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| author | Simon Peyton Jones <simonpj@microsoft.com> | 2021-05-04 23:41:48 +0100 |
|---|---|---|
| committer | Marge Bot <ben+marge-bot@smart-cactus.org> | 2021-05-11 23:00:27 -0400 |
| commit | c77179492032f4d8752481ad3e0d65d7eacb74f9 (patch) | |
| tree | 2991defee20b9ce1e13d0f3650a97ed830303f7b /compiler/GHC/CoreToStg.hs | |
| parent | 5daf1aa9dd5c03ec782c72f06b4704e31d92ec32 (diff) | |
| download | haskell-c77179492032f4d8752481ad3e0d65d7eacb74f9.tar.gz | |
Fix strictness and arity info in SpecConstr
In GHC.Core.Opt.SpecConstr.spec_one we were giving join-points an
incorrect join-arity -- this was fallout from
commit c71b220491a6ae46924cc5011b80182bcc773a58
Author: Simon Peyton Jones <simonpj@microsoft.com>
Date: Thu Apr 8 23:36:24 2021 +0100
Improvements in SpecConstr
* Allow under-saturated calls to specialise
See Note [SpecConstr call patterns]
This just allows a bit more specialisation to take place.
and showed up in #19780. I refactored the code to make the new
function calcSpecInfo which treats join points separately.
In doing this I discovered two other small bugs:
* In the Var case of argToPat we were treating UnkOcc as
uninteresting, but (by omission) NoOcc as interesting. As a
result we were generating SpecConstr specialisations for functions
with unused arguments. But the absence anlyser does that much
better; doing it here just generates more code. Easily fixed.
* The lifted/unlifted test in GHC.Core.Opt.WorkWrap.Utils.mkWorkerArgs
was back to front (#19794). Easily fixed.
* In the same function, mkWorkerArgs, we were adding an extra argument
nullary join points, which isn't necessary. I added a test for
this. That in turn meant I had to remove an ASSERT in
CoreToStg.mkStgRhs for nullary join points, which was always bogus
but now trips; I added a comment to explain.
Diffstat (limited to 'compiler/GHC/CoreToStg.hs')
| -rw-r--r-- | compiler/GHC/CoreToStg.hs | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/compiler/GHC/CoreToStg.hs b/compiler/GHC/CoreToStg.hs index 9452015ab4..af8c8ae25b 100644 --- a/compiler/GHC/CoreToStg.hs +++ b/compiler/GHC/CoreToStg.hs @@ -771,8 +771,10 @@ mkStgRhs bndr (PreStgRhs bndrs rhs) -- After this point we know that `bndrs` is empty, -- so this is not a function binding - | isJoinId bndr -- must be a nullary join point - = ASSERT(idJoinArity bndr == 0) + + | isJoinId bndr -- Must be a nullary join point + = -- It might have /type/ arguments (T18328), + -- so its JoinArity might be >0 StgRhsClosure noExtFieldSilent currentCCS ReEntrant -- ignored for LNE |