Merge pull request #2100 from jhogberg/john/compiler/module-type-optimization

Apply type optimizations across local function calls

1 files changed, 53 insertions, 0 deletions

diff --git a/lib/compiler/src/beam_ssa_opt.hrl b/lib/compiler/src/beam_ssa_opt.hrl
new file mode 100644
index 0000000000..37711a6f48
--- /dev/null
+++ b/lib/compiler/src/beam_ssa_opt.hrl
@@ -0,0 +1,53 @@
+%%
+%% %CopyrightBegin%
+%%
+%% Copyright Ericsson AB 2019. All Rights Reserved.
+%%
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%%
+%% %CopyrightEnd%
+%%
+
+-include("beam_ssa.hrl").
+
+-record(func_info,
+        {%% Local calls going in/out of this function.
+         in = ordsets:new() :: ordsets:ordset(func_id()),
+         out = ordsets:new() :: ordsets:ordset(func_id()),
+
+         %% Whether the function is exported or not; some optimizations may
+         %% need to be suppressed if it is.
+         exported = true :: boolean(),
+
+         %% The inferred types of each argument (as opposed to parameter),
+         %% indexed by call site.
+         %%
+         %% This is more effective than the naive approach of joining into a
+         %% "parameter_type" as we go as it lets us narrow parameter types
+         %% without having to visit all callers on each pass, which helps a lot
+         %% when dealing with co-recursive functions.
+         arg_types = [] :: list(arg_type_map()),
+
+         %% The inferred return type of this function, this is either [type()]
+         %% or [] to note absence.
+         ret_type = [] :: list()}).
+
+-type arg_key() :: {CallerId :: func_id(),
+                    CallDst :: beam_ssa:b_var()}.
+-type arg_type_map() :: #{ arg_key() => term() }.
+
+%% Per-function metadata used by various optimization passes to perform
+%% module-level optimization. If a function is absent it means that
+%% module-level optimization has been turned off for said function.
+-type func_id() :: beam_ssa:b_local().
+-type func_info_db() :: #{ func_id() => #func_info{} }.