Loop unrolled direct string inject

[benaadams]

+1% RPS - also less complicated; with a single code path rather than three,

Before

Running 30s test @ http://.../plaintext
32 threads and 1024 connections
Thread Stats Avg Stdev Max +/- Stdev
Latency 8.25ms 19.86ms 374.26ms 95.29%
Req/Sec 67.64k 5.91k 113.64k 83.57%
62655516 requests in 30.04s, 7.70GB read
Socket errors: connect 35, read 0, write 0, timeout 0
Requests/sec: 2085664.91
Transfer/sec: 262.55MB

After

Running 30s test @ http://.../plaintext
32 threads and 1024 connections
Thread Stats Avg Stdev Max +/- Stdev
Latency 6.62ms 15.26ms 293.65ms 96.92%
Req/Sec 66.38k 12.62k 128.97k 94.86%
63472957 requests in 30.05s, 7.80GB read
Socket errors: connect 35, read 0, write 0, timeout 0
Requests/sec: 2112232.38
Transfer/sec: 265.90MB

[davidfowl]

null

[halter73]

I like that this PR removes more code than it adds, but this part now seems slightly more complicated. Are we sure that manual unrolling is faster?

[benaadams]

Yep: #399 (comment)
Non-unrolled (SequentialPointer)
Incrementing value on each unroll step (UnrolledPointer)
Adding to value on each step; and incrementing it at end (UnrolledParallelPointer)

[halter73]

I remember that now 😄 It's interesting how UnrolledParallelPointer is so consistently better from 1 character all the way to 16384 character strings.

It might be interesting to see how something unaligned like a 33 character string performs, since I don't think any of the test cases hit both loops in GetAsciiStringImplementationB (UnrolledParallelPointer).

[benaadams]

Ah good point, will get that in new tests when doing looking for new numbers.

The ParallelPointer works because the cpu can pipeline the instructions as they are independent of each other (i.e. the effects of one line don't effect the results of the next); incrementing the pointer at each step means the next step can't run until that pointer addition is completed as its dependent on the result. Is also one of the problems with i++ in a regular loop; the next i++ can't be run until that has completed as it is dependent of its result.

[benaadams]

Also If I didn't unroll I think this would be a perf regression as the string is initialized; rather than being operations on initialized stack memory; then a memcopy to an uninitialized string; however I think the code being less weird makes up for that...

[halter73]

I definitely like the code being less weird. Interesting point about the instruction pipelining. That explains the somewhat unintuitive results. It's amazing the stuff you have to consider at this level of optimization. Someday maybe the compiler will be smart enough to do this kind of thing for us.

I'm going to keep this PR open pending the new numbers.

[benaadams]

Updated with unrolling and improved instruction ordering from #519

[benaadams]

There is a further combining change that will this fixed block (as buffers are already fixed) - but this stands alone as is.

[halter73]

Thanks for all research/testing you put into this. LGTM.

[benaadams]

Rebased

[halter73]

Actually, before I merge this, do you have the test script and results that show this is the fasted way to create a string from ASCII bytes?

#399 (comment) doesn't cover the current implementation.

[benaadams]

Sure :D

[benaadams]

Still need to do the benchmarking with various sizes; though taking a step as the bracketed chunk where i, input and output are modified the step count growth vs length looks like the following for step sizes 12,6,4,1 - at 12.

119 being 12 steps (120 dropping back to 10 steps as is multiple of 12)

count	steps
1	1
2	2
3	3
4	1
5	2
6	1
7	2
8	3
9	4
10	2
11	3
12	1
13	2
14	3
15	4
16	2
17	3
18	2
19	2
20	3
21	4
22	3
23	4
24	2
25	3
26	4
27	5
28	3
29	4
30	3
31	3
32	4
33	5
34	4
35	5
36	3

Working for a 14 stage pipelined cpu so i is available for the next if statement 14 instructions later; though it looks like the most recent chips have moved from 14 stages to 20-24.

Is different for the non-byte conversion copy as int and longs (and vectors) can be used.

[benaadams]

Running benchmarks now

[benaadams]

Benchmark using System.Text.Encoding.ASCII.GetString, current one stack, and unrolled version (this PR).

Actually creating the strings to test properly.

