Adjust Activations for specialise and work/wrap, and better simplify in InlineRules

[ghc-hetmet.git] / compiler / specialise / SpecConstr.lhs

diff --git a/compiler/specialise/SpecConstr.lhs b/compiler/specialise/SpecConstr.lhs
index 36dda5e..404b6cc 100644 (file)
--- a/compiler/specialise/SpecConstr.lhs
+++ b/compiler/specialise/SpecConstr.lhs
@@ -39,7 +39,6 @@ import Name
 import DynFlags                ( DynFlags(..) )
 import StaticFlags     ( opt_PprStyle_Debug )
 import StaticFlags     ( opt_SpecInlineJoinPoints )
-import BasicTypes      ( Activation(..) )
 import Maybes          ( orElse, catMaybes, isJust, isNothing )
 import Demand
 import DmdAnal         ( both )
@@ -1179,18 +1178,19 @@ spec_one env fn arg_bndrs body (call_pat@(qvars, pats), rule_number)
                -- Usual w/w hack to avoid generating 
                -- a spec_rhs of unlifted type and no args
        
-             fn_name   = idName fn
-             fn_loc    = nameSrcSpan fn_name
-             spec_occ  = mkSpecOcc (nameOccName fn_name)
-             rule_name = mkFastString ("SC:" ++ showSDoc (ppr fn <> int rule_number))
-             spec_rhs  = mkLams spec_lam_args spec_body
-             spec_str  = calcSpecStrictness fn spec_lam_args pats
-             spec_id   = mkUserLocal spec_occ spec_uniq (mkPiTypes spec_lam_args body_ty) fn_loc
-                           `setIdStrictness` spec_str          -- See Note [Transfer strictness]
-                           `setIdArity` count isId spec_lam_args
-             body_ty   = exprType spec_body
-             rule_rhs  = mkVarApps (Var spec_id) spec_call_args
-             rule      = mkLocalRule rule_name specConstrActivation fn_name qvars pats rule_rhs
+             fn_name    = idName fn
+             fn_loc     = nameSrcSpan fn_name
+             spec_occ   = mkSpecOcc (nameOccName fn_name)
+             rule_name  = mkFastString ("SC:" ++ showSDoc (ppr fn <> int rule_number))
+             spec_rhs   = mkLams spec_lam_args spec_body
+             spec_str   = calcSpecStrictness fn spec_lam_args pats
+             spec_id    = mkUserLocal spec_occ spec_uniq (mkPiTypes spec_lam_args body_ty) fn_loc
+                            `setIdStrictness` spec_str         -- See Note [Transfer strictness]
+                            `setIdArity` count isId spec_lam_args
+             body_ty    = exprType spec_body
+             rule_rhs   = mkVarApps (Var spec_id) spec_call_args
+              inline_act = idInlineActivation fn
+             rule       = mkLocalRule rule_name inline_act fn_name qvars pats rule_rhs
        ; return (spec_usg, OS call_pat rule spec_id spec_rhs) }
 
 calcSpecStrictness :: Id                    -- The original function
@@ -1215,18 +1215,23 @@ calcSpecStrictness fn qvars pats
           | (Var _, args) <- collectArgs e = go env ds args
     go_one env _         _ = env
 
--- In which phase should the specialise-constructor rules be active?
--- Originally I made them always-active, but Manuel found that
--- this defeated some clever user-written rules.  So Plan B
--- is to make them active only in Phase 0; after all, currently,
--- the specConstr transformation is only run after the simplifier
--- has reached Phase 0.  In general one would want it to be 
--- flag-controllable, but for now I'm leaving it baked in
---                                     [SLPJ Oct 01]
-specConstrActivation :: Activation
-specConstrActivation = ActiveAfter 0   -- Baked in; see comments above
 \end{code}
 
+Note [Transfer activation]
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+In which phase should the specialise-constructor rules be active?
+Originally I made them always-active, but Manuel found that this
+defeated some clever user-written rules.  Then I made them active only
+in Phase 0; after all, currently, the specConstr transformation is
+only run after the simplifier has reached Phase 0, but that meant
+that specialisations didn't fire inside wrappers; see test
+simplCore/should_compile/spec-inline.
+
+So now I just use the inline-activation of the parent Id, as the
+activation for the specialiation RULE, just like the main specialiser;
+see Note [Auto-specialisation and RULES] in Specialise.
+
+
 Note [Transfer strictness]
 ~~~~~~~~~~~~~~~~~~~~~~~~~~
 We must transfer strictness information from the original function to