Index: trunk/Source/WTF/wtf/Atomics.h
===================================================================
--- trunk/Source/WTF/wtf/Atomics.h	(revision 166233)
+++ trunk/Source/WTF/wtf/Atomics.h	(revision 166234)
@@ -105,20 +105,34 @@
         "movw %1, #1\n\t"
         "ldrex %2, %0\n\t"
         "cmp %3, %2\n\t"
         "bne.n 0f\n\t"
         "strex %1, %4, %0\n\t"
         "0:"
         : "+Q"(*location), "=&r"(result), "=&r"(tmp)
         : "r"(expected), "r"(newValue)
         : "memory");
     result = !result;
+#elif CPU(ARM64) && COMPILER(GCC)
+    unsigned tmp;
+    unsigned result;
+    asm volatile(
+        "mov %w1, #1\n\t"
+        "ldxr %w2, [%0]\n\t"
+        "cmp %w3, %w2\n\t"
+        "b.ne 0f\n\t"
+        "stxr %w1, %w4, [%0]\n\t"
+        "0:"
+        : "+r"(location), "=&r"(result), "=&r"(tmp)
+        : "r"(expected), "r"(newValue)
+        : "memory");
+    result = !result;
 #elif CPU(ARM64)
     unsigned tmp;
     unsigned result;
     asm volatile(
         "mov %w1, #1\n\t"
         "ldxr %w2, %0\n\t"
         "cmp %w3, %w2\n\t"
         "b.ne 0f\n\t"
         "stxr %w1, %w4, %0\n\t"
         "0:"
@@ -145,20 +159,34 @@
 #if CPU(X86_64)
     bool result;
     asm volatile(
         "lock; cmpxchgq %3, %2\n\t"
         "sete %1"
         : "+a"(expected), "=q"(result), "+m"(*location)
         : "r"(newValue)
         : "memory"
         );
     return result;
+#elif CPU(ARM64) && COMPILER(GCC)
+    bool result;
+    void* tmp;
+    asm volatile(
+        "mov %w1, #1\n\t"
+        "ldxr %x2, [%0]\n\t"
+        "cmp %x3, %x2\n\t"
+        "b.ne 0f\n\t"
+        "stxr %w1, %x4, [%0]\n\t"
+        "0:"
+        : "+r"(location), "=&r"(result), "=&r"(tmp)
+        : "r"(expected), "r"(newValue)
+        : "memory");
+    return !result;
 #elif CPU(ARM64)
     bool result;
     void* tmp;
     asm volatile(
         "mov %w1, #1\n\t"
         "ldxr %x2, %0\n\t"
         "cmp %x3, %x2\n\t"
         "b.ne 0f\n\t"
         "stxr %w1, %x4, %0\n\t"
         "0:"