BenchmarkDotNet-Dev=v0.8.0.0+
OS=Microsoft Windows NT 6.2.9200.0
Processor=Intel(R) Core(TM) i7-4720HQ CPU @ 2.60GHz, ProcessorCount=8
HostCLR=MS.NET 4.0.30319.42000, Arch=64-bit  [RyuJIT]
Type=AsciiCreate  Mode=Throughput  Platform=X64  Jit=RyuJit  .NET=HostFramework  toolchain=Classic  Runtime=Clr  Warmup=5  Target=10

Method	Len	AvrTime	StdDev	op/s	improve
GetAsciiStringEncoding	0	6.3856 ns	0.1169 ns	156,653,606.68
GetAsciiStringStack	0	5.2684 ns	0.0127 ns	189,810,626.86	21%
GetAsciiStringUnrolled	0	4.4208 ns	0.0140 ns	226,204,241.47	44%
GetAsciiStringEncoding	1	26.5309 ns	0.0356 ns	37,691,946.79
GetAsciiStringStack	1	14.1725 ns	0.2380 ns	70,578,500.95	87%
GetAsciiStringUnrolled	1	7.7349 ns	0.1323 ns	129,320,578.74	243%
GetAsciiStringEncoding	2	27.6725 ns	0.0320 ns	36,137,019.03
GetAsciiStringStack	2	15.0977 ns	0.0635 ns	66,236,222.20	83%
GetAsciiStringUnrolled	2	8.4002 ns	0.1619 ns	119,088,715.40	230%
GetAsciiStringEncoding	3	28.5409 ns	0.4908 ns	35,047,572.85
GetAsciiStringStack	3	15.9660 ns	0.1267 ns	62,636,685.04	79%
GetAsciiStringUnrolled	3	8.8578 ns	0.0329 ns	112,895,812.72	222%
GetAsciiStringEncoding	4	30.9573 ns	0.1652 ns	32,303,440.88
GetAsciiStringStack	4	16.9224 ns	0.0369 ns	59,093,455.47	83%
GetAsciiStringUnrolled	4	8.6447 ns	0.0486 ns	115,681,631.66	258%
GetAsciiStringEncoding	5	32.2680 ns	0.3021 ns	30,993,097.10
GetAsciiStringStack	5	18.0094 ns	0.1083 ns	55,528,407.74	79%
GetAsciiStringUnrolled	5	9.1457 ns	0.0315 ns	109,342,438.67	253%
GetAsciiStringEncoding	6	33.5031 ns	0.7046 ns	29,860,766.68
GetAsciiStringStack	6	18.6508 ns	0.0533 ns	53,617,329.77	80%
GetAsciiStringUnrolled	6	9.1732 ns	0.0298 ns	109,014,335.28	265%
GetAsciiStringEncoding	7	34.7881 ns	0.4244 ns	28,749,689.65
GetAsciiStringStack	7	19.6855 ns	0.0596 ns	50,799,349.04	77%
GetAsciiStringUnrolled	7	9.3058 ns	0.2003 ns	107,507,156.82	274%
GetAsciiStringEncoding	8	36.1978 ns	0.3716 ns	27,628,883.07
GetAsciiStringStack	8	20.8175 ns	0.0728 ns	48,037,145.01	74%
GetAsciiStringUnrolled	8	10.4343 ns	0.0367 ns	95,838,567.13	247%
GetAsciiStringEncoding	9	37.5087 ns	0.4505 ns	26,664,301.05
GetAsciiStringStack	9	23.7708 ns	0.0672 ns	42,068,676.64	58%
GetAsciiStringUnrolled	9	10.9736 ns	0.1783 ns	91,151,113.04	242%
GetAsciiStringEncoding	10	38.3184 ns	0.6713 ns	26,104,951.22
GetAsciiStringStack	10	24.6946 ns	0.1382 ns	40,495,935.51	55%
GetAsciiStringUnrolled	10	10.9550 ns	0.2587 ns	91,330,664.10	250%
GetAsciiStringEncoding	11	39.4201 ns	0.7459 ns	25,376,511.38
GetAsciiStringStack	11	25.8510 ns	0.0512 ns	38,683,433.65	52%
GetAsciiStringUnrolled	11	11.1191 ns	0.0402 ns	89,936,842.58	254%
GetAsciiStringEncoding	12	41.3879 ns	0.4545 ns	24,164,485.71
GetAsciiStringStack	12	26.2828 ns	0.4456 ns	38,058,145.12	57%
GetAsciiStringUnrolled	12	11.9781 ns	0.1244 ns	83,494,318.91	246%
GetAsciiStringEncoding	13	41.4398 ns	0.9442 ns	24,143,681.18
GetAsciiStringStack	13	27.9275 ns	0.0937 ns	35,807,368.88	48%
GetAsciiStringUnrolled	13	12.5717 ns	0.0533 ns	79,545,230.02	229%
GetAsciiStringEncoding	14	42.5840 ns	0.7131 ns	23,489,419.87
