Always enable copy propagation.

[nate-chandler]

Update the default SILOptions value for CopyPropagation and LexicalLifetimes.

[atrick]

💯 This means we can finally canonicalize OSSA form, so we aren't hiding compiler bugs and hoping no one notices

[nate-chandler]

@swift-ci please benchmark

[nate-chandler]

@swift-ci please test

[swift-ci]

Performance (x86_64): -O

Regression	OLD	NEW	DELTA	RATIO
FindString.Rec3.Substring	183	200	+9.3%	0.92x (?)
FindString.Loop1.Substring	483	521	+7.9%	0.93x (?)
RemoveWhereQuadraticString	294	317	+7.8%	0.93x (?)
EqualSubstringSubstring	39	42	+7.7%	0.93x (?)
Improvement	OLD	NEW	DELTA	RATIO
StringFromLongWholeSubstring	5	4	-20.0%	1.25x

Code size: -O

Improvement	OLD	NEW	DELTA	RATIO
Combos.o	6038	5974	-1.1%	1.01x

Performance (x86_64): -Osize

Regression	OLD	NEW	DELTA	RATIO
FlattenListLoop	1780	2638	+48.2%	0.67x (?)
FlattenListFlatMap	4924	6635	+34.7%	0.74x (?)
ObserverForwarderStruct	955	1140	+19.4%	0.84x (?)
PrefixAnyCollection	180	198	+10.0%	0.91x
PrefixAnySeqCRangeIterLazy	176	193	+9.7%	0.91x
PrefixAnySeqCntRangeLazy	176	193	+9.7%	0.91x
DropWhileAnyCollection	198	216	+9.1%	0.92x
StringComparison_emoji	424	460	+8.5%	0.92x (?)
RemoveWhereQuadraticString	292	315	+7.9%	0.93x (?)
Improvement	OLD	NEW	DELTA	RATIO
DataCountMedium	34	28	-17.6%	1.21x
DictionaryKeysContainsCocoa	29	24	-17.2%	1.21x (?)
DataSubscriptSmall	37	31	-16.2%	1.19x
DropWhileAnySeqCRangeIter	217	182	-16.1%	1.19x
DropWhileAnySeqCntRange	209	182	-12.9%	1.15x (?)
DataAccessBytesMedium	91	82	-9.9%	1.11x (?)
DataCountSmall	31	28	-9.7%	1.11x
DataAccessBytesSmall	108	98	-9.3%	1.10x
DropFirstAnyCollection	198	180	-9.1%	1.10x (?)
StringBuilderSmallReservingCapacity	342	315	-7.9%	1.09x (?)

Code size: -Osize

Regression	OLD	NEW	DELTA	RATIO
ObserverForwarderStruct.o	3087	3142	+1.8%	0.98x

Performance (x86_64): -Onone

Regression	OLD	NEW	DELTA	RATIO
OpaqueConsumingUsers	14500	18500	+27.6%	0.78x
LinkedList	43920	54080	+23.1%	0.81x
RandomDoubleOpaqueDef	51900	55900	+7.7%	0.93x (?)
Improvement	OLD	NEW	DELTA	RATIO
NSStringConversion.Long	8413	5136	-39.0%	1.64x
NSStringConversion.Medium	3205	2021	-36.9%	1.59x
NSStringConversion.LongUTF8	3127	2032	-35.0%	1.54x
NSStringConversion.MutableCopy.Long	2758	1883	-31.7%	1.46x
NSStringConversion.MutableCopy.LongUTF8	2010	1456	-27.6%	1.38x
NSStringConversion.UTF8	3708	2697	-27.3%	1.37x
NSStringConversion.MutableCopy.Medium	2372	1784	-24.8%	1.33x
StringWalk	15400	11880	-22.9%	1.30x
StrComplexWalk	19580	16430	-16.1%	1.19x
NSStringConversion.MutableCopy.UTF8	1726	1529	-11.4%	1.13x (?)
DataToStringSmall	6250	5600	-10.4%	1.12x (?)
CSVParsingAlt2	3157	2860	-9.4%	1.10x (?)
NSError	704	653	-7.2%	1.08x (?)
CharIteration_chinese_unicodeScalars_Backwards	89520	83160	-7.1%	1.08x (?)
CharIteration_utf16_unicodeScalars_Backwards	138760	129040	-7.0%	1.08x (?)

Code size: -swiftlibs

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: 12-Core Intel Xeon E5
  Processor Speed: 2.7 GHz
  Number of Processors: 1
  Total Number of Cores: 12
  L2 Cache (per Core): 256 KB
  L3 Cache: 30 MB
  Memory: 64 GB