This PR improves our reasoning about when to (and, more importantly, when not to) create deferred type references. We now create fewer deferred type references which improves overall compile times for the repro in #36566 by around 4%.

Fixes #36566.

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Heya @ahejlsberg, I've started to run the perf test suite on this PR at cba9ff3. You can monitor the build here. It should now contribute to this PR's status checks.

Heya @ahejlsberg, I've started to run the extended test suite on this PR at cba9ff3. You can monitor the build here. It should now contribute to this PR's status checks.

Heya @ahejlsberg, I've started to run the parallelized Definitely Typed test suite on this PR at cba9ff3. You can monitor the build here. It should now contribute to this PR's status checks.

Heya @ahejlsberg, I've started to run the parallelized community code test suite on this PR at cba9ff3. You can monitor the build here. It should now contribute to this PR's status checks.

The user suite test run you requested has finished and failed. I've opened a PR with the baseline diff from master.

@typescript-bot test this
@typescript-bot user test this
@typescript-bot run dt
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Heya @ahejlsberg, I've started to run the parallelized Definitely Typed test suite on this PR at e1fd56a. You can monitor the build here. It should now contribute to this PR's status checks.

Heya @ahejlsberg, I've started to run the perf test suite on this PR at e1fd56a. You can monitor the build here. It should now contribute to this PR's status checks.

Update: The results are in!

Heya @ahejlsberg, I've started to run the extended test suite on this PR at e1fd56a. You can monitor the build here. It should now contribute to this PR's status checks.

Heya @ahejlsberg, I've started to run the parallelized community code test suite on this PR at e1fd56a. You can monitor the build here. It should now contribute to this PR's status checks.

@ahejlsberg
The results of the perf run you requested are in!

Here they are:

Comparison Report - master..36607

Metric	master	36607	Delta	Best	Worst
Angular - node (v10.16.3, x64)
Memory used	356,421k (± 0.01%)	358,155k (± 0.02%)	+1,735k (+ 0.49%)	358,014k	358,397k
Parse Time	1.60s (± 0.50%)	1.61s (± 0.71%)	+0.01s (+ 0.69%)	1.60s	1.65s
Bind Time	0.89s (± 0.77%)	0.88s (± 0.92%)	-0.00s (- 0.56%)	0.86s	0.90s
Check Time	4.65s (± 0.54%)	4.67s (± 0.58%)	+0.02s (+ 0.34%)	4.61s	4.73s
Emit Time	5.18s (± 0.52%)	5.19s (± 0.52%)	+0.01s (+ 0.19%)	5.16s	5.26s
Total Time	12.32s (± 0.42%)	12.35s (± 0.41%)	+0.03s (+ 0.23%)	12.27s	12.47s
Monaco - node (v10.16.3, x64)
Memory used	364,637k (± 0.01%)	364,628k (± 0.02%)	-9k (- 0.00%)	364,490k	364,781k
Parse Time	1.24s (± 0.77%)	1.25s (± 0.40%)	+0.00s (+ 0.08%)	1.24s	1.26s
Bind Time	0.78s (± 0.48%)	0.77s (± 0.58%)	-0.00s (- 0.39%)	0.76s	0.78s
Check Time	4.69s (± 0.48%)	4.67s (± 0.30%)	-0.02s (- 0.41%)	4.65s	4.71s
Emit Time	2.90s (± 0.46%)	2.89s (± 0.85%)	-0.01s (- 0.28%)	2.85s	2.97s
Total Time	9.61s (± 0.34%)	9.58s (± 0.35%)	-0.03s (- 0.30%)	9.53s	9.69s
TFS - node (v10.16.3, x64)
Memory used	324,095k (± 0.01%)	324,224k (± 0.09%)	+130k (+ 0.04%)	323,979k	325,312k
Parse Time	0.95s (± 0.70%)	0.94s (± 0.36%)	-0.01s (- 0.74%)	0.94s	0.95s
Bind Time	0.75s (± 1.00%)	0.74s (± 1.31%)	-0.01s (- 1.07%)	0.72s	0.76s
Check Time	4.25s (± 0.48%)	4.23s (± 0.58%)	-0.02s (- 0.56%)	4.18s	4.29s
Emit Time	3.04s (± 0.82%)	3.01s (± 0.79%)	-0.03s (- 0.92%)	2.95s	3.05s
Total Time	8.98s (± 0.39%)	8.92s (± 0.37%)	-0.07s (- 0.73%)	8.84s	8.99s
Angular - node (v12.1.0, x64)
Memory used	332,321k (± 0.02%)	333,844k (± 0.01%)	+1,523k (+ 0.46%)	333,736k	333,935k
Parse Time	1.56s (± 0.51%)	1.56s (± 0.43%)	+0.00s (+ 0.32%)	1.55s	1.58s
Bind Time	0.86s (± 0.77%)	0.87s (± 0.64%)	+0.01s (+ 0.58%)	0.86s	0.88s
Check Time	4.57s (± 0.59%)	4.57s (± 0.57%)	-0.00s (- 0.04%)	4.52s	4.64s
Emit Time	5.37s (± 0.62%)	5.38s (± 0.68%)	+0.01s (+ 0.20%)	5.31s	5.46s
Total Time	12.37s (± 0.24%)	12.39s (± 0.33%)	+0.02s (+ 0.17%)	12.31s	12.49s
Monaco - node (v12.1.0, x64)
Memory used	344,524k (± 0.02%)	344,487k (± 0.01%)	-37k (- 0.01%)	344,406k	344,535k
Parse Time	1.21s (± 0.55%)	1.21s (± 0.58%)	-0.00s (- 0.08%)	1.20s	1.23s
Bind Time	0.75s (± 0.89%)	0.74s (± 0.64%)	-0.01s (- 0.93%)	0.73s	0.75s
Check Time	4.54s (± 0.55%)	4.56s (± 0.39%)	+0.01s (+ 0.24%)	4.50s	4.58s
Emit Time	2.96s (± 1.17%)	2.97s (± 0.74%)	+0.01s (+ 0.30%)	2.94s	3.03s
Total Time	9.47s (± 0.51%)	9.48s (± 0.36%)	+0.01s (+ 0.11%)	9.40s	9.55s
TFS - node (v12.1.0, x64)
Memory used	306,373k (± 0.01%)	306,425k (± 0.02%)	+51k (+ 0.02%)	306,337k	306,600k
Parse Time	0.94s (± 0.55%)	0.94s (± 0.50%)	+0.00s (+ 0.11%)	0.93s	0.95s
Bind Time	0.71s (± 0.85%)	0.70s (± 0.48%)	-0.00s (- 0.28%)	0.70s	0.71s
Check Time	4.18s (± 0.51%)	4.20s (± 0.61%)	+0.02s (+ 0.48%)	4.13s	4.26s
Emit Time	3.05s (± 0.73%)	3.07s (± 0.59%)	+0.02s (+ 0.56%)	3.02s	3.10s
Total Time	8.87s (± 0.48%)	8.91s (± 0.40%)	+0.04s (+ 0.44%)	8.86s	9.01s
Angular - node (v8.9.0, x64)
Memory used	351,509k (± 0.01%)	353,139k (± 0.01%)	+1,630k (+ 0.46%)	353,047k	353,241k
Parse Time	2.10s (± 0.48%)	2.11s (± 0.52%)	+0.02s (+ 0.81%)	2.08s	2.13s
Bind Time	0.92s (± 0.92%)	0.93s (± 0.60%)	+0.01s (+ 1.19%)	0.92s	0.94s
Check Time	5.46s (± 0.64%)	5.39s (± 0.48%)	-0.07s (- 1.25%)	5.33s	5.45s
Emit Time	6.21s (± 0.73%)	6.22s (± 0.93%)	+0.01s (+ 0.18%)	6.15s	6.38s
Total Time	14.69s (± 0.46%)	14.65s (± 0.43%)	-0.03s (- 0.23%)	14.55s	14.81s
Monaco - node (v8.9.0, x64)
Memory used	362,875k (± 0.01%)	362,882k (± 0.01%)	+7k (+ 0.00%)	362,749k	363,001k
Parse Time	1.56s (± 0.72%)	1.55s (± 0.38%)	-0.00s (- 0.06%)	1.54s	1.57s
Bind Time	0.95s (± 0.70%)	0.95s (± 0.70%)	+0.00s (+ 0.32%)	0.94s	0.97s
Check Time	5.41s (± 1.58%)	5.34s (± 0.90%)	-0.06s (- 1.18%)	5.30s	5.51s
Emit Time	3.23s (± 4.81%)	3.36s (± 3.10%)	+0.13s (+ 3.96%)	2.97s	3.49s
Total Time	11.15s (± 0.89%)	11.21s (± 0.73%)	+0.06s (+ 0.53%)	10.99s	11.43s
TFS - node (v8.9.0, x64)
Memory used	323,458k (± 0.01%)	323,440k (± 0.02%)	-18k (- 0.01%)	323,365k	323,566k
Parse Time	1.25s (± 0.30%)	1.26s (± 0.70%)	+0.01s (+ 0.64%)	1.25s	1.28s
Bind Time	0.76s (± 0.59%)	0.76s (± 0.91%)	-0.00s (- 0.40%)	0.74s	0.77s
Check Time	4.83s (± 0.49%)	4.82s (± 0.94%)	-0.01s (- 0.27%)	4.74s	4.94s
Emit Time	3.19s (± 0.71%)	3.19s (± 0.61%)	-0.00s (- 0.09%)	3.15s	3.23s
Total Time	10.04s (± 0.34%)	10.02s (± 0.61%)	-0.01s (- 0.14%)	9.90s	10.14s
Angular - node (v8.9.0, x86)
Memory used	199,873k (± 0.03%)	200,712k (± 0.03%)	+839k (+ 0.42%)	200,617k	200,883k
Parse Time	2.03s (± 0.58%)	2.04s (± 0.53%)	+0.01s (+ 0.34%)	2.01s	2.06s
Bind Time	1.04s (± 0.78%)	1.06s (± 0.47%)	+0.01s (+ 1.25%)	1.05s	1.07s
Check Time	4.97s (± 0.37%)	4.93s (± 0.51%)	-0.04s (- 0.72%)	4.87s	4.98s
Emit Time	6.09s (± 1.90%)	6.10s (± 1.71%)	+0.01s (+ 0.13%)	5.92s	6.31s
Total Time	14.13s (± 0.93%)	14.13s (± 0.80%)	-0.01s (- 0.05%)	13.93s	14.39s
Monaco - node (v8.9.0, x86)
Memory used	203,723k (± 0.02%)	203,723k (± 0.02%)	+1k (+ 0.00%)	203,609k	203,815k
Parse Time	1.60s (± 0.93%)	1.61s (± 0.46%)	+0.00s (+ 0.12%)	1.59s	1.62s
Bind Time	0.77s (± 0.78%)	0.77s (± 1.56%)	+0.00s (+ 0.52%)	0.76s	0.81s
Check Time	5.16s (± 1.38%)	5.14s (± 0.83%)	-0.02s (- 0.43%)	5.07s	5.24s
Emit Time	3.13s (± 2.59%)	3.16s (± 1.15%)	+0.03s (+ 0.96%)	3.07s	3.22s
Total Time	10.67s (± 0.57%)	10.68s (± 0.27%)	+0.01s (+ 0.12%)	10.60s	10.74s
TFS - node (v8.9.0, x86)
Memory used	182,614k (± 0.03%)	182,570k (± 0.01%)	-44k (- 0.02%)	182,529k	182,629k
Parse Time	1.31s (± 1.09%)	1.30s (± 0.44%)	-0.00s (- 0.38%)	1.28s	1.31s
Bind Time	0.71s (± 0.99%)	0.71s (± 1.15%)	+0.00s (+ 0.14%)	0.70s	0.73s
Check Time	4.54s (± 0.50%)	4.57s (± 0.41%)	+0.03s (+ 0.59%)	4.53s	4.61s
Emit Time	2.97s (± 0.73%)	2.95s (± 1.03%)	-0.02s (- 0.77%)	2.84s	3.00s
Total Time	9.53s (± 0.33%)	9.53s (± 0.41%)	0.00s ( 0.00%)	9.39s	9.59s