GetAsciiStringStack	14	28.7776 ns	0.0347 ns	34,749,284.35	48%
GetAsciiStringUnrolled	14	12.6846 ns	0.0922 ns	78,839,682.77	236%
GetAsciiStringEncoding	15	43.9742 ns	0.8635 ns	22,749,156.48
GetAsciiStringStack	15	29.2612 ns	0.5262 ns	34,185,525.67	50%
GetAsciiStringUnrolled	15	13.6817 ns	0.0275 ns	73,090,731.51	221%
GetAsciiStringEncoding	16	45.9021 ns	0.2249 ns	21,786,010.31
GetAsciiStringStack	16	29.9649 ns	0.1471 ns	33,373,174.51	53%
GetAsciiStringUnrolled	16	13.3515 ns	0.0315 ns	74,898,410.71	244%
GetAsciiStringEncoding	17	46.4066 ns	0.8744 ns	21,556,146.45
GetAsciiStringStack	17	32.5104 ns	0.1292 ns	30,759,880.93	43%
GetAsciiStringUnrolled	17	14.2499 ns	0.0330 ns	70,176,184.27	226%
GetAsciiStringEncoding	18	47.7287 ns	0.9818 ns	20,960,404.20
GetAsciiStringStack	18	33.3996 ns	0.1483 ns	29,941,062.05	43%
GetAsciiStringUnrolled	18	14.1331 ns	0.3225 ns	70,790,910.88	238%
GetAsciiStringEncoding	19	50.1159 ns	0.4713 ns	19,955,429.95
GetAsciiStringStack	19	34.1617 ns	0.6572 ns	29,283,121.90	47%
GetAsciiStringUnrolled	19	15.0138 ns	0.0493 ns	66,606,101.65	234%
GetAsciiStringEncoding	20	51.2267 ns	0.7124 ns	19,524,742.60
GetAsciiStringStack	20	34.1321 ns	0.1323 ns	29,298,333.32	50%
GetAsciiStringUnrolled	20	15.9209 ns	0.0690 ns	62,811,618.89	222%
GetAsciiStringEncoding	21	53.6812 ns	0.3992 ns	18,629,494.19
GetAsciiStringStack	21	36.2021 ns	0.6744 ns	27,632,007.81	48%
GetAsciiStringUnrolled	21	16.1166 ns	0.0845 ns	62,049,295.47	233%
GetAsciiStringEncoding	22	55.7167 ns	0.5608 ns	17,949,692.37
GetAsciiStringStack	22	36.9721 ns	0.7434 ns	27,058,138.63	51%
GetAsciiStringUnrolled	22	16.5684 ns	0.0796 ns	60,357,337.53	236%
GetAsciiStringEncoding	23	57.2454 ns	0.2286 ns	17,468,913.98
GetAsciiStringStack	23	38.5952 ns	0.1944 ns	25,910,598.31	48%
GetAsciiStringUnrolled	23	16.5282 ns	0.2687 ns	60,517,895.58	246%
GetAsciiStringEncoding	24	59.6127 ns	0.4782 ns	16,775,996.18
GetAsciiStringStack	24	39.7004 ns	0.0633 ns	25,188,702.34	50%
GetAsciiStringUnrolled	24	17.2569 ns	0.0566 ns	57,948,493.11	245%
GetAsciiStringEncoding	25	61.6060 ns	0.4221 ns	16,232,917.54
GetAsciiStringStack	25	40.2711 ns	1.0238 ns	24,846,854.39	53%
GetAsciiStringUnrolled	25	17.4347 ns	0.3267 ns	57,376,492.61	253%
GetAsciiStringEncoding	26	62.3887 ns	1.2943 ns	16,035,269.35
GetAsciiStringStack	26	40.7875 ns	0.3357 ns	24,518,893.70	53%
GetAsciiStringUnrolled	26	17.1934 ns	0.0860 ns	58,163,222.65	263%
GetAsciiStringEncoding	27	64.8049 ns	0.2827 ns	15,431,208.76
GetAsciiStringStack	27	42.9668 ns	0.6764 ns	23,279,426.67	51%
GetAsciiStringUnrolled	27	18.0682 ns	0.2526 ns	55,356,551.04	259%
GetAsciiStringEncoding	28	66.1509 ns	1.2633 ns	15,122,360.94
GetAsciiStringStack	28	44.3772 ns	0.1273 ns	22,534,274.55	49%
GetAsciiStringUnrolled	28	18.8945 ns	0.0650 ns	52,926,029.44	250%
GetAsciiStringEncoding	29	67.6734 ns	1.1017 ns	14,780,678.02
GetAsciiStringStack	29	45.6187 ns	0.1284 ns	21,920,981.49	48%
GetAsciiStringUnrolled	29	19.2249 ns	0.2184 ns	52,022,283.77	252%
GetAsciiStringEncoding	30	69.7017 ns	1.4238 ns	14,352,693.17
GetAsciiStringStack	30	46.4138 ns	0.0906 ns	21,545,385.42	50%
