diff options
Diffstat (limited to 'compiler/codeGen')
| -rw-r--r-- | compiler/codeGen/StgCmmBind.hs | 36 |
1 files changed, 21 insertions, 15 deletions
diff --git a/compiler/codeGen/StgCmmBind.hs b/compiler/codeGen/StgCmmBind.hs index e8fd8f8d9b..f8fdb894b4 100644 --- a/compiler/codeGen/StgCmmBind.hs +++ b/compiler/codeGen/StgCmmBind.hs @@ -299,24 +299,30 @@ mkRhsClosure dflags bndr _cc _bi [] -- No args; a thunk (StgApp fun_id args) - | args `lengthIs` (arity-1) - && all (isGcPtrRep . idPrimRep . unsafe_stripNV) fvs - && isUpdatable upd_flag - && arity <= mAX_SPEC_AP_SIZE dflags - && not (gopt Opt_SccProfilingOn dflags) - -- not when profiling: we don't want to - -- lose information about this particular - -- thunk (e.g. its type) (#949) - - -- Ha! an Ap thunk + -- We are looking for an "ApThunk"; see data con ApThunk in StgCmmClosure + -- of form (x1 x2 .... xn), where all the xi are locals (not top-level) + -- So the xi will all be free variables + | args `lengthIs` (n_fvs-1) -- This happens only if the fun_id and + -- args are all distinct local variables + -- The "-1" is for fun_id + -- Missed opportunity: (f x x) is not detected + , all (isGcPtrRep . idPrimRep . unsafe_stripNV) fvs + , isUpdatable upd_flag + , n_fvs <= mAX_SPEC_AP_SIZE dflags + , not (gopt Opt_SccProfilingOn dflags) + -- not when profiling: we don't want to + -- lose information about this particular + -- thunk (e.g. its type) (#949) + + -- Ha! an Ap thunk = cgRhsStdThunk bndr lf_info payload where - lf_info = mkApLFInfo bndr upd_flag arity - -- the payload has to be in the correct order, hence we can't - -- just use the fvs. - payload = StgVarArg fun_id : args - arity = length fvs + n_fvs = length fvs + lf_info = mkApLFInfo bndr upd_flag n_fvs + -- the payload has to be in the correct order, hence we can't + -- just use the fvs. + payload = StgVarArg fun_id : args ---------- Default case ------------------ mkRhsClosure dflags bndr cc _ fvs upd_flag args body |