[Bug target/120870] [16/17 regression] CPython miscompiled with preserve_none and CFLAGS="-O2 -march=znver2 -ggdb3"

[ubizjak at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120870

--- Comment #58 from Uroš Bizjak <ubizjak at gmail dot com> ---
Comment on attachment 64443
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=64443
v2 of the untested patch.


> static unsigned int
> find_drap_reg (void)
> {
>+  if (cfun->machine->call_saved_registers == TYPE_PRESERVE_NONE
>+      || (cfun->machine->call_saved_registers
>+        == TYPE_NO_CALLEE_SAVED_REGISTERS))
>+    return X86_NO_CALLEE_DRAP_REG;
>+

HJ, do we also need to check TYPE_NO_CALLER_SAVED_REGISTERS here?