Merge branch 'bjorn/compiler/match-fail/OTP-9842' into maint

* bjorn/compiler/match-fail/OTP-9842:
  Add the beam_except pass to optimize exceptions
  Eliminate the match_fail primop in v3_kernel and later passes

11 files changed, 270 insertions, 81 deletions

diff --git a/lib/compiler/src/Makefile b/lib/compiler/src/Makefile
index 7a237608ad..3415517fff 100644
--- a/lib/compiler/src/Makefile
+++ b/lib/compiler/src/Makefile
@@ -53,6 +53,7 @@ MODULES =  \
 	beam_dead \
 	beam_dict \
 	beam_disasm \
+	beam_except \
 	beam_flatten \
 	beam_jump \
 	beam_listing \
diff --git a/lib/compiler/src/beam_except.erl b/lib/compiler/src/beam_except.erl
new file mode 100644
index 0000000000..fb1a43cd9e
--- /dev/null
+++ b/lib/compiler/src/beam_except.erl
@@ -0,0 +1,149 @@
+%%
+%% %CopyrightBegin%
+%%
+%% Copyright Ericsson AB 2011. All Rights Reserved.
+%%
+%% The contents of this file are subject to the Erlang Public License,
+%% Version 1.1, (the "License"); you may not use this file except in
+%% compliance with the License. You should have received a copy of the
+%% Erlang Public License along with this software. If not, it can be
+%% retrieved online at http://www.erlang.org/.
+%%
+%% Software distributed under the License is distributed on an "AS IS"
+%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+%% the License for the specific language governing rights and limitations
+%% under the License.
+%%
+%% %CopyrightEnd%
+%%
+
+-module(beam_except).
+-export([module/2]).
+
+%%% Rewrite certain calls to erlang:error/{1,2} to specialized
+%%% instructions:
+%%%
+%%% erlang:error({badmatch,Value})       => badmatch Value
+%%% erlang:error({case_clause,Value})    => case_end Value
+%%% erlang:error({try_clause,Value})     => try_case_end Value
+%%% erlang:error(if_clause)              => if_end
+%%% erlang:error(function_clause, Args)  => jump FuncInfoLabel
+%%%
+
+-import(lists, [reverse/1]).
+
+module({Mod,Exp,Attr,Fs0,Lc}, _Opt) ->
+    Fs = [function(F) || F <- Fs0],
+    {ok,{Mod,Exp,Attr,Fs,Lc}}.
+
+function({function,Name,Arity,CLabel,Is0}) ->
+    try
+	Is = function_1(Is0),
+	{function,Name,Arity,CLabel,Is}
+    catch
+	Class:Error ->
+	    Stack = erlang:get_stacktrace(),
+	    io:fwrite("Function: ~w/~w\n", [Name,Arity]),
+	    erlang:raise(Class, Error, Stack)
+    end.
+
+-record(st,
+	{lbl,					%func_info label
+	 loc					%location for func_info
+	 }).
+
+function_1(Is0) ->
+    case Is0 of
+	[{label,Lbl},{line,Loc}|_] ->
+	    St = #st{lbl=Lbl,loc=Loc},
+	    translate(Is0, St, []);
+	[{label,_}|_] ->
+	    %% No line numbers. The source must be a .S file.
+	    %% There is no need to do anything.
+	    Is0
+    end.
+
+translate([{call_ext,Ar,{extfunc,erlang,error,Ar}}=I|Is], St, Acc) ->
+    translate_1(Ar, I, Is, St, Acc);
+translate([{call_ext_only,Ar,{extfunc,erlang,error,Ar}}=I|Is], St, Acc) ->
+    translate_1(Ar, I, Is, St, Acc);
+translate([{call_ext_last,Ar,{extfunc,erlang,error,Ar},_}=I|Is], St, Acc) ->
+    translate_1(Ar, I, Is, St, Acc);
+translate([I|Is], St, Acc) ->
+    translate(Is, St, [I|Acc]);
+translate([], _, Acc) ->
+    reverse(Acc).
+
+translate_1(Ar, I, Is, St, [{line,_}=Line|Acc1]=Acc0) ->
+    case dig_out(Ar, Acc1) of
+	no ->
+	    translate(Is, St, [I|Acc0]);
+	{yes,function_clause,Acc2} ->
