Check all store modes for COW backing store access

thibaudmichaud · V8 LUCI CQ · commit 9c0d3a4e07ac · 2022-11-08T17:30:27.000Z
R=jkummerow@chromium.org Bug: chromium:1382434 Change-Id: I06d239a70eba125b1074542cb93def2b1f011f81 Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/4013686 Commit-Queue: Thibaud Michaud <thibaudm@chromium.org> Reviewed-by: Jakob Kummerow <jkummerow@chromium.org> Cr-Commit-Position: refs/heads/main@{#84127}
diff --git a/src/compiler/heap-refs.h b/src/compiler/heap-refs.h
@@ -56,7 +56,8 @@ class PropertyAccessInfo;
 enum class AccessMode { kLoad, kStore, kStoreInLiteral, kHas, kDefine };
 
 inline bool IsAnyStore(AccessMode mode) {
-  return mode == AccessMode::kStore || mode == AccessMode::kStoreInLiteral;
+  return mode == AccessMode::kStore || mode == AccessMode::kStoreInLiteral ||
+         mode == AccessMode::kDefine;
 }
 
 enum class OddballType : uint8_t {
diff --git a/src/compiler/js-native-context-specialization.cc b/src/compiler/js-native-context-specialization.cc
@@ -3399,7 +3399,7 @@ JSNativeContextSpecialization::BuildElementAccess(
 
     // Don't try to store to a copy-on-write backing store (unless supported by
     // the store mode).
-    if (keyed_mode.access_mode() == AccessMode::kStore &&
+    if (IsAnyStore(keyed_mode.access_mode()) &&
         IsSmiOrObjectElementsKind(elements_kind) &&
         !IsCOWHandlingStoreMode(keyed_mode.store_mode())) {
       effect = graph()->NewNode(

Original file line number	Diff line number	Diff line change
`@@ -56,7 +56,8 @@ class PropertyAccessInfo;`
`56`	`56`	`enum class AccessMode { kLoad, kStore, kStoreInLiteral, kHas, kDefine };`
`57`	`57`
`58`	`58`	`inline bool IsAnyStore(AccessMode mode) {`
`59`		`- return mode == AccessMode::kStore \|\| mode == AccessMode::kStoreInLiteral;`
	`59`	`+ return mode == AccessMode::kStore \|\| mode == AccessMode::kStoreInLiteral \|\|`
	`60`	`+ mode == AccessMode::kDefine;`
`60`	`61`	`}`
`61`	`62`
`62`	`63`	`enum class OddballType : uint8_t {`