GetAsciiStringUnrolled	30	19.4372 ns	0.0333 ns	51,447,912.17	258%
GetAsciiStringEncoding	31	72.1075 ns	0.2739 ns	13,868,378.19
GetAsciiStringStack	31	47.6223 ns	0.1275 ns	20,998,716.21	51%
GetAsciiStringUnrolled	31	19.7378 ns	0.0677 ns	50,664,745.01	265%
GetAsciiStringEncoding	32	73.2524 ns	1.2367 ns	13,655,225.80
GetAsciiStringStack	32	48.6683 ns	0.1808 ns	20,547,546.18	50%
GetAsciiStringUnrolled	32	20.0676 ns	0.3995 ns	49,850,387.65	265%
GetAsciiStringEncoding	33	75.1232 ns	1.5505 ns	13,316,941.26
GetAsciiStringStack	33	48.9495 ns	0.8913 ns	20,435,699.37	53%
GetAsciiStringUnrolled	33	19.9889 ns	0.3932 ns	50,044,933.43	276%
GetAsciiStringEncoding	34	77.7999 ns	0.2349 ns	12,853,606.68
GetAsciiStringStack	34	50.8965 ns	0.1369 ns	19,647,835.70	53%
GetAsciiStringUnrolled	34	20.9920 ns	0.5173 ns	47,665,557.86	271%
GetAsciiStringEncoding	35	78.5528 ns	1.3023 ns	12,733,714.97
GetAsciiStringStack	35	52.0398 ns	0.0678 ns	19,216,097.64	51%
GetAsciiStringUnrolled	35	21.5082 ns	0.0653 ns	46,494,278.30	265%
GetAsciiStringEncoding	36	81.6082 ns	0.3671 ns	12,253,899.17
GetAsciiStringStack	36	53.0631 ns	0.2213 ns	18,845,817.06	54%
GetAsciiStringUnrolled	36	21.8861 ns	0.0575 ns	45,691,340.13	273%
GetAsciiStringEncoding	37	83.3324 ns	0.1186 ns	12,000,157.43
GetAsciiStringStack	37	53.5346 ns	0.8940 ns	18,684,623.54	56%
GetAsciiStringUnrolled	37	22.2454 ns	0.0648 ns	44,953,534.62	275%
GetAsciiStringEncoding	38	84.4947 ns	1.8243 ns	11,840,440.96
GetAsciiStringStack	38	54.9712 ns	0.1666 ns	18,191,500.92	54%
GetAsciiStringUnrolled	38	22.4304 ns	0.0635 ns	44,582,722.44	277%
GetAsciiStringEncoding	39	85.6394 ns	1.4394 ns	11,680,099.44
GetAsciiStringStack	39	56.3114 ns	0.2481 ns	17,758,714.44	52%
GetAsciiStringUnrolled	39	22.4097 ns	0.3473 ns	44,633,799.76	282%
GetAsciiStringEncoding	40	87.3818 ns	2.1064 ns	11,450,364.87
GetAsciiStringStack	40	59.0741 ns	2.1585 ns	16,949,255.23	48%
GetAsciiStringUnrolled	40	22.6736 ns	0.0466 ns	44,104,264.61	285%
GetAsciiStringEncoding	41	90.7927 ns	0.4290 ns	11,014,331.78
GetAsciiStringStack	41	60.4196 ns	2.0145 ns	16,568,306.71	50%
GetAsciiStringUnrolled	41	23.3923 ns	0.3983 ns	42,761,169.33	288%
GetAsciiStringEncoding	42	90.2018 ns	1.6380 ns	11,089,743.59
GetAsciiStringStack	42	59.0223 ns	1.1791 ns	16,949,383.85	53%
GetAsciiStringUnrolled	42	24.0117 ns	0.0715 ns	41,646,755.61	276%
GetAsciiStringEncoding	43	94.2435 ns	0.0716 ns	10,610,815.97
GetAsciiStringStack	43	64.5399 ns	1.0718 ns	15,498,455.18	46%
GetAsciiStringUnrolled	43	24.0080 ns	0.4103 ns	41,664,737.61	293%
GetAsciiStringEncoding	44	94.1801 ns	1.5597 ns	10,620,745.12
GetAsciiStringStack	44	64.1763 ns	1.1878 ns	15,587,172.37	47%
GetAsciiStringUnrolled	44	24.1789 ns	0.0571 ns	41,358,593.30	289%
GetAsciiStringEncoding	45	98.0178 ns	0.0738 ns	10,202,236.96
GetAsciiStringStack	45	66.2021 ns	0.2113 ns	15,105,405.65	48%
GetAsciiStringUnrolled	45	25.1663 ns	0.1113 ns	39,736,450.43	289%
GetAsciiStringEncoding	46	99.0558 ns	1.0954 ns	10,096,513.56
GetAsciiStringStack	46	65.7820 ns	1.1988 ns	15,206,552.63	51%