+	    case {Line,St} of
+		{{line,Loc},#st{lbl=Fi,loc=Loc}} ->
+		    Instr = {jump,{f,Fi}},
+		    translate(Is, St, [Instr|Acc2]);
+		{_,_} ->
+		    %% This must be "error(function_clause, Args)" in
+		    %% the Erlang source code. Don't translate.
+		    translate(Is, St, [I|Acc0])
+	    end;
+	{yes,Instr,Acc2} ->
+	    translate(Is, St, [Instr,Line|Acc2])
+    end.
+
+dig_out(Ar, [{kill,_}|Is]) ->
+    dig_out(Ar, Is);
+dig_out(1, [{block,Bl0}|Is]) ->
+    case dig_out_block(reverse(Bl0)) of
+	no -> no;
+	{yes,What,[]} ->
+	    {yes,What,Is};
+	{yes,What,Bl} ->
+	    {yes,What,[{block,Bl}|Is]}
+    end;
+dig_out(2, [{block,Bl}|Is]) ->
+    case dig_out_block_fc(Bl) of
+	no -> no;
+	{yes,What} -> {yes,What,Is}
+    end;
+dig_out(_, _) -> no.
+
+dig_out_block([{set,[{x,0}],[{atom,if_clause}],move}]) ->
+    {yes,if_end,[]};
+dig_out_block([{set,[{x,0}],[{literal,{Exc,Value}}],move}|Is]) ->
+    translate_exception(Exc, {literal,Value}, Is, 0);
+dig_out_block([{set,[{x,0}],[Tuple],move},
+	       {set,[],[Value],put},
+	       {set,[],[{atom,Exc}],put},
+	       {set,[Tuple],[],{put_tuple,2}}|Is]) ->
+    translate_exception(Exc, Value, Is, 3);
+dig_out_block([{set,[],[Value],put},
+	       {set,[],[{atom,Exc}],put},
+	       {set,[{x,0}],[],{put_tuple,2}}|Is]) ->
+    translate_exception(Exc, Value, Is, 3);
+dig_out_block(_) -> no.
+
+translate_exception(badmatch, Val, Is, Words) ->
+    {yes,{badmatch,Val},fix_block(Is, Words)};
+translate_exception(case_clause, Val, Is, Words) ->
+    {yes,{case_end,Val},fix_block(Is, Words)};
+translate_exception(try_clause, Val, Is, Words) ->
+    {yes,{try_case_end,Val},fix_block(Is, Words)};
+translate_exception(_, _, _, _) -> no.
+
+fix_block(Is, 0) ->
+    reverse(Is);
+fix_block(Is0, Words) ->
+    [{set,[],[],{alloc,Live,{F1,F2,Needed,F3}}}|Is] = reverse(Is0),
+    [{set,[],[],{alloc,Live,{F1,F2,Needed-Words,F3}}}|Is].
+
+dig_out_block_fc([{set,[],[],{alloc,Live,_}}|Bl]) ->
+    dig_out_fc(Bl, Live-1, nil);
+dig_out_block_fc(_) -> no.
+
+dig_out_fc([{set,[Dst],[{x,Reg},Dst0],put_list}|Is], Reg, Dst0) ->
+    dig_out_fc(Is, Reg-1, Dst);
+dig_out_fc([{set,[{x,0}],[{atom,function_clause}],move}], -1, {x,1}) ->
+    {yes,function_clause};
+dig_out_fc(_, _, _) -> no.
diff --git a/lib/compiler/src/compile.erl b/lib/compiler/src/compile.erl
index a17a10046e..9b505ad15c 100644
--- a/lib/compiler/src/compile.erl
+++ b/lib/compiler/src/compile.erl
@@ -629,6 +629,8 @@ asm_passes() ->
       [{unless,no_postopt,
 	[{pass,beam_block},
 	 {iff,dblk,{listing,"block"}},
+	 {unless,no_except,{pass,beam_except}},
+	 {iff,dexcept,{listing,"except"}},
 	 {unless,no_bopt,{pass,beam_bool}},
 	 {iff,dbool,{listing,"bool"}},
 	 {unless,no_topt,{pass,beam_type}},
diff --git a/lib/compiler/src/compiler.app.src b/lib/compiler/src/compiler.app.src
index fb06f2521c..1133882728 100644
--- a/lib/compiler/src/compiler.app.src
+++ b/lib/compiler/src/compiler.app.src
@@ -28,6 +28,7 @@
 	     beam_dead,
 	     beam_dict,
 	     beam_disasm,
+	     beam_except,
 	     beam_flatten,
 	     beam_jump,
 	     beam_listing,
diff --git a/lib/compiler/src/v3_codegen.erl b/lib/compiler/src/v3_codegen.erl
index e7dae67085..6623485609 100644
--- a/lib/compiler/src/v3_codegen.erl
+++ b/lib/compiler/src/v3_codegen.erl
@@ -53,7 +53,6 @@
 
