[Bug target/80080] S390: Isses with emitted cs-instructions for __atomic builtins.

[vogt at linux dot vnet.ibm.com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80080

--- Comment #5 from Dominik Vogt <vogt at linux dot vnet.ibm.com> ---
What case do you mean?  The

+  if (oldval != old_reg)
+    emit_move_insn (old_reg, oldval);

at the end should make sure that the oldval-rtx is either not changed by the
call, or its value is copied into old_reg at runtime.  In both cases, the value
of old_reg should be the old value to be returned (as it was hopefully before
the patch).  Me and Stefan have spent quite some time to proof read this patch;
do you see somethings we might have overlooked?