ts2do · Pull Request #1944 · dotnet/runtime (original) (raw)
Add uses of DateTime.GetDate (renamed from GetDatePart) where appropriate.
Add internal DateTime.GetTime method to eliminate duplicate computations.
Note that the change to TimeZoneInfo.TransitionTimeToDateTime, which adds TimeOfDay directly in ticks precision, can't break anything because the TransitionTime constructor ensures that TimeOfDay doesn't have sub-millisecond time.
Here are the relevant microbenchmarks in dotnet/performance, of which the rows with the bold text being the build with the changes:
System.Tests.Perf_DateTime
| Method | format | Mean | Error | StdDev | Median | Min | Max | Ratio | Gen 0 | Gen 1 | Gen 2 | Allocated |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ToString | ? | 292.30 ns | 3.399 ns | 2.838 ns | 292.33 ns | 286.58 ns | 296.96 ns | 0.99 | 0.0144 | - | - | 64 B |
| ToString | ? | 295.86 ns | 2.520 ns | 2.104 ns | 296.08 ns | 291.85 ns | 300.16 ns | 1.00 | 0.0143 | - | - | 64 B |
| ToString | G | 293.25 ns | 3.067 ns | 2.869 ns | 293.66 ns | 288.34 ns | 297.03 ns | 0.99 | 0.0143 | - | - | 64 B |
| ToString | G | 295.89 ns | 3.830 ns | 3.583 ns | 295.99 ns | 289.15 ns | 303.13 ns | 1.00 | 0.0143 | - | - | 64 B |
| ToString | o | 66.41 ns | 0.943 ns | 0.882 ns | 66.37 ns | 64.78 ns | 67.96 ns | 0.72 | 0.0190 | - | - | 80 B |
| ToString | o | 92.34 ns | 0.826 ns | 0.773 ns | 92.28 ns | 91.13 ns | 93.41 ns | 1.00 | 0.0191 | - | - | 80 B |
| ToString | r | 52.63 ns | 0.433 ns | 0.384 ns | 52.64 ns | 51.90 ns | 53.41 ns | 0.92 | 0.0190 | - | - | 80 B |
| ToString | r | 57.13 ns | 0.514 ns | 0.481 ns | 56.93 ns | 56.59 ns | 58.31 ns | 1.00 | Base | 0.0189 | - | - |
| ToString | s | 289.34 ns | 3.105 ns | 2.904 ns | 289.99 ns | 283.88 ns | 292.82 ns | 1.02 | 0.0150 | - | - | 64 B |
| ToString | s | 284.92 ns | 1.898 ns | 1.683 ns | 285.08 ns | 281.30 ns | 287.85 ns | 1.00 | 0.0151 | - | - | 64 B |
System.Tests.Perf_DateTimeOffset
| Method | format | value | Mean | Error | StdDev | Median | Min | Max | Ratio | Gen 0 | Gen 1 | Gen 2 | Allocated |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ToString | ? | ? | 666.74 ns | 6.687 ns | 6.255 ns | 664.85 ns | 658.04 ns | 681.22 ns | 1.01 | 0.0296 | - | - | 128 B |
| ToString | ? | ? | 662.49 ns | 5.139 ns | 4.555 ns | 663.86 ns | 653.89 ns | 670.28 ns | 1.00 | 0.0294 | - | - | 128 B |
| ToString | ? | 12/30/2017 3:45:22 AM -08:00 | 658.87 ns | 5.386 ns | 5.038 ns | 658.13 ns | 651.09 ns | 670.00 ns | 0.98 | 0.0286 | - | - | 128 B |
| ToString | ? | 12/30/2017 3:45:22 AM -08:00 | 671.86 ns | 5.994 ns | 5.607 ns | 673.26 ns | 663.39 ns | 683.24 ns | 1.00 | 0.0294 | - | - | 128 B |