System

Machine Name	ts-ci-ubuntu
Platform	linux 4.4.0-166-generic
Architecture	x64
Available Memory	16 GB
Available Memory	4 GB
CPUs	4 × Intel(R) Core(TM) i7-4770 CPU @ 3.40GHz

Hosts

• node (v10.16.3, x64)
• node (v12.1.0, x64)
• node (v8.9.0, x64)
• node (v8.9.0, x86)

Scenarios

• Angular - node (v10.16.3, x64)
• Angular - node (v12.1.0, x64)
• Angular - node (v8.9.0, x64)
• Angular - node (v8.9.0, x86)
• Monaco - node (v10.16.3, x64)
• Monaco - node (v12.1.0, x64)
• Monaco - node (v8.9.0, x64)
• Monaco - node (v8.9.0, x86)
• TFS - node (v10.16.3, x64)
• TFS - node (v12.1.0, x64)
• TFS - node (v8.9.0, x64)
• TFS - node (v8.9.0, x86)

Benchmark	Name	Iterations
Current	36607	10
Baseline	master	10

@typescript-bot run dt

Heya @ahejlsberg, I've started to run the parallelized Definitely Typed test suite on this PR at 6ebc9e3. You can monitor the build here. It should now contribute to this PR's status checks.

Tests look clean. Only change is a minor type ordering difference in a few error messages in RWC.

10-run average from the original machine shows a 5% improvement. Very nice!