Merge branch 'bjorn/compiler/optimizations/OTP-11584'

* bjorn/compiler/optimizations/OTP-11584:
  Teach sys_core_fold:eval_case/2 to cope with handwritten Core Erlang
  sys_core_fold: Remove a redundant word in a comment

2 files changed, 37 insertions, 2 deletions

diff --git a/lib/compiler/test/core_SUITE.erl b/lib/compiler/test/core_SUITE.erl
index 1a521c3591..aa222c48de 100644
--- a/lib/compiler/test/core_SUITE.erl
+++ b/lib/compiler/test/core_SUITE.erl
@@ -24,7 +24,7 @@
 	 dehydrated_itracer/1,nested_tries/1,
 	 seq_in_guard/1,make_effect_seq/1,eval_is_boolean/1,
 	 unsafe_case/1,nomatch_shadow/1,reversed_annos/1,
-	 map_core_test/1]).
+	 map_core_test/1,eval_case/1]).
 
 -include_lib("test_server/include/test_server.hrl").
 
@@ -50,7 +50,7 @@ groups() ->
     [{p,test_lib:parallel(),
       [dehydrated_itracer,nested_tries,seq_in_guard,make_effect_seq,
        eval_is_boolean,unsafe_case,nomatch_shadow,reversed_annos,
-       map_core_test
+       map_core_test,eval_case
    ]}].
 
 
@@ -76,6 +76,7 @@ end_per_group(_GroupName, Config) ->
 ?comp(nomatch_shadow).
 ?comp(reversed_annos).
 ?comp(map_core_test).
+?comp(eval_case).
 
 try_it(Mod, Conf) ->
     Src = filename:join(?config(data_dir, Conf), atom_to_list(Mod)),
diff --git a/lib/compiler/test/core_SUITE_data/eval_case.core b/lib/compiler/test/core_SUITE_data/eval_case.core
new file mode 100644
index 0000000000..f2776e2b1f
--- /dev/null
+++ b/lib/compiler/test/core_SUITE_data/eval_case.core
@@ -0,0 +1,34 @@
+module 'eval_case' ['eval_case'/0]
+    attributes []
+'eval_case'/0 =
+    fun () ->
+	case <> of
+	  <> when 'true' ->
+	      case apply 'do_case'/0() of
+		<'ok'> when 'true' ->
+		    'ok'
+		( <_cor0> when 'true' ->
+		      primop 'match_fail'
+			  ({'badmatch',_cor0})
+		  -| ['compiler_generated'] )
+	      end
+	  ( <> when 'true' ->
+		( primop 'match_fail'
+		      ({'function_clause'})
+		  -| [{'function_name',{'eval_case',0}}] )
+	    -| ['compiler_generated'] )
+	end
+'do_case'/0 =
+    fun () ->
+        case let <_cor0> =
+	     apply 'id'/1(42)
+                  in  let <_cor1> =
+		      call 'erlang':'+'
+			  (_cor0, 7)
+		  in {'x',_cor1} of
+	     <{'x',49}> when 'true' ->
+	          'ok'
+        end
+'id'/1 =
+    fun (_cor0) -> _cor0
+end