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| author | Sebastian Graf <sebastian.graf@kit.edu> | 2019-02-07 15:34:07 +0100 |
|---|---|---|
| committer | Marge Bot <ben+marge-bot@smart-cactus.org> | 2019-04-30 20:23:21 -0400 |
| commit | 014ed644eea9037427c1ebeaac16189b00f9dbc7 (patch) | |
| tree | 4e41d1183e559e81a0fbdb1cf9c16fae0448ee43 /compiler/coreSyn/CoreLint.hs | |
| parent | 1abb76ab8e32e7be224631506201d1beec62a5c2 (diff) | |
| download | haskell-014ed644eea9037427c1ebeaac16189b00f9dbc7.tar.gz | |
Compute demand signatures assuming idArity
This does four things:
1. Look at `idArity` instead of manifest lambdas to decide whether to use LetUp
2. Compute the strictness signature in LetDown assuming at least `idArity`
incoming arguments
3. Remove the special case for trivial RHSs, which is subsumed by 2
4. Don't perform the W/W split when doing so would eta expand a binding.
Otherwise we would eta expand PAPs, causing unnecessary churn in the
Simplifier.
NoFib Results
--------------------------------------------------------------------------------
Program Allocs Instrs
--------------------------------------------------------------------------------
fannkuch-redux +0.3% 0.0%
gg -0.0% -0.1%
maillist +0.2% +0.2%
minimax 0.0% +0.8%
pretty 0.0% -0.1%
reptile -0.0% -1.2%
--------------------------------------------------------------------------------
Min -0.0% -1.2%
Max +0.3% +0.8%
Geometric Mean +0.0% -0.0%
Diffstat (limited to 'compiler/coreSyn/CoreLint.hs')
| -rw-r--r-- | compiler/coreSyn/CoreLint.hs | 26 |
1 files changed, 3 insertions, 23 deletions
diff --git a/compiler/coreSyn/CoreLint.hs b/compiler/coreSyn/CoreLint.hs index 2210716fd5..ef4e858568 100644 --- a/compiler/coreSyn/CoreLint.hs +++ b/compiler/coreSyn/CoreLint.hs @@ -570,15 +570,9 @@ lintSingleBinding top_lvl_flag rec_flag (binder,rhs) (addWarnL (text "INLINE binder is (non-rule) loop breaker:" <+> ppr binder)) -- Only non-rule loop breakers inhibit inlining - -- Check whether arity and demand type are consistent (only if demand analysis - -- already happened) - -- - -- Note (Apr 2014): this is actually ok. See Note [Demand analysis for trivial right-hand sides] - -- in DmdAnal. After eta-expansion in CorePrep the rhs is no longer trivial. - -- ; let dmdTy = idStrictness binder - -- ; checkL (case dmdTy of - -- StrictSig dmd_ty -> idArity binder >= dmdTypeDepth dmd_ty || exprIsTrivial rhs) - -- (mkArityMsg binder) + -- We used to check that the dmdTypeDepth of a demand signature never + -- exceeds idArity, but that is an unnecessary complication, see + -- Note [idArity varies independently of dmdTypeDepth] in DmdAnal -- Check that the binder's arity is within the bounds imposed by -- the type and the strictness signature. See Note [exprArity invariant] @@ -2565,20 +2559,6 @@ mkKindErrMsg tyvar arg_ty hang (text "Arg type:") 4 (ppr arg_ty <+> dcolon <+> ppr (typeKind arg_ty))] -{- Not needed now -mkArityMsg :: Id -> MsgDoc -mkArityMsg binder - = vcat [hsep [text "Demand type has", - ppr (dmdTypeDepth dmd_ty), - text "arguments, rhs has", - ppr (idArity binder), - text "arguments,", - ppr binder], - hsep [text "Binder's strictness signature:", ppr dmd_ty] - - ] - where (StrictSig dmd_ty) = idStrictness binder --} mkCastErr :: CoreExpr -> Coercion -> Type -> Type -> MsgDoc mkCastErr expr = mk_cast_err "expression" "type" (ppr expr) |