https://gcc.gnu.org/bugzilla/show_bug.cgi?id=124649
--- Comment #5 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
This is what I am testing:
```
diff --git a/gcc/regcprop.cc b/gcc/regcprop.cc
index b1f00ca0435..9a9b77e0ff5 100644
--- a/gcc/regcprop.cc
+++ b/gcc/regcprop.cc
@@ -431,6 +431,13 @@ maybe_mode_change (machine_mode orig_mode, machine_mode
copy_mode,
machine_mode new_mode, unsigned int regno,
unsigned int copy_regno ATTRIBUTE_UNUSED)
{
+ /* All three modes precision have to be ordered to each other. */
+ if (!ordered_p (GET_MODE_PRECISION (orig_mode),
+ GET_MODE_PRECISION (copy_mode))
+ || !ordered_p (GET_MODE_PRECISION (copy_mode),
+ GET_MODE_PRECISION (new_mode)))
+ return NULL_RTX;
+
if (partial_subreg_p (copy_mode, orig_mode)
&& partial_subreg_p (copy_mode, new_mode))
return NULL_RTX;
```