 %% Main codegen structure.
 -record(cg, {lcount=1,				%Label counter
-	     finfo,				%Function info label
 	     bfail,				%Fail label for BIFs
 	     break,				%Break label
 	     recv,				%Receive label
@@ -126,7 +125,6 @@ cg_fun(Les, Hvs, Vdb, AtomMod, NameArity, Anno, St0) ->
 			 stk=[]}, 0, Vdb),
     {B,_Aft,St} = cg_list(Les, 0, Vdb, Bef,
 			  St3#cg{bfail=0,
-				 finfo=Fi,
 				 ultimate_failure=UltimateMatchFail,
 				 is_top_block=true}),
     {Name,Arity} = NameArity,
@@ -147,8 +145,6 @@ cg({match,M,Rs}, Le, Vdb, Bef, St) ->
     match_cg(M, Rs, Le, Vdb, Bef, St);
 cg({guard_match,M,Rs}, Le, Vdb, Bef, St) ->
     guard_match_cg(M, Rs, Le, Vdb, Bef, St);
-cg({match_fail,F}, Le, Vdb, Bef, St) ->
-    match_fail_cg(F, Le, Vdb, Bef, St);
 cg({call,Func,As,Rs}, Le, Vdb, Bef, St) ->
     call_cg(Func, As, Rs, Le, Vdb, Bef, St);
 cg({enter,Func,As}, Le, Vdb, Bef, St) ->
@@ -294,39 +290,6 @@ match_cg({block,Es}, Le, _Fail, Bef, St) ->
     Int = clear_dead(Bef, Le#l.i, Le#l.vdb),
     block_cg(Es, Le, Int, St).
 
