Fix the native code translation of bs_match_string

This fixes a HiPE bug reported on erlang-questions on 2/11/2016.

The BEAM to ICode tranaslation of the bs_match_string instruction,
written long ago for binaries (i.e., with byte-sized strings), tried
to do a `clever' translation of even bit-sized strings using a HiPE
primop that took a `Size' argument expressed in *bytes*.
ICode is not really the place to do such a thing, and moreover there
is really no reason for the HiPE primop not to take a Size argument
expressed in *bits* instead.  This commit changes the `Size' argument
to be in bits, postpones the translation of the bs_match_string primop

Fixed in a pair-programming/debugging session with @margnus1.
until RTL and does a proper translation using bit-sized quantities there.

2 files changed, 7 insertions, 29 deletions

diff --git a/lib/hipe/icode/hipe_beam_to_icode.erl b/lib/hipe/icode/hipe_beam_to_icode.erl
index 224aacd8d7..3386523206 100644
--- a/lib/hipe/icode/hipe_beam_to_icode.erl
+++ b/lib/hipe/icode/hipe_beam_to_icode.erl
@@ -763,32 +763,10 @@ trans_fun([{test,bs_test_unit,{f,Lbl},[Ms,Unit]}|
 		[MsVar], [], Env, Instructions);
 trans_fun([{test,bs_match_string,{f,Lbl},[Ms,BitSize,Bin]}|
 	   Instructions], Env) -> 
-  True = mk_label(new),
-  FalseLabName = map_label(Lbl),
-  TrueLabName = hipe_icode:label_name(True),
+  %% the current match buffer
   MsVar = mk_var(Ms),
-  TmpVar = mk_var(new),
-  ByteSize = BitSize div 8,
-  ExtraBits = BitSize rem 8,
-  WordSize = hipe_rtl_arch:word_size(),
-  if ExtraBits =:= 0 ->
-      trans_op_call({hipe_bs_primop,{bs_match_string,Bin,ByteSize}}, Lbl, 
-		    [MsVar], [MsVar], Env, Instructions);
-      BitSize =< ((WordSize * 8) - 5) -> 
-      <<Int:BitSize, _/bits>> = Bin,
-      {I1,Env1} = trans_one_op_call({hipe_bs_primop,{bs_get_integer,BitSize,0}}, Lbl, 
-				    [MsVar], [TmpVar, MsVar], Env), 
-      I2 = hipe_icode:mk_type([TmpVar], {integer,Int}, TrueLabName, FalseLabName),
-      I1 ++ [I2,True] ++ trans_fun(Instructions, Env1);
-     true ->
-      <<RealBin:ByteSize/binary, Int:ExtraBits, _/bits>> = Bin,
-      {I1,Env1} = trans_one_op_call({hipe_bs_primop,{bs_match_string,RealBin,ByteSize}}, Lbl, 
-				    [MsVar], [MsVar], Env),
-      {I2,Env2} = trans_one_op_call({hipe_bs_primop,{bs_get_integer,ExtraBits,0}}, Lbl, 
-				    [MsVar], [TmpVar, MsVar], Env1),
-      I3 = hipe_icode:mk_type([TmpVar], {integer,Int}, TrueLabName, FalseLabName),
-      I1 ++ I2 ++ [I3,True] ++ trans_fun(Instructions, Env2)
-  end;
+  Primop = {hipe_bs_primop, {bs_match_string, Bin, BitSize}},
+  trans_op_call(Primop, Lbl, [MsVar], [MsVar], Env, Instructions);
 trans_fun([{bs_context_to_binary,Var}|Instructions], Env) -> 
   %% the current match buffer
   IVars = [trans_arg(Var)],
diff --git a/lib/hipe/icode/hipe_icode_primops.erl b/lib/hipe/icode/hipe_icode_primops.erl
index cee37b6a57..2a141c514e 100644
--- a/lib/hipe/icode/hipe_icode_primops.erl
+++ b/lib/hipe/icode/hipe_icode_primops.erl
@@ -287,8 +287,8 @@ pp(Dev, Op) ->
 	  io:format(Dev, "bs_start_match<~w>", [Max]);
 	{{bs_start_match, Type}, Max} ->
 	  io:format(Dev, "bs_start_match<~w,~w>", [Type,Max]);
-	{bs_match_string, String, SizeInBytes} ->
-	  io:format(Dev, "bs_match_string<~w, ~w>", [String, SizeInBytes]);
+	{bs_match_string, String, SizeInBits} ->
+	  io:format(Dev, "bs_match_string<~w, ~w>", [String, SizeInBits]);
 	{bs_get_integer, Size, Flags} ->
 	  io:format(Dev, "bs_get_integer<~w, ~w>", [Size, Flags]);
 	{bs_get_float, Size, Flags} ->
@@ -596,10 +596,10 @@ type(Primop, Args) ->
 	erl_types:t_subtract(Type, erl_types:t_matchstate()),
 	erl_types:t_matchstate_slot(
 	  erl_types:t_inf(Type, erl_types:t_matchstate()), 0));
-    {hipe_bs_primop, {bs_match_string,_,Bytes}} ->
+    {hipe_bs_primop, {bs_match_string,_,Bits}} ->
       [MatchState] = Args,
       BinType = erl_types:t_matchstate_present(MatchState),
-      NewBinType = match_bin(erl_types:t_bitstr(0, Bytes*8), BinType),
+      NewBinType = match_bin(erl_types:t_bitstr(0, Bits), BinType),
       erl_types:t_matchstate_update_present(NewBinType, MatchState);
     {hipe_bs_primop, {bs_test_unit,Unit}} ->
       [MatchState] = Args,