GetAsciiStringUnrolled	46	24.8659 ns	0.1466 ns	40,216,996.50	298%
GetAsciiStringEncoding	47	100.5068 ns	1.7285 ns	9,952,447.51
GetAsciiStringStack	47	67.0547 ns	1.0724 ns	14,916,921.07	50%
GetAsciiStringUnrolled	47	26.0434 ns	0.0496 ns	38,397,582.45	286%
GetAsciiStringEncoding	48	103.1534 ns	2.1085 ns	9,698,258.21
GetAsciiStringStack	48	68.5015 ns	1.2879 ns	14,603,261.11	51%
GetAsciiStringUnrolled	48	25.6282 ns	0.0812 ns	39,019,914.17	302%
GetAsciiStringEncoding	49	105.4773 ns	0.2176 ns	9,480,753.86
GetAsciiStringStack	49	69.8814 ns	0.1102 ns	14,309,994.81	51%
GetAsciiStringUnrolled	49	26.2259 ns	0.4283 ns	38,139,942.99	302%
GetAsciiStringEncoding	50	105.8742 ns	2.3254 ns	9,449,573.99
GetAsciiStringStack	50	72.1130 ns	1.4607 ns	13,872,718.84	47%
GetAsciiStringUnrolled	50	27.0894 ns	0.0830 ns	36,915,135.99	291%
GetAsciiStringEncoding	51	108.0370 ns	1.8221 ns	9,258,663.41
GetAsciiStringStack	51	71.8510 ns	1.2263 ns	13,921,578.35	50%
GetAsciiStringUnrolled	51	27.5972 ns	0.0934 ns	36,236,016.91	291%
GetAsciiStringEncoding	52	111.2204 ns	0.5066 ns	8,991,338.42
GetAsciiStringStack	52	74.0626 ns	0.2539 ns	13,502,248.36	50%
GetAsciiStringUnrolled	52	28.0177 ns	0.0908 ns	35,692,135.88	297%
GetAsciiStringEncoding	53	112.8264 ns	0.4104 ns	8,863,283.66
GetAsciiStringStack	53	73.6823 ns	1.2595 ns	13,575,649.67	53%
GetAsciiStringUnrolled	53	27.3605 ns	0.1276 ns	36,549,857.05	312%
GetAsciiStringEncoding	54	113.3157 ns	2.1419 ns	8,827,987.21
GetAsciiStringStack	54	75.0048 ns	0.1700 ns	13,332,547.88	51%
GetAsciiStringUnrolled	54	27.7896 ns	0.1065 ns	35,985,175.13	308%
GetAsciiStringEncoding	55	116.2862 ns	0.4476 ns	8,599,596.39
GetAsciiStringStack	55	73.8734 ns	1.4245 ns	13,541,596.32	57%
GetAsciiStringUnrolled	55	28.6603 ns	0.5177 ns	34,902,674.33	306%
GetAsciiStringEncoding	56	119.3017 ns	0.6499 ns	8,382,354.51
GetAsciiStringStack	56	76.9783 ns	0.1384 ns	12,990,710.99	55%
GetAsciiStringUnrolled	56	29.6072 ns	0.0882 ns	33,775,831.87	303%
GetAsciiStringEncoding	57	120.4755 ns	0.4232 ns	8,300,538.22
GetAsciiStringStack	57	76.0326 ns	1.1544 ns	13,155,230.15	58%
GetAsciiStringUnrolled	57	29.7165 ns	0.1258 ns	33,651,973.98	305%
GetAsciiStringEncoding	58	120.5535 ns	2.0244 ns	8,297,355.82
GetAsciiStringStack	58	80.0423 ns	0.4938 ns	12,493,844.30	51%
GetAsciiStringUnrolled	58	29.6413 ns	0.5289 ns	33,746,998.70	307%
GetAsciiStringEncoding	59	122.3798 ns	2.1938 ns	8,173,850.58
GetAsciiStringStack	59	78.7113 ns	1.2848 ns	12,707,904.94	55%
GetAsciiStringUnrolled	59	29.8788 ns	0.3652 ns	33,473,395.01	310%
GetAsciiStringEncoding	60	124.1719 ns	2.2164 ns	8,055,862.63
GetAsciiStringStack	60	81.2583 ns	0.1796 ns	12,306,498.43	53%
GetAsciiStringUnrolled	60	30.9875 ns	0.0536 ns	32,271,166.04	301%
GetAsciiStringEncoding	61	127.6635 ns	0.6244 ns	7,833,272.08
GetAsciiStringStack	61	83.5114 ns	0.2375 ns	11,974,507.46	53%
GetAsciiStringUnrolled	61	31.3584 ns	0.0419 ns	31,889,447.49	307%
GetAsciiStringEncoding	62	127.9033 ns	2.2352 ns	7,820,741.67
GetAsciiStringStack	62	80.2288 ns	1.4863 ns	12,468,431.42	59%
GetAsciiStringUnrolled	62	31.5566 ns	0.0629 ns	31,689,252.11	305%
