Adapt putGeneric() to handle the IF_ABSENT flag

* Rename Flags.isSetExisting() to Flags.isPutIfPresent() for clarity.

Author: eregon

truffle/src/com.oracle.truffle.api.object/src/com/oracle/truffle/api/object/DynamicObjectLibraryImpl.java

@@ -1233,7 +1233,7 @@ protected boolean putImpl(DynamicObject object, Shape cachedShape, Object key, O
                 } else if (c instanceof PutCacheData putCache && putCache.putFlags == putFlags && putCache.propertyFlags == propertyFlags) {
                     Property newProperty = putCache.property;
                     if (newProperty == null) {
-                        assert Flags.isSetExisting(putFlags);
+                        assert Flags.isPutIfPresent(putFlags);
                         return false;
                     } else {
                         Location location = newProperty.getLocation();
@@ -1271,7 +1271,7 @@ protected boolean putIntImpl(DynamicObject object, Shape cachedShape, Object key
                 } else if (c instanceof PutCacheData putCache && putCache.putFlags == putFlags && putCache.propertyFlags == propertyFlags) {
                     Property newProperty = putCache.property;
                     if (newProperty == null) {
-                        assert Flags.isSetExisting(putFlags);
+                        assert Flags.isPutIfPresent(putFlags);
                         return false;
                     } else {
                         Location location = newProperty.getLocation();
@@ -1339,7 +1339,7 @@ protected boolean putLongImpl(DynamicObject object, Shape cachedShape, Object ke
                 } else if (c instanceof PutCacheData putCache && putCache.putFlags == putFlags && putCache.propertyFlags == propertyFlags) {
                     Property newProperty = putCache.property;
                     if (newProperty == null) {
-                        assert Flags.isSetExisting(putFlags);
+                        assert Flags.isPutIfPresent(putFlags);
                         return false;
                     } else {
                         Location location = newProperty.getLocation();
@@ -1388,7 +1388,7 @@ protected boolean putDoubleImpl(DynamicObject object, Shape cachedShape, Object
                 } else if (c instanceof PutCacheData putCache && putCache.putFlags == putFlags && putCache.propertyFlags == propertyFlags) {
                     Property newProperty = putCache.property;
                     if (newProperty == null) {
-                        assert Flags.isSetExisting(putFlags);
+                        assert Flags.isPutIfPresent(putFlags);
                         return false;
                     } else {
                         Location location = newProperty.getLocation();
@@ -1462,7 +1462,7 @@ protected KeyCacheNode insertIntoPutCache(DynamicObject object, Shape cachedShap
 
         private Shape getNewShape(DynamicObject object, Object value, int newPropertyFlags, int putFlags, Property property, Shape oldShape) {
             if (property == null) {
-                if (Flags.isSetExisting(putFlags)) {
+                if (Flags.isPutIfPresent(putFlags)) {
                     return oldShape;
                 } else {
                     return ObsolescenceStrategy.singleton().defineProperty(oldShape, cachedKey, value, newPropertyFlags, putFlags);

truffle/src/com.oracle.truffle.api.object/src/com/oracle/truffle/api/object/Flags.java

@@ -77,10 +77,14 @@ static boolean isImplicitCastIntToDouble(int flags) {
         return getFlag(flags, IMPLICIT_CAST_INT_TO_DOUBLE);
     }
 
-    static boolean isSetExisting(int flags) {
+    static boolean isPutIfPresent(int flags) {
         return getFlag(flags, IF_PRESENT);
     }
 
+    static boolean isPutIfAbsent(int flags) {
+        return getFlag(flags, IF_ABSENT);
+    }
+
     static boolean isUpdateFlags(int flags) {
         return getFlag(flags, UPDATE_FLAGS);
     }

truffle/src/com.oracle.truffle.api.object/src/com/oracle/truffle/api/object/ObsolescenceStrategy.java

@@ -175,15 +175,19 @@ public void visitObjectArray(int index, int count) {
 
     @TruffleBoundary
     boolean putGeneric(DynamicObject object, Object key, Object value, int newPropertyFlags, int putFlags, Shape s, Property existingProperty) {
-        if (existingProperty == null && Flags.isSetExisting(putFlags)) {
-            return false;
-        }
-        if (existingProperty != null && !Flags.isUpdateFlags(putFlags) && existingProperty.getLocation().canStore(value)) {
-            existingProperty.getLocation().setSafe(object, value, false, false);
-            return true;
+        if (existingProperty == null) {
+            if (Flags.isPutIfPresent(putFlags)) {
+                return false;
+            }
         } else {
-            return putGenericSlowPath(object, key, value, newPropertyFlags, putFlags, s, existingProperty);
+            if (Flags.isPutIfAbsent(putFlags)) {
+                return true;
+            } else if (!Flags.isUpdateFlags(putFlags) && existingProperty.getLocation().canStore(value)) {
+                existingProperty.getLocation().setSafe(object, value, false, false);
+                return true;
+            }
         }
+        return putGenericSlowPath(object, key, value, newPropertyFlags, putFlags, s, existingProperty);
     }
 
     private boolean putGenericSlowPath(DynamicObject object, Object key, Object value, int newPropertyFlags, int putFlags,
@@ -197,12 +201,14 @@ private boolean putGenericSlowPath(DynamicObject object, Object key, Object valu
             oldShape = object.getShape();
             final Property existingProperty = reusePropertyLookup(key, initialShape, propertyOfInitialShape, oldShape);
             if (existingProperty == null) {
-                if (Flags.isSetExisting(putFlags)) {
+                if (Flags.isPutIfPresent(putFlags)) {
                     return false;
                 } else {
                     newShape = defineProperty(oldShape, key, value, newPropertyFlags, existingProperty, putFlags);
                     property = newShape.getProperty(key);
                 }
+            } else if (Flags.isPutIfAbsent(putFlags)) {
+                return true;
             } else if (Flags.isUpdateFlags(putFlags) && newPropertyFlags != existingProperty.getFlags()) {
                 newShape = defineProperty(oldShape, key, value, newPropertyFlags, existingProperty, putFlags);
                 property = newShape.getProperty(key);
@@ -211,6 +217,7 @@ private boolean putGenericSlowPath(DynamicObject object, Object key, Object valu
                     newShape = oldShape;
                     property = existingProperty;
                 } else {
+                    assert !Flags.isUpdateFlags(putFlags) || newPropertyFlags == existingProperty.getFlags();
                     newShape = defineProperty(oldShape, key, value, existingProperty.getFlags(), existingProperty, putFlags);
                     property = newShape.getProperty(key);
                 }
@@ -224,6 +231,8 @@ private boolean putGenericSlowPath(DynamicObject object, Object key, Object valu
             location.setSafe(object, value, false, true);
             DynamicObjectSupport.setShapeWithStoreFence(object, newShape);
             updateShape(object);
+        } else if (Flags.isPutIfAbsent(putFlags)) {
+            return true;
         } else {
             location.setSafe(object, value, false, false);
         }