[resubmit] BigInteger parsing optimization for large decimal string by key-moon · Pull Request #55121 · dotnet/runtime

key-moon · 2021-07-03T08:53:12Z

I accidentally deleted the forked repository, so I will resubmit the PR #51953 . Please refer to the previous discussion there. I apologize for the inconvenience.

Current BigNumer.NumberToBigInteger method is implemented using naive algorithm. It runs in Θ(N^2) time where N is number of digits. I implemented faster method known as divide-and-conquer algorithm. It runs Θ(N (log(N))^2). Since this algorithms running time has large constant factor, naive method is faster when N is small. So This method is only apply when N is large enough. (specifically, use divide-and-conquer method when N is more than 20000.)

I created branch from #47842 as it looks like #47842 will be merged shortly.

benchmark result

Previous method

BenchmarkDotNet=v0.12.1.1528-nightly, OS=Windows 10.0.19042.928 (20H2/October2020Update)
Intel Core i7-7500U CPU 2.70GHz (Kaby Lake), 1 CPU, 4 logical and 2 physical cores
.NET SDK=6.0.100-preview.3.21202.5
[Host] : .NET 6.0.0 (6.0.21.20104), X64 RyuJIT
Job-CHCQPG : .NET 6.0.0 (42.42.42.42424), X64 RyuJIT
PowerPlanMode=00000000-0000-0000-0000-000000000000 Arguments=/p:DebugType=portable Toolchain=CoreRun IterationTime=250.0000 ms MaxIterationCount=20 MinIterationCount=15 WarmupCount=1

Method	numberString	Mean	Error	StdDev	Median	Min	Max	Gen 0	Gen 1	Gen 2	Allocated
Parse	12345678901(...)01234567890 [20000]	2.611 ms	0.1786 ms	0.2057 ms	2.661 ms	2.208 ms	2.996 ms	26.7857	-	-	56 KB
Parse	12345678901(...)01234567890 [40000]	9.028 ms	0.7436 ms	0.8265 ms	8.816 ms	8.072 ms	10.909 ms	31.2500	-	-	96 KB
Parse	12345678901(...)01234567890 [60000]	18.521 ms	0.5179 ms	0.5756 ms	18.552 ms	17.349 ms	19.541 ms	71.4286	-	-	151 KB
Parse	12345678901(...)01234567890 [80000]	32.904 ms	1.1486 ms	1.2290 ms	32.761 ms	30.984 ms	34.686 ms	-	-	-	191 KB
Parse	12345678901(...)01234567890 [100000]	51.271 ms	1.7700 ms	2.0384 ms	51.186 ms	48.447 ms	54.856 ms	-	-	-	246 KB
Parse	12345678901(...)01234567890 [120000]	74.285 ms	3.6392 ms	3.8939 ms	73.489 ms	68.604 ms	82.719 ms	-	-	-	286 KB
Parse	12345678901(...)01234567890 [140000]	100.248 ms	5.2825 ms	5.8715 ms	98.712 ms	92.597 ms	113.046 ms	-	-	-	341 KB
Parse	12345678901(...)01234567890 [160000]	127.443 ms	4.8226 ms	5.5537 ms	125.749 ms	120.504 ms	138.583 ms	-	-	-	381 KB
Parse	12345678901(...)01234567890 [180000]	162.028 ms	4.9852 ms	5.7409 ms	162.142 ms	151.841 ms	171.640 ms	-	-	-	436 KB
Parse	12345678901(...)01234567890 [200000]	224.511 ms	16.7864 ms	19.3313 ms	224.392 ms	192.558 ms	255.098 ms	-	-	-	476 KB
Parse	12345678901(...)01234567890 [220000]	240.451 ms	10.9087 ms	12.1250 ms	234.971 ms	226.956 ms	265.072 ms	-	-	-	531 KB
Parse	12345678901(...)01234567890 [240000]	300.378 ms	25.1560 ms	27.9608 ms	296.348 ms	267.565 ms	357.131 ms	-	-	-	572 KB
Parse	12345678901(...)01234567890 [260000]	346.397 ms	26.8156 ms	29.8054 ms	335.024 ms	320.430 ms	412.120 ms	-	-	-	626 KB
Parse	12345678901(...)01234567890 [280000]	384.442 ms	12.8365 ms	14.2678 ms	381.489 ms	367.624 ms	420.767 ms	-	-	-	666 KB
Parse	12345678901(...)01234567890 [300000]	433.914 ms	9.1847 ms	10.5772 ms	433.046 ms	414.254 ms	452.394 ms	-	-	-	721 KB