GetAsciiStringEncoding	63	131.2502 ns	0.7832 ns	7,619,293.34
GetAsciiStringStack	63	82.7944 ns	0.1248 ns	12,078,135.20	59%
GetAsciiStringUnrolled	63	31.7394 ns	0.4595 ns	31,513,044.38	314%
GetAsciiStringEncoding	64	131.6511 ns	2.2129 ns	7,597,935.94
GetAsciiStringStack	64	83.1658 ns	1.4310 ns	12,027,648.41	58%
GetAsciiStringUnrolled	64	32.6071 ns	0.1295 ns	30,668,607.09	304%
GetAsciiStringEncoding	65	135.3443 ns	0.6890 ns	7,388,747.27
GetAsciiStringStack	65	84.9220 ns	0.1228 ns	11,775,541.60	59%
GetAsciiStringUnrolled	65	31.7158 ns	0.1263 ns	31,530,531.78	327%
GetAsciiStringEncoding	66	135.0913 ns	2.3630 ns	7,404,615.66
GetAsciiStringStack	66	86.0645 ns	1.5442 ns	11,622,842.55	57%
GetAsciiStringUnrolled	66	33.2187 ns	0.0711 ns	30,103,693.98	307%
GetAsciiStringEncoding	67	138.7461 ns	0.7294 ns	7,207,595.76
GetAsciiStringStack	67	87.7398 ns	0.1579 ns	11,397,373.75	58%
GetAsciiStringUnrolled	67	33.4898 ns	0.1348 ns	29,860,305.66	314%
GetAsciiStringEncoding	68	140.8501 ns	0.4850 ns	7,099,828.93
GetAsciiStringStack	68	87.3443 ns	1.6001 ns	11,452,703.01	61%
GetAsciiStringUnrolled	68	33.0939 ns	0.1394 ns	30,217,519.35	326%
GetAsciiStringEncoding	69	142.5339 ns	0.4401 ns	7,015,938.07
GetAsciiStringStack	69	88.8778 ns	0.2925 ns	11,251,514.35	60%
GetAsciiStringUnrolled	69	34.4021 ns	0.0976 ns	29,068,243.59	314%
GetAsciiStringEncoding	70	140.9871 ns	2.4454 ns	7,094,888.18
GetAsciiStringStack	70	89.2703 ns	0.1105 ns	11,201,951.18	58%
GetAsciiStringUnrolled	70	34.9844 ns	0.1052 ns	28,584,449.34	303%
GetAsciiStringEncoding	71	146.0357 ns	0.2601 ns	6,847,659.91
GetAsciiStringStack	71	89.8671 ns	0.2524 ns	11,127,632.92	63%
GetAsciiStringUnrolled	71	35.3492 ns	0.1708 ns	28,289,851.51	313%
GetAsciiStringEncoding	72	148.1829 ns	0.5846 ns	6,748,517.06
GetAsciiStringStack	72	88.3982 ns	1.9460 ns	11,317,275.51	68%
GetAsciiStringUnrolled	72	35.7736 ns	0.3331 ns	27,955,864.23	314%
GetAsciiStringEncoding	73	148.0275 ns	2.7551 ns	6,757,795.67
GetAsciiStringStack	73	92.4239 ns	0.3745 ns	10,819,884.44	60%
GetAsciiStringUnrolled	73	36.0294 ns	0.1245 ns	27,755,415.65	311%
GetAsciiStringEncoding	74	151.8114 ns	0.6224 ns	6,587,226.78
GetAsciiStringStack	74	94.2859 ns	0.2559 ns	10,606,116.19	61%
GetAsciiStringUnrolled	74	36.1004 ns	0.0660 ns	27,700,617.45	321%
GetAsciiStringEncoding	75	154.2497 ns	1.5087 ns	6,483,590.82
GetAsciiStringStack	75	95.4720 ns	0.7033 ns	10,474,807.55	62%
GetAsciiStringUnrolled	75	36.2059 ns	0.6294 ns	27,628,000.50	326%
GetAsciiStringEncoding	76	156.0395 ns	0.6231 ns	6,408,733.44
GetAsciiStringStack	76	95.5809 ns	0.1158 ns	10,462,351.87	63%
GetAsciiStringUnrolled	76	37.2298 ns	0.1399 ns	26,860,595.07	319%
GetAsciiStringEncoding	77	157.7147 ns	1.1237 ns	6,340,870.47
GetAsciiStringStack	77	94.9998 ns	1.6717 ns	10,529,523.89	66%
GetAsciiStringUnrolled	77	37.4612 ns	0.1892 ns	26,694,958.74	321%
GetAsciiStringEncoding	78	159.1194 ns	0.5110 ns	6,284,649.51
GetAsciiStringStack	78	96.7728 ns	1.0274 ns	10,334,566.30	64%
GetAsciiStringUnrolled	78	37.6939 ns	0.1153 ns	26,529,707.40	322%
GetAsciiStringEncoding	79	160.8513 ns	0.2415 ns	6,216,934.22
