Re: [GHC] #3772: Methods not inlined

[GHC]

#3772: Methods not inlined
-+--
  Reporter:  rl  |  Owner:  
  Type:  bug | Status:  closed  
  Priority:  normal  |  Milestone:  6.12 branch 
 Component:  Compiler|Version:  6.12.1  
Resolution:  fixed   |   Keywords:  
Difficulty:  | Os:  Unknown/Multiple
  Testcase:  simplCore/should_compile/T3772  |   Architecture:  Unknown/Multiple
   Failure:  Runtime performance bug |  
-+--
Changes (by simonpj):

  * status:  new => closed
  * testcase:  => simplCore/should_compile/T3772
  * resolution:  => fixed


Comment:

 Actually I fixed this one but forgot to update Trac:
 {{{
 Tue Jan  5 10:16:00 GMT 2010  simo...@microsoft.com
   * Undo the fix for Trac #3772 and do it a new way

   The main idea is that I'm now treating a single-method dictionary very
   much like a multi-method dictionary.  In particular, it respond to
   exprIsConApp_maybe, even though newtypes aren't *really* proper
   constructors.

   See long comments with Note [Single-method classes] for why
   this slight hack is justified.

 M ./compiler/basicTypes/MkId.lhs -8 +4
 M ./compiler/typecheck/TcInstDcls.lhs -25 +67

 Mon Dec 21 16:04:31 GMT 2009  simo...@microsoft.com
   * Fix Trac #3772: dict funs for single-field classes

   This patch fixes a bug that meant that INLINE pragamas on
   a method of a single-field class didn't work properly.

   See Note [Single-method classes] in TcInstDcls, and Trac #3772

 M ./compiler/typecheck/TcInstDcls.lhs -34 +61
 }}}
 There's a test in the regression suite.  Do not attempt to merge to 6.12;
 the code base is very different in this respect.

 Simon

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Re: [GHC] #3772: Methods not inlined

[GHC]

#3772: Methods not inlined
-+--
Reporter:  rl|Owner: 
Type:  bug   |   Status:  new
Priority:  normal|Milestone:  6.12 branch
   Component:  Compiler  |  Version:  6.12.1 
Keywords:|   Difficulty: 
  Os:  Unknown/Multiple  | Testcase: 
Architecture:  Unknown/Multiple  |  Failure:  Runtime performance bug
-+--
Changes (by igloo):

  * milestone:  => 6.12 branch


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Re: [GHC] #3772: Methods not inlined

[GHC]

#3772: Methods not inlined
-+--
Reporter:  rl|   Owner: 
Type:  bug   |  Status:  new
Priority:  normal|   Milestone: 
   Component:  Compiler  | Version:  6.12.1 
  Resolution:|Keywords: 
  Os:  Unknown/Multiple  |Testcase: 
Architecture:  Unknown/Multiple  | Failure:  Runtime performance bug
-+--
Comment (by rl):

 Argh, please ignore `Tst.hs`, uploading files is too hard for me...

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[GHC] #3772: Methods not inlined

[GHC]

#3772: Methods not inlined
-+--
Reporter:  rl|   Owner: 
Type:  bug   |  Status:  new
Priority:  normal|   Component:  Compiler   
 Version:  6.12.1|Keywords: 
  Os:  Unknown/Multiple  |Testcase: 
Architecture:  Unknown/Multiple  | Failure:  Runtime performance bug
-+--
 This affects both 6.12 and the HEAD (albeit differently) but works fine
 with 6.10. It also works if everything is in one module. We are interested
 in the function `U.foo`; in particular, we want the call to `deepSeq`
 (resulting from inlining `T.apply`) to be inlined. This is what we get
 with 6.10 (compiling with `-O2`):
 {{{
 go_riA :: [GHC.Types.Double] -> ()
 go_riA =
   \ (ds_agP :: [GHC.Types.Double]) ->
 case ds_agP of wild_agQ {
   [] -> GHC.Unit.();
   : y_agU ys_agV ->
 case y_agU of tpl2_ah1 { GHC.Types.D# ipv_ah3 -> go_riA ys_agV }
 }

 U.foo :: GHC.Types.Int -> ()
 U.foo =
   \ (n_afR :: GHC.Types.Int) ->
 case n_afR of w_Xhn { GHC.Types.I# ww_ahi ->
 go_riA (T.$wgen @ GHC.Types.Double T.$f2 ww_ahi)
 }
 }}}
 Everything has been nicely inlined. With 6.12, we get this:
 {{{
 U.foo [NEVER Nothing] :: GHC.Types.Int -> ()
 U.foo =
   \ (n_adD :: GHC.Types.Int) ->
 case n_adD of _ { GHC.Types.I# ww_afv ->
 let {
   eta_sgc :: [GHC.Types.Double]
   eta_sgc = T.$wgen @ GHC.Types.Double T.$fCDouble ww_afv } in
 __inline_me (GHC.Base.foldr
@ GHC.Types.Double @ () (T.$fCDouble1 @ ()) GHC.Unit.()
 eta_sgc)
 }
 }}}
 The `deepSeq` call has been inlined but hasn't been optimised, I guess
 because GHC retained the `__inline_me` for some reason. Things are even
 worse with the HEAD:
 {{{
 U.foo :: GHC.Types.Int -> ()
 U.foo =
   \ (n_aaO :: GHC.Types.Int) ->
 case n_aaO of _ { GHC.Types.I# ww_abR ->
 T.$fC[]1
   @ GHC.Types.Double
   T.$fCDouble
   @ ()
   (T.$w$cgen @ GHC.Types.Double T.$fCDouble ww_abR)
   GHC.Unit.()
 }
 }}}
 Here, `deepSeq` hasn't even been inlined. But let's add a dummy method to
 `DeepSeq`:
 {{{
 class DeepSeq a where
   deepSeq :: a -> b -> b

   dummy :: a
   dummy = undefined
 }}}
 Now, the HEAD actually inlines the call:
 {{{
 go_rcM :: [GHC.Types.Double] -> ()
 go_rcM =
   \ (ds_acl :: [GHC.Types.Double]) ->
 case ds_acl of _ {
   [] -> GHC.Unit.();
   : y_acq ys_acr ->
 case y_acq of _ { GHC.Types.D# _ -> go_rcM ys_acr }
 }

 U.foo :: GHC.Types.Int -> ()
 U.foo =
   \ (n_aaQ :: GHC.Types.Int) ->
 case n_aaQ of _ { GHC.Types.I# ww_abI ->
 go_rcM (T.$w$cgen @ GHC.Types.Double T.$fCDouble ww_abI)
 }
 }}}
 Unfortunately, 6.12 still doesn't.

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