diff options
| -rw-r--r-- | lib/compiler/src/sys_core_fold.erl | 45 |
1 files changed, 7 insertions, 38 deletions
diff --git a/lib/compiler/src/sys_core_fold.erl b/lib/compiler/src/sys_core_fold.erl index 7e219da0af..4939a94a92 100644 --- a/lib/compiler/src/sys_core_fold.erl +++ b/lib/compiler/src/sys_core_fold.erl @@ -1997,53 +1997,22 @@ case_opt_compiler_generated(Core) -> %% case_expand_var(Expr0, Sub) -> Expr -%% If Expr0 is a variable that has been previously matched and -%% is known to be a tuple, return the tuple instead. Otherwise +%% If Expr0 is a variable that is known to be bound to a +%% constructed tuple, return the tuple instead. Otherwise %% return Expr0 unchanged. -%% + case_expand_var(E, #sub{t=Tdb}) -> Key = cerl:var_name(E), case Tdb of - #{Key:=T0} -> - case cerl:is_c_tuple(T0) of - false -> - E; - true -> - %% The pattern was a tuple. Now we must make sure - %% that the elements of the tuple are suitable. In - %% particular, we don't want binary or map - %% construction here, since that means that the - %% binary or map will be constructed in the 'case' - %% argument. That is wasteful for binaries. Even - %% worse is that any map pattern that use the ':=' - %% operator will fail when used in map - %% construction (only the '=>' operator is allowed - %% when constructing a map from scratch). - try - cerl_trees:map(fun coerce_to_data/1, T0) - catch - throw:impossible -> - %% Something unsuitable was found (map or - %% or binary). Keep the variable. - E - end + #{Key:=T} -> + case cerl:is_c_tuple(T) of + false -> E; + true -> T end; _ -> E end. -%% coerce_to_data(Core) -> Core' -%% Coerce an element originally from a pattern to an data item or or -%% variable. Throw an 'impossible' exception if non-data Core Erlang -%% terms such as binary construction or map construction are -%% encountered. - -coerce_to_data(C) -> - case cerl:is_data(C) orelse cerl:is_c_var(C) of - true -> C; - false -> throw(impossible) - end. - %% case_opt_nomatch(E, Clauses, LitExpr) -> Clauses' %% Remove all clauses that cannot possibly match. |