diff options
| author | Simon Peyton Jones <simonpj@microsoft.com> | 2018-12-12 17:22:07 +0000 |
|---|---|---|
| committer | Simon Peyton Jones <simonpj@microsoft.com> | 2018-12-12 17:38:25 +0000 |
| commit | d77501cd5b9060e38acd50e11e0c5aae89d75b65 (patch) | |
| tree | a6cba21b5adb5c04b476c92bf33436bd1a880981 /compiler/simplStg | |
| parent | ded4a1db4d61b1bc8b5fd73e8eb87cf572efda35 (diff) | |
| download | haskell-d77501cd5b9060e38acd50e11e0c5aae89d75b65.tar.gz | |
Improvements to demand analysis
This patch collects a few improvements triggered by Trac #15696,
and fixing Trac #16029
* Stop making toCleanDmd behave specially for unlifted types.
This special case was the cause of stupid behaviour in Trac
#16029. And to my joy I discovered the let/app invariant
rendered it unnecessary. (Maybe the special case pre-dated
the let/app invariant.)
Result: less special-case handling in the compiler, and
better perf for the compiled code.
* In WwLib.mkWWstr_one, treat seqDmd like U(AAA). It was not
being so treated before, which again led to stupid code.
* Update and improve Notes
There are .stderr test wibbles because we get slightly different
strictness signatures for an argumment of unlifted type:
<L,U> rather than <S,U> for Int#
<S,U> rather than <S(S),U(U)> for Int
Diffstat (limited to 'compiler/simplStg')
| -rw-r--r-- | compiler/simplStg/StgLiftLams/Analysis.hs | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/compiler/simplStg/StgLiftLams/Analysis.hs b/compiler/simplStg/StgLiftLams/Analysis.hs index 5b87f58ce0..7fb60df0b0 100644 --- a/compiler/simplStg/StgLiftLams/Analysis.hs +++ b/compiler/simplStg/StgLiftLams/Analysis.hs @@ -342,7 +342,7 @@ rhsDmdShell bndr where is_thunk = idArity bndr == 0 -- Let's pray idDemandInfo is still OK after unarise... - (ds, cd) = toCleanDmd (idDemandInfo bndr) (idType bndr) + (ds, cd) = toCleanDmd (idDemandInfo bndr) tagSkeletonAlt :: CgStgAlt -> (Skeleton, IdSet, LlStgAlt) tagSkeletonAlt (con, bndrs, rhs) |