Implemented method

BenchmarkDotNet=v0.12.1.1528-nightly, OS=Windows 10.0.19042.928 (20H2/October2020Update)
Intel Core i7-7500U CPU 2.70GHz (Kaby Lake), 1 CPU, 4 logical and 2 physical cores
.NET SDK=6.0.100-preview.3.21202.5
[Host] : .NET 6.0.0 (6.0.21.20104), X64 RyuJIT
Job-YASIZJ : .NET 6.0.0 (42.42.42.42424), X64 RyuJIT
PowerPlanMode=00000000-0000-0000-0000-000000000000 Arguments=/p:DebugType=portable Toolchain=CoreRun IterationTime=250.0000 ms MaxIterationCount=20 MinIterationCount=15 WarmupCount=1

Method	numberString	Mean	Error	StdDev	Median	Min	Max	Gen 0	Gen 1	Gen 2	Allocated
Parse	12345678901(...)01234567890 [20000]	2.017 ms	0.0559 ms	0.0643 ms	2.024 ms	1.921 ms	2.127 ms	140.6250	-	-	288 KB
Parse	12345678901(...)01234567890 [40000]	6.237 ms	0.1116 ms	0.0932 ms	6.218 ms	6.127 ms	6.434 ms	437.5000	83.3333	-	994 KB
Parse	12345678901(...)01234567890 [60000]	15.522 ms	1.3853 ms	1.5953 ms	15.153 ms	13.686 ms	18.949 ms	1062.5000	218.7500	-	2,831 KB
Parse	12345678901(...)01234567890 [80000]	20.554 ms	0.4685 ms	0.5208 ms	20.429 ms	19.880 ms	21.552 ms	1181.8182	181.8182	-	3,572 KB
Parse	12345678901(...)01234567890 [100000]	39.146 ms	1.8050 ms	1.8536 ms	38.681 ms	36.992 ms	44.189 ms	3000.0000	333.3333	-	7,680 KB
Parse	12345678901(...)01234567890 [120000]	47.999 ms	1.5866 ms	1.8271 ms	47.429 ms	46.147 ms	51.705 ms	3750.0000	250.0000	-	10,447 KB
Parse	12345678901(...)01234567890 [140000]	41.915 ms	1.3341 ms	1.3700 ms	41.657 ms	40.299 ms	44.621 ms	2166.6667	500.0000	-	6,532 KB
Parse	12345678901(...)01234567890 [160000]	67.668 ms	1.4404 ms	1.6010 ms	67.296 ms	65.587 ms	70.763 ms	4750.0000	250.0000	-	12,897 KB
Parse	12345678901(...)01234567890 [180000]	103.943 ms	2.4616 ms	2.8347 ms	103.285 ms	100.249 ms	109.843 ms	6500.0000	500.0000	-	18,962 KB
Parse	12345678901(...)01234567890 [200000]	136.343 ms	3.9093 ms	4.0146 ms	135.607 ms	131.575 ms	148.198 ms	9500.0000	500.0000	-	28,922 KB
Parse	12345678901(...)01234567890 [220000]	154.695 ms	3.6123 ms	3.7096 ms	154.182 ms	149.801 ms	163.375 ms	17500.0000	500.0000	-	40,999 KB
Parse	12345678901(...)01234567890 [240000]	184.792 ms	20.8938 ms	24.0613 ms	173.449 ms	163.513 ms	234.269 ms	16000.0000	1000.0000	-	39,244 KB
Parse	12345678901(...)01234567890 [260000]	160.434 ms	3.0439 ms	3.5053 ms	160.026 ms	155.602 ms	167.424 ms	12500.0000	500.0000	-	33,322 KB
Parse	12345678901(...)01234567890 [280000]	134.838 ms	2.4207 ms	2.2644 ms	134.531 ms	132.314 ms	139.587 ms	9500.0000	500.0000	-	22,696 KB
Parse	12345678901(...)01234567890 [300000]	140.690 ms	2.4686 ms	2.4245 ms	141.285 ms	134.758 ms	144.021 ms	7500.0000	1500.0000	1000.0000	24,318 KB

Co-authored-by: Stephen Toub <stoub@microsoft.com>

ghost · 2021-07-03T08:53:18Z

Tagging subscribers to this area: @dotnet/area-system-numerics
See info in area-owners.md if you want to be subscribed.