| ToString | G | ? | 308.34 ns | 4.298 ns | 3.810 ns | 308.64 ns | 300.68 ns | 315.02 ns | 1.01 | 0.0148 | - | - | 64 B |
| ToString | G | ? | 304.10 ns | 2.380 ns | 2.226 ns | 304.11 ns | 300.51 ns | 307.61 ns | 1.00 | 0.0150 | - | - | 64 B |
| ToString | o | ? | 76.22 ns | 0.368 ns | 0.308 ns | 76.17 ns | 75.78 ns | 76.92 ns | 0.69 | 0.0209 | - | - | 88 B |
| ToString | o | ? | 110.96 ns | 1.202 ns | 1.066 ns | 110.72 ns | 109.07 ns | 113.46 ns | 1.00 | 0.0206 | - | - | 88 B |
| ToString | r | ? | 63.59 ns | 0.742 ns | 0.620 ns | 63.76 ns | 62.62 ns | 64.42 ns | 0.97 | 0.0190 | - | - | 80 B |
| ToString | r | ? | 65.52 ns | 0.940 ns | 0.880 ns | 65.33 ns | 63.77 ns | 67.45 ns | 1.00 | 0.0190 | - | - | 80 B |
| ToString | s | ? | 304.85 ns | 3.213 ns | 3.006 ns | 305.61 ns | 298.44 ns | 309.04 ns | 1.00 | 0.0147 | - | - | 64 B |
| ToString | s | ? | 305.75 ns | 3.682 ns | 3.444 ns | 304.98 ns | 300.63 ns | 310.69 ns | 1.00 | 0.0148 | - | - | 64 B |
System.Buffers.Text.Tests.Utf8FormatterTests.FormatterDateTimeOffsetNow
| Method | Mean | Error | StdDev | Median | Min | Max | Ratio | Gen 0 | Gen 1 | Gen 2 | Allocated |
|---|---|---|---|---|---|---|---|---|---|---|---|
| FormatterDateTimeOffsetNow | 44.22 ns | 0.473 ns | 0.442 ns | 44.35 ns | 43.59 ns | 45.01 ns | 0.62 | - | - | - | - |
| FormatterDateTimeOffsetNow | 71.83 ns | 0.662 ns | 0.587 ns | 71.79 ns | 71.00 ns | 73.06 ns | 1.00 | - | - | - | - |
System.Text.Json.Tests.Perf_DateTimes
| Method | Formatted | SkipValidation | Mean | Error | StdDev | Median | Min | Max | Ratio | Gen0 | Gen1 | Gen2 | Allocated |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| WriteDateTimes | False | False | 6.700 ms | 0.0729 ms | 0.0647 ms | 6.700 ms | 6.584 ms | 6.801 ms | 0.72 | - | - | - | 140 B |
| WriteDateTimes | False | False | 9.313 ms | 0.1085 ms | 0.0962 ms | 9.310 ms | 9.159 ms | 9.498 ms | 1.00 | - | - | - | 120 B |
| WriteDateTimes | False | True | 6.513 ms | 0.0543 ms | 0.0453 ms | 6.529 ms | 6.428 ms | 6.578 ms | 0.71 | - | - | - | 120 B |
| WriteDateTimes | False | True | 9.149 ms | 0.0635 ms | 0.0563 ms | 9.149 ms | 9.025 ms | 9.231 ms | 1.00 | - | - | - | 120 B |
| WriteDateTimes | True | False | 7.284 ms | 0.0855 ms | 0.0758 ms | 7.270 ms | 7.145 ms | 7.394 ms | 0.73 | - | - | - | 120 B |
| WriteDateTimes | True | False | 9.926 ms | 0.1158 ms | 0.1083 ms | 9.918 ms | 9.735 ms | 10.091 ms | 1.00 | - | - | - | 120 B |
| WriteDateTimes | True | True | 7.343 ms | 0.0763 ms | 0.0714 ms | 7.328 ms | 7.250 ms | 7.479 ms | 0.73 | - | - | - | 141 B |
| WriteDateTimes | True | True | 10.120 ms | 0.1492 ms | 0.1323 ms | 10.077 ms | 9.938 ms | 10.373 ms | 1.00 | - | - | - | 120 B |