Changeset 259554 in webkit

Timestamp:

Apr 5, 2020 11:23:25 AM (4 years ago)

Author:

keith_miller@apple.com

Message:

ensureStillAliveHere can take the value in any location
​https://bugs.webkit.org/show_bug.cgi?id=210028

Reviewed by Mark Lam.

It shouldn't matter if the value is on the stack or in a register
because we're not going to do anything with it. Also, there's no
reason to clobber memory.

• runtime/EnsureStillAliveHere.h:

(JSC::ensureStillAliveHere):

Location:

trunk/Source/JavaScriptCore

Files:

• ChangeLog (modified) (1 diff)
• runtime/EnsureStillAliveHere.h (modified) (1 diff)
• runtime/JSCJSValue.h (modified) (1 diff)

trunk/Source/JavaScriptCore/ChangeLog

@@ +1 @@
+2020-04-05  Keith Miller  <keith_miller@apple.com>
+
+        ensureStillAliveHere can take the value in any location
+        https://bugs.webkit.org/show_bug.cgi?id=210028
+
+        Reviewed by Mark Lam.
+
+        It shouldn't matter if the value is on the stack or in a register
+        because we're not going to do anything with it. Also, there's no
+        reason to clobber memory.
+
+        * runtime/EnsureStillAliveHere.h:
+        (JSC::ensureStillAliveHere):
+
 2020-04-05  Zan Dobersek  <zdobersek@igalia.com>
 

trunk/Source/JavaScriptCore/runtime/EnsureStillAliveHere.h

@@ -32 +32 @@
 ALWAYS_INLINE void ensureStillAliveHere(uint64_t value)
 {
-    asm volatile ("" : : "r"(value) : "memory");
+    asm volatile ("" : : "g"(value) : );
 }
 
 ALWAYS_INLINE void ensureStillAliveHere(const void* pointer)
 {
-    asm volatile ("" : : "r"(pointer) : "memory");
+    asm volatile ("" : : "g"(pointer) : );
 }
 

trunk/Source/JavaScriptCore/runtime/JSCJSValue.h

@@ -643 +643 @@
 {
 #if USE(JSVALUE64)
-    asm volatile ("" : : "r"(bitwise_cast<uint64_t>(value)) : "memory");
+    asm volatile ("" : : "g"(bitwise_cast<uint64_t>(value)) : );
 #else
-    asm volatile ("" : : "r"(value.payload()) : "memory");
+    asm volatile ("" : : "g"(value.payload()) : );
 #endif
 }