Issue Details

I accidentally deleted the forked repository, so I will resubmit the PR #51953 . Please refer to the previous discussion there. I apologize for the inconvenience.

Current BigNumer.NumberToBigInteger method is implemented using naive algorithm. It runs in Θ(N^2) time where N is number of digits. I implemented faster method known as divide-and-conquer algorithm. It runs Θ(N (log(N))^2). Since this algorithms running time has large constant factor, naive method is faster when N is small. So This method is only apply when N is large enough. (specifically, use divide-and-conquer method when N is more than 20000.)

I created branch from #47842 as it looks like #47842 will be merged shortly.

benchmark result

Previous method

BenchmarkDotNet=v0.12.1.1528-nightly, OS=Windows 10.0.19042.928 (20H2/October2020Update)
Intel Core i7-7500U CPU 2.70GHz (Kaby Lake), 1 CPU, 4 logical and 2 physical cores
.NET SDK=6.0.100-preview.3.21202.5
[Host] : .NET 6.0.0 (6.0.21.20104), X64 RyuJIT
Job-CHCQPG : .NET 6.0.0 (42.42.42.42424), X64 RyuJIT
PowerPlanMode=00000000-0000-0000-0000-000000000000 Arguments=/p:DebugType=portable Toolchain=CoreRun IterationTime=250.0000 ms MaxIterationCount=20 MinIterationCount=15 WarmupCount=1

Method	numberString	Mean	Error	StdDev	Median	Min	Max	Gen 0	Gen 1	Gen 2	Allocated
Parse	12345678901(...)01234567890 [20000]	2.611 ms	0.1786 ms	0.2057 ms	2.661 ms	2.208 ms	2.996 ms	26.7857	-	-	56 KB
Parse	12345678901(...)01234567890 [40000]	9.028 ms	0.7436 ms	0.8265 ms	8.816 ms	8.072 ms	10.909 ms	31.2500	-	-	96 KB
Parse	12345678901(...)01234567890 [60000]	18.521 ms	0.5179 ms	0.5756 ms	18.552 ms	17.349 ms	19.541 ms	71.4286	-	-	151 KB
Parse	12345678901(...)01234567890 [80000]	32.904 ms	1.1486 ms	1.2290 ms	32.761 ms	30.984 ms	34.686 ms	-	-	-	191 KB
Parse	12345678901(...)01234567890 [100000]	51.271 ms	1.7700 ms	2.0384 ms	51.186 ms	48.447 ms	54.856 ms	-	-	-	246 KB
Parse	12345678901(...)01234567890 [120000]	74.285 ms	3.6392 ms	3.8939 ms	73.489 ms	68.604 ms	82.719 ms	-	-	-	286 KB
Parse	12345678901(...)01234567890 [140000]	100.248 ms	5.2825 ms	5.8715 ms	98.712 ms	92.597 ms	113.046 ms	-	-	-	341 KB
Parse	12345678901(...)01234567890 [160000]	127.443 ms	4.8226 ms	5.5537 ms	125.749 ms	120.504 ms	138.583 ms	-	-	-	381 KB
Parse	12345678901(...)01234567890 [180000]	162.028 ms	4.9852 ms	5.7409 ms	162.142 ms	151.841 ms	171.640 ms	-	-	-	436 KB
Parse	12345678901(...)01234567890 [200000]	224.511 ms	16.7864 ms	19.3313 ms	224.392 ms	192.558 ms	255.098 ms	-	-	-	476 KB
Parse	12345678901(...)01234567890 [220000]	240.451 ms	10.9087 ms	12.1250 ms	234.971 ms	226.956 ms	265.072 ms	-	-	-	531 KB
Parse	12345678901(...)01234567890 [240000]	300.378 ms	25.1560 ms	27.9608 ms	296.348 ms	267.565 ms	357.131 ms	-	-	-	572 KB
Parse	12345678901(...)01234567890 [260000]	346.397 ms	26.8156 ms	29.8054 ms	335.024 ms	320.430 ms	412.120 ms	-	-	-	626 KB
Parse	12345678901(...)01234567890 [280000]	384.442 ms	12.8365 ms	14.2678 ms	381.489 ms	367.624 ms	420.767 ms	-	-	-	666 KB
Parse	12345678901(...)01234567890 [300000]	433.914 ms	9.1847 ms	10.5772 ms	433.046 ms	414.254 ms	452.394 ms	-	-	-	721 KB

