[Truffle] Fixed a performance issue when adding two Strings by preser…

…ving a negotiated code range.
jruby · Oct 13, 2015 · c3ad290 · c3ad290
1 parent 3aa50dc
commit c3ad290
Showing 2 changed files with 19 additions and 2 deletions.
diff --git a/truffle/src/main/java/org/jruby/truffle/nodes/core/StringNodes.java b/truffle/src/main/java/org/jruby/truffle/nodes/core/StringNodes.java
@@ -111,7 +111,8 @@ public AddNode(RubyContext context, SourceSection sourceSection) {
         @Specialization(guards = "isRubyString(other)")
         public DynamicObject add(DynamicObject string, DynamicObject other) {
             final Encoding enc = StringOperations.checkEncoding(getContext(), string, StringOperations.getCodeRangeable(other), this);
-            final DynamicObject ret = createString(StringSupport.addByteLists(StringOperations.getByteList(string), StringOperations.getByteList(other)));
+            final int codeRange = StringOperations.commonCodeRange(Layouts.STRING.getCodeRange(string), Layouts.STRING.getCodeRange(other));
+            final DynamicObject ret = Layouts.STRING.createString(getContext().getCoreLibrary().getStringFactory(), StringSupport.addByteLists(StringOperations.getByteList(string), StringOperations.getByteList(other)), codeRange, null);
 
             if (taintResultNode == null) {
                 CompilerDirectives.transferToInterpreter();

diff --git a/truffle/src/main/java/org/jruby/truffle/runtime/core/StringOperations.java b/truffle/src/main/java/org/jruby/truffle/runtime/core/StringOperations.java
@@ -189,5 +189,21 @@ public static ByteList encodeByteList(CharSequence value, Encoding encoding) {
     public static ByteList getByteList(DynamicObject object) {
         return Layouts.STRING.getByteList(object);
     }
-
+
+    public static int commonCodeRange(int first, int second) {
+        if (first == second) {
+            return first;
+        }
+
+        if ((first == StringSupport.CR_UNKNOWN) || (second == StringSupport.CR_UNKNOWN)) {
+            return StringSupport.CR_UNKNOWN;
+        }
+
+        if ((first == StringSupport.CR_BROKEN) || (second == StringSupport.CR_BROKEN)) {
+            return StringSupport.CR_BROKEN;
+        }
+
+        // If we get this far, one must be CR_7BIT and the other must be CR_VALID, so promote to the more general code range.
+        return StringSupport.CR_VALID;
+    }
 }