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| author | Ömer Sinan Ağacan <omeragacan@gmail.com> | 2019-09-13 09:46:17 +0300 |
|---|---|---|
| committer | Marge Bot <ben+marge-bot@smart-cactus.org> | 2019-10-01 16:55:37 -0400 |
| commit | 8924224ecfa065ebc67b96a90d01cf9d2edd0e77 (patch) | |
| tree | 4701376daaa5c7f29a63a4642934e7b9953c9b5d | |
| parent | 0956c1941bbd80fb6218b4ddeb0e9bd822d71855 (diff) | |
| download | haskell-8924224ecfa065ebc67b96a90d01cf9d2edd0e77.tar.gz | |
Make small INLINE functions behave properly
Simon writes:
Currently we check for a type arg rather than isTyCoArg. This in turn
makes INLINE things look bigger than they should be, and stops them
being inlined into boring contexts when they perfectly well could be.
E.g.
f x = g <refl> x
{-# INLINE g #-}
... (map (f x) xs) ...
The context is boring, so don't inline unconditionally. But f's RHS is
no bigger than its call, provided you realise that the coercion argument
is ultimately cost-free.
This happens in practice for $WHRefl. It's not a big deal: at most it
means we have an extra function call overhead. But it's untidy, and
actually worse than what happens without an INLINE pragma.
Fixes #17182
This makes 0.0% change in nofib binary sizes.
| -rw-r--r-- | compiler/coreSyn/CoreUnfold.hs | 6 | ||||
| -rw-r--r-- | testsuite/tests/deSugar/should_compile/T2431.stderr | 5 |
2 files changed, 7 insertions, 4 deletions
diff --git a/compiler/coreSyn/CoreUnfold.hs b/compiler/coreSyn/CoreUnfold.hs index 689ad874da..6535d37307 100644 --- a/compiler/coreSyn/CoreUnfold.hs +++ b/compiler/coreSyn/CoreUnfold.hs @@ -441,10 +441,10 @@ inlineBoringOk e go :: Int -> CoreExpr -> Bool go credit (Lam x e) | isId x = go (credit+1) e | otherwise = go credit e - go credit (App f (Type {})) = go credit f - go credit (App f a) | credit > 0 + go credit (App f a) | isTyCoArg a = go credit f + | credit > 0 , exprIsTrivial a = go (credit-1) f - go credit (Tick _ e) = go credit e -- dubious + go credit (Tick _ e) = go credit e -- dubious go credit (Cast e _) = go credit e go _ (Var {}) = boringCxtOk go _ _ = boringCxtNotOk diff --git a/testsuite/tests/deSugar/should_compile/T2431.stderr b/testsuite/tests/deSugar/should_compile/T2431.stderr index 30b5f8c358..92d99a8d14 100644 --- a/testsuite/tests/deSugar/should_compile/T2431.stderr +++ b/testsuite/tests/deSugar/should_compile/T2431.stderr @@ -10,7 +10,7 @@ T2431.$WRefl [InlPrag=INLINE[0]] :: forall a. a :~: a Str=m, Unf=Unf{Src=InlineStable, TopLvl=True, Value=True, ConLike=True, WorkFree=True, Expandable=True, - Guidance=ALWAYS_IF(arity=0,unsat_ok=True,boring_ok=False) + Guidance=ALWAYS_IF(arity=0,unsat_ok=True,boring_ok=True) Tmpl= \ (@ a) -> T2431.Refl @ a @ a @~ (<a>_N :: a GHC.Prim.~# a)}] T2431.$WRefl = \ (@ a) -> T2431.Refl @ a @ a @~ (<a>_N :: a GHC.Prim.~# a) @@ -110,3 +110,6 @@ T2431.$tc'Refl $tc'Refl2 1# $krep3 + + + |