Implemented method

BenchmarkDotNet=v0.12.1.1528-nightly, OS=Windows 10.0.19042.928 (20H2/October2020Update)
Intel Core i7-7500U CPU 2.70GHz (Kaby Lake), 1 CPU, 4 logical and 2 physical cores
.NET SDK=6.0.100-preview.3.21202.5
[Host] : .NET 6.0.0 (6.0.21.20104), X64 RyuJIT
Job-YASIZJ : .NET 6.0.0 (42.42.42.42424), X64 RyuJIT
PowerPlanMode=00000000-0000-0000-0000-000000000000 Arguments=/p:DebugType=portable Toolchain=CoreRun IterationTime=250.0000 ms MaxIterationCount=20 MinIterationCount=15 WarmupCount=1

Method	numberString	Mean	Error	StdDev	Median	Min	Max	Gen 0	Gen 1	Gen 2	Allocated
Parse	12345678901(...)01234567890 [20000]	2.017 ms	0.0559 ms	0.0643 ms	2.024 ms	1.921 ms	2.127 ms	140.6250	-	-	288 KB
Parse	12345678901(...)01234567890 [40000]	6.237 ms	0.1116 ms	0.0932 ms	6.218 ms	6.127 ms	6.434 ms	437.5000	83.3333	-	994 KB
Parse	12345678901(...)01234567890 [60000]	15.522 ms	1.3853 ms	1.5953 ms	15.153 ms	13.686 ms	18.949 ms	1062.5000	218.7500	-	2,831 KB
Parse	12345678901(...)01234567890 [80000]	20.554 ms	0.4685 ms	0.5208 ms	20.429 ms	19.880 ms	21.552 ms	1181.8182	181.8182	-	3,572 KB
Parse	12345678901(...)01234567890 [100000]	39.146 ms	1.8050 ms	1.8536 ms	38.681 ms	36.992 ms	44.189 ms	3000.0000	333.3333	-	7,680 KB
Parse	12345678901(...)01234567890 [120000]	47.999 ms	1.5866 ms	1.8271 ms	47.429 ms	46.147 ms	51.705 ms	3750.0000	250.0000	-	10,447 KB
Parse	12345678901(...)01234567890 [140000]	41.915 ms	1.3341 ms	1.3700 ms	41.657 ms	40.299 ms	44.621 ms	2166.6667	500.0000	-	6,532 KB
Parse	12345678901(...)01234567890 [160000]	67.668 ms	1.4404 ms	1.6010 ms	67.296 ms	65.587 ms	70.763 ms	4750.0000	250.0000	-	12,897 KB
Parse	12345678901(...)01234567890 [180000]	103.943 ms	2.4616 ms	2.8347 ms	103.285 ms	100.249 ms	109.843 ms	6500.0000	500.0000	-	18,962 KB
Parse	12345678901(...)01234567890 [200000]	136.343 ms	3.9093 ms	4.0146 ms	135.607 ms	131.575 ms	148.198 ms	9500.0000	500.0000	-	28,922 KB
Parse	12345678901(...)01234567890 [220000]	154.695 ms	3.6123 ms	3.7096 ms	154.182 ms	149.801 ms	163.375 ms	17500.0000	500.0000	-	40,999 KB
Parse	12345678901(...)01234567890 [240000]	184.792 ms	20.8938 ms	24.0613 ms	173.449 ms	163.513 ms	234.269 ms	16000.0000	1000.0000	-	39,244 KB
Parse	12345678901(...)01234567890 [260000]	160.434 ms	3.0439 ms	3.5053 ms	160.026 ms	155.602 ms	167.424 ms	12500.0000	500.0000	-	33,322 KB
Parse	12345678901(...)01234567890 [280000]	134.838 ms	2.4207 ms	2.2644 ms	134.531 ms	132.314 ms	139.587 ms	9500.0000	500.0000	-	22,696 KB
Parse	12345678901(...)01234567890 [300000]	140.690 ms	2.4686 ms	2.4245 ms	141.285 ms	134.758 ms	144.021 ms	7500.0000	1500.0000	1000.0000	24,318 KB

Author:	key-moon
Assignees:	-
Labels:	`area-System.Numerics`
Milestone:	-

jeffhandley · 2021-07-23T21:33:13Z

@tannergooding This PR is assigned to you for follow-up/decision before the RC1 snap.

