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| author | Sebastian Graf <sebastian.graf@kit.edu> | 2020-10-30 17:20:37 +0100 |
|---|---|---|
| committer | Marge Bot <ben+marge-bot@smart-cactus.org> | 2020-11-20 02:09:51 -0500 |
| commit | 0aec78b6c97cee58ba20bfcb959f1369b80c4e4c (patch) | |
| tree | 3e48861640dbeb7a9d7784f0f02c2bc564af50ec /testsuite/tests/stranal/sigs/UnsatFun.stderr | |
| parent | 321d1bd8a79ab39c3c9e8697fffb0107c43f83cf (diff) | |
| download | haskell-0aec78b6c97cee58ba20bfcb959f1369b80c4e4c.tar.gz | |
Demand: Interleave usage and strictness demands (#18903)
As outlined in #18903, interleaving usage and strictness demands not
only means a more compact demand representation, but also allows us to
express demands that we weren't easily able to express before.
Call demands are *relative* in the sense that a call demand `Cn(cd)`
on `g` says "`g` is called `n` times. *Whenever `g` is called*, the
result is used according to `cd`". Example from #18903:
```hs
h :: Int -> Int
h m =
let g :: Int -> (Int,Int)
g 1 = (m, 0)
g n = (2 * n, 2 `div` n)
{-# NOINLINE g #-}
in case m of
1 -> 0
2 -> snd (g m)
_ -> uncurry (+) (g m)
```
Without the interleaved representation, we would just get `L` for the
strictness demand on `g`. Now we are able to express that whenever
`g` is called, its second component is used strictly in denoting `g`
by `1C1(P(1P(U),SP(U)))`. This would allow Nested CPR to unbox the
division, for example.
Fixes #18903.
While fixing regressions, I also discovered and fixed #18957.
Metric Decrease:
T13253-spj
Diffstat (limited to 'testsuite/tests/stranal/sigs/UnsatFun.stderr')
| -rw-r--r-- | testsuite/tests/stranal/sigs/UnsatFun.stderr | 28 |
1 files changed, 14 insertions, 14 deletions
diff --git a/testsuite/tests/stranal/sigs/UnsatFun.stderr b/testsuite/tests/stranal/sigs/UnsatFun.stderr index 325d25ced7..18723bad40 100644 --- a/testsuite/tests/stranal/sigs/UnsatFun.stderr +++ b/testsuite/tests/stranal/sigs/UnsatFun.stderr @@ -1,13 +1,13 @@ ==================== Strictness signatures ==================== UnsatFun.$trModule: -UnsatFun.f: <B,1*U(U)><B,A>b -UnsatFun.g: <B,1*U(U)>b -UnsatFun.g': <L,1*U(U)> -UnsatFun.g3: <L,U(U)> -UnsatFun.h: <C(S),1*C1(U)> -UnsatFun.h2: <S,1*U><L,1*C1(U)> -UnsatFun.h3: <C(S),1*C1(U)> +UnsatFun.f: <SP(M)><B>b +UnsatFun.g: <SP(M)>b +UnsatFun.g': <1P(U)> +UnsatFun.g3: <A> +UnsatFun.h: <SCS(U)> +UnsatFun.h2: <SU><1C1(U)> +UnsatFun.h3: <SCS(A)> @@ -25,12 +25,12 @@ UnsatFun.h3: m1 ==================== Strictness signatures ==================== UnsatFun.$trModule: -UnsatFun.f: <B,1*U(U)><B,A>b -UnsatFun.g: <B,1*U(U)>b -UnsatFun.g': <L,1*U(U)> -UnsatFun.g3: <L,U(U)> -UnsatFun.h: <C(S),1*C1(U)> -UnsatFun.h2: <S,1*U><L,1*C1(U)> -UnsatFun.h3: <C(S),1*C1(U)> +UnsatFun.f: <SP(M)><B>b +UnsatFun.g: <SP(M)>b +UnsatFun.g': <1P(U)> +UnsatFun.g3: <A> +UnsatFun.h: <SCS(U)> +UnsatFun.h2: <SU><1C1(U)> +UnsatFun.h3: <SCS(A)> |