added TUPLE_FROM_LIST operation

Author: tomasstupka

graalpython/com.oracle.graal.python.test/testData/goldenFiles/CompilerTests/testTupleLiteralExpand.co

@@ -7,5 +7,5 @@ Disassembly of <module>:
 000000        10 COLLECTION_ADD_COLLECTION         0    (list)
 000014        12 LOAD_BYTE_O                       5
 000000        14 COLLECTION_ADD_STACK              1    (list)
-000000        16 COLLECTION_FROM_COLLECTION        0    (tuple)
-000000        18 RETURN_VALUE
+000000        16 TUPLE_FROM_LIST
+000000        17 RETURN_VALUE

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/compiler/Compiler.java

@@ -124,6 +124,7 @@
 import static com.oracle.graal.python.compiler.OpCodes.STORE_NAME;
 import static com.oracle.graal.python.compiler.OpCodes.STORE_SUBSCR;
 import static com.oracle.graal.python.compiler.OpCodes.THROW;
+import static com.oracle.graal.python.compiler.OpCodes.TUPLE_FROM_LIST;
 import static com.oracle.graal.python.compiler.OpCodes.UNARY_OP;
 import static com.oracle.graal.python.compiler.OpCodes.UNPACK_EX;
 import static com.oracle.graal.python.compiler.OpCodes.UNPACK_SEQUENCE;
@@ -1632,9 +1633,7 @@ public Void visit(ExprTy.Tuple node) {
                         collectIntoArray(node.elements, CollectionBits.KIND_TUPLE);
                     } else {
                         collectIntoArray(node.elements, CollectionBits.KIND_LIST);
-                        // FIXME this operation copies the underlying storage, we should make a
-                        // separate instruction for shallow conversion
-                        addOp(COLLECTION_FROM_COLLECTION, CollectionBits.KIND_TUPLE);
+                        addOp(TUPLE_FROM_LIST);
                     }
                     return null;
                 case Del:

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/compiler/OpCodes.java

@@ -547,6 +547,14 @@ public enum OpCodes {
      * Pushes: converted collection
      */
     COLLECTION_FROM_COLLECTION(1, 1, 1),
+    /**
+     * Converts list to tuple by reusing the underlying storage.
+     *
+     * Pops: list
+     *
+     * Pushes: tuple
+     */
+    TUPLE_FROM_LIST(0, 1, 1),
     /**
      * Adds an item to a collection that is multiple items deep under the top of the stack,
      * determined by the immediate argument.

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/nodes/bytecode/PBytecodeRootNode.java

@@ -1239,6 +1239,11 @@ private Object bytecodeLoop(VirtualFrame virtualFrame, Frame localFrame, Bytecod
                         stackTop = bytecodeAddToCollection(virtualFrame, stackTop, beginBci, localNodes, depth, type, useCachedNodes);
                         break;
                     }
+                    case OpCodesConstants.TUPLE_FROM_LIST: {
+                        setCurrentBci(virtualFrame, bciSlot, bci);
+                        bytecodeTupleFromList(virtualFrame, stackTop);
+                        break;
+                    }
                     case OpCodesConstants.KWARGS_DICT_MERGE: {
                         setCurrentBci(virtualFrame, bciSlot, bci);
                         KwargsMergeNode mergeNode = insertChildNode(localNodes, bci, UNCACHED_KWARGS_MERGE, KwargsMergeNodeGen.class, NODE_KWARGS_MERGE, useCachedNodes);
@@ -4238,6 +4243,12 @@ private int bytecodeAddToCollection(VirtualFrame virtualFrame, int initialStackT
         return stackTop;
     }
 
+    private void bytecodeTupleFromList(VirtualFrame virtualFrame, int stackTop) {
+        PList list = (PList) virtualFrame.getObject(stackTop);
+        Object result = factory.createTuple(list.getSequenceStorage());
+        virtualFrame.setObject(stackTop, result);
+    }
+
     private int bytecodeUnpackSequence(VirtualFrame virtualFrame, int stackTop, int bci, Node[] localNodes, int count, boolean useCachedNodes) {
         UnpackSequenceNode unpackNode = insertChildNode(localNodes, bci, UNCACHED_UNPACK_SEQUENCE, UnpackSequenceNodeGen.class, NODE_UNPACK_SEQUENCE, useCachedNodes);
         Object collection = virtualFrame.getObject(stackTop);