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| author | Simon Peyton Jones <simonpj@microsoft.com> | 2016-02-11 11:00:24 +0000 |
|---|---|---|
| committer | Simon Peyton Jones <simonpj@microsoft.com> | 2016-02-11 11:00:24 +0000 |
| commit | 62d1888ff45bd817409be2c3eacdc86cfef4bed8 (patch) | |
| tree | be9ad430fd1e06c3f9b654cdfff43374c453b8b2 | |
| parent | 850085555a1103810d57f0d9835f4d525fd8ec00 (diff) | |
| download | haskell-62d1888ff45bd817409be2c3eacdc86cfef4bed8.tar.gz | |
Comments about ru_auto
...following a question from Conal
| -rw-r--r-- | compiler/coreSyn/CoreSyn.hs | 13 | ||||
| -rw-r--r-- | compiler/main/TidyPgm.hs | 16 |
2 files changed, 16 insertions, 13 deletions
diff --git a/compiler/coreSyn/CoreSyn.hs b/compiler/coreSyn/CoreSyn.hs index c725dc3737..f06097a02f 100644 --- a/compiler/coreSyn/CoreSyn.hs +++ b/compiler/coreSyn/CoreSyn.hs @@ -864,15 +864,16 @@ data CoreRule -- See Note [OccInfo in unfoldings and rules] -- Locality - ru_auto :: Bool, -- ^ @True@ <=> this rule is auto-generated - -- @False@ <=> generated at the users behest - -- Main effect: reporting of orphan-hood + ru_auto :: Bool, -- ^ @True@ <=> this rule is auto-generated + -- (notably by Specialise or SpecConstr) + -- @False@ <=> generated at the users behest + -- See Note [Trimming auto-rules] in TidyPgm + -- for the sole purpose of this field. - ru_origin :: !Module, -- ^ 'Module' the rule was defined in, used + ru_origin :: !Module, -- ^ 'Module' the rule was defined in, used -- to test if we should see an orphan rule. - ru_orphan :: !IsOrphan, - -- ^ Whether or not the rule is an orphan. + ru_orphan :: !IsOrphan, -- ^ Whether or not the rule is an orphan. ru_local :: Bool -- ^ @True@ iff the fn at the head of the rule is -- defined in the same module as the rule diff --git a/compiler/main/TidyPgm.hs b/compiler/main/TidyPgm.hs index c524bdf4c3..63f4c2665f 100644 --- a/compiler/main/TidyPgm.hs +++ b/compiler/main/TidyPgm.hs @@ -887,9 +887,13 @@ reference to f_spec except from the RULE. Now that RULE *might* be useful to an importing module, but that is purely speculative, and meanwhile the code is taking up space and -codegen time. So is seeems better to drop the binding for f_spec if -the auto-generated rule is the *only* reason that it is being kept -alive. +codegen time. I found that binary sizes jumped by 6-10% when I +started to specialise INLINE functions (again, Note [Inline +specialisations] in Specialise). + +So it seeems better to drop the binding for f_spec, and the rule +itself, if the auto-generated rule is the *only* reason that it is +being kept alive. (The RULE still might have been useful in the past; that is, it was the right thing to have generated it in the first place. See Note @@ -902,12 +906,10 @@ So findExternalRules does this: * Remove all auto rules that mention bindings that have been removed (this is done by filtering by keep_rule) -So if a binding is kept alive for some *other* reason (e.g. f_spec is +NB: if a binding is kept alive for some *other* reason (e.g. f_spec is called in the final code), we keep the rule too. -I found that binary sizes jumped by 6-10% when I started to specialise -INLINE functions (again, Note [Inline specialisations] in Specialise). -Adding trimAutoRules removed all this bloat. +This stuff is the only reason for the ru_auto field in a Rule. -} findExternalRules :: Bool -- Omit pragmas |