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authorJohn Högberg <[email protected]>2018-09-28 14:08:23 +0200
committerGitHub <[email protected]>2018-09-28 14:08:23 +0200
commit7d941c529dc9db016af30cdace2df089d1648dbf (patch)
treece04f9922931e927ca22d75a2cd0fd4d0d0328eb /lib/compiler/src/v3_kernel.erl
parent08ef38b2c9f84ed118e693bff38efa69fc2c7eb8 (diff)
parentafa36d2081927c46a4c3ddceb40276fc7756bb51 (diff)
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Merge pull request #1958 from jhogberg/john/compiler/ssa-bsm-opt
Rewrite BSM optimizations in the new SSA-based intermediate format
Diffstat (limited to 'lib/compiler/src/v3_kernel.erl')
-rw-r--r--lib/compiler/src/v3_kernel.erl37
1 files changed, 3 insertions, 34 deletions
diff --git a/lib/compiler/src/v3_kernel.erl b/lib/compiler/src/v3_kernel.erl
index fe8e252e5a..f7ca66b1da 100644
--- a/lib/compiler/src/v3_kernel.erl
+++ b/lib/compiler/src/v3_kernel.erl
@@ -82,8 +82,7 @@
-export([module/2,format_error/1]).
-import(lists, [map/2,foldl/3,foldr/3,mapfoldl/3,splitwith/2,member/2,
- keymember/3,keyfind/3,partition/2,droplast/1,last/1,sort/1,
- reverse/1]).
+ keyfind/3,partition/2,droplast/1,last/1,sort/1,reverse/1]).
-import(ordsets, [add_element/2,del_element/2,union/2,union/1,subtract/2]).
-import(cerl, [c_tuple/1]).
@@ -1416,7 +1415,6 @@ is_remote_bif(_, _, _) -> false.
%% called for effect only.
bif_vals(dsetelement, 3) -> 0;
-bif_vals(bs_context_to_binary, 1) -> 0;
bif_vals(_, _) -> 1.
bif_vals(_, _, _) -> 1.
@@ -2337,8 +2335,7 @@ uexpr(#k_bif{anno=A,op=Op,args=As}=Bif, {break,Rs}, St0) ->
{Brs,St1} = bif_returns(Op, Rs, St0),
{Bif#k_bif{anno=#k{us=Used,ns=lit_list_vars(Brs),a=A},ret=Brs},
Used,St1};
-uexpr(#k_match{anno=A,vars=Vs0,body=B0}, Br, St0) ->
- Vs = handle_reuse_annos(Vs0, St0),
+uexpr(#k_match{anno=A,vars=Vs,body=B0}, Br, St0) ->
Rs = break_rets(Br),
{B1,Bu,St1} = umatch(B0, Br, St0),
case is_in_guard(St1) of
@@ -2441,33 +2438,6 @@ make_fdef(Anno, Name, Arity, Vs, Body) ->
vars=Vs,body=Body,ret=[]},
#k_fdef{anno=Anno,func=Name,arity=Arity,vars=Vs,body=Match}.
-
-%% handle_reuse_annos([#k_var{}], State) -> State.
-%% In general, it is only safe to reuse a variable for a match context
-%% if the original value of the variable will no longer be needed.
-%%
-%% If a variable has been bound in an outer letrec and is therefore
-%% free in the current function, the variable may still be used.
-%% We don't bother to check whether the variable is actually used,
-%% but simply clears the 'reuse_for_context' annotation for any variable
-%% that is free.
-handle_reuse_annos(Vs, St) ->
- [handle_reuse_anno(V, St) || V <- Vs].
-
-handle_reuse_anno(#k_var{anno=A}=V, St) ->
- case member(reuse_for_context, A) of
- false -> V;
- true -> handle_reuse_anno_1(V, St)
- end.
-
-handle_reuse_anno_1(#k_var{anno=Anno,name=Vname}=V, #kern{ff={F,A}}=St) ->
- FreeVs = get_free(F, A, St),
- case keymember(Vname, #k_var.name, FreeVs) of
- true -> V#k_var{anno=Anno--[reuse_for_context]};
- false -> V
- end;
-handle_reuse_anno_1(V, _St) -> V.
-
%% get_free(Name, Arity, State) -> [Free].
%% store_free(Name, Arity, [Free], State) -> State.
@@ -2511,8 +2481,7 @@ umatch(#k_alt{anno=A,first=F0,then=T0}, Br, St0) ->
Used = union(Fu, Tu),
{#k_alt{anno=#k{us=Used,ns=[],a=A},first=F1,then=T1},
Used,St2};
-umatch(#k_select{anno=A,var=V0,types=Ts0}, Br, St0) ->
- V = handle_reuse_anno(V0, St0),
+umatch(#k_select{anno=A,var=V,types=Ts0}, Br, St0) ->
{Ts1,Tus,St1} = umatch_list(Ts0, Br, St0),
Used = case member(no_usage, get_kanno(V)) of
true -> Tus;