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authorBjörn Gustavsson <[email protected]>2014-02-13 11:44:39 +0100
committerBjörn Gustavsson <[email protected]>2014-02-13 11:44:39 +0100
commit0f5547c39ae8679a4395c90c8d7cc7465b3e63f3 (patch)
tree2d0794afecc24720cbacf9a21a320eb6733a2893
parenta1f8870a3fbd9f1902d22450bd00d83bf686dc20 (diff)
parent85cc321c5d3d1e78a895a549a856266228a75a02 (diff)
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Merge branch 'nox/compiler/v3_core-case-arg-opt'
* nox/compiler/v3_core-case-arg-opt: Optimise case arguments in sys_core_fold Run sys_core_fold twice if any inliner is used
-rw-r--r--lib/compiler/src/compile.erl6
-rw-r--r--lib/compiler/src/sys_core_fold.erl78
2 files changed, 82 insertions, 2 deletions
diff --git a/lib/compiler/src/compile.erl b/lib/compiler/src/compile.erl
index 5588f1fbe5..e79fe41f9b 100644
--- a/lib/compiler/src/compile.erl
+++ b/lib/compiler/src/compile.erl
@@ -626,7 +626,8 @@ core_passes() ->
{iff,dcorefold,{listing,"corefold"}},
{core_inline_module,fun test_core_inliner/1,fun core_inline_module/1},
{iff,dinline,{listing,"inline"}},
- {core_fold_after_inlining,fun test_core_inliner/1,fun core_fold_module_after_inlining/1},
+ {core_fold_after_inlining,fun test_any_inliner/1,
+ fun core_fold_module_after_inlining/1},
?pass(core_transforms)]},
{iff,dcopt,{listing,"copt"}},
{iff,'to_core',{done,"core"}}]}
@@ -1172,6 +1173,9 @@ test_core_inliner(#compile{options=Opts}) ->
end, Opts)
end.
+test_any_inliner(St) ->
+ test_old_inliner(St) orelse test_core_inliner(St).
+
core_old_inliner(#compile{code=Code0,options=Opts}=St) ->
{ok,Code} = sys_core_inline:module(Code0, Opts),
{ok,St#compile{code=Code}}.
diff --git a/lib/compiler/src/sys_core_fold.erl b/lib/compiler/src/sys_core_fold.erl
index 500d431afe..e2b9213891 100644
--- a/lib/compiler/src/sys_core_fold.erl
+++ b/lib/compiler/src/sys_core_fold.erl
@@ -353,7 +353,12 @@ expr(#c_case{}=Case0, Ctxt, Sub) ->
Case = Case1#c_case{arg=Arg2,clauses=Cs2},
warn_no_clause_match(Case1, Case),
Expr = eval_case(Case, Sub),
- bsm_an(Expr);
+ case move_case_into_arg(Case, Sub) of
+ impossible ->
+ bsm_an(Expr);
+ Other ->
+ expr(Other, Ctxt, sub_new_preserve_types(Sub))
+ end;
Other ->
expr(Other, Ctxt, Sub)
end;
@@ -2606,6 +2611,77 @@ opt_simple_let_2(Let, Vs0, Arg0, Body, value, Sub) ->
value, Sub)
end.
+move_case_into_arg(#c_case{arg=#c_let{vars=OuterVars0,arg=OuterArg,
+ body=InnerArg0}=Outer,
+ clauses=InnerClauses}=Inner, Sub) ->
+ %%
+ %% case let <OuterVars> = <OuterArg> in <InnerArg> of
+ %% <InnerClauses>
+ %% end
+ %%
+ %% ==>
+ %%
+ %% let <OuterVars> = <OuterArg>
+ %% in case <InnerArg> of <InnerClauses> end
+ %%
+ ScopeSub0 = sub_subst_scope(Sub#sub{t=[]}),
+ {OuterVars,ScopeSub} = pattern_list(OuterVars0, ScopeSub0),
+ InnerArg = body(InnerArg0, ScopeSub),
+ Outer#c_let{vars=OuterVars,arg=OuterArg,
+ body=Inner#c_case{arg=InnerArg,clauses=InnerClauses}};
+move_case_into_arg(#c_case{arg=#c_case{arg=OuterArg,
+ clauses=[OuterCa0,OuterCb]}=Outer,
+ clauses=InnerClauses}=Inner0, Sub) ->
+ case is_failing_clause(OuterCb) of
+ true ->
+ #c_clause{pats=OuterPats0,guard=OuterGuard0,
+ body=InnerArg0} = OuterCa0,
+ %%
+ %% case case <OuterArg> of
+ %% <OuterPats> when <OuterGuard> -> <InnerArg>
+ %% <OuterCb>
+ %% ...
+ %% end of
+ %% <InnerClauses>
+ %% end
+ %%
+ %% ==>
+ %%
+ %% case <OuterArg> of
+ %% <OuterPats> when <OuterGuard> ->
+ %% case <InnerArg> of <InnerClauses> end
+ %% <OuterCb>
+ %% end
+ %%
+ ScopeSub0 = sub_subst_scope(Sub#sub{t=[]}),
+ {OuterPats,ScopeSub} = pattern_list(OuterPats0, ScopeSub0),
+ OuterGuard = guard(OuterGuard0, ScopeSub),
+ InnerArg = body(InnerArg0, ScopeSub),
+ Inner = Inner0#c_case{arg=InnerArg,clauses=InnerClauses},
+ OuterCa = OuterCa0#c_clause{pats=OuterPats,guard=OuterGuard,
+ body=Inner},
+ Outer#c_case{arg=OuterArg,
+ clauses=[OuterCa,OuterCb]};
+ false ->
+ impossible
+ end;
+move_case_into_arg(#c_case{arg=#c_seq{arg=OuterArg,body=InnerArg}=Outer,
+ clauses=InnerClauses}=Inner, _Sub) ->
+ %%
+ %% case do <OuterArg> <InnerArg> of
+ %% <InnerClauses>
+ %% end
+ %%
+ %% ==>
+ %%
+ %% do <OuterArg>
+ %% case <InnerArg> of <InerClauses> end
+ %%
+ Outer#c_seq{arg=OuterArg,
+ body=Inner#c_case{arg=InnerArg,clauses=InnerClauses}};
+move_case_into_arg(_, _) ->
+ impossible.
+
%% In guards only, rewrite a case in a let argument like
%%
%% let <Var> = case <> of