From 651b36a791f22b55b999292dd05ffc0cdbaa744d Mon Sep 17 00:00:00 2001
From: Julian Garn <julian.garn@gmx.at>
Date: Fri, 9 Sep 2022 14:25:07 +0200
Subject: [PATCH] Added optimizations back

---
 .../js/builtins/IteratorFunctionBuiltins.java |  2 +-
 .../js/nodes/access/IteratorToArrayNode.java  | 21 +++++++++++++++++--
 2 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/graal-js/src/com.oracle.truffle.js/src/com/oracle/truffle/js/builtins/IteratorFunctionBuiltins.java b/graal-js/src/com.oracle.truffle.js/src/com/oracle/truffle/js/builtins/IteratorFunctionBuiltins.java
index 1cb987cc980..a4358f6d443 100644
--- a/graal-js/src/com.oracle.truffle.js/src/com/oracle/truffle/js/builtins/IteratorFunctionBuiltins.java
+++ b/graal-js/src/com.oracle.truffle.js/src/com/oracle/truffle/js/builtins/IteratorFunctionBuiltins.java
@@ -100,7 +100,7 @@ public abstract static class JSIteratorFromNode extends JSBuiltinNode {
         @Child private GetIteratorDirectNode getIteratorDirectNode;
         @Child private OrdinaryHasInstanceNode ordinaryHasInstanceNode;
 
-        private ConditionProfile usingIteratorProfile = ConditionProfile.createBinaryProfile();
+        private final ConditionProfile usingIteratorProfile = ConditionProfile.createBinaryProfile();
 
         public JSIteratorFromNode(JSContext context, JSBuiltin builtin) {
             super(context, builtin);
diff --git a/graal-js/src/com.oracle.truffle.js/src/com/oracle/truffle/js/nodes/access/IteratorToArrayNode.java b/graal-js/src/com.oracle.truffle.js/src/com/oracle/truffle/js/nodes/access/IteratorToArrayNode.java
index 0c165cc97b1..11ea4c81ec9 100644
--- a/graal-js/src/com.oracle.truffle.js/src/com/oracle/truffle/js/nodes/access/IteratorToArrayNode.java
+++ b/graal-js/src/com.oracle.truffle.js/src/com/oracle/truffle/js/nodes/access/IteratorToArrayNode.java
@@ -42,6 +42,7 @@
 
 import java.util.Set;
 
+import com.oracle.truffle.api.CompilerDirectives;
 import com.oracle.truffle.api.dsl.Cached;
 import com.oracle.truffle.api.dsl.Executed;
 import com.oracle.truffle.api.dsl.Specialization;
@@ -62,6 +63,10 @@ public abstract class IteratorToArrayNode extends JavaScriptNode {
     @Child @Executed JavaScriptNode iteratorNode;
     @Child private IteratorGetNextValueNode iteratorStepNode;
 
+    @CompilerDirectives.CompilationFinal private int capacity = 0;
+    @CompilerDirectives.CompilationFinal private boolean first = true;
+
+
     protected IteratorToArrayNode(JSContext context, JavaScriptNode iteratorNode, IteratorGetNextValueNode iteratorStepNode) {
         this.context = context;
         this.iteratorNode = iteratorNode;
@@ -75,12 +80,24 @@ public static IteratorToArrayNode create(JSContext context, JavaScriptNode itera
 
     @Specialization(guards = "!iteratorRecord.isDone()")
     protected Object doIterator(VirtualFrame frame, IteratorRecord iteratorRecord,
+                                @Cached BranchProfile firstGrowProfile,
                                 @Cached BranchProfile growProfile) {
-        SimpleArrayList<Object> elements = new SimpleArrayList<>();
+        SimpleArrayList<Object> elements = new SimpleArrayList<>(capacity);
         Object value;
         while ((value = iteratorStepNode.execute(frame, iteratorRecord)) != null) {
-            elements.add(value, growProfile);
+            elements.add(value, first ? firstGrowProfile : growProfile);
         }
+
+        if (CompilerDirectives.inInterpreter()) {
+            if (first) {
+                capacity = elements.size();
+                first = false;
+            } else if (capacity != elements.size()) {
+                //Capacity is changing even though we are still in interpreter. Assume fluctuating capacity values.
+                capacity = 0;
+            }
+        }
+
         return JSArray.createZeroBasedObjectArray(context, getRealm(), elements.toArray());
     }