tannergooding · 2021-08-02T16:07:51Z

Thanks for the contribution here @key-moon. Due to it being so late in the cycle, this is going to miss out on the .NET 6 release and we'll instead be able to merge it after the RC1 snap and we begin accepting changes for .NET 7 (ETA: 3-4 weeks)

jeffhandley · 2021-09-04T02:29:55Z

@key-moon I wanted to let you know we're still working on some .NET 6.0 RC2 items, so we're a bit delayed on reviewing this. It'll likely be a couple more weeks. Thanks for your contributions and patience!

tannergooding · 2021-09-23T17:17:48Z

 {
- foreach (ReadOnlyMemory<char> digitsChunk in number.digits.GetChunks())
+ if (number.digits.Length <= s_naiveThreshold)
+ {


Given how big each path is, I would if it would be better to break them into 2 helper methods. Basically leaving:
if(number.digits.Length<=s_naiveThreshold){AlgorithmA(...);}else{AlgorithmB(...);}
-- The method is getting pretty big, which means the JIT might give up on optimizing it otherwise (haven't confirmed if it actually does).

Sorry for late replying. I think this is worth doing in terms of improving readability. I will implement it as soon as possible.

I have implemented and benchmarked. As a result, there is no significant difference in speed and memory. However, readability has definitely been improved.
Benchmark result
Job-VEBSQX: before split to methods (a9942c5)
Job-HLAVXS: after split to methods (460664f)
BenchmarkDotNet=v0.13.1.1611-nightly, OS=Windows 10.0.22000 11th Gen Intel Core i7-1165G7 2.80GHz, 1 CPU, 8 logical and 4 physical cores .NET SDK=6.0.100-rc.1.21463.6 [Host] : .NET 5.0.9 (5.0.921.35908), X64 RyuJIT Job-VEBSQX : .NET 6.0.0 (42.42.42.42424), X64 RyuJIT Job-HLAVXS : .NET 6.0.0 (42.42.42.42424), X64 RyuJIT PowerPlanMode=00000000-0000-0000-0000-000000000000 Arguments=/p:DebugType=portable,-bl:benchmarkdotnet.binlog IterationTime=250.0000 ms MaxIterationCount=20 MinIterationCount=15 WarmupCount=1
Method Job Toolchain numberString Mean Error StdDev Median Min Max Ratio RatioSD Gen 0 Gen 1 Gen 2 Allocated
Parse Job-VEBSQX \artifacts-a9942c\bin\testhost\net6.0-windows-Release-x64\shared\Microsoft.NETCore.App\6.0.0\corerun.exe 12345678901(...)01234567890 [50000] 10.50 ms 0.350 ms 0.389 ms 10.56 ms 9.902 ms 11.42 ms 1.00 0.00 312.5000 93.7500 - 2 MB
Parse Job-HLAVXS \artifacts-460664\bin\testhost\net6.0-windows-Release-x64\shared\Microsoft.NETCore.App\6.0.0\corerun.exe 12345678901(...)01234567890 [50000] 10.29 ms 0.384 ms 0.427 ms 10.34 ms 9.563 ms 11.13 ms 0.98 0.03 312.5000 93.7500 - 2 MB
Parse Job-VEBSQX \artifacts-a9942c\bin\testhost\net6.0-windows-Release-x64\shared\Microsoft.NETCore.App\6.0.0\corerun.exe 12345678901(...)01234567890 [100000] 36.77 ms 1.531 ms 1.702 ms 36.58 ms 33.684 ms 40.74 ms 1.00 0.00 1125.0000 250.0000 - 7 MB
Parse Job-HLAVXS \artifacts-460664\bin\testhost\net6.0-windows-Release-x64\shared\Microsoft.NETCore.App\6.0.0\corerun.exe 12345678901(...)01234567890 [100000] 36.64 ms 1.445 ms 1.606 ms 36.23 ms 33.401 ms 39.95 ms 1.00 0.07 1166.6667 166.6667 - 7 MB
Parse Job-VEBSQX \artifacts-a9942c\bin\testhost\net6.0-windows-Release-x64\shared\Microsoft.NETCore.App\6.0.0\corerun.exe 12345678901(...)01234567890 [150000] 41.08 ms 1.350 ms 1.555 ms 40.75 ms 38.486 ms 44.25 ms 1.00 0.00 1000.0000 500.0000 - 7 MB
