Merge branch 'egil/fix-compiler-beam_bsm/OTP-12758'

* egil/fix-compiler-beam_bsm/OTP-12758:
  compiler: Add tests for beam_bsm get_map_elements
  compiler: Teach beam_bsm get_map_elements instruction

2 files changed, 22 insertions, 1 deletions

diff --git a/lib/compiler/src/beam_bsm.erl b/lib/compiler/src/beam_bsm.erl
index 2a15c1ddf3..ee3e88959d 100644
--- a/lib/compiler/src/beam_bsm.erl
+++ b/lib/compiler/src/beam_bsm.erl
@@ -242,6 +242,12 @@ btb_reaches_match_2([{bif,_,{f,F},Ss,Dst}=I|Is], Regs0, D0) ->
     Regs = btb_kill([Dst], Regs0),
     D = btb_follow_branch(F, Regs, D0),
     btb_reaches_match_1(Is, Regs, D);
+btb_reaches_match_2([{get_map_elements,{f,F},Src,{list,Ls}}=I|Is], Regs0, D0) ->
+    {Ss,Ds} = beam_utils:split_even(Ls),
+    btb_ensure_not_used([Src|Ss], I, Regs0),
+    Regs = btb_kill(Ds, Regs0),
+    D = btb_follow_branch(F, Regs, D0),
+    btb_reaches_match_1(Is, Regs, D);
 btb_reaches_match_2([{test,bs_start_match2,{f,F},Live,[Ctx,_],Ctx}=I|Is],
 		    Regs0, D0) ->
     CtxRegs = btb_context_regs(Regs0),
diff --git a/lib/compiler/test/warnings_SUITE.erl b/lib/compiler/test/warnings_SUITE.erl
index f6ba75577d..5742b7e6cf 100644
--- a/lib/compiler/test/warnings_SUITE.erl
+++ b/lib/compiler/test/warnings_SUITE.erl
@@ -38,7 +38,8 @@
 -export([pattern/1,pattern2/1,pattern3/1,pattern4/1,
 	 guard/1,bad_arith/1,bool_cases/1,bad_apply/1,
          files/1,effect/1,bin_opt_info/1,bin_construction/1,
-	 comprehensions/1,maps/1,redundant_boolean_clauses/1,
+	 comprehensions/1,maps/1,maps_bin_opt_info/1,
+         redundant_boolean_clauses/1,
 	 latin1_fallback/1,underscore/1,no_warnings/1]).
 
 % Default timetrap timeout (set in init_per_testcase).
@@ -64,6 +65,7 @@ groups() ->
       [pattern,pattern2,pattern3,pattern4,guard,
        bad_arith,bool_cases,bad_apply,files,effect,
        bin_opt_info,bin_construction,comprehensions,maps,
+       maps_bin_opt_info,
        redundant_boolean_clauses,latin1_fallback,
        underscore,no_warnings]}].
 
@@ -619,6 +621,19 @@ maps(Config) when is_list(Config) ->
     run(Config, Ts),
     ok.
 
+maps_bin_opt_info(Config) when is_list(Config) ->
+    Ts = [{map_bsm,
+           <<"
+             t1(<<0:8,7:8,T/binary>>,#{val := I}=M) ->
+                 t1(T, M#{val := I+1});
+             t1(<<_:8>>,M) ->
+                 M.
+           ">>,
+           [bin_opt_info],
+           {warnings,[{2,beam_bsm,bin_opt}]}}],
+    [] = run(Config, Ts),
+    ok.
+
 redundant_boolean_clauses(Config) when is_list(Config) ->
     Ts = [{redundant_boolean_clauses,
            <<"