From 3092fc21c57a34a7ee5e2699ba39bb37edd8c4d8 Mon Sep 17 00:00:00 2001
From: Hans Bolinder <hasse@erlang.org>
Date: Thu, 20 Aug 2015 15:52:33 +0200
Subject: dialyzer: Fix erlang:abs/1

Fix the range type of erlang:abs/1.
---
 lib/hipe/cerl/erl_bif_types.erl | 29 ++++++++++++++++++++++++++---
 1 file changed, 26 insertions(+), 3 deletions(-)

(limited to 'lib/hipe/cerl/erl_bif_types.erl')

diff --git a/lib/hipe/cerl/erl_bif_types.erl b/lib/hipe/cerl/erl_bif_types.erl
index f49089d41c..5387edfb47 100644
--- a/lib/hipe/cerl/erl_bif_types.erl
+++ b/lib/hipe/cerl/erl_bif_types.erl
@@ -514,14 +514,15 @@ type(erlang, 'bsl', 2, Xs, Opaques) ->
 type(erlang, 'bnot', 1, Xs, Opaques) ->
  strict(erlang, 'bnot', 1, Xs,
 	 fun ([X1]) ->
-	     case arith('bnot', X1, Opaques) of
+	     case arith_bnot(X1, Opaques) of
 	       error -> t_integer();
 	       {ok, T} -> T
 	     end
 	 end, Opaques);
 %% Guard bif, needs to be here.
 type(erlang, abs, 1, Xs, Opaques) ->
-  strict(erlang, abs, 1, Xs, fun ([X]) -> X end, Opaques);
+  strict(erlang, abs, 1, Xs,
+         fun ([X1]) -> arith_abs(X1, Opaques) end, Opaques);
 %% This returns (-X)-1, so it often gives a negative result.
 %%  strict(erlang, 'bnot', 1, Xs, fun (_) -> t_integer() end, Opaques);
 type(erlang, append, 2, Xs, _Opaques) -> type(erlang, '++', 2, Xs); % alias
@@ -1927,7 +1928,7 @@ negwidth(X, N) ->
     false -> negwidth(X, N+1)
   end.
 
-arith('bnot', X1, Opaques) ->
+arith_bnot(X1, Opaques) ->
   case t_is_integer(X1, Opaques) of
     false -> error;
     true ->
@@ -1937,6 +1938,28 @@ arith('bnot', X1, Opaques) ->
 			infinity_add(infinity_inv(Min1), -1))}
   end.
 
+arith_abs(X1, Opaques) ->
+  case t_is_integer(X1, Opaques) of
+    false ->
+      case t_is_float(X1, Opaques) of
+        true -> t_float();
+        false -> t_number()
+      end;
+    true ->
+      Min1 = number_min(X1, Opaques),
+      Max1 = number_max(X1, Opaques),
+      {NewMin, NewMax} =
+        case infinity_geq(Min1, 0) of
+          true -> {Min1, Max1};
+          false ->
+            case infinity_geq(Max1, 0) of
+              true  -> {0, infinity_inv(Min1)};
+              false -> {infinity_inv(Max1), infinity_inv(Min1)}
+            end
+        end,
+      t_from_range(NewMin, NewMax)
+  end.
+
 arith_mult(Min1, Max1, Min2, Max2) ->
   Tmp_list = [infinity_mult(Min1, Min2), infinity_mult(Min1, Max2),
 	      infinity_mult(Max1, Min2), infinity_mult(Max1, Max2)],
-- 
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