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| author | simonpj@microsoft.com <unknown> | 2009-11-19 12:57:11 +0000 |
|---|---|---|
| committer | simonpj@microsoft.com <unknown> | 2009-11-19 12:57:11 +0000 |
| commit | 6a944ae7fe1e8e2e456c68717188463263f8978f (patch) | |
| tree | 8a190b684af10b9e4fef1ed6ad397b0d346dc055 /compiler/prelude | |
| parent | c93e8323ab49dd369e8b5f04027462a6fc1b8249 (diff) | |
| download | haskell-6a944ae7fe1e8e2e456c68717188463263f8978f.tar.gz | |
Implement -fexpose-all-unfoldings, and fix a non-termination bug
The -fexpose-all-unfoldings flag arranges to put unfoldings for *everything*
in the interface file. Of course, this makes the file a lot bigger, but
it also makes it complete, and that's great for supercompilation; or indeed
any whole-program work.
Consequences:
* Interface files need to record loop-breaker-hood. (Previously,
loop breakers were never exposed, so that info wasn't necessary.)
Hence a small interface file format change.
* When inlining, must check loop-breaker-hood. (Previously, loop
breakers didn't have an unfolding at all, so no need to check.)
* Ditto in exprIsConApp_maybe. Roman actually tripped this bug,
because a DFun, which had an unfolding, was also a loop breaker
* TidyPgm.tidyIdInfo must be careful to preserve loop-breaker-hood
So Id.idUnfolding checks for loop-breaker-hood and returns NoUnfolding
if so. When you want the unfolding regardless of loop-breaker-hood,
use Id.realIdUnfolding.
I have not documented the flag yet, because it's experimental. Nor
have I tested it thoroughly. But with the flag off (the normal case)
everything should work.
Diffstat (limited to 'compiler/prelude')
| -rw-r--r-- | compiler/prelude/PrelRules.lhs | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/compiler/prelude/PrelRules.lhs b/compiler/prelude/PrelRules.lhs index 236cee6074..1515fb9827 100644 --- a/compiler/prelude/PrelRules.lhs +++ b/compiler/prelude/PrelRules.lhs @@ -21,7 +21,7 @@ module PrelRules ( primOpRules, builtinRules ) where import CoreSyn import MkCore ( mkWildCase ) -import Id ( idUnfolding ) +import Id ( realIdUnfolding ) import Literal ( Literal(..), mkMachInt, mkMachWord , literalType , word2IntLit, int2WordLit @@ -551,7 +551,7 @@ match_eq_string _ = Nothing --------------------------------------------------- -- The rule is this: -- inline f_ty (f a b c) = <f's unfolding> a b c --- (if f has an unfolding) +-- (if f has an unfolding, EVEN if it's a loop breaker) -- -- It's important to allow the argument to 'inline' to have args itself -- (a) because its more forgiving to allow the programmer to write @@ -564,7 +564,7 @@ match_eq_string _ = Nothing match_inline :: [Expr CoreBndr] -> Maybe (Expr CoreBndr) match_inline (Type _ : e : _) | (Var f, args1) <- collectArgs e, - Just unf <- maybeUnfoldingTemplate (idUnfolding f) + Just unf <- maybeUnfoldingTemplate (realIdUnfolding f) = Just (mkApps unf args1) match_inline _ = Nothing |