#13221: OccurAnal fails to rediscover join points -------------------------------------+------------------------------------- Reporter: lukemaurer | Owner: lukemaurer Type: bug | Status: new Priority: high | Milestone: 8.2.1 Component: Compiler | Version: 8.1 Resolution: | Keywords: JoinPoints Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by simonpj): * priority: normal => high * milestone: 8.4.1 => 8.2.1 @@ -1,2 +1,15 @@ - Not clear why the warning from `OccurAnal` about rediscovering join points - is ever firing. There's one circumstance I can think of, namely the + Ben writes: I've noticed that a new WARN in OccurAnal seems to be quite + loud. Validations now produce thousands of lines of the form, + {{{ + WARNING: file compiler/simplCore/OccurAnal.hs, line 2633 + OccurAnal failed to rediscover join point(s): [$j_shTG] + WARNING: file compiler/simplCore/OccurAnal.hs, line 2633 + OccurAnal failed to rediscover join point(s): [$w$j_sl22] + WARNING: file compiler/simplCore/OccurAnal.hs, line 2633 + OccurAnal failed to rediscover join point(s): [$w$j_sl1W] + WARNING: file compiler/simplCore/OccurAnal.hs, line 2633 + OccurAnal failed to rediscover join point(s): [$w$j_sl1Q] + }}} + + It is not clear why the warning from `OccurAnal` about rediscovering join + points is ever firing. There's one circumstance I can think of, namely the @@ -6,2 +19,1 @@ - This isn't hard evidence of something wrong, but it indicates the - occurrence analyzer may be missing something. + This isn't hard evidence of something wrong, but it is deeply suspicious. New description: Ben writes: I've noticed that a new WARN in OccurAnal seems to be quite loud. Validations now produce thousands of lines of the form, {{{ WARNING: file compiler/simplCore/OccurAnal.hs, line 2633 OccurAnal failed to rediscover join point(s): [$j_shTG] WARNING: file compiler/simplCore/OccurAnal.hs, line 2633 OccurAnal failed to rediscover join point(s): [$w$j_sl22] WARNING: file compiler/simplCore/OccurAnal.hs, line 2633 OccurAnal failed to rediscover join point(s): [$w$j_sl1W] WARNING: file compiler/simplCore/OccurAnal.hs, line 2633 OccurAnal failed to rediscover join point(s): [$w$j_sl1Q] }}} It is not clear why the warning from `OccurAnal` about rediscovering join points is ever firing. There's one circumstance I can think of, namely the special typing rule allowing jumps from β-redexes, but the warning fires repeatedly and β-redexes don't survive the simplifier. This isn't hard evidence of something wrong, but it is deeply suspicious. -- Comment: Let's at least investigate before releasing 8.2. It's extremely fishy. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13221#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler