Starting with GHC 8.2 (rc1 -- head) I noticed that the SpecConstr pass does not always optimize completely with SpecConstr-heavy code. Setting ```-fmax-worker-args=100``` leads to complete specialization again. However, given that code annotated with ```SPEC``` should be optimized until no more ```SPEC``` arguments are alive, shouldn't ```callToNewPats``` in ```compiler/specialise/SpecConstr.hs``` specialize \*irrespective\* of the size of the worker argument list? Code that actually fails to specialize is fairly large, hence no test case -- though I have some files with core output showing insufficient specialization. (I'd be willing to write a patch for this) <details><summary>Trac metadata</summary> | Trac field | Value | | ---------------------- | -------------- | | Version | 8.2.1-rc3 | | Type | FeatureRequest | | TypeOfFailure | OtherFailure | | Priority | normal | | Resolution | Unresolved | | Component | Compiler | | Test case | | | Differential revisions | | | BlockedBy | | | Related | | | Blocking | | | CC | | | Operating system | | | Architecture | | </details> <!-- {"blocked_by":[],"summary":"Allow more worker arguments in SpecConstr","status":"New","operating_system":"","component":"Compiler","related":[],"milestone":"8.2.2","resolution":"Unresolved","owner":{"tag":"Unowned"},"version":"8.2.1-rc3","keywords":["Fusion","JoinPoints,"],"differentials":[],"test_case":"","architecture":"","cc":[""],"type":"FeatureRequest","description":"Starting with GHC 8.2 (rc1 -- head) I noticed that the SpecConstr pass does not always optimize completely with SpecConstr-heavy code.\r\nSetting ```-fmax-worker-args=100``` leads to complete specialization again.\r\n\r\nHowever, given that code annotated with ```SPEC``` should be optimized until no more ```SPEC``` arguments are alive, shouldn't ```callToNewPats``` in ```compiler/specialise/SpecConstr.hs``` specialize *irrespective* of the size of the worker argument list?\r\n\r\nCode that actually fails to specialize is fairly large, hence no test case -- though I have some files with core output showing insufficient specialization.\r\n\r\n(I'd be willing to write a patch for this)","type_of_failure":"OtherFailure","blocking":[]} -->