[stdilb]Re-enable iterator benchmarks, remove longSharedPrefix from hashing b…

[lancep]

rdar://problem/44944382

[lancep]

@swift-ci please smoke test

[lancep]

@swift-ci please benchmark

[swift-ci]

Build comment file:

Performance: -O

TEST	MIN	MAX	MEAN	MAX_RSS
Added
NormalizedIterator_abnormal	1547	1594	1563	—
NormalizedIterator_ascii	177	180	178	—
NormalizedIterator_emoji	1319	1350	1329	—
NormalizedIterator_fastPrenormal	1613	1642	1623	—
NormalizedIterator_latin1	525	525	525	—
NormalizedIterator_nonBMPSlowestPrenormal	1715	1756	1729	—
NormalizedIterator_slowerPrenormal	1005	1006	1006	—
NormalizedIterator_zalgo	3837	3857	3846	—
Removed
StringHashing_longSharedPrefix	1133	1134	1133	—

Code size: -O

TEST	OLD	NEW	DELTA	RATIO
Regression
StringComparison.o	37900	44374	+17.1%	0.85x

Performance: -Osize

TEST	MIN	MAX	MEAN	MAX_RSS
Added
NormalizedIterator_abnormal	1594	1646	1612	—
NormalizedIterator_ascii	205	211	207	—
NormalizedIterator_emoji	1361	1378	1367	—
NormalizedIterator_fastPrenormal	1625	1682	1658	—
NormalizedIterator_latin1	545	545	545	—
NormalizedIterator_nonBMPSlowestPrenormal	1770	1841	1800	—
NormalizedIterator_slowerPrenormal	1027	1029	1028	—
NormalizedIterator_zalgo	3925	4024	3964	—
Removed
StringHashing_longSharedPrefix	1133	1149	1138	—

Code size: -Osize

TEST	OLD	NEW	DELTA	RATIO
Regression
StringComparison.o	33796	38854	+15.0%	0.87x

Performance: -Onone

TEST	MIN	MAX	MEAN	MAX_RSS
Added
NormalizedIterator_abnormal	1653	1693	1667	—
NormalizedIterator_ascii	294	295	294	—
NormalizedIterator_emoji	1356	1386	1366	—
NormalizedIterator_fastPrenormal	1675	1712	1687	—
NormalizedIterator_latin1	632	633	632	—
NormalizedIterator_nonBMPSlowestPrenormal	1755	1785	1765	—
NormalizedIterator_slowerPrenormal	1089	1090	1089	—
NormalizedIterator_zalgo	3883	3902	3891	—
Removed
StringHashing_longSharedPrefix	1228	1299	1257	—

How to read the data

The tables contain differences in performance which are larger than 8% and differences in code size which are larger than 1%.

If you see any unexpected regressions, you should consider fixing the
regressions before you merge the PR.

Noise: Sometimes the performance results (not code size!) contain false
alarms. Unexpected regressions which are marked with '(?)' are probably noise.
If you see regressions which you cannot explain you can try to run the
benchmarks again. If regressions still show up, please consult with the
performance team (@eeckstein).

Hardware Overview

  Model Name: Mac Pro
  Model Identifier: MacPro6,1
  Processor Name: 8-Core Intel Xeon E5
  Processor Speed: 3 GHz
  Number of Processors: 1
  Total Number of Cores: 8
  L2 Cache (per Core): 256 KB
  L3 Cache: 25 MB
  Memory: 64 GB

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