[Bug c++/104243] Optimization requires __sync_synchronize

[aklitzing at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104243

--- Comment #5 from A. Klitzing <aklitzing at gmail dot com> ---
Created attachment 52294
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=52294&action=edit
assembler output

By the way... If idx is not initialized it will work, too.

@@ -4,7 +4,7 @@
 int main(int argc, char** argv)
 {
         const QString pVersion = QStringLiteral("1.12.2");
-        int idx = 0;
+        int idx;
         const auto& version = QVersionNumber::fromString(pVersion, &idx);

         // #ifdef Q_CC_GNU