Parse Job-HLAVXS \artifacts-460664\bin\testhost\net6.0-windows-Release-x64\shared\Microsoft.NETCore.App\6.0.0\corerun.exe 12345678901(...)01234567890 [150000] 40.97 ms 0.742 ms 0.762 ms 41.26 ms 39.155 ms 42.20 ms 1.01 0.04 1000.0000 500.0000 - 7 MB
Parse Job-VEBSQX \artifacts-a9942c\bin\testhost\net6.0-windows-Release-x64\shared\Microsoft.NETCore.App\6.0.0\corerun.exe 12345678901(...)01234567890 [200000] 129.14 ms 3.434 ms 3.527 ms 129.89 ms 120.135 ms 133.89 ms 1.00 0.00 4500.0000 500.0000 - 28 MB
Parse Job-HLAVXS \artifacts-460664\bin\testhost\net6.0-windows-Release-x64\shared\Microsoft.NETCore.App\6.0.0\corerun.exe 12345678901(...)01234567890 [200000] 130.05 ms 2.571 ms 2.279 ms 130.45 ms 125.832 ms 134.43 ms 1.01 0.04 4500.0000 500.0000 - 28 MB
Parse Job-VEBSQX \artifacts-a9942c\bin\testhost\net6.0-windows-Release-x64\shared\Microsoft.NETCore.App\6.0.0\corerun.exe 12345678901(...)01234567890 [250000] 160.84 ms 8.920 ms 9.544 ms 158.21 ms 146.879 ms 179.63 ms 1.00 0.00 5500.0000 500.0000 - 34 MB
Parse Job-HLAVXS \artifacts-460664\bin\testhost\net6.0-windows-Release-x64\shared\Microsoft.NETCore.App\6.0.0\corerun.exe 12345678901(...)01234567890 [250000] 162.85 ms 7.046 ms 8.114 ms 161.09 ms 145.608 ms 178.37 ms 1.01 0.08 5500.0000 500.0000 - 34 MB
Parse Job-VEBSQX \artifacts-a9942c\bin\testhost\net6.0-windows-Release-x64\shared\Microsoft.NETCore.App\6.0.0\corerun.exe 12345678901(...)01234567890 [300000] 132.28 ms 3.731 ms 3.992 ms 131.79 ms 122.929 ms 137.93 ms 1.00 0.00 3500.0000 1500.0000 1000.0000 24 MB
Parse Job-HLAVXS \artifacts-460664\bin\testhost\net6.0-windows-Release-x64\shared\Microsoft.NETCore.App\6.0.0\corerun.exe 12345678901(...)01234567890 [300000] 134.72 ms 5.300 ms 6.103 ms 133.63 ms 123.651 ms 147.27 ms 1.03 0.06 3500.0000 1500.0000 1000.0000 24 MB
Parse Job-VEBSQX \artifacts-a9942c\bin\testhost\net6.0-windows-Release-x64\shared\Microsoft.NETCore.App\6.0.0\corerun.exe 12345678901(...)01234567890 [350000] 356.66 ms 20.078 ms 21.484 ms 351.60 ms 321.365 ms 406.99 ms 1.00 0.00 14000.0000 12000.0000 11000.0000 71 MB
Parse Job-HLAVXS \artifacts-460664\bin\testhost\net6.0-windows-Release-x64\shared\Microsoft.NETCore.App\6.0.0\corerun.exe 12345678901(...)01234567890 [350000] 354.54 ms 17.497 ms 19.448 ms 348.05 ms 323.012 ms 396.16 ms 0.99 0.07 15000.0000 13000.0000 12000.0000 71 MB
Parse Job-VEBSQX \artifacts-a9942c\bin\testhost\net6.0-windows-Release-x64\shared\Microsoft.NETCore.App\6.0.0\corerun.exe 12345678901(...)01234567890 [400000] 524.19 ms 47.271 ms 54.437 ms 510.63 ms 461.465 ms 640.54 ms 1.00 0.00 17000.0000 3000.0000 2000.0000 107 MB
Parse Job-HLAVXS \artifacts-460664\bin\testhost\net6.0-windows-Release-x64\shared\Microsoft.NETCore.App\6.0.0\corerun.exe 12345678901(...)01234567890 [400000] 553.00 ms 91.333 ms 105.179 ms 487.60 ms 444.111 ms 710.82 ms 1.06 0.21 17000.0000 3000.0000 2000.0000 107 MB
Parse Job-VEBSQX \artifacts-a9942c\bin\testhost\net6.0-windows-Release-x64\shared\Microsoft.NETCore.App\6.0.0\corerun.exe 12345678901(...)01234567890 [450000] 627.40 ms 91.780 ms 105.695 ms 570.04 ms 526.129 ms 800.22 ms 1.00 0.00 24000.0000 1000.0000 - 149 MB
Parse Job-HLAVXS \artifacts-460664\bin\testhost\net6.0-windows-Release-x64\shared\Microsoft.NETCore.App\6.0.0\corerun.exe 12345678901(...)01234567890 [450000] 554.17 ms 49.428 ms 56.921 ms 542.68 ms 472.918 ms 657.23 ms 0.90 0.14 24000.0000 1000.0000 - 149 MB