-%% match_fail_cg(FailReason, Le, Vdb, StackReg, State) ->
-%%	{[Ainstr],StackReg,State}.
-%%  Generate code for the match_fail "call".  N.B. there is no generic
-%%  case for when the fail value has been created elsewhere.
-
-match_fail_cg({function_clause,As}, Le, Vdb, Bef, St) ->
-    %% Must have the args in {x,0}, {x,1},...
-    {Sis,Int} = cg_setup_call(As, Bef, Le#l.i, Vdb),
-    {Sis ++ [{jump,{f,St#cg.finfo}}],
-     Int#sr{reg=clear_regs(Int#sr.reg)},St};
-match_fail_cg({badmatch,Term}, Le, Vdb, Bef, St) ->
-    R = cg_reg_arg(Term, Bef),
-    Int0 = clear_dead(Bef, Le#l.i, Vdb),
-    {Sis,Int} = adjust_stack(Int0, Le#l.i, Le#l.i+1, Vdb),
-    {Sis ++ [line(Le),{badmatch,R}],
-     Int#sr{reg=clear_regs(Int0#sr.reg)},St};
-match_fail_cg({case_clause,Reason}, Le, Vdb, Bef, St) ->
-    R = cg_reg_arg(Reason, Bef),
-    Int0 = clear_dead(Bef, Le#l.i, Vdb),
-    {Sis,Int} = adjust_stack(Int0, Le#l.i, Le#l.i+1, Vdb),
-    {Sis++[line(Le),{case_end,R}],
-     Int#sr{reg=clear_regs(Bef#sr.reg)},St};
-match_fail_cg(if_clause, Le, Vdb, Bef, St) ->
-    Int0 = clear_dead(Bef, Le#l.i, Vdb),
-    {Sis,Int1} = adjust_stack(Int0, Le#l.i, Le#l.i+1, Vdb),
-    {Sis++[line(Le),if_end],Int1#sr{reg=clear_regs(Int1#sr.reg)},St};
-match_fail_cg({try_clause,Reason}, Le, Vdb, Bef, St) ->
-    R = cg_reg_arg(Reason, Bef),
-    Int0 = clear_dead(Bef, Le#l.i, Vdb),
-    {Sis,Int} = adjust_stack(Int0, Le#l.i, Le#l.i+1, Vdb),
-    {Sis ++ [line(Le),{try_case_end,R}],
-     Int#sr{reg=clear_regs(Int0#sr.reg)},St}.
-
 %% bsm_rename_ctx([Clause], Var) -> [Clause]
 %%  We know from an annotation that the register for a binary can
 %%  be reused for the match context because the two are not truly
diff --git a/lib/compiler/src/v3_kernel.erl b/lib/compiler/src/v3_kernel.erl
index d76291f57f..f2eaa37617 100644
--- a/lib/compiler/src/v3_kernel.erl
+++ b/lib/compiler/src/v3_kernel.erl
@@ -83,6 +83,7 @@
 -import(lists, [map/2,foldl/3,foldr/3,mapfoldl/3,splitwith/2,member/2,
 		keymember/3,keyfind/3]).
 -import(ordsets, [add_element/2,del_element/2,union/2,union/1,subtract/2]).
+-import(cerl, [c_tuple/1]).
 
 -include("core_parse.hrl").
 -include("v3_kernel.hrl").
@@ -422,10 +423,11 @@ expr(#c_call{anno=A,module=M0,name=F0,args=Cargs}, Sub, St0) ->
     end;
 expr(#c_primop{anno=A,name=#c_literal{val=match_fail},args=Cargs0}, Sub, St0) ->
     Cargs = translate_match_fail(Cargs0, Sub, A, St0),
-    %% This special case will disappear.
     {Kargs,Ap,St} = atomic_list(Cargs, Sub, St0),
     Ar = length(Cargs),
-    Call = #k_call{anno=A,op=#k_internal{name=match_fail,arity=Ar},args=Kargs},
+    Call = #k_call{anno=A,op=#k_remote{mod=#k_atom{val=erlang},
+				       name=#k_atom{val=error},
+				       arity=Ar},args=Kargs},
     {Call,Ap,St};
 expr(#c_primop{anno=A,name=#c_literal{val=N},args=Cargs}, Sub, St0) ->
     {Kargs,Ap,St1} = atomic_list(Cargs, Sub, St0),
@@ -455,14 +457,14 @@ expr(#ireceive_accept{anno=A}, _Sub, St) -> {#k_receive_accept{anno=A},[],St}.
 translate_match_fail(Args, Sub, Anno, St) ->
     case Args of
 	[#c_tuple{es=[#c_literal{val=function_clause}|As]}] ->
-	    translate_match_fail_1(Anno, Args, As, Sub, St);
+	    translate_match_fail_1(Anno, As, Sub, St);
 	[#c_literal{val=Tuple}] when is_tuple(Tuple) ->
 	    %% The inliner may have created a literal out of
 	    %% the original #c_tuple{}.
 	    case tuple_to_list(Tuple) of
 		[function_clause|As0] ->
 		    As = [#c_literal{val=E} || E <- As0],
-		    translate_match_fail_1(Anno, Args, As, Sub, St);
+		    translate_match_fail_1(Anno, As, Sub, St);
 		_ ->
 		    Args
 	    end;
@@ -471,7 +473,7 @@ translate_match_fail(Args, Sub, Anno, St) ->
 	    Args
     end.
 
