[Bug rtl-optimization/89436] [8/9 Regression] ICE in glibc/sysdeps/ieee754/dbl-64/e_pow.c (during RTL pass: cprop_hardreg: internal compiler error: qsort checking failed)

[amonakov at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89436

--- Comment #2 from Alexander Monakov <amonakov at gcc dot gnu.org> ---
This was previously reported as PR 86096. Let me copy-paste my response from
there:

df_mw_compare has:

   if (mw1->mw_reg != mw2->mw_reg)
     return mw1->mw_order - mw2->mw_order;

Note mw_reg in the 'if' vs mw_order in the 'return'. This is invalid.

It's simpler and more efficient to just use mw_order as the last tie-breaker
regardless of mw_reg value.