From ad242a0c7a63c853f4f80ee7a722a304c4837565 Mon Sep 17 00:00:00 2001
From: Sam Harwell <sam@tunnelvisionlabs.com>
Date: Tue, 27 Nov 2012 08:36:04 -0600
Subject: [PATCH] No need to offset the shift value when the offset is 0

---
 .../org/antlr/v4/tool/templates/codegen/Java/Java.stg | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/tool/resources/org/antlr/v4/tool/templates/codegen/Java/Java.stg b/tool/resources/org/antlr/v4/tool/templates/codegen/Java/Java.stg
index 6fe64b812..18838152a 100644
--- a/tool/resources/org/antlr/v4/tool/templates/codegen/Java/Java.stg
+++ b/tool/resources/org/antlr/v4/tool/templates/codegen/Java/Java.stg
@@ -463,7 +463,16 @@ testShiftInRange(shiftAmount) ::= <<
 
 // produces smaller bytecode only when bits.ttypes contains more than two items
 bitsetBitfieldComparison(s, bits) ::= <%
-(<testShiftInRange({<s.varName> - <bits.shift>})> && ((1L \<\< (<s.varName> - <bits.shift>)) & (<bits.ttypes:{ttype | (1L \<\< (<ttype> - <bits.shift>))}; separator=" | ">)) != 0)
+(<testShiftInRange({<offsetShift(s.varName, bits.shift)>})> && ((1L \<\< <offsetShift(s.varName, bits.shift)>) & (<bits.ttypes:{ttype | (1L \<\< <offsetShift(ttype, bits.shift)>)}; separator=" | ">)) != 0)
+%>
+
+isZero ::= [
+"0":true,
+default:false
+]
+
+offsetShift(shiftAmount, offset) ::= <%
+<if(!isZero.(offset))>(<shiftAmount> - <offset>)<else><shiftAmount><endif>
 %>
 
 // produces more efficient bytecode when bits.ttypes contains at most two items