-translate_match_fail_1(Anno, Args, As, Sub, #kern{ff=FF}) ->
+translate_match_fail_1(Anno, As, Sub, #kern{ff=FF}) ->
     AnnoFunc = case keyfind(function_name, 1, Anno) of
 		   false ->
 		       none;			%Force rewrite.
@@ -481,10 +483,10 @@ translate_match_fail_1(Anno, Args, As, Sub, #kern{ff=FF}) ->
     case {AnnoFunc,FF} of
 	{Same,Same} ->
 	    %% Still in the correct function.
-	    Args;
+	    translate_fc(As);
 	{{F,_},F} ->
 	    %% Still in the correct function.
-	    Args;
+	    translate_fc(As);
 	_ ->
 	    %% Wrong function or no function_name annotation.
 	    %%
@@ -493,9 +495,12 @@ translate_match_fail_1(Anno, Args, As, Sub, #kern{ff=FF}) ->
 	    %% the current function). match_fail(function_clause) will
 	    %% only work at the top level of the function it was originally
 	    %% defined in, so we will need to rewrite it to a case_clause.
-	    [#c_tuple{es=[#c_literal{val=case_clause},#c_tuple{es=As}]}]
+	    [c_tuple([#c_literal{val=case_clause},c_tuple(As)])]
     end.
 
+translate_fc(Args) ->
+    [#c_literal{val=function_clause},make_list(Args)].
+
 %% call_type(Module, Function, Arity) -> call | bif | apply | error.
 %%  Classify the call.
 call_type(#c_literal{val=M}, #c_literal{val=F}, Ar) when is_atom(M), is_atom(F) ->
@@ -1494,7 +1499,6 @@ iletrec_funs_gen(Fs, FreeVs, St) ->
 %% is_exit_expr(Kexpr) -> boolean().
 %%  Test whether Kexpr always exits and never returns.
 
-is_exit_expr(#k_call{op=#k_internal{name=match_fail,arity=1}}) -> true;
 is_exit_expr(#k_receive_next{}) -> true;
 is_exit_expr(_) -> false.
 
diff --git a/lib/compiler/src/v3_life.erl b/lib/compiler/src/v3_life.erl
index fac9a9843d..93f8034230 100644
--- a/lib/compiler/src/v3_life.erl
+++ b/lib/compiler/src/v3_life.erl
@@ -89,19 +89,8 @@ function(#k_fdef{anno=#k{a=Anno},func=F,arity=Ar,vars=Vs,body=Kb}) ->
     end.
 
 %% body(Kbody, I, Vdb) -> {[Expr],MaxI,Vdb}.
-%%  Handle a body, need special cases for transforming match_fails.
-%%  We KNOW that they only occur last in a body.
-
-body(#k_seq{arg=#k_put{anno=Pa,arg=Arg,ret=[R]},
-	    body=#k_enter{anno=Ea,op=#k_internal{name=match_fail,arity=1},
-			  args=[R]}},
-      I, Vdb0) ->
-    Vdb1 = use_vars(Pa#k.us, I, Vdb0),		%All used here
-    {[match_fail(Arg, I, Pa#k.a ++ Ea#k.a)],I,Vdb1};
-body(#k_enter{anno=Ea,op=#k_internal{name=match_fail,arity=1},args=[Arg]},
-      I, Vdb0) ->
-    Vdb1 = use_vars(Ea#k.us, I, Vdb0),
-    {[match_fail(Arg, I, Ea#k.a)],I,Vdb1};
+%%  Handle a body.
+
 body(#k_seq{arg=Ke,body=Kb}, I, Vdb0) ->
     %%ok = io:fwrite("life ~w:~p~n", [?LINE,{Ke,I,Vdb0}]),
     A = get_kanno(Ke),
@@ -353,25 +342,6 @@ guard_clause(#k_guard_clause{anno=A,guard=Kg,body=Kb}, Ls, I, Ctxt, Vdb0) ->
        i=I,vdb=use_vars((get_kanno(Kg))#k.us, I+2, Vdb1),
        a=A#k.a}.
 
