Bug 1602720 part 4 - Factor out jsop_initelem_array fast path code into initArrayElemTryFastPath. r=tcampbell

No change in behavior.

Differential Revision: https://phabricator.services.mozilla.com/D56533

--HG--
extra : moz-landing-system : lando

js/src/jit/IonBuilder.cpp

@@ -7368,53 +7368,75 @@ AbortReasonOr<Ok> IonBuilder::jsop_initelem_inc() {
   return resumeAfter(initElem);
 }
 
-AbortReasonOr<Ok> IonBuilder::jsop_initelem_array() {
-  MDefinition* value = current->pop();
-  MDefinition* obj = current->peek(-1);
+AbortReasonOr<Ok> IonBuilder::initArrayElemTryFastPath(bool* emitted,
+                                                       MDefinition* obj,
+                                                       MDefinition* id,
+                                                       MDefinition* value) {
+  MOZ_ASSERT(*emitted == false);
+  MOZ_ASSERT(*pc == JSOP_INITELEM_ARRAY);
 
   // Make sure that arrays have the type being written to them by the
   // intializer, and that arrays are marked as non-packed when writing holes
   // to them during initialization.
-  bool needStub = false;
-  if (!obj->isNewArray() || shouldAbortOnPreliminaryGroups(obj)) {
-    needStub = true;
-  } else if (!obj->resultTypeSet() || obj->resultTypeSet()->unknownObject() ||
-             obj->resultTypeSet()->getObjectCount() != 1) {
-    needStub = true;
-  } else {
-    MOZ_ASSERT(obj->resultTypeSet()->getObjectCount() == 1);
-    TypeSet::ObjectKey* initializer = obj->resultTypeSet()->getObject(0);
-    if (value->type() == MIRType::MagicHole) {
-      if (!initializer->hasFlags(constraints(), OBJECT_FLAG_NON_PACKED)) {
-        needStub = true;
-      }
-    } else if (!initializer->unknownProperties()) {
-      HeapTypeSetKey elemTypes = initializer->property(JSID_VOID);
-      if (!TypeSetIncludes(elemTypes.maybeTypes(), value->type(),
-                           value->resultTypeSet())) {
-        elemTypes.freeze(constraints());
-        needStub = true;
-      }
+
+  if (!obj->isNewArray()) {
+    return Ok();
+  }
+
+  if (shouldAbortOnPreliminaryGroups(obj)) {
+    return Ok();
+  }
+
+  if (!obj->resultTypeSet() || obj->resultTypeSet()->unknownObject() ||
+      obj->resultTypeSet()->getObjectCount() != 1) {
+    return Ok();
+  }
+
+  TypeSet::ObjectKey* initializer = obj->resultTypeSet()->getObject(0);
+  if (value->type() == MIRType::MagicHole) {
+    if (!initializer->hasFlags(constraints(), OBJECT_FLAG_NON_PACKED)) {
+      return Ok();
+    }
+  } else if (!initializer->unknownProperties()) {
+    HeapTypeSetKey elemTypes = initializer->property(JSID_VOID);
+    if (!TypeSetIncludes(elemTypes.maybeTypes(), value->type(),
+                         value->resultTypeSet())) {
+      elemTypes.freeze(constraints());
+      return Ok();
     }
   }
 
+  MOZ_TRY(initArrayElementFastPath(obj->toNewArray(), id, value,
+                                   /* addResumePoint = */ true));
+
+  *emitted = true;
+  return Ok();
+}
+
+AbortReasonOr<Ok> IonBuilder::jsop_initelem_array() {
+  MDefinition* value = current->pop();
+  MDefinition* obj = current->peek(-1);
+
   uint32_t index = GET_UINT32(pc);
-  if (needStub) {
-    MOZ_ASSERT(index <= INT32_MAX,
-               "the bytecode emitter must fail to compile code that would "
-               "produce JSOP_INITELEM_ARRAY with an index exceeding "
-               "int32_t range");
-    MCallInitElementArray* store =
-        MCallInitElementArray::New(alloc(), obj, constantInt(index), value);
-    current->add(store);
-    return resumeAfter(store);
-  }
+  MOZ_ASSERT(index <= INT32_MAX,
+             "the bytecode emitter must fail to compile code that would "
+             "produce JSOP_INITELEM_ARRAY with an index exceeding "
+             "int32_t range");
+
+  bool emitted = false;
 
   MConstant* id = MConstant::New(alloc(), Int32Value(index));
   current->add(id);
 
-  return initArrayElementFastPath(obj->toNewArray(), id, value,
-                                  /* addResumePoint = */ true);
+  MOZ_TRY(initArrayElemTryFastPath(&emitted, obj, id, value));
+  if (emitted) {
+    return Ok();
+  }
+
+  MCallInitElementArray* store =
+      MCallInitElementArray::New(alloc(), obj, id, value);
+  current->add(store);
+  return resumeAfter(store);
 }
 
 AbortReasonOr<Ok> IonBuilder::initArrayElementFastPath(

js/src/jit/IonBuilder.h

@@ -611,6 +611,10 @@ class IonBuilder : public MIRGenerator,
       TypedObjectPrediction objTypeReprs, MDefinition* value,
       TypedObjectPrediction elemTypeReprs, uint32_t elemSize);
 
+  AbortReasonOr<Ok> initArrayElemTryFastPath(bool* emitted, MDefinition* obj,
+                                             MDefinition* id,
+                                             MDefinition* value);
+
   AbortReasonOr<Ok> initArrayElementFastPath(
       MNewArray* obj, MDefinition* id, MDefinition* value,
       bool addResumePointAndIncrementInitializedLength);