GetAsciiStringStack	79	97.1092 ns	0.6307 ns	10,298,105.84	66%
GetAsciiStringUnrolled	79	38.0406 ns	0.0952 ns	26,287,872.84	323%
GetAsciiStringEncoding	80	162.7922 ns	0.1236 ns	6,142,804.59
GetAsciiStringStack	80	97.2582 ns	1.6836 ns	10,284,926.70	67%
GetAsciiStringUnrolled	80	38.7057 ns	0.1788 ns	25,836,519.59	321%
GetAsciiStringEncoding	81	164.8054 ns	0.6023 ns	6,067,839.94
GetAsciiStringStack	81	98.9893 ns	0.3707 ns	10,102,234.68	66%
GetAsciiStringUnrolled	81	38.5821 ns	0.4893 ns	25,922,840.20	327%
GetAsciiStringEncoding	82	164.4606 ns	3.0080 ns	6,082,474.45
GetAsciiStringStack	82	101.8905 ns	0.3400 ns	9,814,560.89	61%
GetAsciiStringUnrolled	82	39.5835 ns	0.1506 ns	25,263,381.37	315%
GetAsciiStringEncoding	83	169.1799 ns	1.9086 ns	5,911,560.52
GetAsciiStringStack	83	102.3499 ns	0.1015 ns	9,770,413.77	65%
GetAsciiStringUnrolled	83	39.7400 ns	0.1270 ns	25,163,801.81	326%
GetAsciiStringEncoding	84	171.2053 ns	1.0942 ns	5,841,170.60
GetAsciiStringStack	84	102.7868 ns	0.0867 ns	9,728,881.62	67%
GetAsciiStringUnrolled	84	38.7474 ns	0.1879 ns	25,808,736.27	342%
GetAsciiStringEncoding	85	171.8738 ns	0.1169 ns	5,818,223.42
GetAsciiStringStack	85	103.3070 ns	0.3461 ns	9,679,989.19	66%
GetAsciiStringUnrolled	85	40.1327 ns	0.7376 ns	24,925,562.60	328%
GetAsciiStringEncoding	86	173.7038 ns	0.2520 ns	5,756,938.21
GetAsciiStringStack	86	103.4217 ns	1.7671 ns	9,671,915.62	68%
GetAsciiStringUnrolled	86	39.3751 ns	0.1796 ns	25,397,296.51	341%
GetAsciiStringEncoding	87	176.3119 ns	1.2414 ns	5,672,038.63
GetAsciiStringStack	87	104.5131 ns	1.0896 ns	9,569,184.02	69%
GetAsciiStringUnrolled	87	41.4257 ns	0.4225 ns	24,141,951.05	326%
GetAsciiStringEncoding	88	175.5169 ns	3.0111 ns	5,699,097.18
GetAsciiStringStack	88	105.3018 ns	1.9435 ns	9,499,680.74	67%
GetAsciiStringUnrolled	88	41.2813 ns	1.1543 ns	24,241,871.01	325%
GetAsciiStringEncoding	89	179.6256 ns	0.8114 ns	5,567,242.43
GetAsciiStringStack	89	107.8481 ns	0.4060 ns	9,272,427.18	67%
GetAsciiStringUnrolled	89	41.6976 ns	0.6848 ns	23,988,523.91	331%
GetAsciiStringEncoding	90	181.7802 ns	0.7951 ns	5,501,249.25
GetAsciiStringStack	90	107.6579 ns	2.1216 ns	9,292,196.34	69%
GetAsciiStringUnrolled	90	42.3043 ns	0.1081 ns	23,638,425.66	330%
GetAsciiStringEncoding	91	183.0337 ns	0.7597 ns	5,463,563.38
GetAsciiStringStack	91	108.3365 ns	1.9540 ns	9,233,437.60	69%
GetAsciiStringUnrolled	91	42.6017 ns	0.1799 ns	23,473,649.09	330%
GetAsciiStringEncoding	92	185.0401 ns	0.9934 ns	5,404,381.54
GetAsciiStringStack	92	108.8356 ns	1.8898 ns	9,190,881.37	70%
GetAsciiStringUnrolled	92	43.3148 ns	0.1385 ns	23,087,012.82	327%
GetAsciiStringEncoding	93	186.6905 ns	0.1691 ns	5,356,463.16
GetAsciiStringStack	93	110.5899 ns	0.2924 ns	9,042,481.81	69%
GetAsciiStringUnrolled	93	42.5325 ns	0.6945 ns	23,517,405.59	339%
GetAsciiStringEncoding	94	189.1519 ns	1.5878 ns	5,287,106.88
GetAsciiStringStack	94	112.0398 ns	0.4531 ns	8,925,538.96	69%
GetAsciiStringUnrolled	94	43.5655 ns	0.6660 ns	22,959,189.35	334%
GetAsciiStringEncoding	95	191.0141 ns	1.0566 ns	5,235,370.32
