[GHC] #9537: concatMap does not participate in list fusion
#9537: concatMap does not participate in list fusion -------------------------------------+------------------------------------- Reporter: dfeuer | Owner: Type: bug | Status: new Priority: normal | Milestone: 7.8.4 Component: libraries/base | Version: 7.9 Keywords: fusion | Operating System: Architecture: Unknown/Multiple | Unknown/Multiple Difficulty: Unknown | Type of failure: Runtime Blocked By: | performance bug Related Tickets: | Test Case: | Blocking: | Differential Revisions: -------------------------------------+------------------------------------- Joachim Breitner raised this issue in an [http://www.haskell.org/pipermail /haskell-cafe/2011-December/097228.html email to haskell-cafe] in 2011, but he never got a response. For some reason, list comprehensions desugar to `concatMap` forms written to fuse, but the actual `concatMap` function is not written so. Unless there is a good reason for this, we should make it fuse. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9537 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#9537: concatMap is not a good producer for list fusion -------------------------------------+------------------------------------- Reporter: dfeuer | Owner: ekmett Type: bug | Status: patch Priority: normal | Milestone: 7.10.1 Component: Core | Version: 7.9 Libraries | Keywords: fusion Resolution: | Architecture: Unknown/Multiple Operating System: | Difficulty: Unknown Unknown/Multiple | Blocked By: Type of failure: Runtime | Related Tickets: performance bug | Test Case: | Blocking: | Differential Revisions: Phab:D348 | -------------------------------------+------------------------------------- Changes (by dfeuer): * cc: core-libraries-committee@… (added) * status: new => patch * differential: => Phab:D348 Old description:
Joachim Breitner raised this issue in an [http://www.haskell.org/pipermail/haskell-cafe/2011-December/097228.html email to haskell-cafe] in 2011, but he never got a response. For some reason, list comprehensions desugar to `concatMap` forms written to fuse, but the actual `concatMap` function is not written so. Unless there is a good reason for this, we should make it fuse.
New description: Joachim Breitner raised this issue in an [http://www.haskell.org/pipermail /haskell-cafe/2011-December/097228.html email to haskell-cafe] in 2011, but he never got a response. For some reason, list comprehensions desugar to `concatMap` forms written to fuse fully, but the actual `concatMap` function is not written so. Unless there is a good reason for this, we should make it fuse better. -- -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9537#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#9537: concatMap is not a good producer for list fusion
-------------------------------------+-------------------------------------
Reporter: dfeuer | Owner: ekmett
Type: bug | Status: patch
Priority: normal | Milestone: 7.10.1
Component: Core | Version: 7.9
Libraries | Keywords: fusion
Resolution: | Architecture: Unknown/Multiple
Operating System: | Difficulty: Unknown
Unknown/Multiple | Blocked By:
Type of failure: Runtime | Related Tickets:
performance bug |
Test Case: |
Blocking: |
Differential Revisions: Phab:D348 |
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Comment (by Austin Seipp
#9537: concatMap is not a good producer for list fusion -------------------------------------+------------------------------------- Reporter: dfeuer | Owner: ekmett Type: bug | Status: closed Priority: normal | Milestone: 7.10.1 Component: Core | Version: 7.9 Libraries | Keywords: fusion Resolution: fixed | Architecture: Unknown/Multiple Operating System: | Difficulty: Unknown Unknown/Multiple | Blocked By: Type of failure: Runtime | Related Tickets: performance bug | Test Case: | Blocking: | Differential Revisions: Phab:D348 | -------------------------------------+------------------------------------- Changes (by nomeata): * status: patch => closed * resolution: => fixed -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9537#comment:5 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
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