Fix dialyzer warning and some code refactoring

A previous commit introduced a change that exposed dead code in this
module and caused dialyzer warnings.  This dead code was taken out.
While at it, performed some code refactoring in the handling of the
bs_get_integer primop.

1 files changed, 20 insertions, 19 deletions

diff --git a/lib/hipe/icode/hipe_icode_primops.erl b/lib/hipe/icode/hipe_icode_primops.erl
index 84aae30291..a0deb31c42 100644
--- a/lib/hipe/icode/hipe_icode_primops.erl
+++ b/lib/hipe/icode/hipe_icode_primops.erl
@@ -504,16 +504,16 @@ type(Primop, Args) ->
 	  NewBinType = match_bin(erl_types:t_bitstr(0, Size), BinType),
 	  NewMatchState = 
 	    erl_types:t_matchstate_update_present(NewBinType, MatchState),
-	  if Signed =:= 0 ->
-	      UpperBound = inf_add(safe_bsl(1, Size), -1),
-	      erl_types:t_product([erl_types:t_from_range(0, UpperBound),
-				   NewMatchState]);
-	     Signed =:= 4 ->
-	      erl_types:t_product([erl_types:t_from_range(
-				     inf_inv(safe_bsl(1, Size-1)),
-				     inf_add(safe_bsl(1, Size-1), -1)),
-				   NewMatchState])
-	  end;
+	  Range =
+	    case Signed of
+	      0 ->
+		UpperBound = inf_add(safe_bsl_1(Size), -1),
+		erl_types:t_from_range(0, UpperBound);
+	      4 ->
+		Bound = safe_bsl_1(Size - 1),
+		erl_types:t_from_range(inf_inv(Bound), inf_add(Bound, -1))
+	    end,
+	  erl_types:t_product([Range, NewMatchState]);
 	[_Arg] ->
 	  NewBinType = match_bin(erl_types:t_bitstr(Size, 0), BinType),
 	  NewMatchState = 
@@ -969,18 +969,19 @@ check_fun_args(_, _) ->
 match_bin(Pattern, Match) ->
   erl_types:t_bitstr_match(Pattern, Match).
 
-safe_bsl(0, _) -> 0;
-safe_bsl(Base, Shift) when Shift =< 128 -> Base bsl Shift;
-safe_bsl(Base, _Shift) when Base > 0 -> pos_inf;
-safe_bsl(Base, _Shift) when Base < 0 -> neg_inf.
+-spec safe_bsl_1(non_neg_integer()) -> non_neg_integer() | 'pos_inf'.
+
+safe_bsl_1(Shift) when Shift =< 128 -> 1 bsl Shift;
+safe_bsl_1(_Shift) -> pos_inf.
+
+%%
+%% The following two functions are stripped-down versions of more
+%% general functions that exist in hipe_icode_range.erl
+%%
 
 inf_inv(pos_inf) -> neg_inf;
-inf_inv(neg_inf) -> pos_inf;
-inf_inv(Number) -> -Number.
+inf_inv(Number) when is_integer(Number) -> -Number.
 
 inf_add(pos_inf, _Number) -> pos_inf;
-inf_add(neg_inf, _Number) -> neg_inf;
-inf_add(_Number, pos_inf) -> pos_inf;
-inf_add(_Number, neg_inf) -> neg_inf;
 inf_add(Number1, Number2) when is_integer(Number1), is_integer(Number2) ->
   Number1 + Number2.