Improve reduction of similar intersections in type inference

[ahejlsberg]

Fixes #51399.

[ahejlsberg]

@typescript-bot test this
@typescript-bot user test this inline
@typescript-bot run dt
@typescript-bot perf test faster
@typescript-bot test top100

[typescript-bot]

Heya @ahejlsberg, I've started to run the parallelized Definitely Typed test suite on this PR at 47858b0. You can monitor the build here.

[typescript-bot]

Heya @ahejlsberg, I've started to run the extended test suite on this PR at 47858b0. You can monitor the build here.

[typescript-bot]

Heya @ahejlsberg, I've started to run the abridged perf test suite on this PR at 47858b0. You can monitor the build here.

Update: The results are in!

[typescript-bot]

Heya @ahejlsberg, I've started to run the diff-based user code test suite on this PR at 47858b0. You can monitor the build here.

Update: The results are in!

[typescript-bot]

Heya @ahejlsberg, I've started to run the diff-based top-repos suite on this PR at 47858b0. You can monitor the build here.

Update: The results are in!

[typescript-bot]

@ahejlsberg Here are the results of running the user test suite comparing main and refs/pull/51405/merge:

Everything looks good!

[typescript-bot]

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

Here they are:

Comparison Report - main..51405

Metric	main	51405	Delta	Best	Worst
Angular - node (v16.17.1, x64)
Memory used	353,460k (± 0.01%)	353,397k (± 0.01%)	-64k (- 0.02%)	353,283k	353,487k
Parse Time	1.91s (± 0.98%)	1.91s (± 0.70%)	0.00s ( 0.00%)	1.89s	1.96s
Bind Time	0.75s (± 0.82%)	0.75s (± 0.53%)	-0.00s (- 0.27%)	0.74s	0.76s
Check Time	5.72s (± 0.49%)	5.70s (± 0.54%)	-0.03s (- 0.45%)	5.65s	5.77s
Emit Time	6.15s (± 0.61%)	6.10s (± 0.85%)	-0.05s (- 0.86%)	6.02s	6.29s
Total Time	14.54s (± 0.37%)	14.45s (± 0.43%)	-0.08s (- 0.58%)	14.39s	14.69s
Compiler-Unions - node (v16.17.1, x64)
Memory used	198,179k (± 0.36%)	198,509k (± 0.49%)	+330k (+ 0.17%)	197,798k	201,163k
Parse Time	0.79s (± 0.76%)	0.78s (± 0.46%)	-0.00s (- 0.25%)	0.78s	0.79s
Bind Time	0.46s (± 1.21%)	0.45s (± 0.75%)	-0.01s (- 1.09%)	0.45s	0.46s
Check Time	6.54s (± 0.94%)	6.51s (± 0.60%)	-0.03s (- 0.47%)	6.45s	6.60s
Emit Time	2.29s (± 1.33%)	2.29s (± 1.11%)	-0.00s (- 0.04%)	2.23s	2.36s
Total Time	10.08s (± 0.81%)	10.04s (± 0.51%)	-0.04s (- 0.39%)	9.94s	10.15s
Monaco - node (v16.17.1, x64)
Memory used	331,351k (± 0.01%)	331,371k (± 0.01%)	+20k (+ 0.01%)	331,301k	331,425k
Parse Time	1.44s (± 0.75%)	1.43s (± 0.51%)	-0.01s (- 0.62%)	1.42s	1.45s
Bind Time	0.70s (± 0.71%)	0.69s (± 0.80%)	-0.00s (- 0.57%)	0.68s	0.70s
Check Time	5.50s (± 0.63%)	5.49s (± 0.66%)	-0.02s (- 0.29%)	5.43s	5.61s
Emit Time	3.26s (± 0.43%)	3.26s (± 0.46%)	+0.00s (+ 0.06%)	3.23s	3.30s
Total Time	10.90s (± 0.38%)	10.87s (± 0.33%)	-0.03s (- 0.24%)	10.83s	10.98s
TFS - node (v16.17.1, x64)
Memory used	294,145k (± 0.01%)	294,145k (± 0.03%)	+0k (+ 0.00%)	293,924k	294,228k
Parse Time	1.24s (± 1.56%)	1.23s (± 1.53%)	-0.02s (- 1.21%)	1.18s	1.27s
Bind Time	0.64s (± 0.58%)	0.64s (± 0.81%)	-0.00s (- 0.62%)	0.63s	0.65s
Check Time	5.15s (± 0.41%)	5.15s (± 0.44%)	-0.00s (- 0.08%)	5.11s	5.21s
Emit Time	3.49s (± 0.59%)	3.49s (± 0.89%)	+0.00s (+ 0.03%)	3.42s	3.55s
Total Time	10.53s (± 0.44%)	10.51s (± 0.43%)	-0.03s (- 0.25%)	10.39s	10.59s
material-ui - node (v16.17.1, x64)
Memory used	439,258k (± 0.01%)	447,157k (± 0.01%)	+7,898k (+ 1.80%)	447,080k	447,265k
Parse Time	1.74s (± 1.25%)	1.72s (± 1.47%)	-0.02s (- 1.20%)	1.67s	1.76s
Bind Time	0.55s (± 0.68%)	0.54s (± 0.63%)	-0.01s (- 1.47%)	0.53s	0.54s
Check Time	12.58s (± 0.69%)	12.64s (± 0.29%)	+0.06s (+ 0.45%)	12.58s	12.76s
Emit Time	0.00s (± 0.00%)	0.00s (± 0.00%)	0.00s ( NaN%)	0.00s	0.00s
Total Time	14.87s (± 0.70%)	14.90s (± 0.34%)	+0.03s (+ 0.20%)	14.80s	15.03s
xstate - node (v16.17.1, x64)
Memory used	554,948k (± 0.02%)	555,018k (± 0.02%)	+70k (+ 0.01%)	554,822k	555,179k
Parse Time	2.32s (± 0.55%)	2.31s (± 0.54%)	-0.01s (- 0.56%)	2.28s	2.34s
Bind Time	0.90s (± 1.07%)	0.90s (± 2.43%)	+0.00s (+ 0.22%)	0.87s	0.95s
Check Time	1.44s (± 0.70%)	1.42s (± 0.96%)	-0.02s (- 1.59%)	1.39s	1.45s
Emit Time	0.07s (± 0.00%)	0.07s (± 4.37%)	-0.00s (- 2.86%)	0.06s	0.07s
Total Time	4.73s (± 0.34%)	4.70s (± 0.41%)	-0.03s (- 0.57%)	4.66s	4.75s

System

Machine Name	ts-ci-ubuntu
Platform	linux 5.4.0-126-generic
Architecture	x64
Available Memory	16 GB
Available Memory	15 GB
CPUs	4 × Intel(R) Core(TM) i7-4770 CPU @ 3.40GHz

Hosts

• node (v16.17.1, x64)

Scenarios

• Angular - node (v16.17.1, x64)
• Compiler-Unions - node (v16.17.1, x64)
• Monaco - node (v16.17.1, x64)
• TFS - node (v16.17.1, x64)
• material-ui - node (v16.17.1, x64)
• xstate - node (v16.17.1, x64)

Benchmark	Name	Iterations
Current	51405	10
Baseline	main	10

Developer Information:

Download Benchmark

[typescript-bot]

Heya @ahejlsberg, I've run the RWC suite on this PR - assuming you're on the TS core team, you can view the resulting diff here.

[typescript-bot]

@ahejlsberg Here are the results of running the top-repos suite comparing main and refs/pull/51405/merge:

Everything looks good!

[ahejlsberg]

Tests and performance are all unaffected. I think this one is ready to merge.