-%% match_fail(FailValue, I, Anno) -> Expr.
-%%  Generate the correct match_fail instruction.  N.B. there is no
-%%  generic case for when the fail value has been created elsewhere.
-
-match_fail(#k_literal{anno=Anno,val={Atom,Val}}, I, A) when is_atom(Atom) ->
-    match_fail(#k_tuple{anno=Anno,es=[#k_atom{val=Atom},#k_literal{val=Val}]}, I, A);
-match_fail(#k_literal{anno=Anno,val={Atom}}, I, A) when is_atom(Atom) ->
-    match_fail(#k_tuple{anno=Anno,es=[#k_atom{val=Atom}]}, I, A);
-match_fail(#k_tuple{es=[#k_atom{val=function_clause}|As]}, I, A) ->
-    #l{ke={match_fail,{function_clause,literal_list(As, [])}},i=I,a=A};
-match_fail(#k_tuple{es=[#k_atom{val=badmatch},Val]}, I, A) ->
-    #l{ke={match_fail,{badmatch,literal(Val, [])}},i=I,a=A};
-match_fail(#k_tuple{es=[#k_atom{val=case_clause},Val]}, I, A) ->
-    #l{ke={match_fail,{case_clause,literal(Val, [])}},i=I,a=A};
-match_fail(#k_atom{val=if_clause}, I, A) ->
-    #l{ke={match_fail,if_clause},i=I,a=A};
-match_fail(#k_tuple{es=[#k_atom{val=try_clause},Val]}, I, A) ->
-    #l{ke={match_fail,{try_clause,literal(Val, [])}},i=I,a=A}.
-
 %% type(Ktype) -> Type.
 
 type(k_literal) -> literal;
diff --git a/lib/compiler/test/Makefile b/lib/compiler/test/Makefile
index b90adaf917..2ea50b9112 100644
--- a/lib/compiler/test/Makefile
+++ b/lib/compiler/test/Makefile
@@ -10,6 +10,7 @@ MODULES= \
 	apply_SUITE \
 	beam_validator_SUITE \
 	beam_disasm_SUITE \
+	beam_expect_SUITE \
 	bs_bincomp_SUITE \
 	bs_bit_binaries_SUITE \
 	bs_construct_SUITE \
@@ -39,6 +40,7 @@ MODULES= \
 NO_OPT= \
 	andor \
 	apply \
+	beam_expect \
 	bs_construct \
         bs_match \
 	bs_utf \
diff --git a/lib/compiler/test/beam_expect_SUITE.erl b/lib/compiler/test/beam_expect_SUITE.erl
new file mode 100644
index 0000000000..6f216eac4f
--- /dev/null
+++ b/lib/compiler/test/beam_expect_SUITE.erl
@@ -0,0 +1,67 @@
+%%
+%% %CopyrightBegin%
+%%
+%% Copyright Ericsson AB 2011. All Rights Reserved.
+%%
+%% The contents of this file are subject to the Erlang Public License,
+%% Version 1.1, (the "License"); you may not use this file except in
+%% compliance with the License. You should have received a copy of the
+%% Erlang Public License along with this software. If not, it can be
+%% retrieved online at http://www.erlang.org/.
+%%
+%% Software distributed under the License is distributed on an "AS IS"
+%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+%% the License for the specific language governing rights and limitations
+%% under the License.
+%%
+%% %CopyrightEnd%
+%%
+-module(beam_expect_SUITE).
+
+-export([all/0, suite/0,groups/0,init_per_suite/1, end_per_suite/1,
+	 init_per_group/2,end_per_group/2,
+	 coverage/1]).
+
+suite() -> [{ct_hooks,[ts_install_cth]}].
+
+all() ->
+    [coverage].
+
+groups() ->
+    [].
+
+init_per_suite(Config) ->
+    Config.
+
+end_per_suite(_Config) ->
+    ok.
+
+init_per_group(_GroupName, Config) ->
+    Config.
+
+end_per_group(_GroupName, Config) ->
+    Config.
+
+coverage(_) ->
+    File = {file,"fake.erl"},
+    ok = fc(a),
+    {'EXIT',{function_clause,
+	     [{?MODULE,fc,[[x]],[File,{line,2}]}|_]}} =
+	(catch fc([x])),
+    {'EXIT',{function_clause,
+	     [{?MODULE,fc,[y],[File,{line,2}]}|_]}} =
+	(catch fc(y)),
+    {'EXIT',{function_clause,
+	     [{?MODULE,fc,[[a,b,c]],[File,{line,6}]}|_]}} =
+	(catch fc([a,b,c])),
+
+    {'EXIT',{undef,[{erlang,error,[a,b,c],_}|_]}} =
+	(catch erlang:error(a, b, c)),
+    ok.
+
+-file("fake.erl", 1).
+fc(a) ->	                                %Line 2
+    ok;						%Line 3
+fc(L) when length(L) > 2 ->			%Line 4
+    %% Not the same as a "real" function_clause error.
+    error(function_clause, [L]).		%Line 6
diff --git a/lib/compiler/test/compilation_SUITE.erl b/lib/compiler/test/compilation_SUITE.erl
index 1343fbd1c9..1f17664b54 100644
--- a/lib/compiler/test/compilation_SUITE.erl
+++ b/lib/compiler/test/compilation_SUITE.erl
@@ -44,7 +44,7 @@ all() ->
      trycatch_4, opt_crash, otp_5404, otp_5436, otp_5481,
      otp_5553, otp_5632, otp_5714, otp_5872, otp_6121,
      otp_6121a, otp_6121b, otp_7202, otp_7345, on_load,
-     string_table,otp_8949_a,otp_8949_a].
+     string_table,otp_8949_a,otp_8949_a,split_cases].
 
