diff options
Diffstat (limited to 'compiler/simplCore/FloatIn.hs')
| -rw-r--r-- | compiler/simplCore/FloatIn.hs | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/compiler/simplCore/FloatIn.hs b/compiler/simplCore/FloatIn.hs index 07f05493eb..216e848889 100644 --- a/compiler/simplCore/FloatIn.hs +++ b/compiler/simplCore/FloatIn.hs @@ -210,7 +210,7 @@ only way that can happen is if the binding wrapped the literal /in the original input program/. e.g. case x of { DEFAULT -> 1# } But, while this may be unusual it is not actually wrong, and it did -once happen (Trac #15696). +once happen (#15696). Note [Do not destroy the let/app invariant] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ @@ -307,7 +307,7 @@ be dropped right away. fiExpr dflags to_drop lam@(_, AnnLam _ _) | noFloatIntoLam bndrs -- Dump it all here - -- NB: Must line up with noFloatIntoRhs (AnnLam...); see Trac #7088 + -- NB: Must line up with noFloatIntoRhs (AnnLam...); see #7088 = wrapFloats to_drop (mkLams bndrs (fiExpr dflags [] body)) | otherwise -- Float inside @@ -391,7 +391,7 @@ fiExpr dflags to_drop (_,AnnLet bind body) {- Note [Floating primops] ~~~~~~~~~~~~~~~~~~~~~~~~~~ We try to float-in a case expression over an unlifted type. The -motivating example was Trac #5658: in particular, this change allows +motivating example was #5658: in particular, this change allows array indexing operations, which have a single DEFAULT alternative without any binders, to be floated inward. @@ -421,10 +421,10 @@ But there are wrinkles Solution: only float cases into the branches of other cases, and not into the arguments of an application, or the RHS of a let. This is somewhat conservative, but it's simple. And it still hits the - cases like Trac #5658. This is implemented in sepBindsByJoinPoint; + cases like #5658. This is implemented in sepBindsByJoinPoint; if is_case is False we dump all floating cases right here. -* Trac #14511 is another example of why we want to restrict float-in +* #14511 is another example of why we want to restrict float-in of case-expressions. Consider case indexArray# a n of (# r #) -> writeArray# ma i (f r) Now, floating that indexing operation into the (f r) thunk will @@ -613,7 +613,7 @@ would destroy the let/app invariant. (a) any non-one-shot value lambdas or (b) all type lambdas In both cases we'll float straight back out again - NB: Must line up with fiExpr (AnnLam...); see Trac #7088 + NB: Must line up with fiExpr (AnnLam...); see #7088 (a) is important: we /must/ float into a one-shot lambda group (which includes join points). This makes a big difference |