tannergooding · 2021-09-23T18:19:20Z

The overall logic LGTM.

I left a couple nits/comments about adding comments and possibly minor refactorings to help with readability when this inevitably is looked at again in the future. I likewise called out a peculiar scenario around handling fractional digits which I don't believe is possible (happy to be proven wrong here).

It would be great if this could get a second pair of eyes on it (CC. @pgovind, @stephentoub, @bartonjs since you've reviewed or worked on BigInteger semi-recently).

deeprobin · 2021-12-15T07:35:36Z

+ multiplier[0] = TenPowMaxPartial;
+
+ // This loop is executed ceil(log_2(bufferSize)) times.
+ while (true)


If this loop is executed ceil(log_2(bufferSize)), why do you not use a for loop? I think these are better optimized by the JIT.

Please benchmark before/after to make sure that this is really the case.

deeprobin · 2021-12-15T07:56:37Z

+ }
+ }
+
+ private static volatile TypeInfo s_lazyInternalNumber;


Can you add a comment, which explains why this is volatile.

This commits explains the reason. Actually, I didn't understand why volatile is required.
dotnet/corefx@8918578

tannergooding · 2022-01-07T20:42:50Z

@key-moon are you still working on this?

No particular rush, just wanted to ensure that was the case since many people took a break over the holidays. There are still several pending comments above that would need to be resolved.

key-moon · 2022-01-08T17:05:20Z

Yes, I’m still working on this PR. Sorry for the late response. I'll resolve these conversations as soon as possible.

tannergooding · 2022-01-31T18:22:14Z

This has a merge conflict that needs to be resolved. I also resolved a few comments around styling concerns where the code in question isn't new, rather just being moved around.

While I do think that resolving those styling inconsistencies would be nice, since its not new code I think it can happen in an independent PR.

tannergooding · 2022-02-07T18:02:52Z

Closing and reopening to try and get helix to pick up the changes and allow CI to actually run.

tannergooding · 2022-03-14T20:41:52Z

This PR looks generally good, I'd just like to get CI passing before merging.

Merging with main again may allow it to pass.

deeprobin · 2022-03-15T05:57:36Z

Build failures are unrelated

danmoseley · 2022-03-23T20:58:20Z

Thanks @key-moon for your work on this perf improvement!

…otnet#55121) * implement divide-and-conquer method for parsing digits * fix argument order in Assert when x equals to 0 * Apply format fix Co-authored-by: Stephen Toub <stoub@microsoft.com> * add test for non-naive algorithm * add description for naiveThreshold * fix trivial part * add check for boundary condition * add assertions and descriptions * change variable name * remove inappropreate use of var * to use ArrayPool<int>.Shared.Rent for newBuffer allocation * move both algorithms to separate methods * add and fix comments * trivial fix Co-authored-by: Stephen Toub <stoub@microsoft.com>

key-moonand others added 3 commits May 19, 2021 18:46

implement divide-and-conquer method for parsing digits
e93dde5

fix argument order in Assert when x equals to 0
2fdbe45

Apply format fix
7d89c46
Co-authored-by: Stephen Toub <stoub@microsoft.com>

ghost added the area-System.Numerics label Jul 3, 2021

terrajobst added the community-contribution Indicates that the PR has been added by a community member label Jul 19, 2021

jeffhandley assigned tannergooding Jul 23, 2021

jeffhandley requested review from pgovind and tannergooding July 23, 2021 21:33

tannergooding added this to the 7.0.0 milestone Aug 2, 2021