introduce string profiles

Author: lukasstadler

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/modules/BuiltinFunctions.java

@@ -845,16 +845,18 @@ public static GetAttrNode create() {
         public abstract Object executeWithArgs(VirtualFrame frame, Object primary, String name, Object defaultValue);
 
         @SuppressWarnings("unused")
-        @Specialization(limit = "getIntOption(getContext(), AttributeAccessInlineCacheMaxDepth)", guards = {"name.equals(cachedName)", "isNoValue(defaultValue)"})
+        @Specialization(limit = "getIntOption(getContext(), AttributeAccessInlineCacheMaxDepth)", guards = {"stringEquals(cachedName, name, stringProfile)", "isNoValue(defaultValue)"})
         public Object getAttrDefault(VirtualFrame frame, Object primary, String name, PNone defaultValue,
+                        @Cached("createBinaryProfile()") ConditionProfile stringProfile,
                         @Cached("name") String cachedName,
                         @Cached("create(name)") GetFixedAttributeNode getAttributeNode) {
             return getAttributeNode.executeObject(frame, primary);
         }
 
         @SuppressWarnings("unused")
-        @Specialization(limit = "getIntOption(getContext(), AttributeAccessInlineCacheMaxDepth)", guards = {"name.equals(cachedName)", "!isNoValue(defaultValue)"})
+        @Specialization(limit = "getIntOption(getContext(), AttributeAccessInlineCacheMaxDepth)", guards = {"stringEquals(cachedName, name, stringProfile)", "!isNoValue(defaultValue)"})
         Object getAttr(VirtualFrame frame, Object primary, String name, Object defaultValue,
+                        @Cached("createBinaryProfile()") ConditionProfile stringProfile,
                         @Cached("name") String cachedName,
                         @Cached("create(name)") GetFixedAttributeNode getAttributeNode,
                         @Cached("create()") IsBuiltinClassProfile errorProfile) {

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/nodes/PGuards.java

@@ -84,13 +84,21 @@
 import com.oracle.truffle.api.frame.VirtualFrame;
 import com.oracle.truffle.api.interop.TruffleObject;
 import com.oracle.truffle.api.nodes.UnexpectedResultException;
+import com.oracle.truffle.api.profiles.ConditionProfile;
 
 public abstract class PGuards {
 
     /**
      * Specialization guards.
      */
 
+    public static boolean stringEquals(String expected, String other, ConditionProfile profile) {
+        if (profile.profile(expected == other)) {
+            return true;
+        }
+        return expected.equals(other);
+    }
+
     public static boolean isSameObject(Object left, Object right) {
         return left == right;
     }