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| author | Andreas Klebinger <klebinger.andreas@gmx.at> | 2021-05-10 15:47:12 +0200 |
|---|---|---|
| committer | Andreas Klebinger <klebinger.andreas@gmx.at> | 2021-05-10 21:12:53 +0200 |
| commit | 16a50e2d5764b3ea71bd511fa0769255a73dad45 (patch) | |
| tree | 432be54e3b6618e7712a0bcdf1a1f5dffc3b973b | |
| parent | 736d47ffb7370ba4348b142c913b88e4c82347d0 (diff) | |
| download | haskell-wip/andreask/simplLamBndr.tar.gz | |
Document unfolding treatment of simplLamBndr.wip/andreask/simplLamBndr
Fixes #19817
| -rw-r--r-- | compiler/GHC/Core/Opt/Simplify.hs | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/compiler/GHC/Core/Opt/Simplify.hs b/compiler/GHC/Core/Opt/Simplify.hs index dfbfd30e64..3d1a8ce3aa 100644 --- a/compiler/GHC/Core/Opt/Simplify.hs +++ b/compiler/GHC/Core/Opt/Simplify.hs @@ -1554,9 +1554,11 @@ simplLamBndr :: SimplEnv -> InBndr -> SimplM (SimplEnv, OutBndr) -- Used for lambda binders. These sometimes have unfoldings added by -- the worker/wrapper pass that must be preserved, because they can't -- be reconstructed from context. For example: --- f x = case x of (a,b) -> fw a b x --- fw a b x{=(a,b)} = ... --- The "{=(a,b)}" is an unfolding we can't reconstruct otherwise. +-- f x = case x of StrictPair a b -> fw a b x +-- fw a{=OtherCon[]} b{=OtherCon[]} x{=(StrictPair a b)} = ... +-- The "{=(StrictPair a b)}" is an unfolding we can't reconstruct otherwise. +-- Since simplBinder already retains OtherCon bindings we only have to special +-- case core unfoldings like the one for `x`. simplLamBndr env bndr | isId bndr && hasCoreUnfolding old_unf -- Special case = do { (env1, bndr1) <- simplBinder env bndr |