[GHC] #8731: long compilation time for module with large data type and partial record selectors
#8731: long compilation time for module with large data type and partial record selectors -------------------------+------------------------------------------------- Reporter: | Owner: carter | Status: new Type: bug | Milestone: Priority: | Version: 7.8.1-rc1 normal | Operating System: Unknown/Multiple Component: | Type of failure: Compile-time performance bug Compiler | Test Case: Keywords: | Blocking: Architecture: | Unknown/Multiple | Difficulty: | Unknown | Blocked By: | Related Tickets: | -------------------------+------------------------------------------------- in both ghc 7.6 and 7.8rc, the Constants module in LLVM-General-Pure (and a few other similar modules) have surprisingly long (and noticable!) compilation times. This seems to related to how GHC handles a many constructor data type with overlapping field names. the time is nearly the same for building a static module with O1 and O2 {{{ carter repoScratcher/bad-ast » time ghc Constant.hs -O2 1 ↵ [1 of 1] Compiling Constant ( Constant.hs, Constant.o ) ghc Constant.hs -O2 7.52s user 0.23s system 99% cpu 7.755 total }}} {{{ carter repoScratcher/bad-ast » time ghc Constant.hs -O1 [1 of 1] Compiling Constant ( Constant.hs, Constant.o ) ghc Constant.hs -O1 6.62s user 0.20s system 100% cpu 6.768 total }}} heck even with -O0 its slow (though not terrible) {{{ carter repoScratcher/bad-ast » time ghc Constant.hs -O0 [1 of 1] Compiling Constant ( Constant.hs, Constant.o ) ghc Constant.hs -O0 2.76s user 0.14s system 101% cpu 2.873 total }}} Seems like there might something wrong in how we handle data types like this, the complexity need not -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8731> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler
#8731: long compilation time for module with large data type and partial record selectors -------------------------------------------------+------------------------- Reporter: carter | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: Resolution: | 7.8.1-rc1 Operating System: Unknown/Multiple | Keywords: Type of failure: Compile-time performance bug | Architecture: Test Case: | Unknown/Multiple Blocking: | Difficulty: | Unknown | Blocked By: | Related Tickets: -------------------------------------------------+------------------------- Changes (by gidyn): * cc: gideon@… (added) -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8731#comment:1> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler
#8731: long compilation time for module with large data type and partial record selectors -------------------------------------------------+------------------------- Reporter: carter | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: Resolution: | 7.8.1-rc1 Operating System: Unknown/Multiple | Keywords: Type of failure: Compile-time performance bug | Architecture: Test Case: | Unknown/Multiple Blocking: | Difficulty: | Unknown | Blocked By: | Related Tickets: -------------------------------------------------+------------------------- Comment (by carter): rwbarton (on irc) noted this single module also has a nearly 1mb object file! Also apparently most of the code generated / time might be related to the Read and Show instances. (i've not check the latter myself, but sounds plausible) -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8731#comment:2> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler
#8731: long compilation time for module with large data type and partial record selectors -------------------------------------------------+------------------------- Reporter: carter | Owner: Type: bug | Status: new Priority: normal | Milestone: 7.8.2 Component: Compiler | Version: Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time performance bug | Unknown/Multiple Test Case: | Difficulty: Blocking: | Unknown | Blocked By: | Related Tickets: -------------------------------------------------+------------------------- Changes (by thoughtpolice): * version: 7.8.1-rc1 => * milestone: => 7.8.2 Comment: I'm punting this to 7.8.2. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8731#comment:3> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler
#8731: long compilation time for module with large data type and partial record selectors -------------------------------------------------+------------------------- Reporter: carter | Owner: Type: bug | Status: new Priority: normal | Milestone: 7.8.2 Component: Compiler | Version: Resolution: | 7.8.1-rc1 Operating System: Unknown/Multiple | Keywords: Type of failure: Compile-time performance bug | Architecture: Test Case: | Unknown/Multiple Blocking: | Difficulty: | Unknown | Blocked By: | Related Tickets: -------------------------------------------------+------------------------- Changes (by thoughtpolice): * version: => 7.8.1-rc1 -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8731#comment:4> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler
#8731: long compilation time for module with large data type and partial record selectors -------------------------------------------------+------------------------- Reporter: carter | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | 7.10.1 Resolution: | Version: Operating System: Unknown/Multiple | 7.8.1-rc1 Type of failure: Compile-time performance bug | Keywords: Test Case: | Architecture: Blocking: | Unknown/Multiple | Difficulty: | Unknown | Blocked By: | Related Tickets: -------------------------------------------------+------------------------- Changes (by thoughtpolice): * milestone: 7.8.3 => 7.10.1 -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8731#comment:6> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler
#8731: long compilation time for module with large data type and partial record selectors -------------------------------------+------------------------------------- Reporter: carter | Owner: Type: bug | Status: new Priority: normal | Milestone: 7.10.1 Component: Compiler | Version: 7.8.1-rc1 Resolution: | Keywords: Operating System: | Architecture: Unknown/Multiple Unknown/Multiple | Difficulty: Unknown Type of failure: Compile- | Blocked By: time performance bug | Related Tickets: Test Case: | Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- Comment (by thomie): Timing results for the example from comment:1. ||= GHC || -O1 || -O2 || ||= 7.4.2 || 4.9s || 16s || ||= 7.6.3 || 5.0s || 15s || ||= 7.8.3 || 4.4s || 12s || ||= 7.9.20141113 || 4.4s || 14s || Command: `time ghc -fforce-recomp -O<n> Constant.hs` Compilation takes only about 1 second, with either `-O1` or `-O2`, when I remove the `deriving (Eq, Ord, Read, Show)` clause from `data Constant`. The resulting object file also reduces in size from 1mb to 100kb. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8731#comment:7> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler
#8731: long compilation time for module with large data type and partial record selectors -------------------------------------+------------------------------------- Reporter: carter | Owner: Type: bug | Status: new Priority: normal | Milestone: 7.12.1 Component: Compiler | Version: 7.8.1-rc1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple performance bug | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Revisions: -------------------------------------+------------------------------------- Changes (by gidyn): * cc: gideon@… (removed) -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8731#comment:9> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler
#8731: long compilation time for module with large data type and partial record selectors -------------------------------------+------------------------------------- Reporter: carter | Owner: Type: bug | Status: new Priority: normal | Milestone: 7.12.1 Component: Compiler | Version: 7.8.1-rc1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple performance bug | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Revisions: -------------------------------------+------------------------------------- Changes (by gidyn): * cc: gidyn (added) -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8731#comment:10> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler
#8731: long compilation time for module with large data type and partial record selectors -------------------------------------+------------------------------------- Reporter: carter | Owner: Type: bug | Status: new Priority: normal | Milestone: 8.0.1 Component: Compiler | Version: 7.8.1-rc1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple performance bug | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by bgamari): Looks like this may be related to instance deriving, perhaps a duplicate of #10980. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8731#comment:12> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler
#8731: long compilation time for module with large data type and partial record selectors -------------------------------------+------------------------------------- Reporter: carter | Owner: Type: bug | Status: new Priority: normal | Milestone: 8.0.1 Component: Compiler | Version: 7.8.1-rc1 Resolution: | Keywords: deriving-perf Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple performance bug | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by ezyang): * keywords: => deriving-perf -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8731#comment:13> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler
#8731: long compilation time for module with large data type and partial record selectors -------------------------------------+------------------------------------- Reporter: carter | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.8.1-rc1 Resolution: | Keywords: deriving-perf Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple performance bug | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by erikd): * cc: erikd (added) -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8731#comment:15> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler
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