 groups() -> 
     [{vsn, [], [vsn_1, vsn_2, vsn_3]}].
@@ -657,5 +657,19 @@ otp_8949_b(A, B) ->
 	    id(Var)
     end.
     
+split_cases(_) ->
+    dummy1 = do_split_cases(x),
+    {'EXIT',{{badmatch,b},_}} = (catch do_split_cases(y)),
+    ok.
+
+do_split_cases(A) ->
+    case A of
+        x ->
+	    Z = dummy1;
+        _ ->
+	    Z = dummy2,
+	    a=b
+    end,
+    Z.
 
 id(I) -> I.
diff --git a/lib/compiler/test/misc_SUITE.erl b/lib/compiler/test/misc_SUITE.erl
index 9b414cade6..5e13a93c52 100644
--- a/lib/compiler/test/misc_SUITE.erl
+++ b/lib/compiler/test/misc_SUITE.erl
@@ -190,6 +190,15 @@ silly_coverage(Config) when is_list(Config) ->
 		     {label,2}|non_proper_list]}],99},
     ?line expect_error(fun() -> beam_block:module(BlockInput, []) end),
 
+    %% beam_except
+    ExceptInput = {?MODULE,[{foo,0}],[],
+		   [{function,foo,0,2,
+		     [{label,1},
+		      {line,loc},
+		      {func_info,{atom,?MODULE},{atom,foo},0},
+		      {label,2}|non_proper_list]}],99},
+    expect_error(fun() -> beam_except:module(ExceptInput, []) end),
+
     %% beam_bool
     BoolInput = {?MODULE,[{foo,0}],[],
 		  [{function,foo,0,2,
@@ -253,8 +262,15 @@ expect_error(Fun) ->
 	    io:format("~p", [Any]),
 	    ?t:fail(call_was_supposed_to_fail)
     catch
-	_:_ ->
-	    io:format("~p\n", [erlang:get_stacktrace()])
+	Class:Reason ->
+	    Stk = erlang:get_stacktrace(),
+	    io:format("~p:~p\n~p\n", [Class,Reason,Stk]),
+	    case {Class,Reason} of
+		{error,undef} ->
+		    ?t:fail(not_supposed_to_fail_with_undef);
+		{_,_} ->
+		    ok
+	    end
     end.
 
 confused_literals(Config) when is_list(Config) ->