GetAsciiStringStack	95	110.8591 ns	1.6453 ns	9,022,393.76	72%
GetAsciiStringUnrolled	95	44.4152 ns	0.1813 ns	22,515,199.50	330%
GetAsciiStringEncoding	96	192.4730 ns	2.6686 ns	5,196,515.14
GetAsciiStringStack	96	111.7660 ns	1.9298 ns	8,949,874.51	72%
GetAsciiStringUnrolled	96	44.8737 ns	0.2062 ns	22,285,221.73	329%
GetAsciiStringEncoding	508	944.8759 ns	17.0763 ns	1,058,678.46
GetAsciiStringStack	508	579.5744 ns	1.3352 ns	1,725,412.84	63%
GetAsciiStringUnrolled	508	206.7729 ns	0.5415 ns	4,836,256.08	357%
GetAsciiStringEncoding	509	946.5941 ns	17.1607 ns	1,056,758.62
GetAsciiStringStack	509	579.5389 ns	2.1671 ns	1,725,532.93	63%
GetAsciiStringUnrolled	509	204.2443 ns	4.5613 ns	4,898,449.60	364%
GetAsciiStringEncoding	510	938.5520 ns	19.4110 ns	1,065,905.56
GetAsciiStringStack	510	580.9886 ns	1.4832 ns	1,721,214.91	61%
GetAsciiStringUnrolled	510	203.4664 ns	3.5925 ns	4,916,315.08	361%
GetAsciiStringEncoding	511	949.2423 ns	16.6339 ns	1,053,788.50
GetAsciiStringStack	511	575.3920 ns	8.9746 ns	1,738,358.77	65%
GetAsciiStringUnrolled	511	207.0813 ns	0.7946 ns	4,829,088.72	358%
GetAsciiStringEncoding	512	950.7381 ns	17.7106 ns	1,052,171.32
GetAsciiStringStack	512	574.6530 ns	9.7788 ns	1,740,673.21	65%
GetAsciiStringUnrolled	512	208.0087 ns	0.4574 ns	4,807,514.19	357%
GetAsciiStringEncoding	513	953.8168 ns	17.6302 ns	1,048,769.47
GetAsciiStringStack	513	586.0188 ns	2.2532 ns	1,706,454.22	63%
GetAsciiStringUnrolled	513	207.4819 ns	0.8733 ns	4,819,779.47	360%
GetAsciiStringEncoding	543	1,020.3621 ns	1.2628 ns	980,045.67
GetAsciiStringStack	543	610.0105 ns	9.1914 ns	1,639,679.98	67%
GetAsciiStringUnrolled	543	221.1857 ns	0.8742 ns	4,521,155.30	361%
GetAsciiStringEncoding	544	1,024.6794 ns	4.7021 ns	975,934.69
GetAsciiStringStack	544	614.9500 ns	2.1888 ns	1,626,168.30	67%
GetAsciiStringUnrolled	544	222.1349 ns	0.5794 ns	4,501,798.23	361%
GetAsciiStringEncoding	547	1,018.0020 ns	17.9729 ns	982,616.33
GetAsciiStringStack	547	615.6357 ns	9.3914 ns	1,624,707.14	65%
GetAsciiStringUnrolled	547	221.0544 ns	1.1208 ns	4,523,885.37	360%
GetAsciiStringEncoding	576	1,079.6416 ns	0.5652 ns	926,233.57
GetAsciiStringStack	576	650.5971 ns	3.2925 ns	1,537,087.13	66%
GetAsciiStringUnrolled	576	235.2686 ns	1.7363 ns	4,250,684.86	359%
GetAsciiStringEncoding	1024	1,915.6749 ns	6.6849 ns	522,015.39
GetAsciiStringStack	1024	940.9080 ns	18.4671 ns	1,063,194.87	104%
GetAsciiStringUnrolled	1024	408.9411 ns	1.9981 ns	2,445,395.80	368%
GetAsciiStringEncoding	4096	7,642.0782 ns	9.6052 ns	130,854.66
GetAsciiStringStack	4096	3,754.2921 ns	13.0359 ns	266,364.90	104%
GetAsciiStringUnrolled	4096	1,635.3924 ns	11.3656 ns	611,502.51	367%
GetAsciiStringEncoding	8512	15,603.8434 ns	275.6553 ns	64,106.35
GetAsciiStringStack	8512	7,793.4370 ns	12.7716 ns	128,313.42	100%
GetAsciiStringUnrolled	8512	3,274.6417 ns	7.8795 ns	305,378.63	376%

Though Encoding.ASCII.GetString can't be used anyway as a pre-completed array is needed due to string immutableness (ignoring what this PR is doing); so that situation is much worse.

[halter73]

Thanks for redoing the tests.